The forced swimming-induced behavioural immobility response involves histone H3 phospho-acetylation and c-Fos induction in dentate gyrus granule neurons via activation of the N-methyl-D-aspartate/extracellular signal-regulated kinase/mitogen- and stress-activated kinase signalling pathway.

PubMed

Chandramohan, Yalini; Droste, Susanne K; Arthur, J Simon C; Reul, Johannes M H M

2008-05-01

The hippocampus is involved in learning and memory. Previously, we have shown that the acquisition of the behavioural immobility response after a forced swim experience is associated with chromatin modifications and transcriptional induction in dentate gyrus granule neurons. Given that both N-methyl-D-aspartate (NMDA) receptors and the extracellular signal-regulated kinases (ERK) 1/2 signalling pathway are involved in neuroplasticity processes underlying learning and memory, we investigated in rats and mice whether these signalling pathways regulate chromatin modifications and transcriptional events participating in the acquisition of the immobility response. We found that: (i) forced swimming evoked a transient increase in the number of phospho-acetylated histone H3-positive [P(Ser10)-Ac(Lys14)-H3(+)] neurons specifically in the middle and superficial aspects of the dentate gyrus granule cell layer; (ii) antagonism of NMDA receptors and inhibition of ERK1/2 signalling blocked forced swimming-induced histone H3 phospho-acetylation and the acquisition of the behavioural immobility response; (iii) double knockout (DKO) of the histone H3 kinase mitogen- and stress-activated kinases (MSK) 1/2 in mice completely abolished the forced swimming-induced increases in histone H3 phospho-acetylation and c-Fos induction in dentate granule neurons and the behavioural immobility response; (iv) blocking mineralocorticoid receptors, known not to be involved in behavioural immobility in the forced swim test, did not affect forced swimming-evoked histone H3 phospho-acetylation in dentate neurons; and (v) the pharmacological manipulations and gene deletions did not affect behaviour in the initial forced swim test. We conclude that the forced swimming-induced behavioural immobility response requires histone H3 phospho-acetylation and c-Fos induction in distinct dentate granule neurons through recruitment of the NMDA/ERK/MSK 1/2 pathway.

Nano-tags for neonates and ocean-mediated swimming behaviours linked to rapid dispersal of hatchling sea turtles

PubMed Central

Scott, Rebecca; Biastoch, Arne; Roder, Christian; Stiebens, Victor A.; Eizaguirre, Christophe

2014-01-01

Dispersal during juvenile life stages drives the life-history evolution and dynamics of many marine vertebrate populations. However, the movements of juvenile organisms, too small to track using conventional satellite telemetry devices, remain enigmatic. For sea turtles, this led to the paradigm of the ‘lost years' since hatchlings disperse widely with ocean currents. Recently, advances in the miniaturization of tracking technology have permitted the application of nano-tags to track cryptic organisms. Here, the novel use of acoustic nano-tags on neonate loggerhead turtle hatchlings enabled us to witness first-hand their dispersal and behaviour during their first day at sea. We tracked hatchlings distances of up to 15 km and documented their rapid transport (up to 60 m min−1) with surface current flows passing their natal areas. Tracking was complemented with laboratory observations to monitor swimming behaviours over longer periods which highlighted (i) a positive correlation between swimming activity levels and body size and (ii) population-specific swimming behaviours (e.g. nocturnal inactivity) suggesting local oceanic conditions drive the evolution of innate swimming behaviours. Knowledge of the swimming behaviours of small organisms is crucial to improve the accuracy of ocean model simulations used to predict the fate of these organisms and determine resultant population-level implications into adulthood. PMID:25339720

Single and combined effects of microplastics and mercury on juveniles of the European seabass (Dicentrarchus labrax): Changes in behavioural responses and reduction of swimming velocity and resistance time.

PubMed

Barboza, Luís Gabriel Antão; Vieira, Luís Russo; Guilhermino, Lúcia

2018-05-01

Microplastics and mercury are environmental pollutants of great concern. The main goal of the present study was to investigate the effects of these pollutants, both individually and in binary mixtures, on the swimming performance of juvenile European seabass, Dicentrarchus labrax. Microplastics alone, mercury alone and all the mixtures caused significant reduction of the swimming velocity and resistance time of fish. Moreover, changes in behavioural responses including lethargic and erratic swimming behaviour were observed. These results highlight that fish behavioural responses can be used as sensitive endpoint to establish the effects of contamination by microplastics and also emphasizes the need to assess the combined effects of microplastics and other environmental contaminants, with special attention to the effects on behavioural responses in fish and other aquatic species. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

The interaction between water currents and salmon swimming behaviour in sea cages.

PubMed

Johansson, David; Laursen, Frida; Fernö, Anders; Fosseidengen, Jan Erik; Klebert, Pascal; Stien, Lars Helge; Vågseth, Tone; Oppedal, Frode

2014-01-01

Positioning of sea cages at sites with high water current velocities expose the fish to a largely unknown environmental challenge. In this study we observed the swimming behaviour of Atlantic salmon (Salmo salar L.) at a commercial farm with tidal currents altering between low, moderate and high velocities. At high current velocities the salmon switched from the traditional circular polarized group structure, seen at low and moderate current velocities, to a group structure where all fish kept stations at fixed positions swimming against the current. This type of group behaviour has not been described in sea cages previously. The structural changes could be explained by a preferred swimming speed of salmon spatially restricted in a cage in combination with a behavioural plasticity of the fish.

Swimming Behaviour of the upside-down swimming Catfish (Synodontis nigriventris) at high-quality Microgravity - a Drop-Tower Experiment

NASA Astrophysics Data System (ADS)

Knie, M.; Hilbig, R.; Anken, R.

The catfish Synodontis nigriventris often shows a unique swimming behaviour in being oriented upside down In the course of a parabolic aircraft flight PF experiment conducted by Ohnishi et al Abstract COSPAR04-A-00961 2004 www cosis net specimens of this species were subjected to diminished gravity and the dorsal light response DLR was tested Usually the DLR is more clearly exhibited by fish in a low-gravity environment since they then need to use visual input as the major or even the sole cue for postural control It was shown by Ohnishi et al 2004 however that S nigriventris did not reveal a DLR during the PF-phases of diminished gravity and it was concluded that the species has a novel balance sensation which does not induce a DLR In the course of an earlier drop-tower ZARM Bremen experiment we had analysed the swimming behaviour of cichlid fish Oreochromis mossambicus at various levels of diminished gravity ranging from 0 009g until 0 3g the animals were housed within a centrifuge during the drop-tower flights with the finding that the residual level of gravity which is usually gained aboard PFs i e 0 03-0 05g is sufficient for most fish of a given batch to maintain a normal postural control Anken Medicine and Mobility 7 18 2005 The vestibular organ of S nigriventris moreover is assumed to be more sensitive than that of O mossambicus due to hanging utricular otoliths in the upside-down posture Thus we hypothesized that the residual gravity aboard PFs might well be sufficient for the catfish to be perceived and

Ocean acidification impacts on sperm mitochondrial membrane potential bring sperm swimming behaviour near its tipping point.

PubMed

Schlegel, Peter; Binet, Monique T; Havenhand, Jonathan N; Doyle, Christopher J; Williamson, Jane E

2015-04-01

Broadcast spawning marine invertebrates are susceptible to environmental stressors such as climate change, as their reproduction depends on the successful meeting and fertilization of gametes in the water column. Under near-future scenarios of ocean acidification, the swimming behaviour of marine invertebrate sperm is altered. We tested whether this was due to changes in sperm mitochondrial activity by investigating the effects of ocean acidification on sperm metabolism and swimming behaviour in the sea urchin Centrostephanus rodgersii. We used a fluorescent molecular probe (JC-1) and flow cytometry to visualize mitochondrial activity (measured as change in mitochondrial membrane potential, MMP). Sperm MMP was significantly reduced in ΔpH -0.3 (35% reduction) and ΔpH -0.5 (48% reduction) treatments, whereas sperm swimming behaviour was less sensitive with only slight changes (up to 11% decrease) observed overall. There was significant inter-individual variability in responses of sperm swimming behaviour and MMP to acidified seawater. We suggest it is likely that sperm exposed to these changes in pH are close to their tipping point in terms of physiological tolerance to acidity. Importantly, substantial inter-individual variation in responses of sperm swimming to ocean acidification may increase the scope for selection of resilient phenotypes, which, if heritable, could provide a basis for adaptation to future ocean acidification. © 2015. Published by The Company of Biologists Ltd.

Increasing the sensitivity of the visual system reduces kinetotic behaviour of fish under microgravity

NASA Astrophysics Data System (ADS)

Anken, Ralf; Hilbig, Reinhard; Knie, Miriam; Weigele, Jochen; Anken, Ralf

We have shown earlier that some fish of a given batch reveal motion sickness (a kinetosis) at the transition from earth gravity to diminished gravity. The percentual ratios of the various types of behaviour (normal swimming and kinetotic swimming; kinetotic specimens revealed looping responses or spinning movements) highly differed depending on the quality of diminished gravity. At high quality microgravity (HQM, 10-6 g, ZARM drop-tower, Bremen, Germany), kinetoses were exhibited by some 90% of the animals, whereas kinetoses were not as frequently seen at higher G-levels (at 0.03-0.05g during parabolic aircraft flights or during centrifugation in the drop-capsule, only some 15-25% of the animals show kinetoses). In the course of the present study, we further assessed the role of the visual system in maintaining postural control under HQM, when the remaining level of gravity is too low to be used as a vestibular cue. Therefore, larval cichlid fish siblings (Oreochromis mossambicus) were subjected to drop-tower flights at HQM and different kinds of illumination were used. Applying blue light (which leads to an increase of the sensitivity of the visual system and to a general arousal of the animal) resulted in a decrease of kinetotically swimming specimens as compared to white and red light (red light is almost invisible for fish). The final data as well as results from analyses of inner ear otoliths will be communicated at the meeting. We expect that the few fish, which swam normally under white or red light, will have a very low otolith asymmetry (differences in the size of the right versus the left otoliths). Asymmetry may be considerably higher in animals swimming normally under blue light, since these specimens are presumed to rely entirely on visual input; an otolith asymmetry will thus not lead to a computation of erroneous vestibular cues. Acknowledgement: This work was financially supported by the German Aerospace Center (DLR) (FKZ: 50 WB 0527). The excellent technical assistance of Sandra Schroer is highly appreciated.

Readaptation of Fish to 1g after Long-Term Microgravity: Behavioural Results from the STS 89 Mission

NASA Astrophysics Data System (ADS)

Anken, R. H.; Hilbig, R.; Ibsch, M.; Rahmann, H.

The swimming behaviour of adult and neonate swordtail fish Xiphophorus helleri was qualitatively analysed from video recordings taken throughout the STS 89 spaceshuttle mission from launch to landing and thereafter. After the flight, the swimming behaviour of neonate samples was quantitatively assessed in the course of the readaptation to 1g earth gravity at days 0, 1 and 4 after recovery. Regarding the swimming behaviour during the mission, the adult fish swam thigmotactically (i.e., responding to tactile stimuli) along the walls of their aquarium, but like the neonates, they did not show any aberrant behavioural patterns. This indicates that they could easily adapt themselves to microgravity. On mission day 9, however, looping responses (most probably initiated by mechanical disturbances) occurred indicating a continuously performed ``C-start'' escape response (the respective body bend looks like the letter ``C''). Immediately after landing (oberved in videos recorded onboard the space shuttle), the adults performed a head-up swimming beating heavily with the caudal and pectoral fins; this aberrant behaviour gradually decreased during the first hours after recovery

Seahorses under a changing ocean: the impact of warming and acidification on the behaviour and physiology of a poor-swimming bony-armoured fish.

PubMed

Faleiro, Filipa; Baptista, Miguel; Santos, Catarina; Aurélio, Maria L; Pimentel, Marta; Pegado, Maria Rita; Paula, José Ricardo; Calado, Ricardo; Repolho, Tiago; Rosa, Rui

2015-01-01

Seahorses are currently facing great challenges in the wild, including habitat degradation and overexploitation, and how they will endure additional stress from rapid climate change has yet to be determined. Unlike most fishes, the poor swimming skills of seahorses, along with the ecological and biological constraints of their unique lifestyle, place great weight on their physiological ability to cope with climate changes. In the present study, we evaluate the effects of ocean warming (+4°C) and acidification (ΔpH = -0.5 units) on the physiological and behavioural ecology of adult temperate seahorses, Hippocampus guttulatus. Adult seahorses were found to be relatively well prepared to face future changes in ocean temperature, but not the combined effect of warming and acidification. Seahorse metabolism increased normally with warming, and behavioural and feeding responses were not significantly affected. However, during hypercapnia the seahorses exhibited signs of lethargy (i.e. reduced activity levels) combined with a reduction of feeding and ventilation rates. Nonetheless, metabolic rates were not significantly affected. Future ocean changes, particularly ocean acidification, may further threaten seahorse conservation, turning these charismatic fishes into important flagship species for global climate change issues.

Influence of hypergravity on fish inner ear otoliths: II. Incorporation of calcium and kinetotic behaviour.

PubMed

Beier, M; Anken, R H; Rahmann, H

2002-01-01

Larval siblings of cichlid fish (Oreochromis mossambicus) were subjected to hypergravity (hg; 3 g, 14 days) during development. Following the transfer to 1 g (i.e., stopping the centrifuge) they were separated into normally and kinetotically swimming individuals (the latter performed spinning movements). During hg, the animals were maintained in aquarium water containing alizarin-complexone (AC), a fluorescent calcium tracer. Densitometric measurements of AC uptake into inner ear otoliths (optical density of AC/micrometers2) revealed that the kinetotic individuals had incorporated significantly more AC/calcium than the normally behaving fish. Since the amount of otolithic calcium can be taken as an approximation for otolith weight, the present results indicate that the otoliths of kinetotically swimming samples were heavier than those of the normally behaving larvae, thus exhibiting a higher absolute weight asymmetry of the otoliths between the right vs. the left side of the body. This supports an earlier concept according to which otolith (or statolith) asymmetry is the cause for kinetoses such as human static space sickness. c2002 COSPAR. Published by Elsevier Science Ltd. All rights reserved.

Anisotropic swim stress in active matter with nematic order

NASA Astrophysics Data System (ADS)

Yan, Wen; Brady, John F.

2018-05-01

Active Brownian particles (ABPs) transmit a swim pressure {{{\\Pi }}}{{swim}}=n\\zeta {D}{{swim}} to the container boundaries, where ζ is the drag coefficient, D swim is the swim diffusivity and n is the uniform bulk number density far from the container walls. In this work we extend the notion of the isotropic swim pressure to the anisotropic tensorial swim stress {{\\boldsymbol{σ }}}{{swim}}=-n\\zeta {{\\boldsymbol{D}}}{{swim}}, which is related to the anisotropic swim diffusivity {{\\boldsymbol{D}}}{{swim}}. We demonstrate this relationship with ABPs that achieve nematic orientational order via a bulk external field. The anisotropic swim stress is obtained analytically for dilute ABPs in both 2D and 3D systems. The anisotropy, defined as the ratio of the maximum to the minimum of the three principal stresses, is shown to grow exponentially with the strength of the external field. We verify that the normal component of the anisotropic swim stress applies a pressure {{{\\Pi }}}{{swim}}=-({{\\boldsymbol{σ }}}{{swim}}\\cdot {\\boldsymbol{n}})\\cdot {\\boldsymbol{n}} on a wall with normal vector {\\boldsymbol{n}}, and, through Brownian dynamics simulations, this pressure is shown to be the force per unit area transmitted by the active particles. Since ABPs have no friction with a wall, the difference between the normal and tangential stress components—the normal stress difference—generates a net flow of ABPs along the wall, which is a generic property of active matter systems.

Environmental estrogen(s) induced swimming behavioural alterations in adult zebrafish (Danio rerio).

PubMed

Goundadkar, Basavaraj B; Katti, Pancharatna

2017-09-01

The present study is an attempt to investigate the effects of long-term (75days) exposure to environmental estrogens (EE) on the swimming behaviour of zebrafish (Danio rerio). Adult zebrafish were exposed semi-statically to media containing commonly detected estrogenic water contaminants (EE2, DES and BPA) at a concentration (5ng/L) much lower than environmentally recorded levels. Time spent in swimming, surface preference, patterns and path of swimming were recorded (6mins) for each fish using two video cameras on day 15, 30 60 and 75. Video clips were analysed using a software program. Results indicate that chronic exposure to EE leads to increased body weight and size of females, reduced (P<0.05) swimming time, delay in latency, increased (P<0.05) immobility, erratic movements and freezing episodes. We conclude that estrogenic contamination of natural aquatic systems induces alterations in locomotor behaviour and associated physiological disturbances in inhabitant fish fauna. Copyright © 2017 Elsevier B.V. All rights reserved.

Characterization of intermittency in zooplankton behaviour in turbulence.

PubMed

Michalec, François-Gaël; Schmitt, François G; Souissi, Sami; Holzner, Markus

2015-10-01

We consider Lagrangian velocity differences of zooplankters swimming in still water and in turbulence. Using cumulants, we quantify the intermittency properties of their motion recorded using three-dimensional particle tracking velocimetry. Copepods swimming in still water display an intermittent behaviour characterized by a high probability of small velocity increments, and by stretched exponential tails. Low values arise from their steady cruising behaviour while heavy tails result from frequent relocation jumps. In turbulence, we show that at short time scales, the intermittency signature of active copepods clearly differs from that of the underlying flow, and reflects the frequent relocation jumps displayed by these small animals. Despite these differences, we show that copepods swimming in still and turbulent flow belong to the same intermittency class that can be modelled by a log-stable model with non-analytical cumulant generating function. Intermittency in swimming behaviour and relocation jumps may enable copepods to display oriented, collective motion under strong hydrodynamic conditions and thus, may contribute to the formation of zooplankton patches in energetic environments.

Duloxetine and 8-OH-DPAT, but not fluoxetine, reduce depression-like behaviour in an animal model of chronic neuropathic pain.

PubMed

Hu, Bing; Doods, Henri; Treede, Rolf-Detlef; Ceci, Angelo

2016-04-21

The current study assessed whether antidepressant and/or antinociceptive drugs, duloxetine, fluoxetine as well as (±)-8-hydroxy-2-[di-n-propylamino] tetralin (8-OH-DPAT), are able to reverse depression-like behaviour in animals with chronic neuropathic pain. Chronic constriction injury (CCI) of the sciatic nerve in rats was selected as neuropathic pain model. Mechanical hypersensitivity and depression-like behaviour were evaluated 4 weeks after surgery by "electronic algometer" and forced swimming test (FST), which measured the time of immobility, and active behaviours climbing and swimming. The selective noradrenergic and serotonergic uptake blocker duloxetine (20mg/kg) and the selective 5-HT1A agonist 8-OH-DPAT (0.5mg/kg) significantly reversed both mechanical hypersensitivity and depression-like behaviour in CCI animals. Duloxetine significantly reversed depression-like behaviour in CCI rats by increasing the time of climbing and swimming, while 8-OH-DPAT attenuated depression-like behaviour mainly by increasing the time of swimming. However, the selective serotonergic uptake blocker fluoxetine (20mg/kg) failed to attenuate mechanical hypersensitivity and depression-like behaviour, possibly due to confounding pro-nociceptive actions at 5-HT3 receptors. These data suggest to target noradrenergic and 5-HT1A receptors for treatment of chronic pain and its comorbidity depression. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Psychophysiological evidence for the genuineness of swimming-style colour synaesthesia.

PubMed

Rothen, Nicolas; Nikolić, Danko; Jürgens, Uta Maria; Mroczko-Wąsowicz, Aleksandra; Cock, Josephine; Meier, Beat

2013-03-01

Recently, swimming-style colour synaesthesia was introduced as a new form of synaesthesia. A synaesthetic Stroop test was used to establish its genuineness. Since Stroop interference can occur for any type of overlearned association, in the present study we used a modified Stroop test and psychophysiological synaesthetic conditioning to further establish the genuineness of this form of synaesthesia. We compared the performance of a swimming-style colour synaesthete and a control who was trained on swimming-style colour associations. Our results showed that behavioural aspects of swimming-style colour synaesthesia can be mimicked in a trained control. Importantly, however, our results showed a psychophysiological conditioning effect for the synaesthete only. We discuss the theoretical relevance of swimming-style colour synaesthesia according to different models of synaesthesia. We conclude that swimming-style colour synaesthesia is a genuine form of synaesthesia, can be mimicked behaviourally in non-synaesthetes, and is best explained by a re-entrant feedback model. Copyright © 2012 Elsevier Inc. All rights reserved.

Cortisol treatment affects locomotor activity and swimming behaviour of male smallmouth bass engaged in paternal care: A field study using acceleration biologgers.

PubMed

Algera, Dirk A; Brownscombe, Jacob W; Gilmour, Kathleen M; Lawrence, Michael J; Zolderdo, Aaron J; Cooke, Steven J

2017-11-01

Paternal care, where the male provides sole care for the developing brood, is a common form of reproductive investment among teleost fish and ubiquitous in the Centrarchidae family. Throughout the parental care period, nesting males expend energy in a variety of swimming behaviours, including routine and burst swimming, vigilantly monitoring the nest area and protecting the brood from predators. Parental care is an energetically demanding period, which is presumably made even more difficult if fish are exposed to additional challenges such as those arising from human disturbance, resulting in activation of the hypothalamic-pituitary-interrenal axis (i.e., elevation of cortisol). To study this situation, we examined the effects of experimental manipulation of the stress hormone cortisol on locomotor activity and behaviour of nest guarding male smallmouth bass (Micropterus dolomieu). We exogenously elevated circulating cortisol levels (via intracoelomic implants) and attached tri-axial accelerometers to wild smallmouth bass for three days. During the recovery period (i.e., ≤4h post-release), cortisol-treated fish exhibited significantly reduced locomotor activity and performed significantly less burst and routine swimming relative to control fish, indicating cortisol uptake was rapid, as were the associated behavioural responses. Post-recovery (i.e., >4h post-release), fish with high cortisol exhibited lower locomotor activity and reduced routine swimming relative to controls. Fish were less active and reduced routine and burst swimming at night compared to daylight hours, an effect independent of cortisol treatment. Collectively, our results suggest that cortisol treatment (as a proxy for anthropogenic disturbance and stress) contributed to altered behaviour, and consequently cortisol-treated males decreased parental investment in their brood, which could have potential fitness implications. Copyright © 2017 Elsevier Inc. All rights reserved.

On inappropriately used neuronal circuits as a possible basis of the ``loop-swimming'' behaviour of fish under reduced gravity: a theoretical study

NASA Astrophysics Data System (ADS)

Anken, R. H.; Rahmann, H.

One hypothesis for the explanation of the so-called ``loop-swimming'' behaviour in fish when being subjected to reduced gravity assumes that the activities of the differently weighted otoliths of the two labyrinths are well compensated on ground but that a functional asymmetry is induced in weightlessness, resulting in a tonus asymmetry of the body and by this generating the ``loop-swimming'' behaviour. The basis of this abnormal behaviour has to be searched for in the central nervous system (cns), where the signal-transduction from the inner ear- related signal internalisation to the signal response takes place. Circuits within the CNS of fish, that could possibly generate the ``loop-swimming'', might be as follows: An asymmetric activation of vestibulospinal circuits would directly result in a tonus asymmetry of the body. An asymmetric activation of the oculomotor nucleus would generate an asymmetrical rotation of the eyes. This would cause in its turn asymmetric images on the two retinas, which were forwarded to the diencephalic accessory optic system (AOS). It is the task of the AOS to stabilize retinal images, thereby involving the cerebellum, which is the main integration center for sensory and motor modalities. With this, the cerebellar output would generate a tonus asymmetry of the body in order to make the body of the fish follow its eyes. Such movements (especially when assuming an open loop control) would end up in the aforementioned ``loop-swimming'' behaviour.

Effect of the starting and turning performances on the subsequent swimming parameters of elite swimmers.

PubMed

Veiga, Santiago; Roig, Andreu

2017-03-01

In the present research, we examined the effect of the starting and turning performances on the subsequent swimming parameters by (1) comparing the starting and turning velocities with the swimming parameters on the emersion and mid-pool segments and (2) by relating the individual behaviour of swimmers during the start and turns with subsequent behaviour on each swimming lap. One hundred and twelve 100 m performances on the FINA 2013 World Swimming Championships were analysed by an image-processing system (InThePool 2.0®). At the point of the start emersion, the swimming parameters of the 100-m elite swimmers were substantially greater than the mid-pool parameters, except on the breaststroke races. On the other hand, no diminution in the swimming parameters was observed between the turn emersion and the mid-pool swimming, except on the butterfly and backstroke male races. Changes on the surface swimming kinematics were not generally related to the starting or turning parameters, although male swimmers who develop faster starts seem to achieve faster velocities at emersion. Race analysts should be aware of a transfer of momentum when swimmers emerge from underwater with implications on the subsequent swimming kinematics, especially for male swimmers who employ underwater undulatory techniques.

Repeated forced swimming impairs prepulse inhibition and alters brain-derived neurotrophic factor and astroglial parameters in rats.

PubMed

Borsoi, Milene; Antonio, Camila Boque; Müller, Liz Girardi; Viana, Alice Fialho; Hertzfeldt, Vivian; Lunardi, Paula Santana; Zanotto, Caroline; Nardin, Patrícia; Ravazzolo, Ana Paula; Rates, Stela Maris Kuze; Gonçalves, Carlos-Alberto

2015-01-01

Glutamate perturbations and altered neurotrophin levels have been strongly associated with the neurobiology of neuropsychiatric disorders. Environmental stress is a risk factor for mood disorders, disrupting glutamatergic activity in astrocytes in addition to cognitive behaviours. Despite the negative impact of stress-induced neuropsychiatric disorders on public health, the molecular mechanisms underlying the response of the brain to stress has yet to be fully elucidated. Exposure to repeated swimming has proven useful for evaluating the loss of cognitive function after pharmacological and behavioural interventions, but its effect on glutamate function has yet to be fully explored. In the present study, rats previously exposed to repeated forced swimming were evaluated using the novel object recognition test, object location test and prepulse inhibition (PPI) test. In addition, quantification of brain-derived neurotrophic factor (BDNF) mRNA expression and protein levels, glutamate uptake, glutathione, S100B, GluN1 subunit of N-methyl-D-aspartate receptor and calmodulin were evaluated in the frontal cortex and hippocampus after various swimming time points. We found that swimming stress selectively impaired PPI but did not affect memory recognition. Swimming stress altered the frontal cortical and hippocampal BDNF expression and the activity of hippocampal astrocytes by reducing hippocampal glutamate uptake and enhancing glutathione content in a time-dependent manner. In conclusion, these data support the assumption that astrocytes may regulate the activity of brain structures related to cognition in a manner that alters complex behaviours. Moreover, they provide new insight regarding the dynamics immediately after an aversive experience, such as after behavioural despair induction, and suggest that forced swimming can be employed to study altered glutamatergic activity and PPI disruption in rodents. Copyright © 2014. Published by Elsevier Inc.

Seahorses under a changing ocean: the impact of warming and acidification on the behaviour and physiology of a poor-swimming bony-armoured fish

PubMed Central

Baptista, Miguel; Santos, Catarina; Aurélio, Maria L; Pimentel, Marta; Pegado, Maria Rita; Paula, José Ricardo; Calado, Ricardo; Repolho, Tiago; Rosa, Rui

2015-01-01

Abstract Seahorses are currently facing great challenges in the wild, including habitat degradation and overexploitation, and how they will endure additional stress from rapid climate change has yet to be determined. Unlike most fishes, the poor swimming skills of seahorses, along with the ecological and biological constraints of their unique lifestyle, place great weight on their physiological ability to cope with climate changes. In the present study, we evaluate the effects of ocean warming (+4°C) and acidification (ΔpH = −0.5 units) on the physiological and behavioural ecology of adult temperate seahorses, Hippocampus guttulatus. Adult seahorses were found to be relatively well prepared to face future changes in ocean temperature, but not the combined effect of warming and acidification. Seahorse metabolism increased normally with warming, and behavioural and feeding responses were not significantly affected. However, during hypercapnia the seahorses exhibited signs of lethargy (i.e. reduced activity levels) combined with a reduction of feeding and ventilation rates. Nonetheless, metabolic rates were not significantly affected. Future ocean changes, particularly ocean acidification, may further threaten seahorse conservation, turning these charismatic fishes into important flagship species for global climate change issues. PMID:27293694

Cardiac responses of grey seals during diving at sea.

PubMed

Thompson, D; Fedak, M A

1993-01-01

Heart rate, swimming speed and diving depth data were collected from free-ranging grey seals, Halichoerus grypus, as they foraged and travelled in the sea around the Hebrides Islands off western Scotland. Information was collected on a tracking yacht using a combination of sonic and radio telemetry. Diving heart rate declined as a function of dive duration. In long dives, grey seals employed extreme bradycardia, with heart rates falling to 4 beats min-1 for extended periods, despite the animal being free to breath at will. This extreme dive response is part of the normal foraging behaviour. Seals spent 89% of the time submerged during bouts of long dives; swimming was restricted to ascent and descent. Dive durations exceeded estimated aerobic dive limit, even assuming resting metabolic rates. These results indicate that behavioural, and possibly cellular, energy-sparing mechanisms play an important role in diving behaviour of grey seals. This has implications not only for studies of mammalian energetics but also for our understanding of the foraging tactics and prey selection of marine mammals. If some seals are using energy-sparing mechanisms to reduce metabolic costs while at depth, they may be forced to wait for and ambush prey rather than to search for and chase it.

Intoxicated copepods: ingesting toxic phytoplankton leads to risky behaviour

PubMed Central

Lasley-Rasher, Rachel S.; Nagel, Kathryn; Angra, Aakanksha; Yen, Jeannette

2016-01-01

Understanding interactions between harmful algal bloom (HAB) species and their grazers is essential for determining mechanisms of bloom proliferation and termination. We exposed the common calanoid copepod, Temora longicornis to the HAB species Alexandrium fundyense and examined effects on copepod survival, ingestion, egg production and swimming behaviour. A. fundyense was readily ingested by T. longicornis and significantly altered copepod swimming behaviour without affecting copepod survival or fitness. A. fundyense caused T. longicornis to increase their swimming speed, and the straightness of their path long after the copepods had been removed from the A. fundyense treatment. Models suggest that these changes could lead to a 25–56% increase in encounter frequency between copepods and their predators. This work highlights the need to determine how ingesting HAB species alters grazer behaviour as this can have significant impacts on the fate of HAB toxins in marine systems. PMID:27122557

Otolith Asymmetry and kinetotic Behaviour of Fish at High-Quality Microgravity: A Drop-Tower Experiment

NASA Astrophysics Data System (ADS)

Anken, R.; Baur, U.; Forster, A.; Feucht, I.; Hilbig, R.

It has been repeatedly shown earlier that some fish of a given batch reveal motion sickness (a kinetosis) at the transition from 1g to microgravity in the course of parabolic aircraft flight (PF) experiments. Since it is unknown, whether this behaviour is induced by microgravity alone or rather by changing accelerations as they occur during PFs, larval cichlid fish (Oreochromis mossambicus) were subjected to high-quality microgravity (ca. 4.7 sec) in the drop-tower at ZARM, Bremen (Germany). The percentual ratios of the various types of behaviour (normal swimming and kinetotic swimming; kinetotic specimens revealed looping responses/LR or spinning movements/SM) highly differed from those observed in the course of PFs. Whereas kinetoses were observed in some 90% of the individuals who had experienced drops at ZARM (SM: 22%; LR: 69%; n=156 animals), during PFs only a rather small proportion of all animals had shown a kinetotic behaviour (SM: 14%; LR: 10%; n=71 animals; PF campaign June 2003, Hilbig et al., J. vest. Res. 12: 185-189, 2003). Thus, the percentual amount of spinning animals is in a roughly comparable range both during PF and drop-tower microgravity, whereas looping responses are extremely frequently exhibited during exposure to the drop-tower environment. Since the release of the drop-capsule (total mass of the capsule used: 491kg) will inevitably lead to a brisk longitudinal compression of the entire setup, many animals will have been provoked to perform a C-start escape response, which -- during microgravity -- was not discontinued and thus resulted in loop-swimming (like the looping observed during STS-89; Anken et al., Adv. Space Res. 25: 2019-2023, 1998). Data on otolith asymmetry (differences in the size of left vs. right otoliths), which has been shown to be the cause of susceptibility to kinetosis during PFs, will be communicated at the meeting. Acknowledgement: This work was financially supported by the German Aerospace Center (DLR) (FKZ: 50 WB 9997).

Parasite manipulation of brain monoamines in California killifish (Fundulus parvipinnis) by the trematode Euhaplorchis californiensis

USGS Publications Warehouse

Shaw, J.C.; Korzan, W.J.; Carpenter, R.E.; Kuris, A.M.; Lafferty, K.D.; Summers, C.H.; Overli, O.

2009-01-01

California killifish (Fundulus parvipinnis) infected with the brain-encysting trematode Euhaplorchis californiensis display conspicuous swimming behaviours rendering them more susceptible to predation by avian final hosts. Heavily infected killifish grow and reproduce normally, despite having thousands of cysts inside their braincases. This suggests that E. californiensis affects only specific locomotory behaviours. We hypothesised that changes in the serotonin and dopamine metabolism, essential for controlling locomotion and arousal may underlie this behaviour modification. We employed micropunch dissection and HPLC to analyse monoamine and monoamine metabolite concentrations in the brain regions of uninfected and experimentally infected fish. The parasites exerted density-dependent changes in monoaminergic activity distinct from those exhibited by fish subjected to stress. Specifically, E. californiensis inhibited a normally occurring, stress-induced elevation of serotonergic metabolism in the raphae nuclei. This effect was particularly evident in the experimentally infected fish, whose low-density infections were concentrated on the brainstem. Furthermore, high E. californiensis density was associated with increased dopaminergic activity in the hypothalamus and decreased serotonergic activity in the hippocampus. In conclusion, the altered monoaminergic metabolism may explain behavioural differences leading to increased predation of the infected killifish by their final host predators. ?? 2008 The Royal Society.

Size and Cell Number of the Utricle in kinetotically swimming Fish: A parabolic Aircraft Flight Study

NASA Astrophysics Data System (ADS)

Baeuerle, A.; Anken, R.; Baumhauer, N.; Hilbig, R.; Rahmann, H.

Humans taking part in parabolic aircraft flights (PAFs) may suffer from space motion sickness (SMS, a kinetosis). Since it has been repeatedly shown earlier that some fish of a given batch also reveal a kinetotic behaviour during PAFs (especially so-called spinning movements and looping responses), and due to the homology of the vestibular apparatus among all vertebrates, fish can be used as model systems to investigate the origin of susceptibility to motion sickness. Therefore, we examined the utricular maculae (they are responsible for the internalisation of gravity in teleosteans) of fish swimming kinetotically during the μg-phases in the course of PAFs in comparison with animals from the same batch who swam normally. On the light microscopical level, it was found that the total number of both sensory and supporting cells of the utricular maculae did not differ between kinetotic animals as compared to normally swimming fish. Cell density (sensory and supporting cells/100μm -μm), however, was reduced in kinetotic animals (p<0.0001), which seemed to be due to malformed epithelial cells (increase in cell size) of the kinetotic specimens. Susceptibility to kinetoses may therefore originate in asymmetric inner ear otoliths as has been suggested earlier, but also in genetically predispositioned, malformed sensory epithelia. This work was financially supported by the German Aerospace Center (DLR) e.V. (FKZ: 50 WB 9997).

The effect of labyrinthectomy on postural control of upside-down swimming catfish, Synodontis nigriventris, under pseudomicrogravity.

PubMed

Ohnishi, K; Yamamoto, T; Takahashi, A; Tanaka, H; Koyama, M; Ohnishi, T

1999-08-01

The catfish (Synodontis nigriventris) has a unique habitat of keeping an upside-down posture under normal gravity. We examined its postural control under pseudomicrogravity generated artificially, and the effect of unilateral labyrinthectomy on the postural control. The stable swimming posture under pseudomicrogravity was observed in the upside-down swimming catfish but not in the catfish (Corydoras paleatus), which has normal swimming habitat. Furthermore, although S. nigriventris but not C. paleatus could keep the stable swimming posture under normal gravity condition after unilateral labyrinthectomy, the labyrinthectomized fishes could not keep it under pseudomicrogravity. Seven days after the operation, S. nigriventris alone partially recovered the ability to keep an upside-down swimming posture, and did completely, to the control level, 25 days after the operation. Furthermore, when S. nigriventris was under pseudomicrogravity in dark conditions, it showed disturbed swimming postures. These results suggest that the upside-down swimming catfish has superior ability of postural control depending on the labyrinth.

The behaviour and recovery of juvenile lemon sharks Negaprion brevirostris in response to external accelerometer tag attachment.

PubMed

Bullock, R W; Guttridge, T L; Cowx, I G; Elliott, M; Gruber, S H

2015-12-01

Behavioural responses of lemon sharks Negaprion brevirostris to a fin-mounted tag package (CEFAS G6A tri-axial accelerometer with epoxied Sonotronics PT4 acoustic transmitter) were measured in a controlled captive environment (n = 10, total length, LT range 80-140 cm) and in free-ranging sharks upon release (n = 7, LT range 100-160 cm). No changes were detected in behaviour (i.e. swimming speed, tailbeat frequency, time spent resting and frequency of chafing) between control and tagged captive shark trials, suggesting that the tag package itself does not alter behaviour. In the free-ranging trials, an initial period of elevated swimming activity was found in all individuals (represented by overall dynamic body acceleration). Negaprion brevirostris, however, appeared to recover quickly, returning to a steady swimming state between 2 and 35 min after release. Post-release tracking found that all sharks swim immediately for the shoreline and remain within 100 m of shore for prolonged periods. Hence, although N. brevirostris are capable of quick adaptation to stressors and demonstrate rapid recovery in terms of activity, tracking data suggest that they may modify their spatial use patterns post release. This research is important in separating deviation in behaviour due to environmental stressors from artefacts caused by experimental techniques. © 2015 The Fisheries Society of the British Isles.

Effect of horizontal strong static magnetic field on swimming behaviour of Paramecium caudatum

NASA Astrophysics Data System (ADS)

Fujiwara, Yoshihisa; Tomishige, Masahiko; Itoh, Yasuhiro; Fujiwara, Masao; Shibata, Naho; Kosaka, Toshikazu; Hosoya, Hiroshi; Tanimoto, Yoshifumi

2006-05-01

Effect of horizontal strong static magnetic field on swimming behaviour of Paramecium caudatum was studied by using a superconducting magnet. Around a centre of a round vessel, random swimming at 0 T and aligned swimming parallel to the magnetic field (MF) of 8 T were observed. Near a wall of the vessel, however, swimming round and round along the wall at 0 T and aligned swimming of turning at right angles upon collision with the wall, which was remarkable around 1-4 T, were detected. It was experimentally revealed that the former MF-induced parallel swimming at the vessel centre was caused physicochemically by the parallel magnetic orientation of the cell itself. From magnetic field dependence of the extent of the orientation, the magnetic susceptibility anisotropy (χ ∥-χ ⊥) was first obtained to be 3.4× 10-23 emu cell-1 at 298 K for Paramecium caudatum. The orientation of the cell was considered to result from the magnetic orientation of the cell membrane. On the other hand, although mechanisms of the latter swimming near the vessel wall regardless of the absence and presence of the magnetic field are unclear at present, these experimental results indicate that whether the cell exists near the wall alters the magnetic field effect on the swimming in the horizontal magnetic field.

Survey of Different Types of Communication in Swimming Education

ERIC Educational Resources Information Center

Biro, Melinda

2007-01-01

Study aim: To evaluate verbal and non-verbal behaviour of teachers and pupils in elementary swimming education and their impact on pupils' achievements. Material and methods: A total of 77 swimming lessons were videorecorded and coded with the modified Cheffers' Adaptation of Flanders Interaction Analysis System (CAFIAS); 46 PE teachers, swimming…

Swimming behaviour and calcium incorporation into inner ear otoliths of fish after vestibular nerve transection

NASA Astrophysics Data System (ADS)

Edelmann, E.; Anken, R. H.; Rahmann, H.

2004-01-01

Previous investigations on neonate swordtail fish (Xiphophorus helleri) revealed that otolithic calcium incorporation (visualized using the calcium tracer alizarin complexone) and thus otolith growth had ceased after nerve transection, supporting a hypothesis according to which the gravity-dependent otolith growth is regulated neuronally. Subsequent investigations on larval cichlid fish (Oreochromis mossambicus) yielded contrasting results, repeatedly depending on the particular batch of cichlids investigated. Like most neonate swordtails, Type I cichlids revealed a stop of calcium incorporation after unilateral vestibular nerve transection. Their behaviour after transection was normal, and the otolithic calcium incorporation in controls of the same batch was symmetric. In Type II cichlids, however, vestibular nerve transection had no effect on otolithic calcium incorporation. They behaved kinetotically after transection (this kind of kinetosis was qualitatively similar to the swimming behaviour exhibited by larval cichlids during microgravity in the course of parabolic aircraft flights). The otolithic calcium incorporation in control animals was asymmetric. These results show that the effects of vestibular nerve transection as well as the efficacy of the mechanism, which regulates otolith growth/otolithic calcium incorporation, are - depending on the particular batch of animals - genetically predispositioned. In conclusion, the regulation of otolithic calcium incorporation is guided neuronally, in part via the vestibular nerve and, in part, via a further pathway, which remains to be addressed in the course of future investigations.

Influence of long-term altered gravity on the swimming performance of developing cichlid fish: including results from the 2nd German Spacelab Mission D-2

NASA Astrophysics Data System (ADS)

Rahmann, H.; Hilbig, R.; Flemming, J.; Slenzka, K.

This study presents qualitative and quantitative data concerning gravity-dependent changes in the swimming behaviour of developing cichlid fish larvae (Oreochromis mossambicus) after a 9 resp. 10 days exposure to increased acceleration (centrifuge experiments), to reduced gravity (fast-rotating clinostat), changed accelerations (parabolic air craft flights) and to near weightlessness (2nd German Spacelab Mission D-2). Changes of gravity initially cause disturbances of the swimming performance of the fish larvae. With prolonged stay in orbit a step by step normalisation of the swimming behaviour took place in the fish. After return to 1g earth conditions no somersaulting or looping could be detected concerning the fish, but still slow and disorientated movements as compared to controls occurred. The fish larvae adapted to earth gravity within 3-5 days. Fish seem to be in a distinct early developmental stages extreme sensitive and adaptable to altered gravity. However, elder fish either do not react or show compensatory behaviour e.g. escape reactions.

Turbulent flow reduces oxygen consumption in the labriform swimming shiner perch, Cymatogaster aggregata.

PubMed

van der Hoop, Julie M; Byron, Margaret L; Ozolina, Karlina; Miller, David L; Johansen, Jacob L; Domenici, Paolo; Steffensen, John F

2018-06-12

Fish swimming energetics are often measured in laboratory environments which attempt to minimize turbulence, though turbulent flows are common in the natural environment. To test whether the swimming energetics and kinematics of shiner perch, Cymatogaster aggregata (a labriform swimmer), were affected by turbulence, two flow conditions were constructed in a swim-tunnel respirometer. A low-turbulence flow was created using a common swim-tunnel respirometry setup with a flow straightener and fine-mesh grid to minimize velocity fluctuations. A high-turbulence flow condition was created by allowing large velocity fluctuations to persist without a flow straightener or fine grid. The two conditions were tested with particle image velocimetry to confirm significantly different turbulence properties throughout a range of mean flow speeds. Oxygen consumption rate of the swimming fish increased with swimming speed and pectoral fin beat frequency in both flow conditions. Higher turbulence also caused a greater positional variability in swimming individuals (versus low-turbulence flow) at medium and high speeds. Surprisingly, fish used less oxygen in high-turbulence compared with low-turbulence flow at medium and high swimming speeds. Simultaneous measurements of swimming kinematics indicated that these reductions in oxygen consumption could not be explained by specific known flow-adaptive behaviours such as Kármán gaiting or entraining. Therefore, fish in high-turbulence flow may take advantage of the high variability in turbulent energy through time. These results suggest that swimming behaviour and energetics measured in the lab in straightened flow, typical of standard swimming respirometers, might differ from that of more turbulent, semi-natural flow conditions. © 2018. Published by The Company of Biologists Ltd.

The psychoactive drug Escitalopram affects swimming behaviour and increases boldness in zebrafish (Danio rerio).

PubMed

Nielsen, Sebastian V; Kellner, Martin; Henriksen, Per G; Olsén, Håkan; Hansen, Steen H; Baatrup, Erik

2018-05-01

Selective serotonin re-uptake inhibitors are pharmaceuticals used to treat a range of psychological disorders. They are frequently found in surface waters in populated areas. In recent years, they have been shown to affect the behaviour of various aquatic organisms in a way that can have ecological effects. In this study, we exposed zebrafish of both sexes to nominally 0.00, 0.15 and 1.50 µg L -1 Escitalopram in flow-through tanks for three weeks. Subsequently, ten swimming behaviour parameters were quantified using high-resolution video tracking. There were noticeable gender differences in the behaviour responses to Escitalopram. Female fish exposed to 1.50 µg L -1 Escitalopram had a lower maximum swimming velocity, stopped less often and exhibited increased boldness (reduced thigmotaxis) compared to controls. Male fish exposed to 1.50 µg L -1 had a lower maximum swimming velocity compared to control fish. At the end of exposures, both length and weight of the females exposed to 1.50 µg L -1 Escitalopram were significantly less than the group of control fish. In addition, males exposed to 1.50 µg L -1 Escitalopram were significantly shorter than control fish. The behaviour, weight and body length of the fish exposed to nominally 0.15 µg L -1 was not significantly different from control fish in either sex. The results of this study demonstrate that Escitalopram can affect subtle but ecologically important aspects of fish behaviour and lends further credibility to the assumption that Escitalopram is an environmentally active pharmaceutical.

The Effect of an Adapted Swimming Program on the Performance of an Individual with Kyphosis-Scoliosis

ERIC Educational Resources Information Center

Dimitrios, Voutsas; Dimitrios, Kokaridas

2004-01-01

The purpose of this action research study was to examine the effect of an adapted swimming program in terms of improving the performance and behaviour of an individual with kyphosis-scoliosis, with the use of an individualised education approach. The sample consisted of an adult woman with kyphosis-scoliosis. The pre-swimming phase included a…

Spike threshold dynamics in spinal motoneurons during scratching and swimming.

PubMed

Grigonis, Ramunas; Alaburda, Aidas

2017-09-01

Action potential threshold can vary depending on firing history and synaptic inputs. We used an ex vivo carapace-spinal cord preparation from adult turtles to study spike threshold dynamics in motoneurons during two distinct types of functional motor behaviour - fictive scratching and fictive swimming. The threshold potential depolarizes by about 10 mV within each burst of spikes generated during scratch and swim network activity and recovers between bursts to a slightly depolarized level. Slow synaptic integration resulting in a wave of membrane potential depolarization is the factor influencing the threshold potential within firing bursts during motor behaviours. Depolarization of the threshold potential decreases the excitability of motoneurons and may provide a mechanism for stabilization of the response of a motoneuron to intense synaptic inputs to maintain the motor commands within an optimal range for muscle activation. During functional spinal neural network activity motoneurons receive intense synaptic input, and this could modulate the threshold for action potential generation, providing the ability to dynamically adjust the excitability and recruitment order for functional needs. In the present study we investigated the dynamics of action potential threshold during motor network activity. Intracellular recordings from spinal motoneurons in an ex vivo carapace-spinal cord preparation from adult turtles were performed during two distinct types of motor behaviour - fictive scratching and fictive swimming. We found that the threshold of the first spike in episodes of scratching and swimming was the lowest. The threshold potential depolarizes by about 10 mV within each burst of spikes generated during scratch and swim network activity and recovers between bursts to a slightly depolarized level. Depolarization of the threshold potential results in decreased excitability of motoneurons. Synaptic inputs do not modulate the threshold of the first action potential during episodes of scratching or of swimming. There is no correlation between changes in spike threshold and interspike intervals within bursts. Slow synaptic integration that results in a wave of membrane potential depolarization rather than fast synaptic events preceding each spike is the factor influencing the threshold potential within firing bursts during motor behaviours. © 2017 The Authors. The Journal of Physiology © 2017 The Physiological Society.

Progression of behavioural despair in R6/2 and Hdh knock-in mouse models recapitulates depression in Huntington's disease.

PubMed

Ciamei, Alessandro; Detloff, Peter J; Morton, A Jennifer

2015-09-15

In Huntington's disease (HD) depression is observed before the disease is diagnosed, and is likely to be a component of the disease, rather than a consequence. Depression in HD patients does not progress in parallel with other symptoms; rather it peaks at early- to mid-stages of the disease and declines thereafter. In mice, depressive-like behaviours can be measured as an increase in behavioural despair (floating) observed in the forced swim test (FST). Floating in the FST is modulated differently by antidepressants with different mechanisms of action. Drugs that increase levels of serotonin inhibit floating by promoting horizontal swimming, whereas drugs that increase levels of noradrenaline inhibit floating by enhancing vertical swimming (climbing). We compared the FST behavioural profiles of two different allelic series of HD mice, a fragment model (R6/2 mice carrying 120, 250, or 350 CAG repeats), and a knock-in model (Hdh mice carrying 50, 150, or 250 CAG repeats). The FST behavioural profile was similar in both lines. It was characterized by an early-stage increase in floating, and then, as the mice aged, floating decreased, whereas active behaviours of swimming and climbing increased. Our results show that, as with depression in HD patients, floating in HD mice does not progress linearly, suggesting that, at the late stages of the disease, an increase in serotonergic and noradrenergic activity might contribute to lower floating levels in HD mice. If similar compensatory changes occur in humans, this should be taken into account when considering the treatment of depression in HD patients. Copyright © 2015 Elsevier B.V. All rights reserved.

Role of the neostriatal dopaminergic activity in sequencing and selecting behavioural strategies: facilitation of processes involved in selecting the best strategy in a stressful situation.

PubMed

Cools, A R

1980-10-01

The purpose of this study was to detect the behavioural effect of drug-induced changes in the neostriatal dopaminergic activity upon the degree of intrinsic (self-generated) and extrinsic (externally produced) constraints on the selection of behavioural patterns in rats. Both systemic and neostriatal injections of extremely low doses of apomorphine and haloperidol were used to change the neostriatal dopaminergic activity. Behavioural changes were observed in (a) an open-field test, (b) a so-called 'swimming without escape' test, (c) a so-called 'swimming with escape' test, and (d) a test to detect deficiencies in sensory, motor and sensorimotor capacities required to perform both swimming tests. Evidence is found that the neostriatum, especially the neostriatal, dopaminergic activity determines the animal's ability to select the best strategy in a stressful situation by modifying the process of switching strategies under pressure of factors intrinsic to the organism: neither sensory neglect nor inability to initiate voluntary movements underlay the observed phenomena. It is suggested that the neostriatum determines the individual flexibility to cope with available sensory information.

[Hygienic risks in swimming pool: knowledge and behaviours of consumers of three structures in Crema, Parma and Naples].

PubMed

Liguori, G; Castaldi, S; Signorelli, C; Auxilia, F; Alfano, V; Saccani, E; Visciano, A; Fanti, M; Spinelli, A; Pasquarella, C

2007-01-01

The swimmers health's protection and the maintenance of good safety standards of structures can be guaranteed under observance of rules and the well management of the structures and activities. An anonymous questionnaire, with 38 items, was used in order to analyse and better understand the knowledge and behaviour of the users of three swimming pools in Crema, Naples and Parma. Socio-demographic features were similar in the three centres. One of the most important result was that the necessity of showers and foot-bath before entering the swimming pool is not well understood (77% and 78% respectively); caps and foot bath are, instead, almost always worn (98% and 97%). Knowledge on infection diseases transmitted by water is very poor, warts and mycosis being the best known. Sport structures are places where health and wellness can be affected. It is important to underline the role of behavioural rules as the use of showers, caps, and proper shoes. Authors recognize the swimming pool regulations as a valid tool for health promotion. It must be clear and easily understood and it has to be linked to a proper education pathway of all users and employees.

Locomotor activity during the frenzy swim: analysing early swimming behaviour in hatchling sea turtles.

PubMed

Pereira, Carla M; Booth, David T; Limpus, Colin J

2011-12-01

Swimming effort of hatchling sea turtles varies across species. In this study we analysed how swim thrust is produced in terms of power stroke rate, mean maximum thrust per power stroke and percentage of time spent power stroking throughout the first 18 h of swimming after entering the water, in both loggerhead and flatback turtle hatchlings and compared this with previous data from green turtle hatchlings. Loggerhead and green turtle hatchlings had similar power stroke rates and percentage of time spent power stroking throughout the trial, although mean maximum thrust was always significantly higher in green hatchlings, making them the most vigorous swimmers in our three-species comparison. Flatback hatchlings, however, were different from the other two species, with overall lower values in all three swimming variables. Their swimming effort dropped significantly during the first 2 h and kept decreasing significantly until the end of the trial at 18 h. These results support the hypothesis that ecological factors mould the swimming behaviour of hatchling sea turtles, with predator pressure being important in determining the strategy used to swim offshore. Loggerhead and green turtle hatchlings seem to adopt an intensely vigorous and energetically costly frenzy swim that would quickly take them offshore into the open ocean in order to reduce their exposure to near-shore aquatic predators. Flatback hatchlings, however, are restricted in geographic distribution and remain within the continental shelf region where predator pressure is probably relatively constant. For this reason, flatback hatchlings might use only part of their energy reserves during a less vigorous frenzy phase, with lower overall energy expenditure during the first day compared with loggerhead and green turtle hatchlings.

Light-mediated host searching strategies in a fish ectoparasite, Argulus foliaceus L. (crustacea: branchiura).

PubMed

Mikheev, V N; Mikheev, A V; Pasternak, A F; Valtonen, E T

2000-04-01

Argulus foliaceus, an obligate fish ectoparasite, can search for its hosts in both light and dark conditions and uses vision in the light. We have examined what searching mode is used at night, when the infection rate was at its highest, and which stimuli produced by the fish are most important. A change of illumination produced a clear difference in the searching behaviour of adult Argulus females. The mean swimming speed and the area explored were 3-4 times higher in the dark, when the parasite employed a cruising search strategy. This changed to an ambush (hover-and-wait) strategy in the light. The swimming activity is accompanied by changes in metabolic costs; the activity of the electron transport system being approximately 25 % lower in the light. The most pronounced light-induced differences in host-searching behaviour took place in moderately hungry parasites (starved for 24-96 h). Less motivated (just having left a fish) or exhausted animals did not exhibit any clear differences in swimming speed. Among the external signals tested, fish smell, from both perch (Perca fluviatilis) and roach (Rutilus rutilus), induced an elevated swimming speed of the parasite. Periodic water movements caused similar but weaker effects. The effects of these stimuli were observed under both light and dark conditions. We conclude that host-searching behaviour of A. foliaceus is under internal (state of hunger) and external (illumination and host-induced signals) control and involves all its sensory equipment (vision, olfaction and mechano-reception). Perch (but not roach) reduced their swimming speed in the dark, which make them more susceptible to cruising Argulus. Thus the behavioural interplay between hosts and parasites can also influence the infection rate of A. foliaceus found on perch and roach in Finnish lakes.

Cardiorespiratory performance during prolonged swimming tests with salmonids: a perspective on temperature effects and potential analytical pitfalls.

PubMed

Farrell, A P

2007-11-29

A prolonged swimming trial is the most common approach in studying steady-state changes in oxygen uptake, cardiac output and tissue oxygen extraction as a function of swimming speed in salmonids. The data generated by these sorts of studies are used here to support the idea that a maximum oxygen uptake is reached during a critical swimming speed test. Maximum oxygen uptake has a temperature optimum. Potential explanations are advanced to explain why maximum aerobic performance falls off at high temperature. The valuable information provided by critical swimming tests can be confounded by non-steady-state swimming behaviours, which typically occur with increasing frequency as salmonids approach fatigue. Two major concerns are noted. Foremost, measurements of oxygen uptake during swimming can considerably underestimate the true cost of transport near critical swimming speed, apparently in a temperature-dependent manner. Second, based on a comparison with voluntary swimming ascents in a raceway, forced swimming trials in a swim tunnel respirometer may underestimate critical swimming speed, possibly because fish in a swim tunnel respirometer are unable to sustain a ground speed.

Similarities and Differences for Swimming in Larval and Adult Lampreys.

PubMed

McClellan, Andrew D; Pale, Timothée; Messina, J Alex; Buso, Scott; Shebib, Ahmad

2016-01-01

The spinal locomotor networks controlling swimming behavior in larval and adult lampreys may have some important differences. As an initial step in comparing the locomotor systems in lampreys, in larval animals the relative timing of locomotor movements and muscle burst activity were determined and compared to those previously published for adults. In addition, the kinematics for free swimming in larval and adult lampreys was compared in detail for the first time. First, for swimming in larval animals, the neuromechanical phase lag between the onsets or terminations of muscle burst activity and maximum concave curvature of the body increased with increasing distance along the body, similar to that previously shown in adults. Second, in larval lampreys, but not adults, absolute swimming speed (U; mm s(-1)) increased with animal length (L). In contrast, normalized swimming speed (U'; body lengths [bl] s(-1)) did not increase with L in larval or adult animals. In both larval and adult lampreys, U' and normalized wave speed (V') increased with increasing tail-beat frequency. Wavelength and mechanical phase lag did not vary significantly with tail-beat frequency but were significantly different in larval and adult animals. Swimming in larval animals was characterized by a smaller U/V ratio, Froude efficiency, and Strouhal number than in adults, suggesting less efficient swimming for larval animals. In addition, during swimming in larval lampreys, normalized lateral head movements were larger and normalized lateral tail movements were smaller than for adults. Finally, larval animals had proportionally smaller lateral surface areas of the caudal body and fin areas than adults. These differences are well suited for larval sea lampreys that spend most of the time buried in mud/sand, in which swimming efficiency is not critical, compared to adults that would experience significant selection pressure to evolve higher-efficiency swimming to catch up to and attach to fish for feeding as well as engage in long-distance migration during spawning. Finally, the differences in swim efficiency for larval and adult lampreys are compared to other animals employing the anguilliform mode of swimming.

Observations on Side-Swimming Rainbow Trout in Water Recirculation Aquaculture Systems

PubMed Central

Good, Christopher; Davidson, John; Kinman, Christin; Kenney, P. Brett; Bæverfjord, Grete; Summerfelt, Steven

2014-01-01

Abstract During a controlled 6-month study using six replicated water recirculation aquaculture systems (WRASs), it was observed that Rainbow Trout Oncorhynchus mykiss in all WRASs exhibited a higher-than-normal prevalence of side swimming (i.e., controlled, forward swimming but with misaligned orientation such that the fish's sagittal axis is approximately parallel to the horizontal plane). To further our understanding of this abnormality, a substudy was conducted wherein side swimmers and normally swimming fish were selectively sampled from each WRAS and growth performance (length, weight), processing attributes (fillet yield, visceral index, ventrum [i.e., thickness of the ventral “belly flap”] index), blood gas and chemistry parameters, and swim bladder morphology and positioning were compared. Side swimmers were found to be significantly smaller in length and weight and had less fillet yield but higher ventrum indices. Whole-blood analyses demonstrated that, among other things, side swimmers had significantly lower whole-blood pH and higher Pco 2. Side swimmers typically exhibited swim bladder malformations, although the positive predictive value of this subjective assessment was only 73%. Overall, this study found several anatomical and physiological differences between side-swimming and normally swimming Rainbow Trout. Given the reduced weight and fillet yield of market-age side swimmers, producers would benefit from additional research to reduce side-swimming prevalence in their fish stocks. Received March 20, 2014; accepted May 20, 2014 PMID:25250476

In-silico experiments of zebrafish behaviour: modeling swimming in three dimensions

NASA Astrophysics Data System (ADS)

Mwaffo, Violet; Butail, Sachit; Porfiri, Maurizio

2017-01-01

Zebrafish is fast becoming a species of choice in biomedical research for the investigation of functional and dysfunctional processes coupled with their genetic and pharmacological modulation. As with mammals, experimentation with zebrafish constitutes a complicated ethical issue that calls for the exploration of alternative testing methods to reduce the number of subjects, refine experimental designs, and replace live animals. Inspired by the demonstrated advantages of computational studies in other life science domains, we establish an authentic data-driven modelling framework to simulate zebrafish swimming in three dimensions. The model encapsulates burst-and-coast swimming style, speed modulation, and wall interaction, laying the foundations for in-silico experiments of zebrafish behaviour. Through computational studies, we demonstrate the ability of the model to replicate common ethological observables such as speed and spatial preference, and anticipate experimental observations on the correlation between tank dimensions on zebrafish behaviour. Reaching to other experimental paradigms, our framework is expected to contribute to a reduction in animal use and suffering.

In-silico experiments of zebrafish behaviour: modeling swimming in three dimensions

PubMed Central

Mwaffo, Violet; Butail, Sachit; Porfiri, Maurizio

2017-01-01

Zebrafish is fast becoming a species of choice in biomedical research for the investigation of functional and dysfunctional processes coupled with their genetic and pharmacological modulation. As with mammals, experimentation with zebrafish constitutes a complicated ethical issue that calls for the exploration of alternative testing methods to reduce the number of subjects, refine experimental designs, and replace live animals. Inspired by the demonstrated advantages of computational studies in other life science domains, we establish an authentic data-driven modelling framework to simulate zebrafish swimming in three dimensions. The model encapsulates burst-and-coast swimming style, speed modulation, and wall interaction, laying the foundations for in-silico experiments of zebrafish behaviour. Through computational studies, we demonstrate the ability of the model to replicate common ethological observables such as speed and spatial preference, and anticipate experimental observations on the correlation between tank dimensions on zebrafish behaviour. Reaching to other experimental paradigms, our framework is expected to contribute to a reduction in animal use and suffering. PMID:28071731

Individual Differences in Behavioural Despair Predict Brain GSK-3beta Expression in Mice: The Power of a Modified Swim Test

PubMed Central

Markova, Nataliia; Shevtsova, Elena; Bakhmet, Anastassia; Steinbusch, Harry M.

2016-01-01

While deficient brain plasticity is a well-established pathophysiologic feature of depression, little is known about disorder-associated enhanced cognitive processing. Here, we studied a novel mouse paradigm that potentially models augmented learning of adverse memories during development of a depressive-like state. We used a modification of the classic two-day protocol of a mouse Porsolt test with an additional session occurring on Day 5 following the initial exposure. Unexpectedly, floating behaviour and brain glycogen synthase kinase-3 beta (GSK-3beta) mRNA levels, a factor of synaptic plasticity as well as a marker of distress and depression, were increased during the additional swimming session that was prevented by imipramine. Observed increases of GSK-3beta mRNA in prefrontal cortex during delayed testing session correlated with individual parameters of behavioural despair that was not found in the classic Porsolt test. Repeated swim exposure was accompanied by a lower pGSK-3beta/GSK-3beta ratio. A replacement of the second or the final swim sessions with exposure to the context of testing resulted in increased GSK-3beta mRNA level similar to the effects of swimming, while exclusion of the second testing prevented these changes. Together, our findings implicate the activation of brain GSK-3beta expression in enhanced contextual conditioning of adverse memories, which is associated with an individual susceptibility to a depressive syndrome. PMID:27478647

Individual Differences in Behavioural Despair Predict Brain GSK-3beta Expression in Mice: The Power of a Modified Swim Test.

PubMed

Strekalova, Tatyana; Markova, Nataliia; Shevtsova, Elena; Zubareva, Olga; Bakhmet, Anastassia; Steinbusch, Harry M; Bachurin, Sergey; Lesch, Klaus-Peter

2016-01-01

While deficient brain plasticity is a well-established pathophysiologic feature of depression, little is known about disorder-associated enhanced cognitive processing. Here, we studied a novel mouse paradigm that potentially models augmented learning of adverse memories during development of a depressive-like state. We used a modification of the classic two-day protocol of a mouse Porsolt test with an additional session occurring on Day 5 following the initial exposure. Unexpectedly, floating behaviour and brain glycogen synthase kinase-3 beta (GSK-3beta) mRNA levels, a factor of synaptic plasticity as well as a marker of distress and depression, were increased during the additional swimming session that was prevented by imipramine. Observed increases of GSK-3beta mRNA in prefrontal cortex during delayed testing session correlated with individual parameters of behavioural despair that was not found in the classic Porsolt test. Repeated swim exposure was accompanied by a lower pGSK-3beta/GSK-3beta ratio. A replacement of the second or the final swim sessions with exposure to the context of testing resulted in increased GSK-3beta mRNA level similar to the effects of swimming, while exclusion of the second testing prevented these changes. Together, our findings implicate the activation of brain GSK-3beta expression in enhanced contextual conditioning of adverse memories, which is associated with an individual susceptibility to a depressive syndrome.

Repeated forced-swimming test in intact female rats: behaviour, oestrous cycle and enriched environment.

PubMed

Domingues, Karolina; Spezia, Inaê; Theindl, Lais C; Suman, Patrick R; Lima, Fernanda B; Lino de Oliveira, Cilene

2018-03-27

Psychopharmacology used animal models to study the effects of drugs on brain and behaviour. The repeated forced-swimming test (rFST), which is used to assess the gradual effects of antidepressants on rat behaviour, was standardized only in males. Because of the known sex differences in rats, experimental conditions standardized for males may not apply to female rats. Therefore, the present work aimed to standardize experimental and housing conditions for the rFST in female rats. Young or adult Wistar female rats were housed in standard or enriched environments for different experimental periods. As assessed in tested and nontested females, all rats had reached sexual maturity by the time behavioural testing occurred. The rFST consisted of a 15-min session of forced swimming (pretest), followed by 5-min sessions at 1 (test), 7 (retest 1) and 14 days (retest 2) later. The oestrous cycle was registered immediately before every behavioural session. All sessions were videotaped for further analysis. The immobility time of female rats remained similar over the different sessions of rFST independent of the age, the phase of the oestrous cycle or the housing conditions. These data indicate that rFST in female Wistar rats may be reproducible in different experimental conditions.

A taste of the deep-sea: The roles of gustatory and tactile searching behaviour in the grenadier fish Coryphaenoides armatus

NASA Astrophysics Data System (ADS)

Bailey, David M.; Wagner, Hans-Joachim; Jamieson, Alan J.; Ross, Murray F.; Priede, Imants G.

2007-01-01

The deep-sea grenadier fishes ( Coryphaenoides spp.) are among the dominant predators and scavengers in the ocean basins that cover much of Earth's surface. Baited camera experiments were used to study the behaviour of these fishes. Despite the apparent advantages of rapidly consuming food, grenadiers attracted to bait spend a large proportion of their time in prolonged periods of non-feeding activity. Video analysis revealed that fish often adopted a head-down swimming attitude (mean of 21.3° between the fish and seafloor), with swimming velocity negatively related to attitude. The fish also swam around and along vertical and horizontal structures of the lander with their head immediately adjacent to the structure. We initially hypothesised that this behaviour was associated with the use of the short chin barbel in foraging. Barbel histology showed numerous taste buds in the skin, and a barbel nerve with about 20,000 axons in adult fish. A tracing experiment in one undamaged animal revealed the termination fields of the barbel neurons in the trigeminal and rhombencephalic regions, indicating both a mechanoreceptory and a gustatory role for the barbel. Our conclusion was that olfactory foraging becomes ineffective at close ranges and is followed by a search phase using tactile and gustatory sensing by the barbel. The development of this sensory method probably co-evolved alongside behavioural changes in swimming mechanics to allow postural stability at low swimming speeds.

Larval green and white sturgeon swimming performance in relation to water-diversion flows

PubMed Central

Verhille, Christine E.; Poletto, Jamilynn B.; Cocherell, Dennis E.; DeCourten, Bethany; Baird, Sarah; Cech, Joseph J.; Fangue, Nann A.

2014-01-01

Little is known of the swimming capacities of larval sturgeons, despite global population declines in many species due in part to fragmentation of their spawning and rearing habitats by man-made water-diversion structures. Larval green (Acipenser medirostris) and white sturgeon (Acipenser transmontanus) inhabit the highly altered Sacramento–San Joaquin watershed, making them logical species to examine vulnerability to entrainment by altered water flows. The risk of larval sturgeon entrainment is influenced by the ontogeny of swimming capacity and dispersal timing and their interactions with water-diversion structure operations. Therefore, the aim of this study was to describe and compare the ontogeny and allometry of larval green and white sturgeon swimming capacities until completion of metamorphosis into juveniles. Despite the faster growth rates and eventual larger size of larval white sturgeon, green sturgeon critical swimming velocities remained consistently, though modestly, greater than those of white sturgeon throughout the larval life stage. Although behavioural interactions with water-diversion structures are also important considerations, regarding swimming capacity, Sacramento–San Joaquin sturgeons are most vulnerable to entrainment in February–May, when white sturgeon early larvae are in the middle Sacramento River, and April–May, when green sturgeon early larvae are in the upper river. Green sturgeon migrating downstream to the estuary and bays in October–November are also susceptible to entrainment due to their movements combined with seasonal declines in their swimming capacity. An additional inter-species comparison of the allometric relationship between critical swimming velocities and total length with several sturgeon species found throughout the world suggests a similar ontogeny of swimming capacity with growth. Therefore, although dispersal and behaviour differ among river systems and sturgeon species, similar recommendations are applicable for managers seeking to balance water demands with restoration and conservation of sturgeons worldwide. PMID:27293652

Assessment of swimming associated health effects in marine bathing beach: an example from Morib beach (Malaysia).

PubMed

Praveena, Sarva Mangala; Pauzi, Norfasmawati Mohd; Hamdan, Munashamimi; Sham, Shaharuddin Mohd

2015-03-15

A survey among beachgoers was conducted to determine the swimming associated health effects experienced and its relationship with beach water exposure behaviour in Morib beach. For beach water exposure behaviour, the highest frequency of visit among the respondents was once a year (41.9%). For ways of water exposure, whole body exposure including head was the highest (38.5%). For duration of water exposure, 30.8% respondents prefer to be in water for about 30 min with low possibilities of accidental ingestion of beach water. A total of 30.8% of beachgoers in Morib beach were reported of having dermal symptoms. Bivariate analysis showed only water activity, water contact and accidental ingestion of beach water showed significant association with swimming associated health effects experienced by swimmers. This study output showed that epidemiological study can be used to identify swimming associated health effects in beach water exposed to faecal contamination. Copyright © 2015 Elsevier Ltd. All rights reserved.

Behavioural variability and motor performance: Effect of practice specialization in front crawl swimming.

PubMed

Seifert, L; De Jesus, K; Komar, J; Ribeiro, J; Abraldes, J A; Figueiredo, P; Vilas-Boas, J P; Fernandes, R J

2016-06-01

The aim was to examine behavioural variability within and between individuals, especially in a swimming task, to explore how swimmers with various specialty (competitive short distance swimming vs. triathlon) adapt to repetitive events of sub-maximal intensity, controlled in speed but of various distances. Five swimmers and five triathletes randomly performed three variants (with steps of 200, 300 and 400m distances) of a front crawl incremental step test until exhaustion. Multi-camera system was used to collect and analyse eight kinematical and swimming efficiency parameters. Analysis of variance showed significant differences between swimmers and triathletes, with significant individual effect. Cluster analysis put these parameters together to investigate whether each individual used the same pattern(s) and one or several patterns to achieve the task goal. Results exhibited ten patterns for the whole population, with only two behavioural patterns shared between swimmers and triathletes. Swimmers tended to use higher hand velocity and index of coordination than triathletes. Mono-stability occurred in swimmers whatever the task constraint showing high stability, while triathletes revealed bi-stability because they switched to another pattern at mid-distance of the task. Finally, our analysis helped to explain and understand effect of specialty and more broadly individual adaptation to task constraint. Copyright © 2016 Elsevier B.V. All rights reserved.

Chronic perchlorate exposure impairs stickleback reproductive behaviour and swimming performance

PubMed Central

Bernhardt, Richard R.; von Hippel, Frank A.

2011-01-01

Summary We describe behavioural changes in two generations of threespine stickleback (Gasterosteus aculeatus) exposed to environmentally relevant concentrations of perchlorate. The first generation (G0,2002) was exposed as two-year-old adults to perchlorate in experimental groups ranging in concentration from less than the method detection limit (<1.1 ppb) to 18.6 ppm for up to 22 days during their courtship, spawning, egg guarding, and first five days of fry guarding. No differences were noted in the behaviour or reproductive output of these fish that were exposed as adults. However, perchlorate exposure throughout development caused widespread effects in the second generation (G1,2003), which was spawned and raised through sexual maturity in one of four nominal experimental groups (0, 30 and 100 ppm, and a ‘variable’ treatment that progressively increased from <1.1 ppb to approximately 60 ppm perchlorate). Dose-dependent effects were found during the G1,2003’s swimming and behavioural evaluations, including higher mortality rates among treated fish following stressful events. Perchlorate-exposed fish had higher failure rates during swimming trials and failed at lower flow rates than control fish. A number of treated fish exhibited seizures. Progressively fewer males completed benchmark metrics, such as nest building, spawning, nursery formation, or fry production, in a dose-dependent manner. Fewer males from higher treatments courted females, and those that did initiated courtship later and had a reduced behavioural repertoire compared to fish from lower treatments. The lowest observed adverse effect level (LOAEL) for swimming performance, reproductive behaviour, survivorship and recruitment was 30 ppm perchlorate (our lowest G1,2003 treatment), and near complete inhibition of reproductive activity was noted among males raised in 100 ppm perchlorate. A small number of treated G1,2003 females were isolated in aquaria, and some performed reproductive behaviour typical of males, such as biting, leading and zig-zagging in the presence of gravid females. These findings have profound implications for recruitment in wild fish populations exposed to perchlorate, and suggest that perchlorate may disrupt behaviour in other vertebrates as well. PMID:22228909

Surveillance and Conformity in Competitive Youth Swimming

ERIC Educational Resources Information Center

Lang, Melanie

2010-01-01

Underpinned by a Foucauldian analysis of sporting practices, this paper identifies the disciplinary mechanism of surveillance at work in competitive youth swimming. It highlights the ways in which swimmers and their coaches are subject to and apply this mechanism to produce embodied conformity to normative behaviour and obedient, docile bodies.…

Behavioural response of juvenile Chinook salmon Oncorhynchus tshawytscha during a sudden temperature increase and implications for survival

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bellgraph, Brian J.; McMichael, Geoffrey A.; Mueller, Robert P.

2010-01-01

The behaviours of juvenile Chinook salmon Oncorhynchus tshawytscha were evaluated during a temperature increase from 8.8 to 23.2°C, which was designed to simulate unique thermal conditions present in a hydroelectric reservoir. The percent of fish with an active swimming behaviour increased from 26 to 93 % and mean opercular beat rates increased from 76 to 159 beats per minute between basal and maximum temperatures. Fish equilibrium did not change significantly throughout the experiment and relatively little mortality (12 %) occurred. Thermal stress is likely incurred by juvenile salmon experiencing a temperature change of this magnitude; however, stress induced in thismore » study was primarily sublethal. Behavioural changes accompanying thermal stress (e.g., erratic swimming) may increase predation potential in the wild despite being sublethal during laboratory experiments.« less

A fixed-time diffusion analysis method determines that the three cheV genes of Helicobacter pylori differentially affect motility

PubMed Central

Lowenthal, Andrew C.; Simon, Christopher; Fair, Amber S.; Mehmood, Khalid; Terry, Karianne; Anastasia, Stephanie; Ottemann, Karen M.

2009-01-01

Helicobacter pylori is a chemotactic bacterium that has three CheV proteins in its predicted chemotaxis signal transduction system. CheV proteins contain both CheW- and response-regulator-like domains. To determine the function of these proteins, we developed a fixed-time diffusion method that would quantify bacterial direction change without needing to define particular behaviours, to deal with the many behaviours that swimming H. pylori exhibit. We then analysed mutants that had each cheV gene deleted individually and found that the behaviour of each mutant differed substantially from wild-type and the other mutants. cheV1 and cheV2 mutants displayed smooth swimming behaviour, consistent with decreased cellular CheY-P, similar to a cheW mutant. In contrast, the cheV3 mutation had the opposite effect and the mutant cells appeared to change direction frequently. Additional analysis showed that the cheV mutants displayed aberrant behaviour as compared to the wild-type in the soft-agar chemotaxis assay. The soft-agar assay phenotype was less extreme compared to that seen in the fixed-time diffusion model, suggesting that the cheV mutants are able to partially compensate for their defects under some conditions. Each cheV mutant furthermore had defects in mouse colonization that ranged from severe to modest, consistent with a role in chemotaxis. These studies thus show that the H. pylori CheV proteins each differently affect swimming behaviour. PMID:19332820

The effects of aquatic oxygen concentration, body size and respiratory behaviour on the stamina of obligate aquatic (Bufo americanus) and facultative air-breathing (Xenopus laevis and Rana berlandieri) anuran larvae.

PubMed

Wassersug, R J; Feder, M E

1983-07-01

Larvae of the anurans Rana berlandieri and Xenopus laevis have lungs and can breathe air as well as irrigate buccal and pharyngeal surfaces for aquatic respiration. Larvae of Bufo americanus lack lungs until just before metamorphosis and are obligately aquatic. We examined the relationship between the locomotor stamina (time to fatigue), aquatic oxygen concentration, body size, and respiratory behaviour of swimming larvae of these species, with the following results: Stamina is size-dependent in all three species. Aquatic hypoxia reduces stamina in larvae of all three species, but most conspicuously in Bufo. Breathing air increases stamina in Rana larvae, especially in large animals and under aquatic hypoxia. In contrast to Rana larvae, Xenopus larvae swimming in normoxic water undergo a reduction in stamina when allowed to breathe air. In hypoxic water, aerial respiration moderates the reduction in stamina seen in Xenopus larvae. Branchial irrigation is associated with increased stamina in Xenopus, and is increased under hypoxia and at high swimming velocities. Respiratory demand, buoyancy and the drag associated with branchial irrigation all affect respiratory behaviour in Xenopus larvae. The great amount of interspecific variation in the relationship between respiratory behaviour and stamina reveals the importance of measuring performance directly when attempting to interpret the functional significance of respiratory structures and behaviour.

Temperature-dependent changes in the swimming behaviour of Tetrahymena pyriformis-NT1 and their interrelationships with electrophysiology and the state of membrane lipids.

PubMed

Connolly, J G; Brown, I D; Lee, A G; Kerkut, G A

1985-01-01

The swimming velocity and the amplitude of the helical swimming path of T. pyriformis-NT1 cells grown at 20 degrees C (Tg 20 degrees C) and 38 degrees C (Tg 38 degrees C) were monitored between 0 and 40 degrees C in the presence and absence of electric fields. Within physiological limits the swimming velocity increased and the amplitude decreased as temperature was raised. The temperature profiles of these properties were not linear, and showed discontinuities at different temperatures for the different cultures. The break points in Arrhenius plots of the resting potential, regenerative spike magnitude, repolarization time, swimming velocity and swimming amplitude are tabulated and compared. The initial breakpoints upon cooling were clustered about the breakpoints in fluorescence polarization of D.P.H. in extracted phospholipids, and around the transition temperatures estimated from the literature for the pellicular membrane of these cells. The average of the initial breakpoints on cooling was 22.9 degrees C for Tg 38 degrees C cells and 13.7 degrees C for Tg 20 degrees C cells, a shift of 9.2 degrees C. Unlike Paramecium there is no depolarizing receptor potential in Tetrahymena upon warming. It is suggested that this may be the basis of a behavioural difference between Tetrahymena and Paramecium--namely that in Tetrahymena maximum swimming velocity occurs above growth temperature whereas in Paramecium the two points coincide. Swimming velocity and resting potential were correlated with membrane fluidity within physiological limits, but for other parameters the relationship with fluidity was more complex.(ABSTRACT TRUNCATED AT 250 WORDS)

Feeding of swimming Paramecium with fore-aft asymmetry in viscous fluid

NASA Astrophysics Data System (ADS)

Zhang, Peng; Jana, Saikat; Giarra, Matthew; Vlachos, Pavlos; Jung, Sunghwan

2013-11-01

Swimming behaviours and feeding efficiencies of Paramecium Multimicronucleatum with fore-aft asymmetric body shapes are studied experimentally and numerically. Among various possible swimming ways, ciliates typically exhibit only one preferred swimming directions in favorable conditions. Ciliates, like Paramecia, with fore-aft asymmetric shapes preferably swim towards the slender anterior while feeding fluid to the oral groove located at the center of the body. Since both feeding and swimming efficiencies are influenced by fluid motions around the body, it is important to reveal the fluid mechanics around a moving object. Experimentally, μ-PIV methods are employed to characterize the source-dipole streamline patterns and fluid motions around Paramecium. Numerical simulations by boundary element methods are also used to evaluate surface stresses and velocities, which give insights into the efficiencies of swimming and feeding depending on body asymmetry. It is concluded that a slender anterior and fat posterior increases the combined efficiency of swimming and feeding, which matches well with actual shapes of Paramecium. Discrepancies between experiments and simulations are also discussed.

Fish and robots swimming together: attraction towards the robot demands biomimetic locomotion

PubMed Central

Marras, Stefano; Porfiri, Maurizio

2012-01-01

The integration of biomimetic robots in a fish school may enable a better understanding of collective behaviour, offering a new experimental method to test group feedback in response to behavioural modulations of its ‘engineered’ member. Here, we analyse a robotic fish and individual golden shiners (Notemigonus crysoleucas) swimming together in a water tunnel at different flow velocities. We determine the positional preference of fish with respect to the robot, and we study the flow structure using a digital particle image velocimetry system. We find that biomimetic locomotion is a determinant of fish preference as fish are more attracted towards the robot when its tail is beating rather than when it is statically immersed in the water as a ‘dummy’. At specific conditions, the fish hold station behind the robot, which may be due to the hydrodynamic advantage obtained by swimming in the robot's wake. This work makes a compelling case for the need of biomimetic locomotion in promoting robot–animal interactions and it strengthens the hypothesis that biomimetic robots can be used to study and modulate collective animal behaviour. PMID:22356819

Fish and robots swimming together: attraction towards the robot demands biomimetic locomotion.

PubMed

Marras, Stefano; Porfiri, Maurizio

2012-08-07

The integration of biomimetic robots in a fish school may enable a better understanding of collective behaviour, offering a new experimental method to test group feedback in response to behavioural modulations of its 'engineered' member. Here, we analyse a robotic fish and individual golden shiners (Notemigonus crysoleucas) swimming together in a water tunnel at different flow velocities. We determine the positional preference of fish with respect to the robot, and we study the flow structure using a digital particle image velocimetry system. We find that biomimetic locomotion is a determinant of fish preference as fish are more attracted towards the robot when its tail is beating rather than when it is statically immersed in the water as a 'dummy'. At specific conditions, the fish hold station behind the robot, which may be due to the hydrodynamic advantage obtained by swimming in the robot's wake. This work makes a compelling case for the need of biomimetic locomotion in promoting robot-animal interactions and it strengthens the hypothesis that biomimetic robots can be used to study and modulate collective animal behaviour.

Muscle activation behavior in a swimming exergame: Differences by experience and gaming velocity.

PubMed

Soltani, Pooya; Figueiredo, Pedro; Fernandes, Ricardo J; Vilas-Boas, João Paulo

2017-11-01

The effects of playing intensity and prior exergame and sport experience on the activation patterns of upper limb muscles during a swimming exergame were investigated. Surface electromyography of Biceps Brachii, Triceps Brachii, Latissimus Dorsi, Upper Trapezius, and Erector Spinae of twenty participants was recorded, and the game play was divided into normal and fast. Mean muscle activation, normalized to maximum voluntary isometric contraction (MVIC), ranged from 4.9 to 95.2%MVIC and differed between normal and fast swimming for all techniques (p<0.05), except for Latissimus Dorsi during backstroke. After normalizing the %MVIC to playing velocity, selective behaviors were observed between muscles which were sufficient for pragmatic game play. Moreover, prior exergame and real sport experience did not have any effect on the muscle activation changes between normal and fast swimming. These behaviors are likely to happen when players understand the game mechanics, even after a short exposure. Such evaluation might help in adjusting the physical demands of sport exergames, for safe and meaningful experiences. Copyright © 2017 Elsevier Inc. All rights reserved.

Swimming Behavior and Calcium Incorporation into inner Ear Otoliths of Fish after vestibular Nerve Transection

NASA Astrophysics Data System (ADS)

Edelmann, E.; Anken, R.; Rahmann, H.

Previous investigations on neonate swordtail fish (Xiphophorus helleri) revealed that otolithic calcium incorporation (visualized using the calcium-tracer alizarin- complexone) and thus otolith growth had ceased after nerve transection, supporting a hypothesis according to which the gravity-dependent otolith growth is regulated neuronally. Subsequent investigations on larval cichlid fish (Oreochromis mossambicus) yielded contrasting results, repeatedly depending on the particular batch of cichlids investigated: Like neonate swordtails, type I cichlids revealed a stop of calcium incorporation after unilateral vestibular nerve transection. Their behaviour after transection was normal and the otolithic calcium incorporation in controls of the same batch was symmetrical. In type II cichlids, however, vestibular nerve transection had no effect on otolithic calcium incorporation. They behaved kinetotically after transection (this kind of kinetosis was qualitatively similar to the swimming behaviour exhibited by larval cichlids during microgravity in the course of parabolic aircraft flights). The otolithic calcium incorporation in control animals was asymmetrical. These results stongly suggest that the effects of vestibular nerve transection as well as the efficacy of the mechanism, which regulates otolith growth/otolithic calcium incorporation, are - depending on the particular batch of animals - genetically predispositioned. Thus, it is assumed that the mechanisms regulating otolith growth and equlibibrium differ in the two types of cichlid fish. This work was financially supported by the German Aerospace Center (DLR) e.V. (FKZ: 50 WB 9997).

Chemically-dispersed crude oil and dispersant affects sperm fertilizing ability, but not sperm swimming behaviour in capelin (Mallotus villosus).

PubMed

Beirão, José; Litt, Margaret A; Purchase, Craig F

2018-06-05

The effects of petroleum aromatic hydrocarbons (PAHs) on the embryonic and larval life stages of teleosts have been extensively examined. However, very little work has been conducted on how spilled oil affects fish sperm and there is no related knowledge concerning oil dispersing agents. The objective of our study was to determine sperm performance of a teleost fish under direct exposure to different concentrations of WAF (water accommodated fraction) and CEWAF (chemically enhanced water accommodated fraction). Capelin sperm motility, swimming behaviour, and sperm fertilization ability were evaluated in a scenario of an oil spill untreated (WAF) and treated (CEWAF) with the dispersant Corexit ® EC9500A. Sperm fertilizing ability was lower when exposed to CEWAF concentrations of 16.1 × 10 3  μg/L total petroleum hydrocarbons and 47.9 μg/L PAH, and when exposed to the dispersant alone. The mechanism responsible for this reduced fertilizing ability is not clear. However, it is not related to the percentage of motile sperm or sperm swimming behaviour, as these were unaffected. WAF did not alter sperm swimming characteristics nor the fertilizing ability. We suggest the dispersant rather than the dispersed oil is responsible for the decrease in the sperm fertilizing ability and hypothesize that the surfactants present in the dispersant affect sperm membrane functionality. Copyright © 2018. Published by Elsevier Ltd.

Effects of selected metal oxide nanoparticles on Artemia salina larvae: evaluation of mortality and behavioural and biochemical responses.

PubMed

Gambardella, Chiara; Mesarič, Tina; Milivojević, Tamara; Sepčić, Kristina; Gallus, Lorenzo; Carbone, Serena; Ferrando, Sara; Faimali, Marco

2014-07-01

The aim was to investigate the toxicity of selected metal oxide nanoparticles (MO-NPs) on the brine shrimp Artemia salina, by evaluating mortality and behavioural and biochemical responses. Larvae were exposed to tin(IV) oxide (stannic oxide (SnO2)), cerium(IV) oxide (CeO2) and iron(II, III) oxide (Fe3O4) NPs for 48 h in seawater, with MO-NP suspensions from 0.01 to 1.0 mg/mL. Mortality and behavioural responses (swimming speed alteration) and enzymatic activities of cholinesterase, glutathione-S-transferase and catalase were evaluated. Although the MO-NPs did not induce any mortality of the larvae, they caused changes in behavioural and biochemical responses. Swimming speed significantly decreased in larvae exposed to CeO2 NPs. Cholinesterase and glutathione-S-transferase activities were significantly inhibited in larvae exposed to SnO2 NPs, whereas cholinesterase activity significantly increased after CeO2 NP and Fe3O4 NP exposure. Catalase activity significantly increased in larvae exposed to Fe3O4 NPs. In conclusion, swimming alteration and cholinesterase activity represent valid endpoints for MO-NP exposure, while glutathione-S-transferase and catalase activities appear to be NP-specific.

A novel mechanism for mechanosensory-based rheotaxis in larval zebrafish.

PubMed

Oteiza, Pablo; Odstrcil, Iris; Lauder, George; Portugues, Ruben; Engert, Florian

2017-07-27

When flying or swimming, animals must adjust their own movement to compensate for displacements induced by the flow of the surrounding air or water. These flow-induced displacements can most easily be detected as visual whole-field motion with respect to the animal's frame of reference. Despite this, many aquatic animals consistently orient and swim against oncoming flows (a behaviour known as rheotaxis) even in the absence of visual cues. How animals achieve this task, and its underlying sensory basis, is still unknown. Here we show that, in the absence of visual information, larval zebrafish (Danio rerio) perform rheotaxis by using flow velocity gradients as navigational cues. We present behavioural data that support a novel algorithm based on such local velocity gradients that fish use to avoid getting dragged by flowing water. Specifically, we show that fish use their mechanosensory lateral line to first sense the curl (or vorticity) of the local velocity vector field to detect the presence of flow and, second, to measure its temporal change after swim bouts to deduce flow direction. These results reveal an elegant navigational strategy based on the sensing of flow velocity gradients and provide a comprehensive behavioural algorithm, also applicable for robotic design, that generalizes to a wide range of animal behaviours in moving fluids.

Response kinetics of tethered bacteria to stepwise changes in nutrient concentration.

PubMed

Chernova, Anna A; Armitage, Judith P; Packer, Helen L; Maini, Philip K

2003-09-01

We examined the changes in swimming behaviour of the bacterium Rhodobacter sphaeroides in response to stepwise changes in a nutrient (propionate), following the pre-stimulus motion, the initial response and the adaptation to the sustained concentration of the chemical. This was carried out by tethering motile cells by their flagella to glass slides and following the rotational behaviour of their cell bodies in response to the nutrient change. Computerised motion analysis was used to analyse the behaviour. Distributions of run and stop times were obtained from rotation data for tethered cells. Exponential and Weibull fits for these distributions, and variability in individual responses are discussed. In terms of parameters derived from the run and stop time distributions, we compare the responses to stepwise changes in the nutrient concentration and the long-term behaviour of 84 cells under 12 propionate concentration levels from 1 nM to 25 mM. We discuss traditional assumptions for the random walk approximation to bacterial swimming and compare them with the observed R. sphaeroides motile behaviour.

Mate-finding behaviour in Calanus marshallae Frost

PubMed Central

Tsuda, A.

1998-01-01

Mate-finding behaviour by Calanus marshallae Frost, 1974, was observed and video recorded in a 1 m diameter kreisel. Newly moulted females signal to males by depositing vertical pheromone trails many tens of centimetres long. Males search for trails along primarily horizontal trajectories. The orthogonality of signal trace and search trail trajectory maximizes the chance of intersection. Males often initiate a dance of rapid, tight turns upon encountering a pheromone trail, then waggle down it (chase swimming) to the signalling female. She jumps away after initial contact, and the male follows. Many successive approach, bump and jump sequences follow, with mating eventually ensuing. The actual copulatory clasp and spermatophore transfer were not observed, although a few instances of brief attachment and tandem swimming were seen. Male dances occur at times when chase swimming does not follow, and the function of dances is not yet known.

Contaminant mixtures interact to impair predator-avoidance behaviours and survival in a larval amphibian.

PubMed

Sievers, Michael; Hale, Robin; Swearer, Stephen E; Parris, Kirsten M

2018-06-14

Global declines in amphibian populations are a significant conservation concern, and environmental contamination is likely a contributing driver. Although direct toxicity may be partly responsible, contaminants are often present at sub-lethal concentrations in the wild. Behavioural end-points are becoming an increasingly useful method to estimate the impact of contaminants, particularly if the behavioural responses manifest to affect individual fitness (i.e. survival, growth, or reproduction). In the wild, most animals are affected by multiple stressors, and determining how these interact to affect behaviour is critical for understanding the ecological implications of contaminant exposure. Here, we examined the individual and interactive effect of the heavy metal copper and the insecticide imidacloprid on mortality rates and anti-predator behaviours of spotted marsh frog (Limnodynastes tasmaniensis) tadpoles. This common species frequently occupies and breeds in contaminated stormwater and agricultural wetlands, where copper and imidacloprid are often present. These contaminants may alter behaviour via physiological and neurological pathways, as well as affecting how tadpoles respond to chemical cues. Tadpoles suffered unexpectedly high mortality rates when exposed to imidacloprid concentrations well below published LC50 concentrations. Only unexposed tadpoles significantly avoided predator cues. Copper and imidacloprid reduced swimming speed and distance, and escape responses, while increasing erratic swimming. We observed an interactive effect of imidacloprid and copper on erratic swimming, but in general imidacloprid and copper did not act synergistically. Our results suggest that as contaminants enter waterbodies, tadpoles will suffer considerable direct mortality, reduced foraging capacity, and increased susceptibility to predation. Our results provide the first evidence of imidacloprid affecting amphibian behaviour, and highlight both the adverse effects of copper and imidacloprid, and the importance of exploring the effect of multiple contaminants simultaneously. Copyright © 2018 Elsevier Inc. All rights reserved.

Consequences of thermal acclimation for the mating behaviour and swimming performance of female mosquito fish.

PubMed

Wilson, Robbie S; Condon, Catriona H L; Johnston, Ian A

2007-11-29

The mating system of eastern mosquito fish (Gambusia holbrooki) is dominated by male sexual coercion, where all matings are forced and females never appear to cooperate and actively avoid all attempts. Previous research has shown that male G. holbrooki offer a model system for examining the benefits of reversible thermal acclimation for reproductive success, but examining the benefits to female avoidance behaviour has been difficult. In this study, we examined the ability of non-male-deprived female G. holbrooki to avoid forced-coercive matings following acclimation to either 18 or 30 degrees C for six weeks (12h light:12h dark photoperiod). Thermal acclimation of burst and sustained swimming performance was also assessed, as these traits are likely to underlie their ability to avoid forced matings. There was no influence of thermal acclimation on the burst swimming performance of female G. holbrooki over the range 18-30 degrees C; however, sustained swimming performance was significantly lower in the warm- than the cool-acclimation group. For mating behaviour, we tested the hypothesis that acclimation would enhance the ability of female G. holbrooki to avoid forced matings at their host acclimation temperature relative to females acclimated to another environment. However, our hypothesis was not supported. The rate of copulations was almost three times greater for females acclimated to 30 degrees C than 18 degrees C when tested at 30 degrees C, indicating that they possess the ability to alter their avoidance behaviour to 'allow' more copulations in some environments. Coupled with previous studies, female G. holbrooki appear to have greater control on the outcome of coercive mating attempts than previously considered and can alter their propensity to receive forced matings following thermal acclimation. The significance of this change in female mating-avoidance behaviours with thermal acclimation remains to be explored.

Observations on side-swimming rainbow trout Oncorhynchus mykiss in water recirculation aquaculture systems

USDA-ARS?s Scientific Manuscript database

During a controlled 6-month study using six replicated water recirculation aquaculture systems (WRAS), it was observed that rainbow trout Oncorhynchus mykiss in all WRAS exhibited a higher-than-normal prevalence of side-swimming (i.e. controlled, forward swimming, but with misaligned orientation suc...

Behavioural and biochemical investigations of the influence of altered gravity on the CNS of aquatic vertebrates during ontogeny

NASA Astrophysics Data System (ADS)

Slenzka, K.; Appel, R.; Hilbig, R.; Kappel, Th.; Vetter, S.; Freischütz, B.; Rahmann, H.

1994-08-01

Quantitative data are presented on the influences of hyper-gravity (3+/-1g) and of simulated weightlessness (~0g) during early ontogeny of cichild fish (Oreochromis mossambicus) and clawed toad (Xenopus laevis, Daudin) demonstrating changes in the swimming behaviour and the brain energy and plasma membrane metabolism. After return to 1g conditions, hyper-g reared fish and toads express the well known ``loop-swimming'' behaviour. By means of a computer based video analyzing system different types of swimming movements and velocities were quantitatively determined. Analyses of the brain energy and plasma-membrane metabolism of hyper-g fish larvae demonstrated an increase in energy availability (glucose 6Pi dehydrogenase, G-6P-DH), a decrease of cellular energy transformation (creatine kinase activity, CK) but no changes in energy consumptive processes (e.g. ATPases) and cytochrome oxidase activity (Cyt.-Ox). In contrast hypo-g fish larvae showed a slight increase in brain CK activity. In addition, unlike 1g controls, hyper-g fish larvae showed pronounced variations in the composition (=polarity) of sialoglycosphingolipids (=gangliosides), typical constituents of the nerve cell membranes, and a slight increase in the activity of sialidase, the enzyme responsible for ganglioside degradation.

Intra- and Intersexual swim bladder dimorphisms in the plainfin midshipman fish (Porichthys notatus): Implications of swim bladder proximity to the inner ear for sound pressure detection.

PubMed

Mohr, Robert A; Whitchurch, Elizabeth A; Anderson, Ryan D; Forlano, Paul M; Fay, Richard R; Ketten, Darlene R; Cox, Timothy C; Sisneros, Joseph A

2017-11-01

The plainfin midshipman fish, Porichthys notatus, is a nocturnal marine teleost that uses social acoustic signals for communication during the breeding season. Nesting type I males produce multiharmonic advertisement calls by contracting their swim bladder sonic muscles to attract females for courtship and spawning while subsequently attracting cuckholding type II males. Here, we report intra- and intersexual dimorphisms of the swim bladder in a vocal teleost fish and detail the swim bladder dimorphisms in the three sexual phenotypes (females, type I and II males) of plainfin midshipman fish. Micro-computerized tomography revealed that females and type II males have prominent, horn-like rostral swim bladder extensions that project toward the inner ear end organs (saccule, lagena, and utricle). The rostral swim bladder extensions were longer, and the distance between these swim bladder extensions and each inner-ear end organ type was significantly shorter in both females and type II males compared to that in type I males. Our results revealed that the normalized swim bladder length of females and type II males was longer than that in type I males while there was no difference in normalized swim bladder width among the three sexual phenotypes. We predict that these intrasexual and intersexual differences in swim bladder morphology among midshipman sexual phenotypes will afford greater sound pressure sensitivity and higher frequency detection in females and type II males and facilitate the detection and localization of conspecifics in shallow water environments, like those in which midshipman breed and nest. © 2017 Wiley Periodicals, Inc.

Host-finding behaviour and navigation capabilities of symbiotic zooxanthellae

NASA Astrophysics Data System (ADS)

Pasternak, Zohar; Blasius, Bernd; Abelson, Avigdor; Achituv, Yair

2006-05-01

Past studies have shown that the initiation of symbiosis between the Red-Sea soft coral Heteroxenia fuscescens and its symbiotic dinoflagellates occurs due to the chemical attraction of the motile algal cells to substances emanating from the coral polyps. However, the resulting swimming patterns of zooxanthellae have not been previously studied. This work examined algal swimming behaviour, host location and navigation capabilities under four conditions: (1) still water, (2) in still water with waterborne host attractants, (3) in flowing water, and (4) in flow with host attractants. Algae were capable of actively and effectively locating their host in still water as well as in flow. When in water containing host attractants, swimming became slower, motion patterns straighter and the direction of motion was mainly towards the host—even if this meant advancing upstream against flow velocities of up to 0.5 mm s-1. Coral-algae encounter probability decreased the further downstream of the host algae were located, probably due to diffusion of the chemical signal. The results show how the chemoreceptive zooxanthellae modify their swimming pattern, direction, velocity, circuity and turning rate to accommodate efficient navigation in changing environmental conditions.

Dioxin inhibition of swim bladder development in zebrafish: is it secondary to heart failure?

PubMed

Yue, Monica S; Peterson, Richard E; Heideman, Warren

2015-05-01

The swim bladder is a gas-filled organ that is used for regulating buoyancy and is essential for survival in most teleost species. In zebrafish, swim bladder development begins during embryogenesis and inflation occurs within 5 days post fertilization (dpf). Embryos exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) before 96 h post fertilization (hpf) developed swim bladders normally until the growth/elongation phase, at which point growth was arrested. It is known that TCDD exposure causes heart malformations that lead to heart failure in zebrafish larvae, and that blood circulation is a key factor in normal development of the swim bladder. The adverse effects of TCDD exposure on the heart occur during the same period of time that swim bladder development and growth occurs. Based on this coincident timing, and the dependence of swim bladder development on proper circulatory development, we hypothesized that the adverse effects of TCDD on swim bladder development were secondary to heart failure. We compared swim bladder development in TCDD-exposed embryos to: (1) silent heart morphants, which lack cardiac contractility, and (2) transiently transgenic cmlc2:caAHR-2AtRFP embryos, which mimic TCDD-induced heart failure via heart-specific, constitutive activation of AHR signaling. Both of these treatment groups, which were not exposed to TCDD, developed hypoplastic swim bladders of comparable size and morphology to those found in TCDD-exposed embryos. Furthermore, in all treatment groups swim bladder development was arrested during the growth/elongation phase. Together, these findings support a potential role for heart failure in the inhibition of swim bladder development caused by TCDD. Copyright © 2015 Elsevier B.V. All rights reserved.

Effectiveness of a Multisystem Aquatic Therapy for Children with Autism Spectrum Disorders.

PubMed

Caputo, Giovanni; Ippolito, Giovanni; Mazzotta, Marina; Sentenza, Luigi; Muzio, Mara Rosaria; Salzano, Sara; Conson, Massimiliano

2018-06-01

Aquatic therapy improves motor skills of persons with Autism Spectrum Disorders (ASD), but its usefulness for treating functional difficulties needs to be verified yet. We tested effectiveness of a multisystem aquatic therapy on behavioural, emotional, social and swimming skills of children with ASD. Multisystem aquatic therapy was divided in three phases (emotional adaptation, swimming adaptation and social integration) implemented in a 10-months-programme. At post-treatment, the aquatic therapy group showed significant improvements relative to controls on functional adaptation (Vineland Adaptive Behavior Scales), emotional response, adaptation to change and on activity level (Childhood Autism Rating Scale). Swimming skills learning was also demonstrated. Multisystem aquatic therapy is useful for ameliorating functional impairments of children with ASD, going well beyond a swimming training.

Oestrogen-deficient female aromatase knockout (ArKO) mice exhibit depressive-like symptomatology.

PubMed

Dalla, C; Antoniou, K; Papadopoulou-Daifoti, Z; Balthazart, J; Bakker, J

2004-07-01

We recently found that female aromatase knockout (ArKO) mice that are deficient in oestradiol due to a targeted mutation in the aromatase gene show deficits in sexual behaviour that cannot be corrected by adult treatment with oestrogens. We determined here whether these impairments are associated with changes in general levels of activity, anxiety or 'depressive-like' symptomatology due to chronic oestrogen deficiency. We also compared the neurochemical profile of ArKO and wild-type (WT) females, as oestrogens have been shown to modulate dopaminergic, serotonergic and noradrenergic brain activities. ArKO females did not differ from WT in spontaneous motor activity, exploration or anxiety. These findings are in line with the absence of major neurochemical alterations in hypothalamus, prefrontal cortex or striatum, which are involved in the expression of these behaviours. By contrast, ArKO females displayed decreased active behaviours, such as struggling and swimming, and increased passive behaviours, such as floating, in repeated sessions of the forced swim test, indicating that these females exhibit 'depressive-like' symptoms. Adult treatment with oestradiol did not reverse the behavioural deficits observed in the forced swim test, suggesting that they may be due to the absence of oestradiol during development. Accordingly, an increased serotonergic activity was observed in the hippocampus of ArKO females compared with WT, which was also not reversed by adult oestradiol treatment. The possible organizational role of oestradiol on the hippocampal serotonergic system and the 'depressive-like' profile of ArKO females provide new insights into the pathophysiology of depression and the increased vulnerability of women to depression.

The effects of aerobic exercise on depression-like, anxiety-like, and cognition-like behaviours over the healthy adult lifespan of C57BL/6 mice.

PubMed

Morgan, Julie A; Singhal, Gaurav; Corrigan, Frances; Jaehne, Emily J; Jawahar, Magdalene C; Baune, Bernhard T

2018-01-30

Preclinical studies have demonstrated exercise improves various types of behaviours such as anxiety-like, depression-like, and cognition-like behaviours. However, these findings were largely conducted in studies utilising short-term exercise protocols, and the effects of lifetime exercise on these behaviours remain unknown. This study investigates the behavioural effects of lifetime exercise in normal healthy ageing C57BL/6 mice over the adult lifespan. 12 week-old C57BL/6 mice were randomly assigned to voluntary wheel running or non-exercise (control) groups. Exercise commenced at aged 3 months and behaviours were assessed in young adult (Y), early middle age (M), and old (O) mice (n=11-17/group). The open field and elevated zero maze examined anxiety-like behaviours, depression-like behaviours were quantified with the forced swim test, and the Y maze and Barnes maze investigated cognition-like behaviours. The effects of lifetime exercise were not simply an extension of the effects of chronic exercise on anxiety-like, depression-like, and cognition-like behaviours. Exercise tended to reduce overt anxiety-like behaviours with ageing, and improved recognition memory and spatial learning in M mice as was expected. However, exercise also increased anxiety behaviours including greater freezing behaviour that extended spatial learning latencies in Y female mice in particular, while reduced distances travelled contributed to longer spatial memory and cognitive flexibility latencies in Y and O mice. Lifetime exercise may increase neurogenesis-associated anxiety. This could be an evolutionary conserved adaptation that nevertheless has adverse impacts on cognition-like function, with particularly pronounced effects in Y female mice with intact sex hormones. These issues require careful investigation in future rodent studies. Copyright © 2017 Elsevier B.V. All rights reserved.

The use of computed tomography for assessment of the swim bladder in koi carp (Cyprinus carpio).

PubMed

Pees, Michael; Pees, Kathrin; Kiefer, Ingmar

2010-01-01

Seven normal koi (Cyprinus carpio) and seven koi with negative buoyancy were examined using computed tomography (CT) to assess the swim bladder. The volume of the swim bladder was calculated in all animals. In the healthy koi there was a statistical correlation (r = 0.996) between body mass and swim bladder volume with volume (ml) being related to body mass according to the formula 4.9 +/- 0.054 x BM (g). In all koi with buoyancy problems, the gas volume of the swim bladder was reduced. Additionally, fluid was found within the swim bladder in three of the abnormal koi. CT proved to be a quick noninvasive technique for the examination of the swim bladder in koi.

Increased water temperature renders single-housed C57BL/6J mice susceptible to antidepressant treatment in the forced swim test.

PubMed

Bächli, Heidi; Steiner, Michel A; Habersetzer, Ursula; Wotjak, Carsten T

2008-02-11

To investigate genotype x environment interactions in the forced swim test, we tested the influence of water temperature (20 degrees C, 25 degrees C, 30 degrees C) on floating behaviour in single-housed male C57BL/6J and BALB/c mice. We observed a contrasting relationship between floating and water temperature between the two strains, with C57BL/6J floating more and BALB/c floating less with increasing water temperature, independent of the lightening conditions and the time point of testing during the animals' circadian rhythm. Both strains showed an inverse relationship between plasma corticosterone concentration and water temperature, indicating that the differences in stress coping are unrelated to different perception of the aversive encounter. Treatment with desipramine (20mg/kg, i.p.) caused a reduction in immobility time in C57BL/6J mice if the animals were tested at 30 degrees C water temperature, with no effect at 25 degrees C and no effects on forced swim stress-induced corticosterone secretion. The same treatment failed to affect floating behaviour in BALB/c at any temperature, but caused a decrease in plasma corticosterone levels. Taken together we demonstrate that an increase in water temperature in the forced swim test exerts opposite effects on floating behaviour in C57BL/6J and BALB/c and renders single-housed C57BL/6J mice, but not BALB/c mice, susceptible to antidepressant-like behavioral effects of desipramine.

Mechanical performance of aquatic rowing and flying.

PubMed

Walker, J A; Westneat, M W

2000-09-22

Aquatic flight, performed by rowing or flapping fins, wings or limbs, is a primary locomotor mechanism for many animals. We used a computer simulation to compare the mechanical performance of rowing and flapping appendages across a range of speeds. Flapping appendages proved to be more mechanically efficient than rowing appendages at all swimming speeds, suggesting that animals that frequently engage in locomotor behaviours that require energy conservation should employ a flapping stroke. The lower efficiency of rowing appendages across all speeds begs the question of why rowing occurs at all. One answer lies in the ability of rowing fins to generate more thrust than flapping fins during the power stroke. Large forces are necessary for manoeuvring behaviours such as accelerations, turning and braking, which suggests that rowing should be found in slow-swimming animals that frequently manoeuvre. The predictions of the model are supported by observed patterns of behavioural variation among rowing and flapping vertebrates.

Assessment of the effect of prolonged forced swimming on CD-1 mice sperm morphology with and without antioxidant supplementation.

PubMed

Rodriguez, I; Diaz, A; Vaamonde, D

2016-04-01

As physical exercise has been shown to negatively affect sperm morphology, this study was undertaken to assess the effect of a 3-min forced swimming protocol during 50 days, with and without administration of antioxidants [N-acetylcysteine (NAC) and trans-resveratrol], on sperm morphology in CD-1 mice. Forty-four 13-week-old CD-1 mice were randomly allocated to four different groups: mice not submitted to exercise, control group (CG), mice submitted to swimming without administration of antioxidants (EX), mice submitted to swimming that received trans-resveratrol supplementation [exercise group (EX)+Resv] and mice submitted to swimming exercise that received NAC supplementation (EX+NAC). The EX showed 30.5% of spermatozoa with normal morphology, showing significant differences with regard to the CG, which showed 58.5%. The groups receiving antioxidant supplements showed significantly higher percentages of spermatozoa with normal morphology in comparison with the EX group (EX+Resv: 64.1%, EX+NAC: 48.2%). The imposed model of forced swimming caused alterations in sperm morphology. The antioxidants employed seem to be suitable antioxidants for avoiding exercise-associated sperm morphology anomalies in prolonged forced swimming exercise. Trans-resveratrol has proven to be more efficient for this purpose. © 2015 Blackwell Verlag GmbH.

Oceanographic and behavioural assumptions in models of the fate of coral and coral reef fish larvae.

PubMed

Wolanski, Eric; Kingsford, Michael J

2014-09-06

A predictive model of the fate of coral reef fish larvae in a reef system is proposed that combines the oceanographic processes of advection and turbulent diffusion with the biological process of horizontal swimming controlled by olfactory and auditory cues within the timescales of larval development. In the model, auditory cues resulted in swimming towards the reefs when within hearing distance of the reef, whereas olfactory cues resulted in the larvae swimming towards the natal reef in open waters by swimming against the concentration gradients in the smell plume emanating from the natal reef. The model suggested that the self-seeding rate may be quite large, at least 20% for the larvae of rapidly developing reef fish species, which contrasted with a self-seeding rate less than 2% for non-swimming coral larvae. The predicted self-recruitment rate of reefs was sensitive to a number of parameters, such as the time at which the fish larvae reach post-flexion, the pelagic larval duration of the larvae, the horizontal turbulent diffusion coefficient in reefal waters and the horizontal swimming behaviour of the fish larvae in response to auditory and olfactory cues, for which better field data are needed. Thus, the model suggested that high self-seeding rates for reef fish are possible, even in areas where the 'sticky water' effect is minimal and in the absence of long-term trapping in oceanic fronts and/or large-scale oceanic eddies or filaments that are often argued to facilitate the return of the larvae after long periods of drifting at sea. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

Microplastic does not magnify the acute effect of PAH pyrene on predatory performance of a tropical fish (Lates calcarifer).

PubMed

Guven, Olgac; Bach, Lis; Munk, Peter; Dinh, Khuong V; Mariani, Patrizio; Nielsen, Torkel Gissel

2018-05-01

Microplastic (MP) leads to widespread pollution in the marine ecosystem. In addition to the physical hazard posed by ingestion of microplastic particles, concern is also on their potential as vector for transport of hydrophobic contaminants. We experimentally studied the single and interactive effects of microplastic and pyrene, a polycyclic aromatic hydrocarbon, on the swimming behaviour and predatory performance of juvenile barramundi (Lates calcarifer). Juveniles (18+ days post hatch) were exposed to MPs, or pyrene (100 nM), or combination of both, and feeding rate and foraging activity (swimming) were analysed. Exposure to MPs alone did not significantly influence feeding performance of the juveniles, while a dose-effect series of pyrene showed strong effect on fish behaviour when concentrations were above 100 nM. In the test of combined MP and pyrene exposure, we observed no effect on feeding while swimming speed decreased significantly. Thus, our results confirm that short-time exposure to pyrene impacts the performance of fish juveniles, while additional exposure to microplastic at the given conditions influenced their activity only and not their feeding rate. Further studies of the combined effects of microplastics and pollutants on tropical fish behaviour are encouraged. Copyright © 2018 Elsevier B.V. All rights reserved.

Feeding Behaviour, Swimming Activity and Boldness Explain Variation in Feed Intake and Growth of Sole (Solea solea) Reared in Captivity

PubMed Central

Mas-Muñoz, Julia; Komen, Hans; Schneider, Oliver; Visch, Sander W.; Schrama, Johan W.

2011-01-01

The major economic constraint for culturing sole (Solea solea) is its slow and variable growth. The objective was to study the relationship between feed intake/efficiency, growth, and (non-) feeding behaviour of sole. Sixteen juveniles with an average (SD) growth of 2.7 (1.9) g/kg0.8/d were selected on their growth during a 4-week period in which they were housed communally with 84 other fish. Selected fish were housed individually during a second 4-week period to measure individual feed intake, growth, and behaviour. Fish were hand-fed three times a day during the dark phase of the day until apparent satiation. During six different days, behaviour was recorded twice daily during 3 minutes by direct observations. Total swimming activity, frequency of burying and of escapes were recorded. At the beginning and end of the growth period, two sequential behavioural tests were performed: “Novel Environment” and “Light Avoidance”. Fish housed individually still exhibited pronounced variation in feed intake (CV = 23%), growth (CV = 25%) and behavior (CV = 100%). Differences in feed intake account for 79% of the observed individual differences in growth of sole. Fish with higher variation in feed intake between days and between meals within days had significantly a lower total feed intake (r = −0.65 and r = −0.77) and growth. Active fish showed significantly higher feed intake (r = 0.66) and growth (r = 0.58). Boldness during both challenge tests was related to fast growth: (1) fish which reacted with a lower latency time to swim in a novel environment had significantly higher feed intake (r = −0.55) and growth (r = −0.66); (2) fish escaping during the light avoidance test tended to show higher feed intake (P<0.1) and had higher growth (P<0.05). In conclusion, feeding consistency, swimming activity in the tank, and boldness during behavioral tests are related to feed intake and growth of sole in captivity. PMID:21738651

Feeding behaviour, swimming activity and boldness explain variation in feed intake and growth of sole (Solea solea) reared in captivity.

PubMed

Mas-Muñoz, Julia; Komen, Hans; Schneider, Oliver; Visch, Sander W; Schrama, Johan W

2011-01-01

The major economic constraint for culturing sole (Solea solea) is its slow and variable growth. The objective was to study the relationship between feed intake/efficiency, growth, and (non-) feeding behaviour of sole. Sixteen juveniles with an average (SD) growth of 2.7 (1.9) g/kg(0.8)/d were selected on their growth during a 4-week period in which they were housed communally with 84 other fish. Selected fish were housed individually during a second 4-week period to measure individual feed intake, growth, and behaviour. Fish were hand-fed three times a day during the dark phase of the day until apparent satiation. During six different days, behaviour was recorded twice daily during 3 minutes by direct observations. Total swimming activity, frequency of burying and of escapes were recorded. At the beginning and end of the growth period, two sequential behavioural tests were performed: "Novel Environment" and "Light Avoidance". Fish housed individually still exhibited pronounced variation in feed intake (CV = 23%), growth (CV = 25%) and behavior (CV = 100%). Differences in feed intake account for 79% of the observed individual differences in growth of sole. Fish with higher variation in feed intake between days and between meals within days had significantly a lower total feed intake (r = -0.65 and r = -0.77) and growth. Active fish showed significantly higher feed intake (r = 0.66) and growth (r = 0.58). Boldness during both challenge tests was related to fast growth: (1) fish which reacted with a lower latency time to swim in a novel environment had significantly higher feed intake (r = -0.55) and growth (r = -0.66); (2) fish escaping during the light avoidance test tended to show higher feed intake (P<0.1) and had higher growth (P<0.05). In conclusion, feeding consistency, swimming activity in the tank, and boldness during behavioral tests are related to feed intake and growth of sole in captivity.

Swimming behaviour and ascent paths of brook trout in a corrugated culvert

USGS Publications Warehouse

Goerig, Elsa; Bergeron, Normand E.; Castro-Santos, Theodore R.

2017-01-01

Culverts may restrict fish movements under some hydraulic conditions such as shallow flow depths or high velocities. Although swimming capacity imposes limits to passage performance, behaviour also plays an important role in the ability of fish to overcome velocity barriers. Corrugated metal culverts are characterized by unsteady flow and existence of low‐velocity zones, which can improve passage success. Here, we describe swimming behaviour and ascent paths of 148 wild brook trout in a 1.5‐m section of a corrugated metal culvert located in Raquette Stream, Québec, Canada. Five passage trials were conducted in mid‐August, corresponding to specific mean cross‐sectional flow velocities ranging from 0.30 to 0.63 m/s. Fish were individually introduced to the culvert and their movements recorded with a camera located above the water. Lateral and longitudinal positions were recorded at a rate of 3 Hz in order to identify ascent paths. These positions were related to the distribution of flow depths and velocities in the culvert. Brook trout selected flow velocities from 0.2 to 0.5 m/s during their ascents, which corresponded to the available flow velocities in the culvert at the low‐flow conditions. This however resulted in the use of low‐velocity zones at higher flows, mainly located along the walls of the culvert. Some fish also used the corrugations for sheltering, although the behaviour was marginal and did not occur at the highest flow condition. This study improves knowledge on fish behaviour during culvert ascents, which is an important aspect for developing reliable and accurate estimates of fish passage ability.

Magnetic propulsion of robotic sperms at low-Reynolds number

NASA Astrophysics Data System (ADS)

Khalil, Islam S. M.; Fatih Tabak, Ahmet; Klingner, Anke; Sitti, Metin

2016-07-01

We investigate the microswimming behaviour of robotic sperms in viscous fluids. These robotic sperms are fabricated from polystyrene dissolved in dimethyl formamide and iron-oxide nanoparticles. This composition allows the nanoparticles to be concentrated within the bead of the robotic sperm and provide magnetic dipole, whereas the flexibility of the ultra-thin tail enables flagellated locomotion using magnetic fields in millitesla range. We show that these robotic sperms have similar morphology and swimming behaviour to those of sperm cells. Moreover, we show experimentally that our robotic sperms swim controllably at an average speed of approximately one body length per second (around 125 μm s-1), and they are relatively faster than the microswimmers that depend on planar wave propulsion in low-Reynolds number fluids.

Behavioural profiles of two Wistar rat lines selectively bred for high or low anxiety-related behaviour.

PubMed

Liebsch, G; Montkowski, A; Holsboer, F; Landgraf, R

1998-08-01

Over the past years, two breeding lines, derived originally from outbred Wistar rats, have been established that differ markedly and consistently in their anxiety-related behaviour in the elevated plus-maze. At the age of ten weeks, rats were tested once on the elevated plus-maze and the males and females displaying the most anxious and the least anxious behaviour were sib-mated to start a new generation of the high anxiety-related behaviour (HAB) and the low anxiety-related behaviour (LAB) lines, respectively. The resulting difference in emotionality between these two lines was also evident in an open field test and correlated with differences in the forced swim test. In the open field, the HAB rats tended to be less active and explored the central zone of the open field much less than the LAB animals. In the forced swim test, HAB rats started floating earlier, spent significantly more time in this immobile posture and struggled less than LAB rats. However, in an olfactory-cued social discrimination task there was no difference between male and female animals from either line. The overall performance in these various behavioural tests suggests that selective breeding has resulted in rat lines not only differing markedly in their innate anxiety-related behaviour in the plus-maze, but also in other stress-related behavioural performances, suggesting a close link between the emotional evaluation of a novel and stressful situation and an individual's coping strategy.

Towards improved behavioural testing in aquatic toxicology: Acclimation and observation times are important factors when designing behavioural tests with fish.

PubMed

Melvin, Steven D; Petit, Marie A; Duvignacq, Marion C; Sumpter, John P

2017-08-01

The quality and reproducibility of science has recently come under scrutiny, with criticisms spanning disciplines. In aquatic toxicology, behavioural tests are currently an area of controversy since inconsistent findings have been highlighted and attributed to poor quality science. The problem likely relates to limitations to our understanding of basic behavioural patterns, which can influence our ability to design statistically robust experiments yielding ecologically relevant data. The present study takes a first step towards understanding baseline behaviours in fish, including how basic choices in experimental design might influence behavioural outcomes and interpretations in aquatic toxicology. Specifically, we explored how fish acclimate to behavioural arenas and how different lengths of observation time impact estimates of basic swimming parameters (i.e., average, maximum and angular velocity). We performed a semi-quantitative literature review to place our findings in the context of the published literature describing behavioural tests with fish. Our results demonstrate that fish fundamentally change their swimming behaviour over time, and that acclimation and observational timeframes may therefore have implications for influencing both the ecological relevance and statistical robustness of behavioural toxicity tests. Our review identified 165 studies describing behavioural responses in fish exposed to various stressors, and revealed that the majority of publications documenting fish behavioural responses report extremely brief acclimation times and observational durations, which helps explain inconsistencies identified across studies. We recommend that researchers applying behavioural tests with fish, and other species, apply a similar framework to better understand baseline behaviours and the implications of design choices for influencing study outcomes. Copyright © 2017 Elsevier Ltd. All rights reserved.

Measuring abnormal movements in free-swimming fish with accelerometers: implications for quantifying tag and parasite load.

PubMed

Broell, Franziska; Burnell, Celene; Taggart, Christopher T

2016-03-01

Animal-borne data loggers allow movement, associated behaviours and energy expenditure in fish to be quantified without direct observations. As with any tagging, tags that are attached externally may adversely affect fish behaviour, swimming efficiency and survival. We report on free-swimming wild Atlantic cod (Gadus morhua) held in a large mesocosm that exhibited distinctly aberrant rotational swimming (scouring) when externally tagged with accelerometer data loggers. To quantify the phenomenon, the cod were tagged with two sizes of loggers (18 and 6 g; <2% body mass) that measured tri-axial acceleration at 50 Hz. An automated algorithm, based on body angular rotation, was designed to extract the scouring movements from the acceleration signal (98% accuracy). The algorithm also identified the frequency pattern and associated energy expenditure of scouring in relation to tag load (% body weight). The average per cent time spent scouring (5%) was independent of tag load. The vector of the dynamic body acceleration (VeDBA), used as a proxy for energy expenditure, increased with tag load (r(2)=0.51), and suggests that fish with large tags spent more energy when scouring than fish with small tags. The information allowed us to determine potential detrimental effects of an external tag on fish behaviour and how these effects may be mitigated by tag size. The algorithm can potentially identify similar rotational movements associated with spawning, courtship, feeding and parasite-load shedding in the wild. The results infer a more careful interpretation of data derived from external tags and the careful consideration of tag type, drag, buoyancy and placement, as well as animal buoyancy and species. © 2016. Published by The Company of Biologists Ltd.

Simultaneous biologging of heart rate and acceleration, and their relationships with energy expenditure in free-swimming sockeye salmon (Oncorhynchus nerka).

PubMed

Clark, Timothy Darren; Sandblom, E; Hinch, S G; Patterson, D A; Frappell, P B; Farrell, A P

2010-06-01

Monitoring the physiological status and behaviour of free-swimming fishes remains a challenging task, although great promise stems from techniques such as biologging and biotelemetry. Here, implanted data loggers were used to simultaneously measure heart rate (f (H)), visceral temperature, and a derivation of acceleration in two groups of wild adult sockeye salmon (Oncorhynchus nerka) held at two different water speeds (slow and fast). Calibration experiments performed with individual fish in a swim tunnel respirometer generated strong relationships between acceleration, f (H), tail beat frequency and energy expenditure over a wide range of swimming velocities. The regression equations were then used to estimate the overall energy expenditure of the groups of fish held at different water speeds. As expected, fish held at faster water speeds exhibited greater f (H) and acceleration, and correspondingly a higher estimated energy expenditure than fish held at slower water speeds. These estimates were consistent with gross somatic energy density of fish at death, as determined using proximate analyses of a dorsal tissue sample. Heart rate alone and in combination with acceleration, rather than acceleration alone, provided the most accurate proxies for energy expenditure in these studies. Even so, acceleration provided useful information on the behaviour of fish and may itself prove to be a valuable proxy for energy expenditure under different environmental conditions, using a different derivation of the acceleration data, and/or with further calibration experiments. These results strengthen the possibility that biologging or biotelemetry of f (H) and acceleration may be usefully applied to migrating sockeye salmon to monitor physiology and behaviour, and to estimate energy use in the natural environment.

Group Behavioural Responses of Atlantic Salmon (Salmo salar L.) to Light, Infrasound and Sound Stimuli

PubMed Central

Bui, Samantha; Oppedal, Frode; Korsøen, Øyvind J.; Sonny, Damien; Dempster, Tim

2013-01-01

Understanding species-specific flight behaviours is essential in developing methods of guiding fish spatially, and requires knowledge on how groups of fish respond to aversive stimuli. By harnessing their natural behaviours, the use of physical manipulation or other potentially harmful procedures can be minimised. We examined the reactions of sea-caged groups of 50 salmon (1331±364 g) to short-term exposure to visual or acoustic stimuli. In light experiments, fish were exposed to one of three intensities of blue LED light (high, medium and low) or no light (control). Sound experiments included exposure to infrasound (12 Hz), a surface disturbance event, the combination of infrasound and surface disturbance, or no stimuli. Groups that experienced light, infrasound, and the combination of infrasound and surface disturbance treatments, elicited a marked change in vertical distribution, where fish dived to the bottom of the sea-cage for the duration of the stimulus. Light treatments, but not sound, also reduced the total echo-signal strength (indicative of swim bladder volume) after exposure to light, compared to pre-stimulus levels. Groups in infrasound and combination treatments showed increased swimming activity during stimulus application, with swimming speeds tripled compared to that of controls. In all light and sound treatments, fish returned to their pre-stimulus swimming depths and speeds once exposure had ceased. This work establishes consistent, short-term avoidance responses to these stimuli, and provides a basis for methods to guide fish for aquaculture applications, or create avoidance barriers for conservation purposes. In doing so, we can achieve the manipulation of group position with minimal welfare impacts, to create more sustainable practices. PMID:23691087

Group behavioural responses of Atlantic salmon (Salmo salar L.) to light, infrasound and sound stimuli.

PubMed

Bui, Samantha; Oppedal, Frode; Korsøen, Øyvind J; Sonny, Damien; Dempster, Tim

2013-01-01

Understanding species-specific flight behaviours is essential in developing methods of guiding fish spatially, and requires knowledge on how groups of fish respond to aversive stimuli. By harnessing their natural behaviours, the use of physical manipulation or other potentially harmful procedures can be minimised. We examined the reactions of sea-caged groups of 50 salmon (1331 ± 364 g) to short-term exposure to visual or acoustic stimuli. In light experiments, fish were exposed to one of three intensities of blue LED light (high, medium and low) or no light (control). Sound experiments included exposure to infrasound (12 Hz), a surface disturbance event, the combination of infrasound and surface disturbance, or no stimuli. Groups that experienced light, infrasound, and the combination of infrasound and surface disturbance treatments, elicited a marked change in vertical distribution, where fish dived to the bottom of the sea-cage for the duration of the stimulus. Light treatments, but not sound, also reduced the total echo-signal strength (indicative of swim bladder volume) after exposure to light, compared to pre-stimulus levels. Groups in infrasound and combination treatments showed increased swimming activity during stimulus application, with swimming speeds tripled compared to that of controls. In all light and sound treatments, fish returned to their pre-stimulus swimming depths and speeds once exposure had ceased. This work establishes consistent, short-term avoidance responses to these stimuli, and provides a basis for methods to guide fish for aquaculture applications, or create avoidance barriers for conservation purposes. In doing so, we can achieve the manipulation of group position with minimal welfare impacts, to create more sustainable practices.

"Spilling Over": Fish Swimming Kinematics in Cylinder Wakes

NASA Astrophysics Data System (ADS)

Wilson, C. A.; Muhawenimana, V.; Cable, J.

2016-12-01

Our understanding of fish swimming kinematics and behaviour in turbulent altered and pseudo-natural flows remains incomplete. This study aims to examine velocity, turbulence and wake metrics that govern fish stability and other behavioural traits in the turbulent wake of a horizontal cylinder. In a free surface flume, the swimming behaviour of Nile tilapia (Oreochromis niloticus, Silver strain) was monitored over a range of cylinder diameter (D) Reynolds numbers from 2.8 x103 to 25.8 x103. Spills, defined as loss of both balance and posture, were inversely correlated with fish length and weight; where smaller fish in the 50th percentile of standard length, lost balance more often and accounted for 65% of the total number (533) of spills. Additionally, the bigger fish in the 95th percentile, experienced <0.5% of all recorded spills. Such findings are in keeping with a previous study where the spill occurrence increased with decreasing fish length to eddy size ratio. Fish spent the majority of station holding time within a two diameter (2D) distance closest to the flume bed and in a downstream distance of 3D to 6D from the cylinder. The frequency of occurrence of spills increased with increasing Reynolds number for the whole fish population until an intermediate Reynolds number of 11.5 x103 was reached, where the frequency in spills steadily declined with increasing Reynolds number until the end of the test duration. The spill frequency-Reynolds number relationship indicates a shift in cylinder wake dynamics. Further analysis of the measured velocity statistics will help determine the intensity, periodicity and the turbulence length scale of the wake structure and their correlations with the observed fish swimming kinematics.

Long-term effects of microgravity on the swimming behaviour of young rats.

PubMed

Walton, Kerry D; Benavides, Louis; Singh, Neeraj; Hatoum, Nagi

2005-06-01

The postnatal development of sensory systems has been shown in studies over the last four decades to be influenced by experience during critical periods of development. We report here that similar experience-dependent development can be observed in the swimming behaviour of young rats reared from postnatal day 14 (P14) to P30 in the reduced gravitational field of low earth orbit. Animals flown in space when placed in the water on the day of landing maintained their head and forelimbs in a balanced posture. However, until the animals began to swim, their hindquarters showed little lateral postural control resulting in rotation about the longitudinal axis (60 degrees+/-4 deg). Such results suggest an 'unlinking' of postural control of the forequarters from the hindquarters in the early hours after landing. Similar instability seen in animals age-matched to the day of launch (97+/-7 deg) and in ground control animals (9+/-3 deg) was corrected within one or two rotations, even in the absence of swimming. Animals flown in space began to swim sooner after being placed in the water, and the duration of swimming strokes was shorter than in control animals. Motion analysis revealed a difference in the swimming style on landing day. In flight animals, the knee joint was more flexed throughout the stroke, there was a narrower range of movement, and the linear velocity of the tip of the foot was faster throughout most of the stroke than in age-matched control animals. Thus, posture in the water as well as swimming speed and style were altered in the animals flown in space. Some of these characteristics persisted for as long as the animals were followed (30 days). These included the short pre-swimming interval and short stroke duration in flight animals. These findings clearly show that an altered gravitational field influences the postnatal development of motor function. The nature of the differences between animals reared in space for 16 days and those remaining on the ground reflects an adaptation of the flight animals to the microgravity environment. The data suggest that the most fundamental of these adaptations is a resetting of the basic motor rhythm to a higher frequency.

Participation and risk-taking behaviour in sports in children with haemophilia.

PubMed

Köiter, J; van Genderen, F R; Brons, P P T; Nijhuis-van der Sanden, M W G

2009-05-01

The aim of this study was to investigate participation in sports activities and risk-taking behaviour in children with haemophilia and the relationship to personal and health related factors. Ninety-nine children (mean age 12.6 years) completed questionnaires regarding participation in sports and physical education, medication, health related quality of life, and perceived motor competence. Furthermore, weight, height, active range of motion, pain, and muscle strength were assessed. Based on a risk exposure factor (REF) we defined subgroups with low, medium, and high risk when participating in sport. Most children participate in sport five times a week (mean 140 min per week), and little absence during school sports was reported. In general, prophylaxis was not tailored to sport activities. Boys with haemophilia preferred other sports than their Dutch contemporaries. The top-5 being soccer, swimming, tennis, gymnastics, and cardio-fitness for the former; soccer, gymnastics, tennis, hockey, and swimming for the latter. Significant differences between the low risk group and both other groups were found for sport intensity, total energy expenditure (EE) and average risk factor (ARF), however the medium and high-risk groups did not differ in ARF. REF and sport participation increased associated with increasing interest in athletic and motor activities. No significant differences were found between REF groups regarding age, Z-BMI, Z-AROM, Z-Muscle force, and the presence of painful joints. As in normal peers motivation to participate in sport depends upon the enthusiasm and interest, in children with haemophilia choice of sports differs, probably related to sport advice.

Foraging-Based Enrichment Promotes More Varied Behaviour in Captive Australian Fur Seals (Arctocephalus pusillus doriferus)

PubMed Central

Hocking, David P.; Salverson, Marcia; Evans, Alistair R.

2015-01-01

During wild foraging, Australian fur seals (Arctocephalus pusillus doriferus) encounter many different types of prey in a wide range of scenarios, yet in captive environments they are typically provided with a narrower range of opportunities to display their full repertoire of behaviours. This study aimed to quantitatively explore the effect of foraging-based enrichment on the behaviour and activity patterns displayed by two captive Australian fur seals at Melbourne Zoo, Australia. Food was presented as a scatter in open water, in a free-floating ball device, or in a static box device, with each treatment separated by control trials with no enrichment. Both subjects spent more time interacting with the ball and static box devices than the scatter feed. The total time spent pattern swimming was reduced in the enrichment treatments compared to the controls, while the time spent performing random swimming behaviours increased. There was also a significant increase in the total number of bouts of behaviour performed in all three enrichment treatments compared to controls. Each enrichment method also promoted a different suit of foraging behaviours. Hence, rather than choosing one method, the most effective way to increase the diversity of foraging behaviours, while also increasing variation in general activity patterns, is to provide seals with a wide range of foraging scenarios where food is encountered in different ways. PMID:25946412

Limiting swimming pool outbreaks of cryptosporidiosis - the roles of regulations, staff, patrons and research.

PubMed

Ryan, Una; Lawler, Sheleigh; Reid, Simon

2017-02-01

Cryptosporidium is the leading cause of swimming pool outbreaks of gastroenteritis. Transmission occurs through the ingestion of oocysts that are passed in the faeces of an infected person or animal when an accidental faecal release event occurs. Cryptosporidium parasites present specific challenges for infection control as oocysts are highly resistant to chlorine levels used for pool disinfection, infected individuals can shed large numbers of oocysts, there is a long incubation period and shedding of oocysts occurs even after symptom resolution. The purposes of this review are to identify key barriers to limiting swimming pool-associated outbreaks of cryptosporidiosis and to outline needs for research and collaboration to advance co-ordinated management practices. We reviewed swimming pool-associated cryptosporidiosis outbreaks, disinfection teachniques, current regulations and the role of staff and patrons. Key barriers to limiting swimming pool-associated outbreaks of cryptosporidiosis are a lack of uniform national and international standards, poor adherence and understanding of regulations governing staff and patron behaviour, and low levels of public knowledge and awareness.

Paths and patterns: the biology and physics of swimming bacterial populations

NASA Technical Reports Server (NTRS)

Kessler, J. O.; Strittmatter, R. P.; Swartz, D. L.; Wiseley, D. A.; Wojciechowski, M. F.

1995-01-01

The velocity distribution of swimming micro-organisms depends on directional cues supplied by the environment. Directional swimming within a bounded space results in the accumulation of organisms near one or more surfaces. Gravity, gradients of chemical concentration and illumination affect the motile behaviour of individual swimmers. Concentrated populations of organisms scatter and absorb light or consume molecules, such as oxygen. When supply is one-sided, consumption creates gradients; the presence of the population alters the intensity and the symmetry of the environmental cues. Patterns of cues interact dynamically with patterns of the consumer population. In suspensions, spatial variations in the concentration of organisms are equivalent to variations of mean mass density of the fluid. When organisms accumulate in one region whilst moving away from another region, the force of gravity causes convection that translocates both organisms and dissolved substances. The geometry of the resulting concentration-convection patterns has features that are remarkably reproducible. Of interest for biology are (1) the long-range organisation achieved by organisms that do not communicate, and (2) that the entire system, consisting of fluid, cells, directional supply of consumables, boundaries and gravity, generates a dynamic that improves the organisms' habitat by enhancing transport and mixing. Velocity distributions of the bacterium Bacillus subtilis have been measured within the milieu of the spatially and temporally varying oxygen concentration which they themselves create. These distributions of swimming speed and direction are the fundamental ingredients required for a quantitative mathematical treatment of the patterns. The quantitative measurement of swimming behaviour also contributes to our understanding of aerotaxis of individual cells.

Emotional instability but intact spatial cognition in adenosine receptor 1 knock out mice.

PubMed

Lang, Undine E; Lang, Florian; Richter, Kerstin; Vallon, Volker; Lipp, Hans-Peter; Schnermann, Jürgen; Wolfer, David P

2003-10-17

Several lines of evidence point to the involvement of adenosine in the regulation of important central mechanisms such as cognition, arousal, aggression and anxiety. In order to elucidate the involvement of the adenosine A1 receptor (A1AR) in spatial learning and the control of exploratory behaviour, we assessed A1AR knockout mice (A1AR-/-) and their wild-type littermates (A1AR+/+) in a place navigation task in the water maze and in a battery of forced and free exploration tests. In the water maze, A1AR-/- mice showed normal escape latencies and were indistinguishable from controls with respect to measures of spatial performance during both training and probe trial. But despite normal performance they showed increased wall hugging, most prominently after the relocation of the goal platform for reversal training. Quantitative analysis of strategy choices indicated that wall hugging was increased mainly at the expense of chaining and passive floating, whereas the frequency of trials characterised as direct swims or focal searching was normal in A1AR-/- mice. These results indicate intact spatial cognition, but mildly altered emotional reactions to the water maze environment. In line with this interpretation, A1AR-/- mice showed normal levels and patterns of activity, but a mild increase of some measures of anxiety in our battery of forced and free exploration paradigms. These results are in line with findings published using a genetically similar line, but demonstrate that the magnitude of the changes and the range of affected behavioural measures may vary considerably depending on the environmental conditions during testing.

Biosonar behaviour of free-ranging porpoises.

PubMed

Akamatsu, Tomonari; Wang, Ding; Wang, Kexiong; Naito, Yasuhiko

2005-04-22

Detecting objects in their paths is a fundamental perceptional function of moving organisms. Potential risks and rewards, such as prey, predators, conspecifics or non-biological obstacles, must be detected so that an animal can modify its behaviour accordingly. However, to date few studies have considered how animals in the wild focus their attention. Dolphins and porpoises are known to actively use sonar or echolocation. A newly developed miniature data logger attached to a porpoise allows for individual recording of acoustical search efforts and inspection distance based on echolocation. In this study, we analysed the biosonar behaviour of eight free-ranging finless porpoises (Neophocaena phocaenoides) and demonstrated that these animals inspect the area ahead of them before swimming silently into it. The porpoises inspected distances up to 77 m, whereas their swimming distance without using sonar was less than 20 m. The inspection distance was long enough to ensure a wide safety margin before facing real risks or rewards. Once a potential prey item was detected, porpoises adjusted their inspection distance from the remote target throughout their approach.

Impact of metformin treatment and swimming exercise on visfatin levels in high-fat-induced obesity rats.

PubMed

Gao, Ya; Wang, Changjiang; Pan, Tianrong; Luo, Li

2014-02-01

Visfatin is a recently discovered adipocytokine that contributes to glucose and obesity-related conditions. Until now, its responses to the insulin-sensitizing agent metformin and to exercise are largely unknown. We aim to investigate the impact of metformin treatment and/or swimming exercise on serum visfatin and visfatin levels in subcutaneous adipose tissue (SAT), peri-renal adipose tissue (PAT) and skeletal muscle (SM) of high-fat-induced obesity rats. Sprague-Dawley rats were fed a normal diet or a high-fat diet for 16 weeks to develop obesity model. The high-fat-induced obesity model rats were then randomized to metformin (MET), swimming exercise (SWI), or adjunctive therapy of metformin and swimming exercise (MAS), besides high-fat obesity control group and a normal control group, all with 10 rats per group. Zoometric and glycemic parameters, lipid profile, and serum visfatin levels were assessed at baseline and after 6 weeks of therapy. Visfatin levels in SAT, PAT and SM were determined by Western Blot. Metformin and swimming exercise improved lipid profile, and increased insulin sensitivity and body weight reduction were observed. Both metformin and swimming exercise down-regulated visfatin levels in SAT and PAT, while the adjunctive therapy conferred greater benefits, but no changes of visfatin levels were observed in SM. Our results indicate that visfatin down-regulation in SAT and PAT may be one of the mechanisms by which metformin and swimming exercise inhibit obesity.

Puffed and bothered: Personality, performance, and the effects of stress on checkered pufferfish.

PubMed

Pleizier, Naomi; Wilson, Alexander D M; Shultz, Aaron D; Cooke, Steven J

2015-12-01

Although consistent individual-level differences in behaviour are widespread and potentially important in evolutionary and ecological processes, relatively few studies focus on the physiological mechanisms that might underlie and regulate these individual-level differences in wild populations. We conducted experiments to determine whether checkered pufferfish (Sphoeroides testudineus), which were collected from a dynamic (in terms of depth and water temperature) tidal mangrove creek environment in The Bahamas, have consistent individual-level differences in locomotor activity and the response to a simulated predator threat, as well as swimming performance and puffing in response to stressors. The relationships between personality and performance traits were evaluated to determine whether they represented stress-coping styles or syndromes. Subsequently, a displacement study was conducted to determine how personality and performance in the laboratory compared to movements in the field. In addition, we tested whether a physiological dose of the stress hormone cortisol would alter individual consistency in behavioural and performance traits. We found that pufferfish exhibited consistent individual differences in personality traits over time (e.g., activity and the duration of a response to a threat) and that performance was consistent between the lab and the natural enclosure. Locomotor activity and the duration of startled behaviour were not associated with swimming and puffing performance. Locomotor activity, puffing performance, and swimming performance were not related to whether fish returned to the tidal creek of capture after displacement. Similarly, a cortisol treatment did not modify behaviour or performance in the laboratory. The results reveal that consistent individual-level differences in behaviour and performance were present in a population from a fluctuating and physiologically challenging environment but that such traits are not necessarily correlated. We also determined that certain individual performance traits were repeatable between the lab and a natural enclosure. However, we found no evidence of a relationship between exogenous cortisol levels and behavioural traits or performance in these fish, which suggests that other internal and external mechanisms may underlie the behaviours and performance tested. Copyright © 2015 Elsevier Inc. All rights reserved.

Biomechanics of Tetrahymena escaping from a dead end

PubMed Central

Kikuchi, Kenji

2018-01-01

Understanding the behaviours of swimming microorganisms in various environments is important for understanding cell distribution and growth in nature and industry. However, cell behaviour in complex geometries is largely unknown. In this study, we used Tetrahymena thermophila as a model microorganism and experimentally investigated cell behaviour between two flat plates with a small angle. In this configuration, the geometry provided a ‘dead end' line where the two flat plates made contact. The results showed that cells tended to escape from the dead end line more by hydrodynamics than by a biological reaction. In the case of hydrodynamic escape, the cell trajectories were symmetric as they swam to and from the dead end line. Near the dead end line, T. thermophila cells were compressed between the two flat plates while cilia kept beating with reduced frequency; those cells again showed symmetric trajectories, although the swimming velocity decreased. These behaviours were well reproduced by our computational model based on biomechanics. The mechanism of hydrodynamic escape can be understood in terms of the torque balance induced by lubrication flow. We therefore conclude that a cell's escape from the dead end was assisted by hydrodynamics. These findings pave the way for understanding cell behaviour and distribution in complex geometries. PMID:29491169

Male sexual harassment alters female social behaviour towards other females.

PubMed

Darden, Safi K; Watts, Lauren

2012-04-23

Male harassment of females to gain mating opportunities is a consequence of an evolutionary conflict of interest between the sexes over reproduction and is common among sexually reproducing species. Male Trinidadian guppies Poecilia reticulata spend a large proportion of their time harassing females for copulations and their presence in female social groups has been shown to disrupt female-female social networks and the propensity for females to develop social recognition based on familiarity. In this study, we investigate the behavioural mechanisms that may lead to this disruption of female sociality. Using two experiments, we test the hypothesis that male presence will directly affect social behaviours expressed by females towards other females in the population. In experiment one, we tested for an effect of male presence on female shoaling behaviour and found that, in the presence of a free-swimming male guppy, females spent shorter amounts of time with other females than when in the presence of a free-swimming female guppy. In experiment two, we tested for an effect of male presence on the incidence of aggressive behaviour among female guppies. When males were present in a shoal, females exhibited increased levels of overall aggression towards other females compared with female only shoals. Our work provides direct evidence that the presence of sexually harassing males alters female-female social behaviour, an effect that we expect will be recurrent across taxonomic groups.

Electrocommunication behaviour during social interactions in two species of pulse-type weakly electric fishes (Mormyridae).

PubMed

Gebhardt, K; Böhme, M; von der Emde, G

2012-12-01

This study compares electrocommunication behaviour in groups of freely swimming weakly electric fishes of two species, Marcusenius altisambesi and Mormyrus rume. Animals emitted variable temporal sequences of stereotyped electric organ discharges (EOD) that served as communication signals. While the waveform of individual signals remained constant, the inter-discharge interval (IDI) patterns conveyed situation-specific information. Both species showed different types of group behaviour, e.g. they engaged in collective (group) foraging. The results show that in each species, during different behavioural conditions (resting, foraging and agonistic encounters), certain situation-specific IDI patterns occurred. In both species, neighbouring fishes swimming closely together interacted electrically by going in and out of synchronization episodes, i.e. periods of temporally correlated EOD production. These often resulted in echo responses between neighbours. During group foraging, fishes often signalled in a repetitive fixed order (fixed-order signalling). During foraging, EOD emission rates of M. altisambesi were higher and more regular than those of M. rume. The two species also differed in the quantity of group behaviours with M. altisambesi being more social than M. rume, which was reflected in the lack of specific agonistic IDI patterns, more fixed-order signalling and more communal resting behaviour in M. altisambesi. © 2012 The Authors. Journal of Fish Biology © 2012 The Fisheries Society of the British Isles.

Hypericum grandifolium Choisy: a species native to Macaronesian Region with antidepressant effect.

PubMed

Sánchez-Mateo, C C; Bonkanka, C X; Rabanal, R M

2009-01-21

Various species of Hypericum genus have been used in the Canary Islands as sedative, diuretic, vermifuge, wound healing, antihysteric and antidepressant agent. Studies have shown that methanol extract of Hypericum grandifolium Choisy is active in tetrabenazine-induced ptosis and forced swimming tests. In the current study, the aqueous, butanol and chloroform fractions obtained from the methanol extract as well as three sub-fractions derived from the chloroform fraction were evaluated for their central nervous effects in mice, particularly their antidepressant activity. The central nervous effect of different fractions and sub-fractions of Hypericum grandifolium was evaluated in mice using various behavioural models including locomotor and muscle relaxant activity, forced swimming test, effect on normal body temperature, barbiturate-induced sleep, tetrabenazine-induced syndrome and 5-hydroxytryptohan-induced head twitches and syndrome. We found that the butanol and chloroform fractions and all sub-fractions showed an antidepressant effect in the forced swimming test, the chloroform fraction being the most active. They produced no effects or only a slight depression of locomotor activity. Chloroform fraction significantly increased the pentobarbital-induced sleeping time, produced a slight but significant hypothermia and antagonized tetrabenazine-induced ptosis, whereas the butanol fraction produced a slight potentiation of 5-HTP-induced head twitches and syndrome. The present results, together with previous pharmacological and phytochemical data, indicated that Hypericum grandifolium possess antidepressant-like effects in mice and that different constituents, such as the flavonoids and the benzophenone derivatives, could be responsible at least in part for the antidepressant effects observed for this species.

[Swimming programme for mentally retarded children and its impact on skills development].

PubMed

Seif Eldin, A G

2005-07-01

People with Down syndrome suffer from many social, psychological and motor function problems. Current research has looked at swimming programmes to assess their impact on such problems. The programme described here was applied for a 3-month period, with music being used as one of the tools. The results were very positive and children showed significant improvement in agility, self-esteem and behaviour patterns. The programme is thus effective in enhancing the integrated development of children with Down syndrome.

Disposable swim diaper retention of Cryptosporidium-sized particles on human subjects in a recreational water setting.

PubMed

Amburgey, James E; Anderson, J Brian

2011-12-01

Cryptosporidium is a chlorine-resistant protozoan parasite responsible for the majority of waterborne disease outbreaks in recreational water venues in the USA. Swim diapers are commonly used by diaper-aged children participating in aquatic activities. This research was intended to evaluate disposable swim diapers for retaining 5-μm diameter polystyrene microspheres, which were used as non-infectious surrogates for Cryptosporidium oocysts. A hot tub recirculating water without a filter was used for this research. The microsphere concentration in the water was monitored at regular intervals following introduction of microspheres inside of a swim diaper while a human subject undertook normal swim/play activities. Microsphere concentrations in the bulk water showed that the majority (50-97%) of Cryptosporidium-sized particles were released from the swim diaper within 1 to 5 min regardless of the swim diaper type or configuration. After only 10 min of play, 77-100% of the microspheres had been released from all swim diapers tested. This research suggests that the swim diapers commonly used by diaper-aged children in swimming pools and other aquatic activities are of limited value in retaining Cryptosporidium-sized particles. Improved swim diaper solutions are necessary to efficiently retain pathogens and effectively safeguard public health in recreational water venues.

Influence of environmental parameters on movements and habitat utilization of humpback whales (Megaptera novaeangliae) in the Madagascar breeding ground

PubMed Central

Cerchio, Salvatore; Zerbini, Alexandre N.; Geyer, Ygor; Mayer, François-Xavier; Jung, Jean-Luc; Hervé, Maxime R.; Pous, Stephane; Sallée, Jean-Baptiste; Rosenbaum, Howard C.; Adam, Olivier; Charrassin, Jean-Benoit

2016-01-01

Assessing the movement patterns and key habitat features of breeding humpback whales is a prerequisite for the conservation management of this philopatric species. To investigate the interactions between humpback whale movements and environmental conditions off Madagascar, we deployed 25 satellite tags in the northeast and southwest coast of Madagascar. For each recorded position, we collated estimates of environmental variables and computed two behavioural metrics: behavioural state of ‘transiting’ (consistent/directional) versus ‘localized’ (variable/non-directional), and active swimming speed (i.e. speed relative to the current). On coastal habitats (i.e. bathymetry < 200 m and in adjacent areas), females showed localized behaviour in deep waters (191 ± 20 m) and at large distances (14 ± 0.6 km) from shore, suggesting that their breeding habitat extends beyond the shallowest waters available close to the coastline. Males' active swimming speed decreased in shallow waters, but environmental parameters did not influence their likelihood to exhibit localized movements, which was probably dominated by social factors instead. In oceanic habitats, both males and females showed localized behaviours in shallow waters and favoured high chlorophyll-a concentrations. Active swimming speed accounts for a large proportion of observed movement speed; however, breeding humpback whales probably exploit prevailing ocean currents to maximize displacement. This study provides evidence that coastal areas, generally subject to strong human pressure, remain the core habitat of humpback whales off Madagascar. Our results expand the knowledge of humpback whale habitat use in oceanic habitat and response to variability of environmental factors such as oceanic current and chlorophyll level. PMID:28083104

Influence of environmental parameters on movements and habitat utilization of humpback whales (Megaptera novaeangliae) in the Madagascar breeding ground.

PubMed

Trudelle, Laurène; Cerchio, Salvatore; Zerbini, Alexandre N; Geyer, Ygor; Mayer, François-Xavier; Jung, Jean-Luc; Hervé, Maxime R; Pous, Stephane; Sallée, Jean-Baptiste; Rosenbaum, Howard C; Adam, Olivier; Charrassin, Jean-Benoit

2016-12-01

Assessing the movement patterns and key habitat features of breeding humpback whales is a prerequisite for the conservation management of this philopatric species. To investigate the interactions between humpback whale movements and environmental conditions off Madagascar, we deployed 25 satellite tags in the northeast and southwest coast of Madagascar. For each recorded position, we collated estimates of environmental variables and computed two behavioural metrics: behavioural state of 'transiting' (consistent/directional) versus 'localized' (variable/non-directional), and active swimming speed (i.e. speed relative to the current). On coastal habitats (i.e. bathymetry < 200 m and in adjacent areas), females showed localized behaviour in deep waters (191 ± 20 m) and at large distances (14 ± 0.6 km) from shore, suggesting that their breeding habitat extends beyond the shallowest waters available close to the coastline. Males' active swimming speed decreased in shallow waters, but environmental parameters did not influence their likelihood to exhibit localized movements, which was probably dominated by social factors instead. In oceanic habitats, both males and females showed localized behaviours in shallow waters and favoured high chlorophyll- a concentrations. Active swimming speed accounts for a large proportion of observed movement speed; however, breeding humpback whales probably exploit prevailing ocean currents to maximize displacement. This study provides evidence that coastal areas, generally subject to strong human pressure, remain the core habitat of humpback whales off Madagascar. Our results expand the knowledge of humpback whale habitat use in oceanic habitat and response to variability of environmental factors such as oceanic current and chlorophyll level.

Effects of ivermectin on Danio rerio: a multiple endpoint approach: behaviour, weight and subcellular markers.

PubMed

Domingues, I; Oliveira, R; Soares, A M V M; Amorim, M J B

2016-04-01

Ivermectin (IVM) is a broad acting antihelmintic used in various veterinary pharmaceuticals. It has been shown that IVM enters the aquatic compartment and adversely affects organisms including fish. This study is based on the hypothesis that long term exposure to IVM affects fish and thus, the main objective was to assess the chronic effects of 0.25 and 25 µg IVM/L to zebrafish using multiple endpoints representative of several levels of biological organization: weight, behaviour (swimming and feeding) and subcellular markers including biomarkers for oestrogenicity (vitellogenin-VTG), oxidative stress (catalase-CAT and glutathione-S-transferase-GST) and neurotransmission (cholinesterase-ChE). Concentrations as low as 0.25 µg IVM/L disrupted the swimming behaviour, causing fish to spend more time at the bottom of aquaria. Such reduction of the swimming performance affected the feeding ability which is likely responsible for the weight loss. The effects on weight were gender differentiated, being more pronounced in males (0.25 µg IVM/L) than in females (25 µg IVM/L). Fish exposed to 25 µg/L exhibited darker coloration and mild curvature of the spine. No effects on VTG and AChE were observed, but a reduction on CAT and GST levels was observed in fish exposed to 25 µg IVM/L, although these alterations probably only reflect the general condition of the fish which was significantly compromised at this concentration. Despite that predicted environmental concentrations of IVM are below 0.25 µg/L, the behavioural effects may be translated into important ecological impacts, e.g. at predator-prey interactions where fish competitive advantage can be decreased. Future work should address the link between behaviour disruption and population fitness. The current study was based on a one experiment and multiple endpoint (anchored) approach, allowing the results to be integrated and linked towards a mechanistic understanding.

Influence of Anguillicola crassus (Nematoda) and Ichthyophthirius multifiliis (Ciliophora) on swimming activity of European eel Anguilla anguilla.

PubMed

Münderle, M; Sures, B; Taraschewski, H

2004-08-09

We investigated the swimming activity of 70 European eels Anguilla anguilla in relation to natural infection with 2 parasite species: the eel-specific swimbladder nematode Anguillicola crassus and the non-specific skin and gill protozoan Ichthyophthirius multifiliis. We measured how long individual eels exposed to a water current in a swimming channel with a steady-stream profile could withstand the water current. The parasites affected the swimming behaviour of eels in different ways. The maximum period of time the fish were able to swim against the current was not correlated with infection by A. crassus. In contrast, infection with I. multifiliis reduced the swimming time. The protozoan has a higher pathogenicity than the swimbladder nematode, at least in closed systems, where I. multifiliis is able to spread within a few days. Reduction in swimming capacity after infection with the ciliate averaged 47 % compared to capacity prior to infection. Thus, our results do not support the previously suggested strong negative relation between swimming activity of eels and intensity of A. crassus infection, at least in the short-term. However, there are indications in the literature that the pathological effects of A. crassus on the eel swimmbladder may involve a higher energy demand, possibly manifested in a prolonged spawning migration. As a result, eels heavily infected with this parasite may arrive too late at the spawning site to participate in mating. This could ensure a selection of 'good genes'.

The Effect of Drag and Attachment Site of External Tags on Swimming Eels: Experimental Quantification and Evaluation Tool

PubMed Central

Tudorache, Christian; Burgerhout, Erik; Brittijn, Sebastiaan; van den Thillart, Guido

2014-01-01

Telemetry studies on aquatic animals often use external tags to monitor migration patterns and help to inform conservation effort. However, external tags are known to impair swimming energetics dramatically in a variety of species, including the endangered European eel. Due to their high swimming efficiency, anguilliform swimmers are very susceptibility for added drag. Using an integration of swimming physiology, behaviour and kinematics, we investigated the effect of additional drag and site of externally attached tags on swimming mode and costs. The results show a significant effect of a) attachment site and b) drag on multiple energetic parameters, such as Cost Of Transport (COT), critical swimming speed (Ucrit) and optimal swimming speed (Uopt), possibly due to changes in swimming kinematics. Attachment at 0.125 bl from the tip of the snout is a better choice than at the Centre Of Mass (0.35 bl), as it is the case in current telemetry studies. Quantification of added drag effect on COT and Ucrit show a (limited) correlation, suggesting that the Ucrit test can be used for evaluating external tags for telemetry studies until a certain threshold value. Uopt is not affected by added drag, validating previous findings of telemetry studies. The integrative methodology and the evaluation tool presented here can be used for the design of new studies using external telemetry tags, and the (re-) evaluation of relevant studies on anguilliform swimmers. PMID:25409179

The effect of drag and attachment site of external tags on swimming eels: experimental quantification and evaluation tool.

PubMed

Tudorache, Christian; Burgerhout, Erik; Brittijn, Sebastiaan; van den Thillart, Guido

2014-01-01

Telemetry studies on aquatic animals often use external tags to monitor migration patterns and help to inform conservation effort. However, external tags are known to impair swimming energetics dramatically in a variety of species, including the endangered European eel. Due to their high swimming efficiency, anguilliform swimmers are very susceptibility for added drag. Using an integration of swimming physiology, behaviour and kinematics, we investigated the effect of additional drag and site of externally attached tags on swimming mode and costs. The results show a significant effect of a) attachment site and b) drag on multiple energetic parameters, such as Cost Of Transport (COT), critical swimming speed (Ucrit) and optimal swimming speed (Uopt), possibly due to changes in swimming kinematics. Attachment at 0.125 bl from the tip of the snout is a better choice than at the Centre Of Mass (0.35 bl), as it is the case in current telemetry studies. Quantification of added drag effect on COT and Ucrit show a (limited) correlation, suggesting that the Ucrit test can be used for evaluating external tags for telemetry studies until a certain threshold value. Uopt is not affected by added drag, validating previous findings of telemetry studies. The integrative methodology and the evaluation tool presented here can be used for the design of new studies using external telemetry tags, and the (re-) evaluation of relevant studies on anguilliform swimmers.

A proposal for refining the forced swim test in Swiss mice.

PubMed

Costa, Ana Paula Ramos; Vieira, Cintia; Bohner, Lauren O L; Silva, Cristiane Felisbino; Santos, Evelyn Cristina da Silva; De Lima, Thereza Christina Monteiro; Lino-de-Oliveira, Cilene

2013-08-01

The forced swim test (FST) is a preclinical test to the screening of antidepressants based on rats or mice behaviours, which is also sensitive to stimulants of motor activity. This work standardised and validated a method to register the active and passive behaviours of Swiss mice during the FST in order to strength the specificity of the test. Adult male Swiss mice were subjected to the FST for 6 min without any treatment or after intraperitoneal injection of saline (0.1 ml/10 g), antidepressants (imipramine, desipramine, or fluoxetine, 30 mg/kg) or stimulants (caffeine, 30 mg/kg or apomorphine, 10mg/kg). The latency, frequency and duration of behaviours (immobility, swimming, and climbing) were scored and summarised in bins of 6, 4, 2 or 1 min. Parameters were first analysed using Principal Components Analysis generating components putatively related to antidepressant (first and second) or to stimulant effects (third). Antidepressants and stimulants affected similarly the parameters grouped into all components. Effects of stimulants on climbing were better distinguished of antidepressants when analysed during the last 4 min of the FST. Surprisingly, the effects of antidepressants on immobility were better distinguished from saline when parameters were scored in the first 2 min. The method proposed here is able to distinguish antidepressants from stimulants of motor activity using Swiss mice in the FST. This refinement should reduce the number of mice used in preclinical evaluation of antidepressants. Copyright © 2013 Elsevier Inc. All rights reserved.

Function of identified motoneurones and co-ordination of primary and secondary motor systems during zebra fish swimming.

PubMed Central

Liu, D W; Westerfield, M

1988-01-01

1. The activity of the two classes of motoneurones, primary and secondary, which innervate myotomal muscle fibres in the zebra fish, was monitored with electromyographic and intracellular techniques. 2. Simultaneous EMG and intracellular recordings from muscle fibres showed that the activity of the two motor systems and of individual primary motoneurones can be distinguished by recording EMG spikes during swimming. 3. Measurements of EMG spikes demonstrated that primary and secondary motoneurones are co-ordinately activated over a wide range of conditions during normal swimming. 4. During swimming the primary motoneurones within a given segment are usually co-activated although they sometimes fire independently. 5. When different primary motoneurones within a given segment are co-activated, they fire nearly synchronously. 6. We conclude that the primary motoneurones are used principally, although not exclusively, during fast swimming, struggling and the startle response, whereas secondary motoneurones function primarily during slower swimming. PMID:3253426

Adaptation and acclimation of traits associated with swimming capacity in Lake Whitefish (coregonus clupeaformis) ecotypes.

PubMed

Laporte, Martin; Dalziel, Anne C; Martin, Nicolas; Bernatchez, Louis

2016-08-11

Improved performance in a given ecological niche can occur through local adaptation, phenotypic plasticity, or a combination of these mechanisms. Evaluating the relative importance of these two mechanisms is needed to better understand the cause of intra specific polymorphism. In this study, we reared populations of Lake Whitefish (Coregonus clupeaformis) representing the'normal' (benthic form) and the 'dwarf' (derived limnetic form) ecotypes in two different conditions (control and swim-training) to test the relative importance of adaptation and acclimation in the differentiation of traits related to swimming capacity. The dwarf whitefish is a more active swimmer than the normal ecotype, and also has a higher capacity for aerobic energy production in the swimming musculature. We hypothesized that dwarf fish would show changes in morphological and physiological traits consistent with reductions in the energetic costs of swimming and maintenance metabolism. We found differences in traits predicted to decrease the costs of prolonged swimming and standard metabolic rate and allow for a more active lifestyle in dwarf whitefish. Dwarf whitefish evolved a more streamlined body shape, predicted to lead to a decreased drag, and a smaller brain, which may decrease their standard metabolic rate. Contrary to predictions, we also found evidence of acclimation in liver size and metabolic enzyme activities. Results support the view that local adaptation has contributed to the genetically-based divergence of traits associated with swimming activity. Presence of post-zygotic barriers limiting gene flow between these ecotype pairs may have favoured repeated local adaptation to the limnetic niches.

Toxic cocaine- and convulsant-induced modification of forced swimming behaviors and their interaction with ethanol: comparison with immobilization stress

PubMed Central

Hayase, Tamaki; Yamamoto, Yoshiko; Yamamoto, Keiichi

2002-01-01

Background Swimming behaviors in the forced swimming test have been reported to be depressed by stressors. Since toxic convulsion-inducing drugs related to dopamine [cocaine (COC)], benzodiazepine [methyl 6,7-dimethoxy-4-ethyl-β-carboline-carboxylate (DMCM)], γ-aminobutyric acid (GABA) [bicuculline (BIC)], and glutamate [N-methyl-D-aspartate (NMDA)] receptors can function as stressors, the present study compared their effects on the forced swimming behaviors with the effects of immobilization stress (IM) in rats. Their interactions with ethanol (EtOH), the most frequently coabused drug with COC which also induces convulsions as withdrawal symptoms but interferes with the convulsions caused by other drugs, were also investigated. Results Similar to the IM (10 min) group, depressed swimming behaviors (attenuated time until immobility and activity counts) were observed in the BIC (5 mg/kg IP) and DMCM (10 mg/kg IP) groups at the 5 h time point, after which no toxic behavioral symptoms were observed. However, they were normalized to the control levels at the 12 h point, with or without EtOH (1.5 g/kg IP). In the COC (60 mg/kg IP) and NMDA (200 mg/kg IP) groups, the depression occurred late (12 h point), and was normalized by the EtOH cotreatment. At the 5 h point, the COC treatment enhanced the swimming behaviors above the control level. Conclusions Although the physiological stress (IM), BIC, and DMCM also depressed the swimming behaviors, a delayed occurrence and EtOH-induced recovery of depressed swimming were observed only in the COC and NMDA groups. This might be correlated with the previously-reported delayed responses of DA and NMDA neurons rather than direct effects of the drugs, which could be suppressed by EtOH. Furthermore, the characteristic psychostimulant effects of COC seemed to be correlated with an early enhancement of swimming behaviors. PMID:12425723

Investigating Behaviour and Population Dynamics of Striped Marlin (Kajikia audax) from the Southwest Pacific Ocean with Satellite Tags

PubMed Central

Sippel, Tim; Holdsworth, John; Dennis, Todd; Montgomery, John

2011-01-01

Behaviour and distribution of striped marlin within the southwest Pacific Ocean were investigated using electronic tagging data collected from 2005–2008. A continuous-time correlated random-walk Kalman filter was used to integrate double-tagging data exhibiting variable error structures into movement trajectories composed of regular time-steps. This state-space trajectory integration approach improved longitude and latitude error distributions by 38.5 km and 22.2 km respectively. Using these trajectories as inputs, a behavioural classification model was developed to infer when, and where, ‘transiting’ and ‘area-restricted’ (ARB) pseudo-behavioural states occurred. ARB tended to occur at shallower depths (108±49 m) than did transiting behaviours (127±57 m). A 16 day post-release period of diminished ARB activity suggests that patterns of behaviour were affected by the capture and/or tagging events, implying that tagged animals may exhibit atypical behaviour upon release. The striped marlin in this study dove deeper and spent greater time at ≥200 m depth than those in the central and eastern Pacific Ocean. As marlin reached tropical latitudes (20–21°S) they consistently reversed directions, increased swimming speed and shifted to transiting behaviour. Reversals in the tropics also coincided with increases in swimming depth, including increased time ≥250 m. Our research provides enhanced understanding of the behavioural ecology of striped marlin. This has implications for the effectiveness of spatially explicit population models and we demonstrate the need to consider geographic variation when standardizing CPUE by depth, and provide data to inform natural and recreational fishing mortality parameters. PMID:21695132

Phytoplankton can actively diversify their migration strategy in response to turbulent cues

NASA Astrophysics Data System (ADS)

Sengupta, Anupam; Carrara, Francesco; Stocker, Roman

2017-03-01

Marine phytoplankton inhabit a dynamic environment where turbulence, together with nutrient and light availability, shapes species fitness, succession and selection. Many species of phytoplankton are motile and undertake diel vertical migrations to gain access to nutrient-rich deeper layers at night and well-lit surface waters during the day. Disruption of this migratory strategy by turbulence is considered to be an important cause of the succession between motile and non-motile species when conditions turn turbulent. However, this classical view neglects the possibility that motile species may actively respond to turbulent cues to avoid layers of strong turbulence. Here we report that phytoplankton, including raphidophytes and dinoflagellates, can actively diversify their migratory strategy in response to hydrodynamic cues characteristic of overturning by Kolmogorov-scale eddies. Upon experiencing repeated overturning with timescales and statistics representative of ocean turbulence, an upward-swimming population rapidly (5-60 min) splits into two subpopulations, one swimming upward and one swimming downward. Quantitative morphological analysis of the harmful-algal-bloom-forming raphidophyte Heterosigma akashiwo together with a model of cell mechanics revealed that this behaviour was accompanied by a modulation of the cells’ fore-aft asymmetry. The minute magnitude of the required modulation, sufficient to invert the preferential swimming direction of the cells, highlights the advanced level of control that phytoplankton can exert on their migratory behaviour. Together with observations of enhanced cellular stress after overturning and the typically deleterious effects of strong turbulence on motile phytoplankton, these results point to an active adaptation of H. akashiwo to increase the chance of evading turbulent layers by diversifying the direction of migration within the population, in a manner suggestive of evolutionary bet-hedging. This migratory behaviour relaxes the boundaries between the fluid dynamic niches of motile and non-motile phytoplankton, and highlights that rapid responses to hydrodynamic cues are important survival strategies for phytoplankton in the ocean.

Phytoplankton can actively diversify their migration strategy in response to turbulent cues.

PubMed

Sengupta, Anupam; Carrara, Francesco; Stocker, Roman

2017-03-23

Marine phytoplankton inhabit a dynamic environment where turbulence, together with nutrient and light availability, shapes species fitness, succession and selection. Many species of phytoplankton are motile and undertake diel vertical migrations to gain access to nutrient-rich deeper layers at night and well-lit surface waters during the day. Disruption of this migratory strategy by turbulence is considered to be an important cause of the succession between motile and non-motile species when conditions turn turbulent. However, this classical view neglects the possibility that motile species may actively respond to turbulent cues to avoid layers of strong turbulence. Here we report that phytoplankton, including raphidophytes and dinoflagellates, can actively diversify their migratory strategy in response to hydrodynamic cues characteristic of overturning by Kolmogorov-scale eddies. Upon experiencing repeated overturning with timescales and statistics representative of ocean turbulence, an upward-swimming population rapidly (5-60 min) splits into two subpopulations, one swimming upward and one swimming downward. Quantitative morphological analysis of the harmful-algal-bloom-forming raphidophyte Heterosigma akashiwo together with a model of cell mechanics revealed that this behaviour was accompanied by a modulation of the cells' fore-aft asymmetry. The minute magnitude of the required modulation, sufficient to invert the preferential swimming direction of the cells, highlights the advanced level of control that phytoplankton can exert on their migratory behaviour. Together with observations of enhanced cellular stress after overturning and the typically deleterious effects of strong turbulence on motile phytoplankton, these results point to an active adaptation of H. akashiwo to increase the chance of evading turbulent layers by diversifying the direction of migration within the population, in a manner suggestive of evolutionary bet-hedging. This migratory behaviour relaxes the boundaries between the fluid dynamic niches of motile and non-motile phytoplankton, and highlights that rapid responses to hydrodynamic cues are important survival strategies for phytoplankton in the ocean.

The effect of prey density on foraging mode selection in juvenile lumpfish: balancing food intake with the metabolic cost of foraging.

PubMed

Killen, Shaun S; Brown, Joseph A; Gamperl, A Kurt

2007-07-01

1. In many species, individuals will alter their foraging strategy in response to changes in prey density. However, previous work has shown that prey density has differing effects on the foraging mode decisions of ectotherms as compared with endotherms. This is likely due to differences in metabolic demand; however, the relationship between metabolism and foraging mode choice in ectotherms has not been thoroughly studied. 2. Juvenile lumpfish Cyclopterus lumpus forage using one of two modes: they can actively search for prey while swimming, or they can 'sit-and-wait' for prey while clinging to the substrate using a ventral adhesive disk. The presence of these easily distinguishable foraging modes makes juvenile lumpfish ideal for the study of foraging mode choice in ectotherms. 3. Behavioural observations conducted during laboratory experiments showed that juvenile lumpfish predominantly use the 'cling' foraging mode when prey is abundant, but resort to the more costly 'swim' mode to seek out food when prey is scarce. The metabolic cost of active foraging was also quantified for juvenile lumpfish using swim-tunnel respirometry, and a model was devised to predict the prey density at which lumpfish should switch between the swim and cling foraging modes to maximize energy intake. 4. The results of this model do not agree with previous observations of lumpfish behaviour, and thus it appears that juvenile lumpfish do not try to maximize their net energetic gain. Instead, our data suggest that juvenile lumpfish forage in a manner that reduces activity and conserves space in their limited aerobic scope. This behavioural flexibility is of great benefit to this species, as it allows young individuals to divert energy towards growth as opposed to activity. In a broader context, our results support previous speculation that ectotherms often forage in a manner that maintains a minimum prey encounter rate, but does not necessarily maximize net energy gain.

Effects of chronic mild stress on rats selectively bred for behavior related to bipolar disorder and depression.

PubMed

Murray, Ryan; Boss-Williams, Katherine A; Weiss, Jay M

2013-07-02

To test the possibility that chronic mild stress (CMS) might be unreliable in producing its often-intended outcome (i.e., decreased preference for sucrose, hypothesized to represent depression-relevant anhedonia) because it is typically applied to "normal" rats, a CMS procedure was applied to rats that may possess genetic susceptibility to affective disorders, having had been selectively-bred to show behavior indicative of such disorders. These rat lines were: Hyperactive (HYPER) rats, which show characteristics of bipolar disorder, Swim-test Susceptible (SUS) and Swim-test Resistant (RES) rats, being susceptible or resistant to effects of stress in the swim test, Swim High-active (SwHi) and Swim Low-active (SwLo) rats, which innately show high or low activity in the swim test. These selectively-bred lines were compared to normal, non-selectively bred (NS) rats. During CMS, HYPER rats, both females and males, as well as RES and SwHi rats, showed reduced consumption of a palatable 2% sucrose solution, and reduced preference for sucrose (vs. water) in comparison to non-stressed rats (no CMS) of the same lines. In contrast, CMS produced no decrease in sucrose consumption or in preference for sucrose in normal NS rats, and actually a caused a slight increase in sucrose consumption and preference in male NS rats. Other measures that indicate depression - food intake and motor activity in the home cage - were also assessed. SwLo and SwHi showed greater sensitivity to having their home-cage ambulatory activity reduced by CMS than did NS rats, but no other such differences relative to NS rats were seen for these other measures; thus, changes in sucrose intake or preference could not be explained by a change in caloric intake. These results suggest that the genetic attributes of animals can influence the outcome of CMS, and that the application of CMS to normal, non-selected rats may account, at least in part, for the unreliability of CMS in decreasing consumption of palatable substances and decreasing preference for such substances. Copyright © 2013. Published by Elsevier Inc.

Flavonoid-rich fraction of the Monodora tenuifolia seed extract attenuates behavioural alterations and oxidative damage in forced-swim stressed rats.

PubMed

Ekeanyanwu, Raphael Chukwuma; Njoku, Obioma Uzoma

2015-03-01

The antidepressant effects of the flavonoid-rich fraction of Monodora tenuifolia seed extract were examined by assessing the extent of attenuation of behavioural alterations and oxidative damage in the rats that were stressed by forced swim test. Compared with the model control group, the altered behavioural parameters were attenuated significantly (P < 0.05) in the group treated with the flavonoid-rich fraction (100 and 200 mg·kg(-1)), comparable to the group treated with the standard drug, fluoxetine (10 mg·kg(-1)). The flavonoid-rich fraction and fluoxetine improved significantly (P < 0.05) the activities of the antioxidant enzymes such as superoxide dismutase and catalase as well as other biochemical parameters such as reduced glutathione, protein, and nitrite in the brain of the stressed rats. These results suggested that the flavonoid-rich fraction of Monodora tenuifolia seed extract exerted the antidepressant-like effects which could be useful in the management of stress induced disease. Copyright © 2015 China Pharmaceutical University. Published by Elsevier B.V. All rights reserved.

Biosonar behaviour of free-ranging porpoises

PubMed Central

Akamatsu, Tomonari; Wang, Ding; Wang, Kexiong; Naito, Yasuhiko

2005-01-01

Detecting objects in their paths is a fundamental perceptional function of moving organisms. Potential risks and rewards, such as prey, predators, conspecifics or non-biological obstacles, must be detected so that an animal can modify its behaviour accordingly. However, to date few studies have considered how animals in the wild focus their attention. Dolphins and porpoises are known to actively use sonar or echolocation. A newly developed miniature data logger attached to a porpoise allows for individual recording of acoustical search efforts and inspection distance based on echolocation. In this study, we analysed the biosonar behaviour of eight free-ranging finless porpoises (Neophocaena phocaenoides) and demonstrated that these animals inspect the area ahead of them before swimming silently into it. The porpoises inspected distances up to 77 m, whereas their swimming distance without using sonar was less than 20 m. The inspection distance was long enough to ensure a wide safety margin before facing real risks or rewards. Once a potential prey item was detected, porpoises adjusted their inspection distance from the remote target throughout their approach. PMID:15888412

Anxiety-like behaviour in mice exposed to tannery wastewater: The effect of photoelectrooxidation treatment.

PubMed

Siqueira, Ionara Rodrigues; Vanzella, Cláudia; Bianchetti, Paula; Rodrigues, Marco Antonio Siqueira; Stülp, Simone

2011-01-01

The leather industry is a major producer of wastewaters and releases large quantities of many different chemical agents used in hide processing into the environment. Since the central nervous system is sensitive to many different contaminants, our aim was to investigate the neurobehavioral effects of exposure of mice to tannery effluents using animal models of depression and anxiety, namely forced swim and elevated plus-maze. In order to propose a clean technology for the treatment of this effluent, we also investigated the exposure of mice to effluents treated by photoelectrooxidation process (PEO). Adult male Swiss albino mice (CF1 strain) were given free access to water bottles containing an effluent treated by a tannery (non-PEO) or PEO-treated tannery wastewater (0.1 and 1% in drinking water). Exposure to tannery wastewater induced behavioural changes in the mice in elevated plus-maze. Exposure to non-PEO 1% decreased the percentage of time spent in the open arms, indicating anxiety-like behaviour. Exposure to tannery wastewater did not alter immobility time in the forced swim test, suggesting that tannery effluents did not induce depression-like behaviour in the mice. These behavioural data suggest that non-PEO tannery effluent has an anxiogenic effect, whereas PEO-treated tannery effluents do not alter anxiety levels. Copyright © 2011 Elsevier Inc. All rights reserved.

Great hammerhead sharks swim on their side to reduce transport costs

PubMed Central

Payne, Nicholas L.; Iosilevskii, Gil; Barnett, Adam; Fischer, Chris; Graham, Rachel T.; Gleiss, Adrian C.; Watanabe, Yuuki Y.

2016-01-01

Animals exhibit various physiological and behavioural strategies for minimizing travel costs. Fins of aquatic animals play key roles in efficient travel and, for sharks, the functions of dorsal and pectoral fins are considered well divided: the former assists propulsion and generates lateral hydrodynamic forces during turns and the latter generates vertical forces that offset sharks' negative buoyancy. Here we show that great hammerhead sharks drastically reconfigure the function of these structures, using an exaggerated dorsal fin to generate lift by swimming rolled on their side. Tagged wild sharks spend up to 90% of time swimming at roll angles between 50° and 75°, and hydrodynamic modelling shows that doing so reduces drag—and in turn, the cost of transport—by around 10% compared with traditional upright swimming. Employment of such a strongly selected feature for such a unique purpose raises interesting questions about evolutionary pathways to hydrodynamic adaptations, and our perception of form and function. PMID:27457414

Locomotor adaptations of some gelatinous zooplankton.

PubMed

Bone, Q

1985-01-01

Swimming behaviour and locomotor adaptations are described in chaetognaths, larvacean tunicates, some cnidaria, and thaliacean tunicates. The first two groups swim by oscillating a flattened tail, the others by jet propulsion. In chaetognaths, the locomotor muscle fibres are extensively coupled and relatively sparsely innervated, they exhibit compound spike-like potentials. The motoneurons controlling the rhythmic activity of the locomotor muscle lie in a ventral ganglion whose organization is briefly described. Rhythmic swimming bursts in larvaceans are similarly driven by a caudal ganglion near the base of the tail, but each caudal muscle cell is separately innervated by two sets of motor nerves, as well as being coupled to its neighbours. The external epithelium is excitable, and linked to the caudal ganglion by the axons of central cells. Mechanical stimulation of the epithelium evokes receptor potentials followed by action potentials and by bursts of rapid swimming. The trachyline medusa Aglantha and the small siphonophore Chelophyes also show rapid escape responses; in Aglantha these are driven by a specialized giant axon system lacking in other hydromedusae, and in Chelophyes. Slow swimming in Aglantha apparently involves a second nerve supply to the same muscle sheets used in rapid swimming, whereas in Chelophyes slow swimming results from the activity of the smaller posterior nectophore. Slow swimming in siphonophores is more economical than the rapid responses. In the hydrozoan medusa Polyorchis (as in Chelophyes) action potentials in the locomotor muscle sheet change in shape during swimming bursts, and their duration is related to the size of the medusa; they are not simply triggers of muscular contraction. The two groups of thaliacean tunicates are specialized differently. Doliolum is adapted for single rapid jet pulses (during which it achieves instantaneous velocities of 50 body lengths s-l), whilst salps are adapted for slow continuous swimming. The cost of locomotion is greater in Doliolum. Few gelatinous zooplankton show special adaptations both for rapid escape movements, and for slow sustained swimming, those that do deserve further study.

Skin friction enhancement in a model problem of undulatory swimming

NASA Astrophysics Data System (ADS)

Ehrenstein, Uwe; Eloy, Christophe

2013-10-01

To calculate the energy costs of swimming, it is crucial to evaluate the drag force originating from skin friction. In this paper we examine the assumption, known as the 'Bone-Lighthill boundary-layer thinning hypothesis', that undulatory swimming motions induce a drag increase because of the compression of the boundary layer. Studying analytically an incoming flow along a flat plate moving at a normal velocity as a limit case of a yawed cylinder in uniform flow under the laminar boundary layer assumption, we demonstrate that the longitudinal drag scales as the square root of the normal velocity component. This analytical prediction is interpreted in the light of a three-dimensional numerical simulation result for a plate of finite length and width. An analogous two-dimensional Navier-Stokes problem by artificially accelerating the flow in a channel of finite height is proposed and solved numerically, showing the robustness of the analytical results. Solving the problem for an undulatory plate motion similar to fish swimming, we find a drag enhancement which can be estimated to be of the order of 20 %.

Transitions between three swimming gaits in Paramecium escape.

PubMed

Hamel, Amandine; Fisch, Cathy; Combettes, Laurent; Dupuis-Williams, Pascale; Baroud, Charles N

2011-05-03

Paramecium and other protists are able to swim at velocities reaching several times their body size per second by beating their cilia in an organized fashion. The cilia beat in an asymmetric stroke, which breaks the time reversal symmetry of small scale flows. Here we show that Paramecium uses three different swimming gaits to escape from an aggression, applied in the form of a focused laser heating. For a weak aggression, normal swimming is sufficient and produces a steady swimming velocity. As the heating amplitude is increased, a higher acceleration and faster swimming are achieved through synchronized beating of the cilia, which begin by producing oscillating swimming velocities and later give way to the usual gait. Finally, escape from a life-threatening aggression is achieved by a "jumping" gait, which does not rely on the cilia but is achieved through the explosive release of a group of trichocysts in the direction of the hot spot. Measurements through high-speed video explain the role of trichocysts in defending against aggressions while showing unexpected transitions in the swimming of microorganisms. These measurements also demonstrate that Paramecium optimizes its escape pattern by taking advantage of its inertia.

Transitions between three swimming gaits in Paramecium escape

PubMed Central

Hamel, Amandine; Fisch, Cathy; Combettes, Laurent; Dupuis-Williams, Pascale; Baroud, Charles N.

2011-01-01

Paramecium and other protists are able to swim at velocities reaching several times their body size per second by beating their cilia in an organized fashion. The cilia beat in an asymmetric stroke, which breaks the time reversal symmetry of small scale flows. Here we show that Paramecium uses three different swimming gaits to escape from an aggression, applied in the form of a focused laser heating. For a weak aggression, normal swimming is sufficient and produces a steady swimming velocity. As the heating amplitude is increased, a higher acceleration and faster swimming are achieved through synchronized beating of the cilia, which begin by producing oscillating swimming velocities and later give way to the usual gait. Finally, escape from a life-threatening aggression is achieved by a “jumping” gait, which does not rely on the cilia but is achieved through the explosive release of a group of trichocysts in the direction of the hot spot. Measurements through high-speed video explain the role of trichocysts in defending against aggressions while showing unexpected transitions in the swimming of microorganisms. These measurements also demonstrate that Paramecium optimizes its escape pattern by taking advantage of its inertia. PMID:21464291

Diabetic encephalopathy-related depression: experimental evidence that insulin and clonazepam restore antioxidant status in rat brain.

PubMed

Wayhs, Carlos Alberto Yasin; Mescka, Caroline Paula; Guerreiro, Gilian; Moraes, Tarsila Barros; Jacques, Carlos Eduardo Diaz; Rosa, Andrea Pereira; Ferri, Marcelo Kneib; Nin, Maurício Schüler; Dutra-Filho, Carlos Severo; Barros, Helena Maria Tannhauser; Vargas, Carmen Regla

2014-12-01

There is increasing evidence suggesting that oxidative stress plays an important role in the development of many chronic and degenerative conditions such as diabetic encephalopathy and depression. Considering that diabetic rats and mice present higher depressive-like behaviour when submitted to the forced swimming test and that treatment with insulin and/or clonazepam is able to reverse the behavioural changes of the diabetic rats, the present work investigated the antioxidant status, specifically total antioxidant reactivity and antioxidant potential of insulin and clonazepam, as well as the effect of this drugs upon protein oxidative damage and reactive species formation in cortex, hippocampus and striatum from diabetic rats submitted to forced swimming test. It was verified that longer immobility time in diabetic rats and insulin plus clonazepam treatment reversed this depressive-like behaviour. Moreover, data obtained in this study allowed to demonstrate through different parameters such as protein carbonyl content, 2'7'-dichlorofluorescein oxidation, catalase, superoxide dismutase, glutathione peroxidase assay, total radical-trapping antioxidant potential and total antioxidant reactivity that there is oxidative stress in cortex, hippocampus and striatum from diabetic rats under depressive-like behaviour and highlight the insulin and/or clonazepam effect in these different brain areas, restoring antioxidant status and protein damage. Copyright © 2014 John Wiley & Sons, Ltd.

Viscosity-dependent variations in the cell shape and swimming manner of Leptospira.

PubMed

Takabe, Kyosuke; Tahara, Hajime; Islam, Md Shafiqul; Affroze, Samia; Kudo, Seishi; Nakamura, Shuichi

2017-02-01

Spirochaetes are spiral or flat-wave-shaped Gram-negative bacteria that have periplasmic flagella between the peptidoglycan layer and outer membrane. Rotation of the periplasmic flagella transforms the cell body shape periodically, allowing the cell to swim in aqueous environments. Because the virulence of motility-deficient mutants of pathogenic species is drastically attenuated, motility is thought to be an essential virulence factor in spirochaetes. However, it remains unknown how motility practically contributes to the infection process. We show here that the cell body configuration and motility of the zoonotic spirochaete Leptospira changes depending on the viscosity of the medium. Leptospira swim and reverse the swimming direction by transforming the cell body. Motility analysis showed that the frequency of cell shape transformation was increased by increasing the viscosity of the medium. The increased cell body transformation induced highly frequent reversal of the swimming direction. A simple kinetic model based on the experimental results shows that the viscosity-induced increase in reversal limits cell migration, resulting in the accumulation of cells in high-viscosity regions. This behaviour could facilitate the colonization of the spirochaete on host tissues covered with mucosa.

Killifish Hatching and Orientation experiment MA-161

NASA Technical Reports Server (NTRS)

Scheld, H. W.; Boyd, J. F.; Bozarth, G. A.; Conner, J. A.; Eichler, V. B.; Fuller, P. M.; Hoffman, R. B.; Keefe, J. R.; Kuchnow, K. P.; Oppenheimer, J. M.

1976-01-01

The killifish Fundulus heteroclitus was used as a model system for study of embryonic development and vestibular adaptation in orbital flight. Juvenile fish in a zero gravity environment exhibited looping swimming activity similar to that observed during the Skylab 3 mission. Hatchings from a 336 hour egg stage were also observed to loop. At splashdown, both juveniles and hatchings exhibited a typical diving response suggesting relatively normal vestibular function. Juveniles exhibited swimming patterns suggestive of abnormal swim bladders. The embryos exhibited no abnormalities resulting from development in a zero gravity environment.

Developmental changes in head movement kinematics during swimming in Xenopus laevis tadpoles.

PubMed

Hänzi, Sara; Straka, Hans

2017-01-15

During the post-embryonic developmental growth of animals, a number of physiological parameters such as locomotor performance, dynamics and behavioural repertoire are adjusted to match the requirements determined by changes in body size, proportions and shape. Moreover, changes in movement parameters also cause changes in the dynamics of self-generated sensory stimuli, to which motion-detecting sensory systems have to adapt. Here, we examined head movements and swimming kinematics of Xenopus laevis tadpoles with a body length of 10-45 mm (developmental stage 46-54) and compared these parameters with fictive swimming, recorded as ventral root activity in semi-intact in vitro preparations. Head movement kinematics was extracted from high-speed video recordings of freely swimming tadpoles. Analysis of these locomotor episodes indicated that the swimming frequency decreased with development, along with the angular velocity and acceleration of the head, which represent self-generated vestibular stimuli. In contrast, neither head oscillation amplitude nor forward velocity changed with development despite the ∼3-fold increase in body size. The comparison between free and fictive locomotor dynamics revealed very similar swimming frequencies for similarly sized animals, including a comparable developmental decrease of the swimming frequency. Body morphology and the motor output rhythm of the spinal central pattern generator therefore develop concurrently. This study thus describes development-specific naturalistic head motion profiles, which form the basis for more natural stimuli in future studies probing the vestibular system. © 2017. Published by The Company of Biologists Ltd.

Numerical model for the locomotion of spirilla.

PubMed

Ramia, M

1991-11-01

The swimming of trailing, leading, and bipolar spirilla (with realistic flagellar centerline geometries) is considered. A boundary element method is used to predict the instantaneous swimming velocity, counter-rotation angular velocity, and power dissipation of a given organism as functions of time and the geometry of the organism. Based on such velocities, swimming trajectories have been deduced enabling a realistic definition of mean swimming speeds. The power dissipation normalized in terms of the square of the mean swimming speed is considered to be a measure of hydrodynamic efficiency. In addition, kinematic efficiency is defined as the extent of deviation of the swimming motion from that of a previously proposed ideal corkscrew mechanism. The dependence of these efficiencies on the organism's geometry is examined giving estimates of its optimum dimensions. It is concluded that appreciable correlation exists between the two alternative definitions for many of the geometrical parameters considered. Furthermore, the organism having the deduced optimum dimensions closely resembles the real organism as experimentally observed.

Numerical model for the locomotion of spirilla

PubMed Central

Ramia, M.

1991-01-01

The swimming of trailing, leading, and bipolar spirilla (with realistic flagellar centerline geometries) is considered. A boundary element method is used to predict the instantaneous swimming velocity, counter-rotation angular velocity, and power dissipation of a given organism as functions of time and the geometry of the organism. Based on such velocities, swimming trajectories have been deduced enabling a realistic definition of mean swimming speeds. The power dissipation normalized in terms of the square of the mean swimming speed is considered to be a measure of hydrodynamic efficiency. In addition, kinematic efficiency is defined as the extent of deviation of the swimming motion from that of a previously proposed ideal corkscrew mechanism. The dependence of these efficiencies on the organism's geometry is examined giving estimates of its optimum dimensions. It is concluded that appreciable correlation exists between the two alternative definitions for many of the geometrical parameters considered. Furthermore, the organism having the deduced optimum dimensions closely resembles the real organism as experimentally observed. PMID:19431804

Oxygen uptake in Pacific salmon Oncorhynchus spp.: when ecology and physiology meet.

PubMed

Eliason, E J; Farrell, A P

2016-01-01

Over the past several decades, a substantial amount of research has examined how cardiorespiratory physiology supports the diverse activities performed throughout the life cycle of Pacific salmon, genus Oncorhynchus. Pioneering experiments emphasized the importance of aerobic scope in setting the functional thermal tolerance for activity in fishes. Variation in routine metabolism can have important performance and fitness consequences as it is related to dominance, aggression, boldness, territoriality, growth rate, postprandial oxygen consumption, life history, season, time of day, availability of shelter and social interactions. Wild fishes must perform many activities simultaneously (e.g. swim, obtain prey, avoid predators, compete, digest and reproduce) and oxygen delivery is allocated among competing organ systems according to the capacity of the heart to deliver blood. For example, salmonids that are simultaneously swimming and digesting trade-off maximum swimming performance in order to support the oxygen demands of digestion. As adult Pacific salmonids cease feeding in the ocean prior to their home migration, endogenous energy reserves and cardiac capacity are primarily partitioned among the demands for swimming upriver, sexual maturation and spawning behaviours. Furthermore, the upriver spawning migration is under strong selection pressure, given that Pacific salmonids are semelparous (single opportunity to spawn). Consequently, these fishes optimize energy expenditures in a number of ways: strong homing, precise migration timing, choosing forward-assist current paths and exploiting the boundary layer to avoid the strong currents in the middle of the river, using energetically efficient swimming speeds, and recovering rapidly from anaerobic swimming. Upon arrival at the spawning ground, remaining energy can be strategically allocated to the various spawning behaviours. Strong fidelity to natal streams has resulted in reproductively isolated populations that appear to be locally adapted physiologically to their specific environmental conditions. Populations with more challenging migrations have enhanced cardiorespiratory performance. Pacific salmonids are able to maintain aerobic scope across the broad range of temperatures encountered historically during their migration; however, climate change-induced river warming has created lethal conditions for many populations, raising conservation concerns. Despite considerable research examining cardiorespiratory physiology in Pacific salmonids over the last 70 years, critical knowledge gaps are identified. © 2015 The Fisheries Society of the British Isles.

Gastroprotective Properties of Karanjin from Karanja (Pongamia pinnata) Seeds; Role as Antioxidant and H, K-ATPase Inhibitor.

PubMed

Vismaya; Belagihally, Srikanta M; Rajashekhar, Sindhu; Jayaram, Vinay B; Dharmesh, Shylaja M; Thirumakudalu, Sindhu Kanya C

2011-01-01

Plant extracts are the most attractive sources of newer drugs and have been shown to produce promising results for the treatment of gastric ulcers. Karanjin, a furano-flavonoid has been evaluated for anti-ulcerogenic property by employing adult male albino rats. Karanjin (>95% pure) was administered to these rats in two different concentrations, that is, 10 and 20 mg kg(-1) b.w. Ulcers were induced in the experimental animals by swim and ethanol stress. Serum, stomach and liver-tissue homogenates were assessed for biochemical parameters. Karanjin inhibited 50 and 74% of ulcers induced by swim stress at 10 and 20 mg kg(-1) b.w., respectively. Gastric mucin was protected up to 85% in case of swim stress, whereas only 47% mucin recovery was seen in ethanol stress induced ulcers. H(+), K(+)-ATPase activity, which was increased 2-fold in ulcer conditions, was normalized by Karanjin in both swim/ethanol stress-induced ulcer models. Karanjin could inhibit oxidative stress as evidenced by the normalization of lipid peroxidation and antioxidant enzyme (i.e., catalase, peroxidase and superoxide dismutase) levels. Karanjin at concentrations of 20 mg kg(-1) b.w., when administered orally for 14 days, did not indicate any lethal effects. There were no significant differences in total protein, serum glutamate pyruvate transaminase, serum glutamate oxaloacetate transaminase and alkaline phosphatase between normal and Karanjin-treated rats indicating no adverse effect on major organs. During treatment schedule, animals remained as healthy as control animals with normal food and water intake and body weight gain.

Gastroprotective Properties of Karanjin from Karanja (Pongamia pinnata) Seeds; Role as Antioxidant and H+, K+-ATPase Inhibitor

PubMed Central

Vismaya; Belagihally, Srikanta M.; Rajashekhar, Sindhu; Jayaram, Vinay B.; Dharmesh, Shylaja M.; Thirumakudalu, Sindhu Kanya C.

2011-01-01

Plant extracts are the most attractive sources of newer drugs and have been shown to produce promising results for the treatment of gastric ulcers. Karanjin, a furano-flavonoid has been evaluated for anti-ulcerogenic property by employing adult male albino rats. Karanjin (>95% pure) was administered to these rats in two different concentrations, that is, 10 and 20 mg kg−1 b.w. Ulcers were induced in the experimental animals by swim and ethanol stress. Serum, stomach and liver-tissue homogenates were assessed for biochemical parameters. Karanjin inhibited 50 and 74% of ulcers induced by swim stress at 10 and 20 mg kg−1 b.w., respectively. Gastric mucin was protected up to 85% in case of swim stress, whereas only 47% mucin recovery was seen in ethanol stress induced ulcers. H+, K+-ATPase activity, which was increased 2-fold in ulcer conditions, was normalized by Karanjin in both swim/ethanol stress-induced ulcer models. Karanjin could inhibit oxidative stress as evidenced by the normalization of lipid peroxidation and antioxidant enzyme (i.e., catalase, peroxidase and superoxide dismutase) levels. Karanjin at concentrations of 20 mg kg−1 b.w., when administered orally for 14 days, did not indicate any lethal effects. There were no significant differences in total protein, serum glutamate pyruvate transaminase, serum glutamate oxaloacetate transaminase and alkaline phosphatase between normal and Karanjin-treated rats indicating no adverse effect on major organs. During treatment schedule, animals remained as healthy as control animals with normal food and water intake and body weight gain. PMID:21799691

Emergence of anxiety-like behaviours in depressive-like Cpe(fat/fat) mice.

PubMed

Rodriguiz, Ramona M; Wilkins, John J; Creson, Thomas K; Biswas, Reeta; Berezniuk, Iryna; Fricker, Arun D; Fricker, Lloyd D; Wetsel, William C

2013-08-01

Cpe(fat/fat) mice have a point mutation in carboxypeptidase E (Cpe), an exopeptidase that removes C-terminal basic amino acids from intermediates to produce bioactive peptides. The mutation renders the enzyme inactive and unstable. The absence of Cpe activity in these mutants leads to abnormal processing of many peptides, with elevated levels of intermediates and greatly reduced levels of the mature peptides. Cpe(fat/fat) mice develop obesity, diabetes and infertility in adulthood. We examined whether anxiety- and/or depressive-like behaviours are also present. Anxiety-like responses are not evident in young Cpe(fat/fat) mice (∼60 d), but appear in older animals (>90 d). These behaviours are reversed by acute treatment with diazepam or fluoxetine. In contrast, increased immobilities in forced swim and tail suspension are evident in all age groups examined. These behaviours are reversed by acute administration of reboxetine. In comparison acute treatments with fluoxetine or bupropion are ineffective; however, immobility times are normalized with 2 wk treatment. These data demonstrate that Cpe(fat/fat) mice display depressive-like responses aged ∼60 d, whereas anxiety-like behaviours emerge ∼1 month later. In tail suspension, the reboxetine findings show that noradrenergic actions of antidepressants are intact in Cpe(fat/fat) mice. The ability of acute fluoxetine treatment to rescue anxiety-like while leaving depressive-like responses unaffected suggests that serotonin mechanisms underlying these behaviours are different. Since depressive-like responses in the Cpe(fat/fat) mice are rescued by 2 wk, but not acute, treatment with fluoxetine or bupropion, these mice may serve as a useful model that resembles human depression.

Do food and physical activity environments vary between disadvantaged urban and rural areas? Findings from the READI Study.

PubMed

Thornton, Lukar E; Crawford, David A; Cleland, Verity J; Timperio, Anna F; Abbott, Gavin; Ball, Kylie

2012-08-01

The presence or absence of amenities in local neighbourhood environments can either promote or restrict access to opportunities to engage in healthy and/or less healthy behaviours. Rurality is thought to constrain access to facilities and services. This study investigated whether the presence and density of environmental amenities related to physical activity and eating behaviours differs between socioeconomically disadvantaged urban and rural areas in Victoria, Australia. We undertook cross-sectional analysis of environmental data collected in 2007-08 as part of the Resilience for Eating and Activity Despite Inequality (READI) study. These data were sourced and analysed for 40 urban and 40 rural socioeconomically disadvantaged areas. The variables examined were the presence, raw count, count/km2, and count/'000 population of a range of environmental amenities (fast-food restaurants, all supermarkets (also separated by major chain and other supermarkets), greengrocers, playgrounds, gyms/leisure centres, public swimming pools and public open spaces). A greater proportion of urban areas had a fast-food restaurant and gym/leisure centre present while more rural areas contained a supermarket and public swimming pool. All amenities examined (with the exception of swimming pools) were more numerous per km2 in urban areas, however rural areas had a greater number of all supermarkets, other supermarkets, playgrounds, swimming pools and public open space per '000 population. Although opportunities to engage in healthy eating and physical activity exist in many rural areas, a lower density per km2 suggests a greater travel distance may be required to reach these.

Analysis of self-overlap reveals trade-offs in plankton swimming trajectories

PubMed Central

Bianco, Giuseppe; Mariani, Patrizio; Visser, Andre W.; Mazzocchi, Maria Grazia; Pigolotti, Simone

2014-01-01

Movement is a fundamental behaviour of organisms that not only brings about beneficial encounters with resources and mates, but also at the same time exposes the organism to dangerous encounters with predators. The movement patterns adopted by organisms should reflect a balance between these contrasting processes. This trade-off can be hypothesized as being evident in the behaviour of plankton, which inhabit a dilute three-dimensional environment with few refuges or orienting landmarks. We present an analysis of the swimming path geometries based on a volumetric Monte Carlo sampling approach, which is particularly adept at revealing such trade-offs by measuring the self-overlap of the trajectories. Application of this method to experimentally measured trajectories reveals that swimming patterns in copepods are shaped to efficiently explore volumes at small scales, while achieving a large overlap at larger scales. Regularities in the observed trajectories make the transition between these two regimes always sharper than in randomized trajectories or as predicted by random walk theory. Thus, real trajectories present a stronger separation between exploration for food and exposure to predators. The specific scale and features of this transition depend on species, gender and local environmental conditions, pointing at adaptation to state and stage-dependent evolutionary trade-offs. PMID:24789560

Autonomic adaptation after traditional and reverse swimming training periodizations.

PubMed

Clemente-Suárez, Vicente Javier; Fernandes, R J; Arroyo-Toledo, J J; Figueiredo, P; González-Ravé, J M; Vilas-Boas, J P

2015-03-01

The objective of the present study was to analyze the autonomic response of trained swimmers to traditional and reverse training periodization models. Seventeen swimmers were divided in two groups, performing a traditional periodization (TPG) or a reverse periodization (RPG) during a period of 10 weeks. Heart rate variability and 50 m swimming performance were analyzed before and after the training programs. After training, the TPG decreased the values of the high frequency band (HF), the number of differences between adjacent normal R-R intervals longer than 50 ms (NN50) and the percentage of differences between adjacent normal R-R intervals more than 50 ms (pNN50), and the RPG increased the values of HF and square root of the mean of the sum of the squared differences between adjacent normal R-R intervals (RMSSD). None of the groups improved significantly their performance in the 50-m test. The autonomic response of swimmers was different depending on the periodization performed, with the reverse periodization model leading to higher autonomic adaption. Complementary, the data suggests that autonomic adaptations were not critical for the 50-m swimming performance.

Determination of the Threshold of Gravity for the Susceptibility to Kinetosis in Fish - a Centrifuge Experiment in the ZARM Drop-Tower employing gradually reduced Gravity

NASA Astrophysics Data System (ADS)

Anken, R.; Hilbig, R.

In the course of earlier experiments at diminished gravity conditions we have successfully used larval cichlid fish Oreochromis mossambicus as a vertebrate model system in investigating the basic cause of susceptibility to motion sickness kinetosis It was observed that most animals of a given batch reveal kinetoses i e performing looping responses LR or spinning movements SM at high quality microgravity 10-6g ZARM drop-tower whereas comparatively few individuals swim kinetotically at low quality microgravity LQM 0 03-0 05g during parabolic aircraft flights Anken and Hilbig Microgravity Sci Technol 15 52-57 2004 In order to gain further insights into a possible threshold of gravity for inducing motion sickness animals were subjected to drop-tower flights within a centrifuge The levels of gravity applied ranged from 0 009g until 0 3g The lowest level of gravity under which few normally swimming fish were observed ranged around 0 015g Since this is a very low level of gravity the normally swimming fish have to be considered to be either extremely sensitive to any force of gravity in order to use it as a cue for postural control or they use cues other than the residual gravity for maintaining equilibrium Most of the remaining kinetotically swimming animals showed LR whereas few exhibited SM With increasing gravity the ratio of normally swimming and spinning specimens increased accompanied by a decrease in the number of looping larvae Regarding the ratio a shift from LR to SM took place at around 0 02g At 0 3g all animals behaved

Chronic effects of aerobic exercise on gene expression of LOX-1 receptor in the heart of rats fed with high fat diet

PubMed Central

Riahi, Simin; Mohammadi, Mohammad Taghi; Sobhani, Vahid; Soleimany, Mansureh

2015-01-01

Objective(s): Lectin-like low density lipoprotein receptor (LOX-1) has pivot role in vascular complications, which is upregulated in numerous pathological conditions. Since exercise has beneficial effects in prevention of hyperlipidemic complications, present study examined protective effects of aerobic exercise through reduction of LOX-1 expression in heart during dyslipidemia. Materials and Methods: Four groups of rats were used (N=25): Normal, Normal and exercise, High fat and High fat and exercise. High fat diet (HFD) was made by adding 10% animal oil, 2% cholesterol and 0.5% colic acid to standard rodent chow. Exercise protocol consisted of swimming 1 hr/day, and 5 days/week for 8 weeks. Plasma lipids were evaluated at the end of experiment, 48 hr after final session of exercise. At the end, rats were sacrificed and heart was removed for determination of malondialdehyde (MDA) content, and LOX-1 expression. Results: HFD meaningfully changed lipid profile (>50%), but chronic exercise had no significant effects on lipid profile. LOX-1 expression was significantly increased in heart of rats fed with HFD, while swimming exercise considerably reduced gene expression of LOX-1. MDA content was significantly enhanced in rats fed with HFD (4.37±0.6 nmol/mg, P<0.01) compared to normal group (1.56±0.48 nmol/mg), whereas swimming exercise decreased MDA level of heart in rats fed with HFD (2.28±0.32, P<0.01). Conclusion: Findings indicated that swimming exercise is able to diminish heart expression of LOX-1 receptor concomitant reduction of oxidative stress. Since these parameters are involved in generation of dyslipidemic complications, swimming exercise is a good candidate to reduce these complications. PMID:26557970

[Method of studying the effects of pharmacological substances on work capacity of animals in hypobaric hypoxia].

PubMed

Spasov, A A; Kovalev, G V; Tsibanev, A V

1990-08-01

The method of the study of medical agent influence and biological active substances on duration of small laboratory animals swimming has been worked out excluding the air. For this purpose the animals were placed into altitude chamber, filled with water by 1/3 (one-third) of its volume being in antiorthostatic position on dipping into water. It has been established that at the altitude of 4000 (four thousand) meters high the rat swimming duration became shorter in comparison with their work under normal pressure in 2.5-4 times. Bemitil stimulating work in hypobaric hypoxia depresses it sharply. Bemitil stimulating influence on the rat efficiency did not appear with rising. Antioxidant substance ionol increased efficiency in normal conditions and in hypoxia AKS-85 adaptogenic compound increased swimming in the height duration to a greater degree, mildronat substance for efficiency restoration produced actoprotective influence.

The effects of Taraxacum officinale extracts (TOE) supplementation on physical fatigue in mice.

PubMed

Jinchun, Zhang; Jie, Chen

2011-01-01

The study is to investigate the effect of Taraxacum officinale extracts (TOE) supplementation on physical fatigue based on the forced swimming capacity in mice. Forty Kunming male mice were randomly divided into 4 groups, i.e., normal control (NC) and three doses of TOE treated group (High-dose, Middle-dose and Low-dose). Three TOE treated groups were treated by oral TOE with 10, 30 and 100mg/kg b.w respectively for a period of 42 days. The normal control group was given a corresponding volume of sterile distilled water. After 6 weeks, the forced swimming capacity and blood biochemical parameters in mice were measured, and the result showed that TOE had an anti- physical fatigue effect. It enhanced the maximum swimming capacity of mice, effectively delayed the lowering of glucose in the blood, and prevented the increase in lactate and triglyceride concentrations.

Propulsion by a helical flagellum in a capillary tube

NASA Astrophysics Data System (ADS)

Liu, Bin; Breuer, Kenneth S.; Powers, Thomas R.

2014-01-01

We study the microscale propulsion of a rotating helical filament confined by a cylindrical tube, using a boundary-element method for Stokes flow that accounts for helical symmetry. We determine the effect of confinement on swimming speed and power consumption. Except for a small range of tube radii at the tightest confinements, the swimming speed at fixed rotation rate increases monotonically as the confinement becomes tighter. At fixed torque, the swimming speed and power consumption depend only on the geometry of the filament centerline, except at the smallest pitch angles for which the filament thickness plays a role. We find that the "normal" geometry of Escherichia coli flagella is optimized for swimming efficiency, independent of the degree of confinement. The efficiency peaks when the arc length of the helix within a pitch matches the circumference of the cylindrical wall. We also show that a swimming helix in a tube induces a net flow of fluid along the tube.

Exploring a post-traumatic stress disorder paradigm in Flinders sensitive line rats to model treatment-resistant depression I: bio-behavioural validation and response to imipramine.

PubMed

Brand, Sarel Jacobus; Harvey, Brian Herbert

2017-08-01

Co-morbid depression with post-traumatic stress disorder (PTSD) is often treatment resistant. In developing a preclinical model of treatment-resistant depression (TRD), we combined animal models of depression and PTSD to produce an animal with more severe as well as treatment-resistant depressive-like behaviours. Male Flinders sensitive line (FSL) rats, a genetic animal model of depression, were exposed to a stress re-stress model of PTSD [time-dependent sensitisation (TDS)] and compared with stress-naive controls. Seven days after TDS stress, depressive-like and coping behaviours as well as hippocampal and cortical noradrenaline (NA) and 5-hydroxyindoleacetic acid (5HIAA) levels were analysed. Response to sub-chronic imipramine treatment (IMI; 10 mg/kg s.c.×7 days) was subsequently studied. FSL rats demonstrated bio-behavioural characteristics of depression. Exposure to TDS stress in FSL rats correlated negatively with weight gain, while demonstrating reduced swimming behaviour and increased immobility versus unstressed FSL rats. IMI significantly reversed depressive-like (immobility) behaviour and enhanced active coping behaviour (swimming and climbing) in FSL rats. The latter was significantly attenuated in FSL rats exposed to TDS versus unstressed FSL rats. IMI reversed reduced 5HIAA levels in unstressed FSL rats, whereas exposure to TDS negated this effect. Lowered NA levels in FSL rats were sustained after TDS with IMI significantly reversing this in the hippocampus. Combining a gene-X-environment model of depression with a PTSD paradigm produces exaggerated depressive-like symptoms that display an attenuated response to antidepressant treatment. This work confirms combining FSL rats with TDS exposure as a putative animal model of TRD.

Encountering a bait is necessary but insufficient to explain individual variability in vulnerability to angling in two freshwater benthivorous fish in the wild

PubMed Central

Monk, Christopher Thomas; Arlinghaus, Robert

2017-01-01

Fish personality traits, such as swimming activity, or personality related emergent behavioural properties, such as the degree of space use shown by an individual fish, should affect encounter rates between individual fish and fishing gear. Increased encounters should in turn drive vulnerability to capture by passively operated gears. However, empirical evidence documenting a relationship between activity-based behaviours and vulnerability to capture by passive fishing gear in the wild is limited. Using whole-lake acoustic telemetry, we first documented significant repeatabilities over several months in a suite of encounter rate-associated behaviours (swimming distance, activity space size, time on baited feeding sites, switching frequency among baited feeding sites, distance to the lake bottom) in two recreationally important benthivorous cyprinid species, the common carp (Cyprinus carpio) and tench (Tinca tinca). We then experimentally targeted both species using stationary angling on baited feeding sites. Individual fish regularly visited the angling sites, documenting that the fishes encountered the angling baits. When attempting to explain individual variation in vulnerability as a function of repeatable behavioural traits, we found no evidence of a significant relationship among various encounter-based behaviours and vulnerability to angling for both species. There was also no evidence for size selection or for energetically less conditioned fish to be more vulnerable. The data cumulatively suggest that fine-scale behaviours after encountering a bait (e.g., frequency of bait intake) may be ultimately decisive for determining vulnerability to angling in benthivorous fish. Based on our work, fishing-induced selection on encounter-based behaviours in recreational angling for benthivorous fish in the wild appears unlikely. PMID:28301558

Variation in body condition during the post-moult foraging trip of southern elephant seals and its consequences on diving behaviour.

PubMed

Richard, Gaëtan; Vacquié-Garcia, Jade; Jouma'a, Joffrey; Picard, Baptiste; Génin, Alexandre; Arnould, John P Y; Bailleul, Frédéric; Guinet, Christophe

2014-07-15

Mature female southern elephant seals (Mirounga leonina) come ashore only in October to breed and in January to moult, spending the rest of the year foraging at sea. Mature females may lose as much as 50% of their body mass, mostly in lipid stores, during the breeding season due to fasting and lactation. When departing to sea, post-breeding females are negatively buoyant, and the relative change in body condition (i.e. density) during the foraging trip has previously been assessed by monitoring the descent rate during drift dives. However, relatively few drift dives are performed, resulting in low resolution of the temporal reconstruction of body condition change. In this study, six post-breeding females were equipped with time-depth recorders and accelerometers to investigate whether changes in active swimming effort and speed could be used as an alternative method of monitoring density variations throughout the foraging trip. In addition, we assessed the consequences of density change on the swimming efforts of individuals while diving and investigated the effects on dive duration. Both descent swimming speed and ascent swimming effort were found to be strongly correlated to descent rate during drift dives, enabling the fine-scale monitoring of seal density change over the whole trip. Negatively buoyant seals minimized swimming effort during descents, gliding down at slower speeds, and reduced their ascent swimming effort to maintain a nearly constant swimming speed as their buoyancy increased. One per cent of seal density variation over time was found to induce a 20% variation in swimming effort during dives with direct consequences on dive duration. © 2014. Published by The Company of Biologists Ltd.

Elevated carbon dioxide alters the plasma composition and behaviour of a shark

PubMed Central

Green, Leon; Jutfelt, Fredrik

2014-01-01

Increased carbon emissions from fossil fuels are increasing the pCO2 of the ocean surface waters in a process called ocean acidification. Elevated water pCO2 can induce physiological and behavioural effects in teleost fishes, although there appear to be large differences in sensitivity between species. There is currently no information available on the possible responses to future ocean acidification in elasmobranch fishes. We exposed small-spotted catsharks (Scyliorhinus canicula) to either control conditions or a year 2100 scenario of 990 μatm pCO2 for four weeks. We did not detect treatment effects on growth, resting metabolic rate, aerobic scope, skin denticle ultrastructure or skin denticle morphology. However, we found that the elevated pCO2 group buffered internal acidosis via accumulation with an associated increase in Na+, indicating that the blood chemistry remained altered despite the long acclimation period. The elevated pCO2 group also exhibited a shift in their nocturnal swimming pattern from a pattern of many starts and stops to more continuous swimming. Although CO2-exposed teleost fishes can display reduced behavioural asymmetry (lateralization), the CO2-exposed sharks showed increased lateralization. These behavioural effects may suggest that elasmobranch neurophysiology is affected by CO2, as in some teleosts, or that the sharks detect CO2 as a constant stressor, which leads to altered behaviour. The potential direct effects of ocean acidification should henceforth be considered when assessing future anthropogenic effects on sharks. PMID:25232027

Morphological and functional determinants of fluoxetine (Prozac)-induced pulmonary disease in an experimental model.

PubMed

Capelozzi, Marco A; Leick-Maldonado, Edna A; Parra, Edwin R; Martins, Mílton A; Tibério, Iolanda F L C; Capelozzi, Vera L

2007-05-14

Fluoxetine treatment effects were determined by evaluating respiratory mechanics (elastance/resistance) and exhaled nitric oxide, as well as mononuclear and polymorphonuclear cell recruitment into the lungs, in an experimental guinea pig model. Guinea pigs were divided into four groups: Fl (fluoxetine only, n=7); Fl+Sw (fluoxetine and forced swimming, n=7); Ns+Sw (normal saline and forced swimming, n=8); and Ns (normal saline only, n=8). Treated animals received oral fluoxetine (10 mg/(kg day)) for 30 consecutive days. On day 31, all animals were anesthetized and mechanically ventilated so that respiratory system elastance and resistance, as well exhaled nitric oxide, could be determined. The lungs were then excised en bloc for histological and immunohistochemical evaluation. Forced swimming induced bronchodilation in untreated animals and bronchoconstriction in fluoxetine-treated animals. Fluoxetine treatment was also associated with mononuclear infiltration (predominantly into alveolar walls) and neutrophil recruitment. In addition, levels of exhaled nitric oxide, an inflammatory marker, were higher in fluoxetine-treated animals. Swimming-induced stress also amplified mononuclear cell recruitment to the lungs. These results show that, in this experimental model, fluoxetine treatment reproduces the pathology of chronic interstitial pneumonia in humans.

Fine-scale analysis of synchronous breathing in wild Indo-Pacific bottlenose dolphins (Tursiops aduncus).

PubMed

Sakai, Mai; Morisaka, Tadamichi; Kogi, Kazunobu; Hishii, Toru; Kohshima, Shiro

2010-01-01

We quantitatively analysed synchronous breathing for dyads in Indo-Pacific bottlenose dolphins at Mikura Island, Tokyo, Japan. For most cases, we observed dyads swimming in the same direction (97%), in close proximity (i.e., less than 1.5m) and with their body axes parallel as they breathed synchronously. Moreover, the pairs engaged in identical behaviour before and after the synchronous breathing episodes. These results suggest that the dolphins synchronize their movements, and that synchronous breathing is a component of "pair-swimming", an affiliative social behaviour. Same sex pairs of the same age class frequently engaged in synchronous breathing for adults and subadults, as well as mother-calf and escort-calf pairs. The distance between individuals during synchronous breathing for mother-calf pairs was less than for other pairs. The distance observed between individuals for female pairs was less than for male pairs. The time differences between each exhale for each of the two dolphins involved in synchronous breathing episodes for female pairs were smaller than for male pairs, and time differences for adult pairs were smaller than subadult pairs. These results suggest that age and sex class influenced the characteristics of this behaviour. 2009 Elsevier B.V. All rights reserved.

Gravitaxis of Bursaria truncatella: electrophysiological and behavioural analyses of a large ciliate cell.

PubMed

Krause, Martin; Bräucker, Richard

2009-05-01

Bursaria truncatella is a giant ciliate. Its volume of 3 x 10(7)microm(3) and a sedimentation rate of 923microm s(-1) would induce the cell to rapidly sink to the bottom of a pond unless compensating mechanisms exist. The upward swimming behaviour of a cell population (negative gravitaxis) may be either a result of reorientations of the cells (graviorientation) and/or direction-dependent changes in propulsion rate (gravikinesis). The special statocyst hypothesis assumes a stimulation of mechanosensitive ion channels by forces of the cytoplasmic mass acting on the lower membrane. Here, we present basic electrophysiological data on B. truncatella. Investigation of the mechanosensitivity reveals a polar distribution of depolarising and hyperpolarising mechanosensitive channels at least on the dorsal membrane of the cell. Analysis of swimming behaviour demonstrates that Bursaria orients against the gravity vector (r(Oc)=0.34) and performs a negative gravikinesis (-633microm s(-1)) compensating the sedimentation rate by 70%. Under hypergravity conditions gravitaxis in Bursaria is enhanced. Microgravity experiments indicate an incomplete relaxation of graviresponses during 4s of weightlessness. Experimental data are in accordance with the special statocyst hypothesis of graviperception, as was demonstrated in other ciliates.

Electric Field Detection in Sawfish and Shovelnose Rays

PubMed Central

Wueringer, Barbara E.; Jnr, Lyle Squire; Kajiura, Stephen M.; Tibbetts, Ian R.; Hart, Nathan S.; Collin, Shaun P.

2012-01-01

In the aquatic environment, living organisms emit weak dipole electric fields, which spread in the surrounding water. Elasmobranchs detect these dipole electric fields with their highly sensitive electroreceptors, the ampullae of Lorenzini. Freshwater sawfish, Pristis microdon, and two species of shovelnose rays, Glaucostegus typus and Aptychotrema rostrata were tested for their reactions towards weak artificial electric dipole fields. The comparison of sawfishes and shovelnose rays sheds light on the evolution and function of the elongated rostrum (‘saw’) of sawfish, as both groups evolved from a shovelnose ray-like ancestor. Electric stimuli were presented both on the substrate (to mimic benthic prey) and suspended in the water column (to mimic free-swimming prey). Analysis of around 480 behavioural sequences shows that all three species are highly sensitive towards weak electric dipole fields, and initiate behavioural responses at median field strengths between 5.15 and 79.6 nVcm−1. The response behaviours used by sawfish and shovelnose rays depended on the location of the dipoles. The elongation of the sawfish’s rostrum clearly expanded their electroreceptive search area into the water column and enables them to target free-swimming prey. PMID:22848543

Behaviour and Locomotor Activity of a Migratory Catostomid during Fishway Passage

PubMed Central

Silva, Ana T.; Hatry, Charles; Thiem, Jason D.; Gutowsky, Lee F. G.; Hatin, Daniel; Zhu, David Z.; W. Dawson, Jeffery; Katopodis, Christos; J. Cooke, Steven

2015-01-01

Fishways have been developed to restore longitudinal connectivity in rivers. Despite their potential for aiding fish passage, fishways may represent a source of significant energetic expenditure for fish as they are highly turbulent environments. Nonetheless, our understanding of the physiological mechanisms underpinning fishway passage of fish is still limited. We examined swimming behaviour and activity of silver redhorse (Moxostoma anisurum) during its upriver spawning migration in a vertical slot fishway. We used an accelerometer-derived instantaneous activity metric (overall dynamic body acceleration) to estimate location-specific swimming activity. Silver redhorse demonstrated progressive increases in activity during upstream fishway passage. Moreover, location-specific passage duration decreased with an increasing number of passage attempts. Turning basins and the most upstream basin were found to delay fish passage. No relationship was found between basin-specific passage duration and activity and the respective values from previous basins. The results demonstrate that successful fishway passage requires periods of high activity. The resultant energetic expenditure may affect fitness, foraging behaviour and increase susceptibility to predation, compromising population sustainability. This study highlights the need to understand the physiological mechanisms underpinning fishway passage to improve future designs and interpretation of biological evaluations. PMID:25853245

Unsteady bio-fluid dynamics in flying and swimming

NASA Astrophysics Data System (ADS)

Liu, Hao; Kolomenskiy, Dmitry; Nakata, Toshiyuki; Li, Gen

2017-08-01

Flying and swimming in nature present sophisticated and exciting ventures in biomimetics, which seeks sustainable solutions and solves practical problems by emulating nature's time-tested patterns, functions, and strategies. Bio-fluids in insect and bird flight, as well as in fish swimming are highly dynamic and unsteady; however, they have been studied mostly with a focus on the phenomena associated with a body or wings moving in a steady flow. Characterized by unsteady wing flapping and body undulation, fluid-structure interactions, flexible wings and bodies, turbulent environments, and complex maneuver, bio-fluid dynamics normally have challenges associated with low Reynolds number regime and high unsteadiness in modeling and analysis of flow physics. In this article, we review and highlight recent advances in unsteady bio-fluid dynamics in terms of leading-edge vortices, passive mechanisms in flexible wings and hinges, flapping flight in unsteady environments, and micro-structured aerodynamics in flapping flight, as well as undulatory swimming, flapping-fin hydrodynamics, body-fin interaction, C-start and maneuvering, swimming in turbulence, collective swimming, and micro-structured hydrodynamics in swimming. We further give a perspective outlook on future challenges and tasks of several key issues of the field.

Individual-Environment Interactions in Swimming: The Smallest Unit for Analysing the Emergence of Coordination Dynamics in Performance?

PubMed

Guignard, Brice; Rouard, Annie; Chollet, Didier; Hart, John; Davids, Keith; Seifert, Ludovic

2017-08-01

Displacement in competitive swimming is highly dependent on fluid characteristics, since athletes use these properties to propel themselves. It is essential for sport scientists and practitioners to clearly identify the interactions that emerge between each individual swimmer and properties of an aquatic environment. Traditionally, the two protagonists in these interactions have been studied separately. Determining the impact of each swimmer's movements on fluid flow, and vice versa, is a major challenge. Classic biomechanical research approaches have focused on swimmers' actions, decomposing stroke characteristics for analysis, without exploring perturbations to fluid flows. Conversely, fluid mechanics research has sought to record fluid behaviours, isolated from the constraints of competitive swimming environments (e.g. analyses in two-dimensions, fluid flows passively studied on mannequins or robot effectors). With improvements in technology, however, recent investigations have focused on the emergent circular couplings between swimmers' movements and fluid dynamics. Here, we provide insights into concepts and tools that can explain these on-going dynamic interactions in competitive swimming within the theoretical framework of ecological dynamics.

Vortex arrays and ciliary tangles underlie the feeding-swimming trade-off in starfish larvae

NASA Astrophysics Data System (ADS)

Gilpin, William; Prakash, Vivek N.; Prakash, Manu

2017-04-01

Many marine invertebrates have larval stages covered in linear arrays of beating cilia, which propel the animal while simultaneously entraining planktonic prey. These bands are strongly conserved across taxa spanning four major superphyla, and they are responsible for the unusual morphologies of many invertebrate larvae. However, few studies have investigated their underlying hydrodynamics. Here, we study the ciliary bands of starfish larvae, and discover a beautiful pattern of slowly evolving vortices that surrounds the swimming animals. Closer inspection of the bands reveals unusual ciliary `tangles' analogous to topological defects that break up and re-form as the animal adjusts its swimming stroke. Quantitative experiments and modelling demonstrate that these vortices create a physical trade-off between feeding and swimming in heterogeneous environments, which manifests as distinct flow patterns or `eigenstrokes' representing each behaviour--potentially implicating neuronal control of cilia. This quantitative interplay between larval form and hydrodynamic function may generalize to other invertebrates with ciliary bands, and illustrates the potential effects of active boundary conditions in other biological and synthetic systems.

Swim bladder function and buoyancy control in pink snapper (Pagrus auratus) and mulloway (Argyrosomus japonicus).

PubMed

Stewart, John; Hughes, Julian M

2014-04-01

Physoclist fish are able to regulate their buoyancy by secreting gas into their hydrostatic organ, the swim bladder, as they descend through the water column and by resorbing gas from their swim bladder as they ascend. Physoclists are restricted in their vertical movements due to increases in swim bladder gas volume that occur as a result of a reduction in hydrostatic pressure, causing fish to become positively buoyant and risking swim bladder rupture. Buoyancy control, rates of swim bladder gas exchange and restrictions to vertical movements are little understood in marine teleosts. We used custom-built hyperbaric chambers and laboratory experiments to examine these aspects of physiology for two important fishing target species in southern Australia, pink snapper (Pagrus auratus) and mulloway (Argyrosomus japonicus). The swim bladders of pink snapper and mulloway averaged 4.2 and 4.9 % of their total body volumes, respectively. The density of pink snapper was not significantly different to the density of seawater (1.026 g/ml), whereas mulloway were significantly denser than seawater. Pink snapper secreted gas into their swim bladders at a rate of 0.027 ± 0.005 ml/kg/min (mean ± SE), almost 4 times faster than mulloway (0.007 ± 0.001 ml/kg/min). Rates of swim bladder gas resorption were 11 and 6 times faster than the rates of gas secretion for pink snapper and mulloway, respectively. Pink snapper resorbed swim bladder gas at a rate of 0.309 ± 0.069 ml/kg/min, 7 times faster than mulloway (0.044 ± 0.009 ml/kg/min). Rates of gas exchange were not affected by water pressure or water temperature over the ranges examined in either species. Pink snapper were able to acclimate to changes in hydrostatic pressure reasonably quickly when compared to other marine teleosts, taking approximately 27 h to refill their swim bladders from empty. Mulloway were able to acclimate at a much slower rate, taking approximately 99 h to refill their swim bladders. We estimated that the swim bladders of pink snapper and mulloway ruptured after decreases in ~2.5 and 2.75 times the hydrostatic pressure to which the fish were acclimated, respectively. Differences in buoyancy, gas exchange rates, limitations to vertical movements and acclimation times between the two species are discussed in terms of their differing behaviour and ecology.

Passage and behaviour of cultured Lake Sturgeon in a prototype side-baffle fish ladder: I. Ladder hydraulics and fish ascent

USGS Publications Warehouse

Kynard, B.; Pugh, D.; Parker, T.

2011-01-01

Research and development of a fish ladder for sturgeons requires understanding ladder hydraulics and sturgeon behaviour in the ladder to insure the ladder is safe and provides effective passage. After years of research and development, we designed and constructed a full-scale prototype side-baffle ladder inside a spiral flume (38.3m long??1m wide??1m high) on a 6% (1:16.5) slope with a 1.92-m rise in elevation (bottom to top) to test use by sturgeons. Twenty-eight triangular side baffles, each extending part way across the flume, alternated from inside wall to outside wall down the ladder creating two major flow habitats: a continuous, sinusoidal flow down the ladder through the vertical openings of side-baffles and an eddy below each side baffle. Ascent and behaviour was observed on 22 cultured Lake Sturgeon=LS (Acipenser fulvescens) repeatedly tested in groups as juveniles (as small as 105.1cm TL, mean) or as adults (mean TL, 118cm) during four periods (fall 2002 and 2003; spring 2003 and 2007). Percent of juveniles entering the ladder that ascended to the top was greater in spring (72.7%) than in fall (40.9-45.5%) and 90.9% of 11 adults, which ascended as juveniles, ascended to the top. Six LS (27.3%) never swam to the top and seven (31.8%) swam to the top in all tests, indicating great variability among individuals for ascent drive. Some LS swam directly to the top in <1min, but most rested in an eddy during ascent. Juveniles swimming through outside wall baffle slots (mean velocity, 1.2ms-1) swam at 1.8-2.2body lengthss-1 and 3.2-3.3tail beatss-1, either at or approaching prolonged swimming speed. The side-baffle ladder was stream-like and provided key factors for a sturgeon ladder: a continuous flow and no full cross-channel walls, abundant eddies for resting, an acceptable water depth, and a water velocity fish could ascend swimming 2bls-1. A side-baffle ladder passes LS and other moderate-swimming fishes. ?? 2011 Blackwell Verlag, Berlin.

Jump if you can't take the heat: three escape gaits of Paramecium swimming

NASA Astrophysics Data System (ADS)

Baroud, Charles N.; Hamel, Amandine; Fisch, Cathy; Combettes, Laurent; Dupuys-Williams, Pascale

2010-11-01

Paramecium is able to swim at velocities reaching several times its body size per second, by beating its thousands of cilia in an organized fashion. Here we show that Paramecium has in fact three distinct swimming gaits to escape from an aggression in the form of localized heating, depending on the magnitude of the aggression: For a weak agression, normal swimming is sufficient and produces a steady swimming velocity through cilia beating. As the heating amplitude is increased, a higher acceleration and faster swimming are achieved through synchronized beating of the cilia, which later give way to the usual metachronal waves. The synchronized beating yields high initial accelerations but requires the cell to coast through the synchrnized recovery. Finally, escape from a life-threatening agression is achieved by a "jumping" gait which does not rely on the cilia but is achieved from the explosive release of a rod-like organelles in the direction of the hot spot. Measurements through high-speed video explain the role of these rods in defending Paramecium. They also show that the zero-Reynolds number assumption is unverified in most cases.

Accelerometer-derived activity correlates with volitional swimming speed in lake sturgeon (Acipenser fulvescens)

USGS Publications Warehouse

Thiem, J.D.; Dawson, J.W.; Gleiss, A.C.; Martins, E.G.; Haro, Alexander J.; Castro-Santos, Theodore R.; Danylchuk, A.J.; Wilson, R.P.; Cooke, S.J.

2015-01-01

Quantifying fine-scale locomotor behaviours associated with different activities is challenging for free-swimming fish.Biologging and biotelemetry tools can help address this problem. An open channel flume was used to generate volitionalswimming speed (Us) estimates of cultured lake sturgeon (Acipenser fulvescens Rafinesque, 1817) and these were paired withsimultaneously recorded accelerometer-derived metrics of activity obtained from three types of data-storage tags. This studyexamined whether a predictive relationship could be established between four different activity metrics (tail-beat frequency(TBF), tail-beat acceleration amplitude (TBAA), overall dynamic body acceleration (ODBA), and vectorial dynamic body acceleration(VeDBA)) and the swimming speed of A. fulvescens. Volitional Us of sturgeon ranged from 0.48 to 2.70 m·s−1 (0.51–3.18 bodylengths (BL) · s−1). Swimming speed increased linearly with all accelerometer-derived metrics, and when all tag types werecombined, Us increased 0.46 BL·s−1 for every 1 Hz increase in TBF, and 0.94, 0.61, and 0.94 BL·s−1 for every 1g increase in TBAA,ODBA, and VeDBA, respectively. Predictive relationships varied among tag types and tag-specific parameter estimates of Us arepresented for all metrics. This use of acceleration data-storage tags demonstrated their applicability for the field quantificationof sturgeon swimming speed.

Swimming in air-breathing fishes.

PubMed

Lefevre, S; Domenici, P; McKenzie, D J

2014-03-01

Fishes with bimodal respiration differ in the extent of their reliance on air breathing to support aerobic metabolism, which is reflected in their lifestyles and ecologies. Many freshwater species undertake seasonal and reproductive migrations that presumably involve sustained aerobic exercise. In the six species studied to date, aerobic exercise in swim flumes stimulated air-breathing behaviour, and there is evidence that surfacing frequency and oxygen uptake from air show an exponential increase with increasing swimming speed. In some species, this was associated with an increase in the proportion of aerobic metabolism met by aerial respiration, while in others the proportion remained relatively constant. The ecological significance of anaerobic swimming activities, such as sprinting and fast-start manoeuvres during predator-prey interactions, has been little studied in air-breathing fishes. Some species practise air breathing during recovery itself, while others prefer to increase aquatic respiration, possibly to promote branchial ion exchange to restore acid-base balance, and to remain quiescent and avoid being visible to predators. Overall, the diversity of air-breathing fishes is reflected in their swimming physiology as well, and further research is needed to increase the understanding of the differences and the mechanisms through which air breathing is controlled and used during exercise. © 2014 The Fisheries Society of the British Isles.

Depression-related behavioural and neuroendocrine changes in the Spontaneously Diabetic Torii (SDT) fatty rat, an animal model of Type 2 Diabetes Mellitus.

PubMed

Sakimura, Katsuya; Maekawa, Tatsuya; Sasagawa, Kazuo; Ishii, Yukihito; Kume, Shin-Ichi; Ohta, Takeshi

2018-05-14

Depression is one of the most common psychiatric diseases and is commonly comorbid with type 1 or 2 diabetes mellitus (DM). However, the pathophysiology underlying the depressive state in DM remains poorly understood. Animal models are useful tools to investigate the association between depression and DM. In the present study we investigated whether the Spontaneously Diabetic Torii (SDT) fatty rat, a novel animal model of type 2 DM, shows depression-related features. We assessed depression-like behaviour, hyperactivation of the hypothalamic-pituitary-adrenal (HPA) axis, and neurotransmitter levels in the brain. Behaviour was evaluated using a forced swimming test, and the HPA axis was evaluated with changes in plasma corticosterone levels after a swimming stress exposure or dexamethasone challenge. In addition, serotonin (5-hydroxytryptamine; 5-HT), noradrenaline, glutamate and γ-aminobutyric acid (GABA) concentrations in the frontal cortex, hippocampus and brain stem were measured. In the forced swimming test, SDT fatty rats exhibited increased duration of immobility compared with control Sprague-Dawley (SD) rats. Moreover, basal corticosterone levels were significantly elevated in SDT fatty compared with control SD rats. However, there were no stress-induced increases or changes in dexamethasone-induced suppression of corticosterone in SDT fatty compared with control SD rats. Furthermore, there were significant changes in 5-HT concentrations in the prefrontal cortex, and in GABA and glutamate concentrations in the hippocampus in SDT fatty compared with controls. The results of the present study suggest that the SDT fatty rat may be an appropriate model for diabetes with comorbid depression associated with neurotransmitter impairments and aberrant basal HPA hyperactivity. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Optofluidic technology for monitoring rotifer Brachionus calyciflorus responses to regular light pulses

NASA Astrophysics Data System (ADS)

Cartlidge, Rhys; Campana, Olivia; Nugegoda, Dayanthi; Wlodkowic, Donald

2016-12-01

Behavioural alterations can occur as a result of a toxicant exposure at concentrations significantly lower than lethal effects that are commonly measured in acute toxicity testing. The use of alternating light and dark photoperiods to test phototactic responses of aquatic invertebrates in the presence of environmental contaminants provides an attractive analytical avenue. Quantification of phototactic responses represents a sublethal endpoint that can be employed as an early warning signal. Despite the benefits associated with the assessment of these endpoints, there is currently a lack of automated and miniaturized bioanalytical technologies to implement the development of toxicity testing with small aquatic species. In this study we present a proof-of-concept microfluidic Lab-on-a-Chip (LOC) platform for the assessment of rotifer swimming behavior in the presence of the toxicant copper sulfate. The device was designed to assess impact of toxicants at sub-lethal concentrations on freshwater crustacean Brachionus calyciflorus, testing behavioral endpoints such as animal swimming distance, speed and acceleration. The LOC device presented in this work enabled straightforward caging of microscopic crustaceans as well as non-invasive analysis of rapidly swimming animals in a focal plane of a video-microscopy system. The chip-based technology was fabricated using a new photolithography method that enabled formation of thick photoresist layers with minimal distortion. Photoresist molds were then employed for replica molding of LOC devices with poly(dimethylsiloxane) (PDMS) elastomer. The complete bioanalytical system consisted of: (i) microfluidic PDMS chip-based device; (ii) peristaltic microperfusion pumping manifold; (iii) miniaturized CMOS camera for video data acquisition; and (iv) video analysis software algorithms for quantification of changes in swimming behaviour of B. calyciflorus in response to reference toxicants.

Collective hydrodynamics of swimming micro-organisms

NASA Astrophysics Data System (ADS)

Pedley, Timothy

2007-11-01

Since the work of Kessler in the 1980s, and before, there has been considerable interest among fluid dynamicists and physicists in the collective behaviour of swimming micro-organisms in suspension. Since all such cells are denser than the water in which they swim, bioconvection patterns result from upswimming of cells in a chamber of finite depth and from gyrotaxis of bottom-heavy cells in a uniform fluid. Bioconvection has been analysed for dilute suspensions; the theory will be briefly re-examined with emphasis on the additional stress induced by the cells' swimming motions (each cell can be regarded as a force-dipole, or stresslet), because of the new instabilities revealed by Simha & Ramaswamy (2002) for uniform suspensions in the absence of gravity. Even more fascinating coherent structures arise in concentrated suspensions, of bacteria for example, in which cell-cell interactions cannot be ignored. The hypothesis is that such structures emerge from purely hydrodynamic interactions between cells. A variety of models have been developed, which are outlined briefly, but particular attention will be paid to our own model in which cells are represented as inertia-free ``spherical squirmers,'' whose behaviour is dominated by near-field hydrodynamics. Pairwise interactions are computed precisely, and Stokesian dynamics in a periodic box is used to simulate an infinite suspension. Trajectories are computed deterministically, but the long-time spreading of a 3D suspension, from random initial conditions, is diffusive; scaling arguments can be used to estimate the effective diffusivity. However, in 2D there is a strong tendency towards aggregation into clumps or bands. [Recent work reported here has been performed in collaboration with T Ishikawa and J T Locsei.

Evaluation of swimming performance for fish passage of longnose dace Rhinichthys cataractae using an experimental flume.

PubMed

Dockery, D R; McMahon, T E; Kappenman, K M; Blank, M

2017-03-01

The swimming performance of longnose dace Rhinichthys cataractae, the most widely distributed minnow (Cyprinidae) in North America, was assessed in relation to potential passage barriers. The study estimated passage success, maximum ascent distances and maximum sprint speed in an open-channel flume over a range of water velocities and temperatures (10·7, 15·3 and 19·3° C). Rhinichthys cataractae had high passage success (95%) in a 9·2 m flume section at mean test velocities of 39 and 64 cm s -1 , but success rate dropped to 66% at 78 cm s -1 . Only 20% of fish were able to ascend a 2·7 m section with a mean velocity of 122 cm s -1 . Rhinichthys cataractae actively selected low-velocity pathways located along the bottom and corners of the flume at all test velocities and adopted position-holding behaviour at higher water velocities. Mean volitional sprint speed was 174 cm s -1 when fish volitionally sprinted in areas of high water velocities. Swimming performance generally increased with water temperature and fish length. Based on these results, fishways with mean velocities <64 cm s -1 should allow passage of most R. cataractae. Water velocities >100 cm s -1 within structures should be limited to short distance (<1 m) and structures with velocities ≥158 cm s -1 would probably represent movement barriers. Study results highlighted the advantages of evaluating a multitude of swimming performance metrics in an open-channel flume, which can simulate the hydraulic features of fishways and allow for behavioural observations that can facilitate the design of effective passage structures. © 2016 The Fisheries Society of the British Isles.

Human spermatozoa selected by Percoll gradient or swim-up are equally capable of binding to the human zona pellucida and undergoing the acrosome reaction.

PubMed

Morales, P; Vantman, D; Barros, C; Vigil, P

1991-03-01

Several techniques have been used for selecting motile spermatozoa including Percoll and albumin gradients, swim-up, and glass wool filtration. A high yield of motile spermatozoa as well as an enhancement of motility are the most desirable features of a practical method. An equally important consideration is whether or not these techniques select functionally normal spermatozoa. In this study we have compared two methods for separation of motile cells, swim-up and Percoll gradient. Normal semen samples from 12 different men were used in this study. Each sample was simultaneously processed by swim-up and Percoll gradient using modified Tyrode's medium. After the sperm concentration was adjusted to 1 x 10(7) spermatozoa/ml, the suspensions were incubated at 37 degrees C, 5% CO2 in air. In each suspension the percentage of sperm recovery, percentage of motile spermatozoa, percentage of acrosome reacted spermatozoa (either spontaneously or stimulated with human follicular fluid), percentage of zona-free hamster oocytes penetrated, and number of spermatozoa bound to the human zona pellucida were determined. The results obtained indicated that the percentage of sperm recovery was higher with the Percoll gradient than with the swim-up procedure (P less than 0.001). However, no significant differences were found between these two sperm populations in the percentage of motile cells, in the percentage of acrosome reacted spermatozoa, and in the percentage of zona-free hamster oocytes penetrated. In addition, the number of spermatozoa bound per zona pellucida was similar for spermatozoa selected by Percoll or swim-up. We conclude that there were no functional differences between the spermatozoa selected by either method.

11-β hydroxysteroid type 1 knockout mice display an antidepressant-like phenotype in the forced swim test.

PubMed

Slattery, David A; Uzunov, Doncho P; Cryan, John F

2016-02-01

11β-dehydroxysteroid dehydrogenase (HSD) types 1 and 2, enzymes are involved in the activation and inactivation of glucocorticoids in vivo, respectively. Indirect evidence implicates two enzymes in the aetiology of depression but no study has directly assessed the potential role of 11 β-HSD1 in animal tests. We assessed 11 β-HSD1 knockout mice in the forced swim test (FST), tail suspension test (TST) and for locomotor activity. Genetic ablation of the 11β-HSD1 gene results in an antidepressant-like phenotype in the FST; the most widely utilised animal test of antidepressant activity, but not in the related TST. This may be related to the different biological substrates underlying these tests. The decreased FST immobility was not due to alterations in general activity. Taken together these results suggest that 11β-HSD1 may play an important role in depression-related behaviours and further studies are necessary to fully characterise its role in such behaviour.

Physiological, energetic and behavioural correlates of successful fishway passage of adult sockeye salmon Oncorhynchus nerka in the Seton River, British Columbia.

PubMed

Pon, L B; Hinch, S G; Cooke, S J; Patterson, D A; Farrell, A P

2009-04-01

Electromyogram (EMG) radio telemetry was used in conjunction with physiological biopsy to relate prior physiological condition and subsequent swimming energetics and behaviours to passage success of 13 wild adult sockeye salmon Oncorhynchus nerka at a vertical-slot fishway on the Seton River, British Columbia. At the time of capture, plasma lactate, glucose and cortisol levels indicated that fish were not exhibiting unusually high levels of physiological stress. Very few differences existed between successful and unsuccessful fish in body size, initial plasma physiology and energy state and mean swim speed and energy use during passage. Generally, fish did not employ burst swimming during successful or failed attempts at passage, indicating that failure was probably not related to metabolic acidosis. Plasma Na(+) concentration was significantly lower in unsuccessful fish (P < 0.05), which is suggestive of a depressed ionic state or a possible stress component, although values in all fish were within an expected range for migrant adult O. nerka. Nevertheless, six of 13 fish failed to reascend the fishway and remained in the tailrace of the dam for more than a day on average before moving downstream and away from the dam. During this time, fish were observed actively seeking a means of passage, suggesting that there may have been other, undetermined causes of passage failure.

Microcrustacea in flowing water - experimental-analysis of washout times and a field-test

USGS Publications Warehouse

Richardson, W.B.

1992-01-01

1. Flow-chamber experiments were conducted to evaluate the ability of microcrustacea to maintain position in moving water. These results were compared to distributions of zooplankton and water velocity in a stream pool to determine the relationship of animal density to water movement and swimming ability.^2. Cladocerans exhibited negative rheotaxis (directed behaviour against a current) but poor ability to maintain position at velocities >2.5 Cm s-1. Daphnia and scapholeberis were better at avoiding washout than moina and diaphanosoma. At velocities 2.5 Cm s-1, scapholeberis >3.2 Cm s-1 and eucyclops >7.75 Cm s-1. Washout time of daphnia and scapholeberis was positively related to body size and negatively to water velocity and possession of eggs. Washout was inversely related to water velocity for eucyclops.^4. Highest densities of microcrustacea in a stream pool were found in non-flowing or downstream zones of the pool. Benthic (hydracarina, harpacticoid copepods, ostracods) and fast-swimming (cyclopoids) forms were most common in flowing zones. Facultatively benthic cladocera were abundant in regions of no flow. Rotifers and immature copepods were most abundant at the downstream end of the pool.^5. Behavioural mechanisms for remaining in stream pools at times of high flow appear to include: (i) flow avoidance (simocephalus, chydorus, scapholeberis and cyclopoids), (ii) use of benthic habitat (ostracods, harpacticoids, hydracarina), (iii) strong swimming ability (cyclopoids).

Behavioral effects of environmental enrichment on harbor seals (Phoca vitulina concolor) and gray seals (Hafichoerus grypus)

USGS Publications Warehouse

Hunter, S.A.; Bay, M.S.; Martin, M.L.; Hatfield, J.S.

2002-01-01

Zoos and aquariums have been incorporating environmental enrichment into their animal care programs for the past 30 years to increase mental stimulation and promote natural behaviors. However, most attempts to document the effects of enrichment on animal behavior have focused on terrestrial mammals. Staff at the National Aquarium in Baltimore conducted an investigation of the behavioral effects of enrichment on the seven harbor seals and two gray seals housed in the aquarium's outdoor seal exhibit. We expected that enrichment would change the amount of time the animals spent engaged in specific behaviors. The behaviors recorded were: resting in water, resting hauled out, maintenance, breeding display, breeding behavior, aggression, pattern swimming, random swimming, exploration, and out of sight. Activity levels (random swimming and exploration) were expected to increase, while stereotypic behaviors (pattern swimming) were expected to decrease. The frequency and duration of behaviors were documented for 90 hr in both the control phase (without enrichment) and the experimental phase (with enrichment). Statistically significant differences (P<0.05) in the time spent in pattern swimming, random swimming, exploration, and out of sight were observed between the two phases. With enrichment, pattern swimming and out of sight decreased, while random swimming and exploration behavior increased. These findings demonstrate that enrichment can promote behaviors (random swimming and exploration) that are likely to be normal for phocids in the wild, and that may contribute to the behavioral complexity of these seals in captivity.

Behavioral effects of environmental enrichment on harbor seals (Phoca vitulina concolor) and gray seals (Halichoerus grypus)

USGS Publications Warehouse

Hunter, S.A.; Bay, M.S.; Martin, M.L.; Hatfield, J.S.

2002-01-01

Zoos and aquariums have been incorporating environmental enrichment into their animal care programs for the past 30 years to increase mental stimulation and promote natural behaviors. However, most attempts to document the effects of enrichment on animal behavior have focused on terrestrial mammals. Staff at the National Aquarium in Baltimore conducted an investigation of the behavioral effects of enrichment on the seven harbor seals and two gray seals housed in the aquarium's outdoor seal exhibit. We expected that enrichment would change the amount of time the animals spent engaged in specific behaviors. The behaviors recorded were: resting in water, resting hauled out, maintenance, breeding display, breeding behavior, aggression, pattern swimming, random swimming, exploration, and out of sight. Activity levels (random swimming and exploration) were expected to increase, while stereotypic behaviors (pattern swimming) were expected to decrease. The frequency and duration of behaviors were documented for 90 hr in both the control phase (without enrichment) and the experimental phase (with enrichment). Statistically significant differences (P < 0.05) in the time spent in pattern swimming, random swimming, exploration, and out of sight were observed between the two phases. With enrichment, pattern swimming and out of sight decreased, while random swimming and exploration behavior increased. These findings demonstrate that enrichment can promote behaviors (random swimming and exploration) that are likely to be normal for phocids in the wild, and that may contribute to the behavioral complexity of these seals in captivity. ?? 2002 Wiley-Liss, Inc.

Interaction of reelin and stress on immobility in the forced swim test but not dopamine-mediated locomotor hyperactivity or prepulse inhibition disruption: Relevance to psychotic and mood disorders.

PubMed

Notaras, Michael J; Vivian, Billie; Wilson, Carey; van den Buuse, Maarten

2017-07-13

Psychotic disorders, such as schizophrenia, as well as some mood disorders, such as bipolar disorder, have been suggested to share common biological risk factors. One such factor is reelin, a large extracellular matrix glycoprotein that regulates neuronal migration during development as well as numerous activity-dependent processes in the adult brain. The current study sought to evaluate whether a history of stress exposure interacts with endogenous reelin levels to modify behavioural endophenotypes of relevance to psychotic and mood disorders. Heterozygous Reeler Mice (HRM) and wildtype (WT) controls were treated with 50mg/L of corticosterone (CORT) in their drinking water from 6 to 9weeks of age, before undergoing behavioural testing in adulthood. We assessed methamphetamine-induced locomotor hyperactivity, prepulse inhibition (PPI) of acoustic startle, short-term spatial memory in the Y-maze, and depression-like behaviour in the Forced-Swim Test (FST). HRM genotype or CORT treatment did not affect methamphetamine-induced locomotor hyperactivity, a model of psychosis-like behaviour. At baseline, HRM showed decreased PPI at the commonly used 100msec interstimulus interval (ISI), but not at the 30msec ISI or following challenge with apomorphine. A history of CORT exposure potentiated immobility in the FST amongst HRM, but not WT mice. In the Y-maze, chronic CORT treatment decreased novel arm preference amongst HRM, reflecting reduced short-term spatial memory. These data confirm a significant role of endogenous reelin levels on stress-related behaviour, supporting a possible role in both bipolar disorder and schizophrenia. However, an interaction of reelin deficiency with dopaminergic regulation of psychosis-like behaviour remains unclear. Copyright © 2017 Elsevier B.V. All rights reserved.

Effect of 'chronic' versus 'acute' ketamine administration and its 'withdrawal' effect on behavioural alterations in mice: implications for experimental psychosis.

PubMed

Chatterjee, Manavi; Ganguly, Surajit; Srivastava, Mukesh; Palit, Gautam

2011-01-01

Lack of appropriate animal models simulating core behavioural aspects of human psychosis is a major limitation in schizophrenia research. The use of drugs, that is believed to act through N-methyl d-aspartate receptor, has been demonstrated to mimic relatively broader range of behavioural symptoms in putative animal models. Our goal in this study has been to further evaluate one such drug, ketamine in mice and characterize some selective behavioural phenotypes associated with the drug dosage, treatment period and withdrawal effects to extend the understanding of this model. Our results indicate that acute treatment of ketamine (100 mg/kg, i.p.) induced hyperlocomotory response and reduced the 'transfer-latency time' in passive avoidance test but did not have any effect in the forced swim test (negative symptoms). In contrast, chronic administration of ketamine not only produced significant 'hyperactivity' response but also enhanced the immobility period in animals during the forced swim test and reduced the latency period in the passive avoidance test. Further, these behavioural alterations persisted at least for 10 days after the withdrawal of ketamine treatment. These observations were substantiated by using standard typical and atypical antipsychotic drugs, haloperidol (0.25 mg/kg, i.p.), clozapine (10 mg/kg, i.p.) and risperidone (0.025 mg/kg, i.p.). Therefore, the present study suggests that the chronic treatment with ketamine has the potential of exhibiting changes in broader range of behavioural domains than the acute treatment. Hence, animals chronically treated with ketamine might serve as a useful tool to study the underlying pathogenic mechanisms associated with some symptoms in schizophrenia and other psychiatric disorders. Copyright © 2010 Elsevier B.V. All rights reserved.

Lack of vasopressin does not prevent the behavioural and endocrine changes induced by chronic unpredictable stress.

PubMed

Varga, János; Domokos, Agnes; Barna, István; Jankord, Ryan; Bagdy, György; Zelena, Dóra

2011-01-15

Vasopressin (VP) plays an important role in hypothalamo-pituitary-adrenal (HPA) axis regulation and in stress-related disorders. Our previous studies confirmed the role of VP in acute situations, where VP-deficient Brattleboro rats had less depression-like behaviour compared to animals that express VP. In this study, we test the hypothesis that VP-deficient rats are more resistant to the development of chronic HPA axis hyperactivity and depression-like symptoms after chronic unpredictable stress (CUS). Male VP-deficient Brattleboro rats were compared to their heterozygous littermates (controls). CUS consisted of different mild stimuli for 5 weeks. Elevated plus maze and forced swim test were used for behavioural characterization, while organs and blood for HPA axis parameters were collected at the end of the experiment. In controls, CUS resulted in the development of chronic stress state characterized by typical somatic (body weight reduction, thymus involution) and endocrine changes (resting plasma ACTH and corticosterone elevation and POMC mRNA elevation in anterior lobe of the pituitary). Floating time in the forced swim test was enhanced together with reduced open arm entries on elevated plus maze and a reduction in daily food intake. Unexpectedly, the lack of VP did not alter the effect of CUS on the somatic and behavioural measures, but only prevented CUS-induced corticosterone changes. In conclusion, lifelong VP-deficiency has a positive effect on corticosterone elevation following CUS but does not affect the behavioural consequences of CUS. It is likely that the interplay of several related factors, rather than an alteration in a single neuropeptide, modulates behaviour and disease pathogenesis. Copyright © 2010 Elsevier Inc. All rights reserved.

Shared Components of Rhythm Generation for Locomotion and Scratching Exist Prior to Motoneurons

PubMed Central

Hao, Zhao-Zhe; Berkowitz, Ari

2017-01-01

Does the spinal cord use a single network to generate locomotor and scratching rhythms or two separate networks? Previous research showed that simultaneous swim and scratch stimulation (“dual stimulation”) in immobilized, spinal turtles evokes a single rhythm in hindlimb motor nerves with a frequency often greater than during swim stimulation alone or scratch stimulation alone. This suggests that the signals that trigger swimming and scratching converge and are integrated within the spinal cord. However, these results could not determine whether the integration occurs in motoneurons themselves or earlier, in spinal interneurons. Here, we recorded intracellularly from hindlimb motoneurons during dual stimulation. Motoneuron membrane potentials displayed regular oscillations at a higher frequency during dual stimulation than during swim or scratch stimulation alone. In contrast, arithmetic addition of the oscillations during swimming alone and scratching alone with various delays always generated irregular oscillations. Also, the standard deviation of the phase-normalized membrane potential during dual stimulation was similar to those during swimming or scratching alone. In contrast, the standard deviation was greater when pooling cycles of swimming alone and scratching alone for two of the three forms of scratching. This shows that dual stimulation generates a single rhythm prior to motoneurons. Thus, either swimming and scratching largely share a rhythm generator or the two rhythms are integrated into one rhythm by strong interactions among interneurons. PMID:28848402

Quantifying the behavioral response of spawning chum salmon to elevated discharges from Bonneville Dam, Columbia River, USA

USGS Publications Warehouse

Tiffan, K.F.; Haskell, C.A.; Kock, T.J.

2010-01-01

Chum salmon Oncorhynchus keta that spawn in main-stem habitats below Bonneville Dam on the Columbia River, USA, are periodically subjected to elevated discharges that may alter spawning behaviour. We investigated behavioural responses of spawning chum salmon to increased water velocities associated with experimental increases in tailwater elevation using acoustic telemetry and a dual-frequency identification sonar. Chum salmon primarily remained near their redds at base tailwater elevations (3.5 m above mean sea level), but displayed different movement and behavioural responses as elevations were increased to either 4.1 or 4.7m for 8-h periods. When velocities remained suitable (<0.8m s-1) during elevated-tailwater tests, female chum salmon remained near their redds but exhibited reduced digging activity as water velocities increased. However, when velocities exceeded 0.8m s-1, the females that remained on their redds exhibited increased swimming activity and digging virtually ceased. Female and male chum salmon that left their redds when velocities became unsuitable moved mean distances ranging from 32 to 58 m to occupy suitable velocities, but returned to their redds after tailwaters returned to base levels. Spawning events (i.e. egg deposition) were observed for five of nine pairs of chum salmon following tests indicating any disruptions to normal behaviour caused by elevated tailwaters were likely temporary. We believe a chum salmon's decision to either remain on, or leave, its redd during periods of unsuitably high water velocities reflects time invested in the redd and the associated energetic costs it is willing to incur. ?? 2009 John Wiley & Sons, Ltd.

Swim stress reduces chronic pain in mice through an opioid mechanism.

PubMed

Carmody, J; Cooper, K

1987-03-09

Chronic nociception has been studied in male mice by means of the formalin test in which forelimb motor behaviour is scored after subcutaneous formalin injection. The rating remained above 2.0 for 30 min after the injection (scale range 0-3). The magnitude of the nociception has been compared with that reported in other animal types. Mice are more sensitive than rats, cats and monkeys. The stress of a swim of 3 min has been found to reduce nociception by up to 25%. This analgesia is wholly opioid in nature, being abolished by a moderate dose of naloxone (1 mg/kg).

Elevated carbon dioxide alters the plasma composition and behaviour of a shark.

PubMed

Green, Leon; Jutfelt, Fredrik

2014-09-01

Increased carbon emissions from fossil fuels are increasing the pCO2 of the ocean surface waters in a process called ocean acidification. Elevated water pCO2 can induce physiological and behavioural effects in teleost fishes, although there appear to be large differences in sensitivity between species. There is currently no information available on the possible responses to future ocean acidification in elasmobranch fishes. We exposed small-spotted catsharks (Scyliorhinus canicula) to either control conditions or a year 2100 scenario of 990 μatm pCO2 for four weeks. We did not detect treatment effects on growth, resting metabolic rate, aerobic scope, skin denticle ultrastructure or skin denticle morphology. However, we found that the elevated pCO2 group buffered internal acidosis via [Formula: see text] accumulation with an associated increase in Na(+), indicating that the blood chemistry remained altered despite the long acclimation period. The elevated pCO2 group also exhibited a shift in their nocturnal swimming pattern from a pattern of many starts and stops to more continuous swimming. Although CO2-exposed teleost fishes can display reduced behavioural asymmetry (lateralization), the CO2-exposed sharks showed increased lateralization. These behavioural effects may suggest that elasmobranch neurophysiology is affected by CO2, as in some teleosts, or that the sharks detect CO2 as a constant stressor, which leads to altered behaviour. The potential direct effects of ocean acidification should henceforth be considered when assessing future anthropogenic effects on sharks. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

Swim stress, motion, and deformation of active matter: effect of an external field.

PubMed

Takatori, Sho C; Brady, John F

2014-12-21

We analyze the stress, dispersion, and average swimming speed of self-propelled particles subjected to an external field that affects their orientation and speed. The swimming trajectory is governed by a competition between the orienting influence (i.e., taxis) associated with the external (e.g., magnetic, gravitational, thermal, nutrient concentration) field versus the effects that randomize the particle orientations (e.g., rotary Brownian motion and/or an intrinsic tumbling mechanism like the flagella of bacteria). The swimmers' motion is characterized by a mean drift velocity and an effective translational diffusivity that becomes anisotropic in the presence of the orienting field. Since the diffusivity yields information about the micromechanical stress, the anisotropy generated by the external field creates a normal stress difference in the recently developed "swim stress" tensor [Takatori, Yan, and Brady, Phys. Rev. Lett., 2014]. This property can be exploited in the design of soft, compressible materials in which their size, shape, and motion can be manipulated and tuned by loading the material with active swimmers. Since the swimmers exert different normal stresses in different directions, the material can compress/expand, elongate, and translate depending on the external field strength. Such an active system can be used as nano/micromechanical devices and motors. Analytical solutions are corroborated by Brownian dynamics simulations.

Electromyography in the four competitive swimming strokes: a systematic review.

PubMed

Martens, Jonas; Figueiredo, Pedro; Daly, Daniel

2015-04-01

The aim of this paper is to give an overview on 50 years of research in electromyography in the four competitive swimming strokes (crawl, breaststroke, butterfly, and backstroke). A systematic search of the existing literature was conducted using the combined keywords "swimming" and "EMG" on studies published before August 2013, in the electronic databases PubMed, ISI Web of Knowledge, SPORT discus, Academic Search Elite, Embase, CINAHL and Cochrane Library. The quality of each publication was assessed by two independent reviewers using a custom made checklist. Frequency of topics, muscles studied, swimming activities, populations, types of equipment and data treatment were determined from all selected papers and, when possible, results were compared and contrasted. In the first 20 years of EMG studies in swimming, most papers were published as congress proceedings. The methodological quality was low. Crawl stroke was most often studied. There was no standardized manner of defining swimming phases, normalizing the data or of presenting the results. Furthermore, the variability around the mean muscle activation patterns is large which makes it difficult to define a single pattern applicable to all swimmers in any activity examined. Copyright © 2014 Elsevier Ltd. All rights reserved.

Ion selectivity of the Vibrio alginolyticus flagellar motor.

PubMed Central

Liu, J Z; Dapice, M; Khan, S

1990-01-01

The marine bacterium, Vibrio alginolyticus, normally requires sodium for motility. We found that lithium will substitute for sodium. In neutral pH buffers, the membrane potential and swimming speed of glycolyzing bacteria reached maximal values as sodium or lithium concentration was increased. While the maximal potentials obtained in the two cations were comparable, the maximal swimming speed was substantially lower in lithium. Over a wide range of sodium concentration, the bacteria maintained an invariant sodium electrochemical potential as determined by membrane potential and intracellular sodium measurements. Over this range the increase of swimming speed took Michaelis-Menten form. Artificial energization of swimming motility required imposition of a voltage difference in concert with a sodium pulse. The cation selectivity and concentration dependence exhibited by the motile apparatus depended on the viscosity of the medium. In high-viscosity media, swimming speeds were relatively independent of either ion type or concentration. These facts parallel and extend observations of the swimming behavior of bacteria propelled by proton-powered flagella. In particular, they show that ion transfers limit unloaded motor speed in this bacterium and imply that the coupling between ion transfers and force generation must be fairly tight. PMID:2394685

Strain differences in the collective behaviour of zebrafish (Danio rerio) in heterogeneous environment

PubMed Central

Collignon, Bertrand

2016-01-01

Recent studies show differences in individual motion and shoaling tendency between strains of the same species. Here, we analyse collective motion and response to visual stimuli in two morphologically different strains (TL and AB) of zebrafish. For both strains, we observed 10 groups of 5 and 10 zebrafish swimming freely in a large experimental tank with two identical landmarks (cylinders or discs) for 1 h. We tracked the positions of the fish by an automated tracking method and compute several metrics at the group level. First, the probability of the presence shows that both strains avoid free space and are more likely to swim in the vicinity of the walls of the tank and the landmarks. Second, the analysis of landmarks occupancy shows that AB zebrafish are more present in their vicinity than TL ones and that both strains regularly transit from one to the other one with no preference on the long duration. Finally, TL zebrafish show a higher cohesion than AB zebrafish. Thus, environmental heterogeneity and duration of the trials allow to reveal individual and collective behavioural variabilities among different strains of zebrafish. These results provide a new insight into the need to take into account individual variability of zebrafish strains for studying collective behaviour. PMID:27853558

Rational design and dynamics of self-propelled colloidal bead chains: from rotators to flagella.

PubMed

Vutukuri, Hanumantha Rao; Bet, Bram; van Roij, René; Dijkstra, Marjolein; Huck, Wilhelm T S

2017-12-01

The quest for designing new self-propelled colloids is fuelled by the demand for simple experimental models to study the collective behaviour of their more complex natural counterparts. Most synthetic self-propelled particles move by converting the input energy into translational motion. In this work we address the question if simple self-propelled spheres can assemble into more complex structures that exhibit rotational motion, possibly coupled with translational motion as in flagella. We exploit a combination of induced dipolar interactions and a bonding step to create permanent linear bead chains, composed of self-propelled Janus spheres, with a well-controlled internal structure. Next, we study how flexibility between individual swimmers in a chain can affect its swimming behaviour. Permanent rigid chains showed only active rotational or spinning motion, whereas longer semi-flexible chains showed both translational and rotational motion resembling flagella like-motion, in the presence of the fuel. Moreover, we are able to reproduce our experimental results using numerical calculations with a minimal model, which includes full hydrodynamic interactions with the fluid. Our method is general and opens a new way to design novel self-propelled colloids with complex swimming behaviours, using different complex starting building blocks in combination with the flexibility between them.

A role for serotonin in the antidepressant activity of NG-Nitro-L-arginine, in the rat forced swimming test.

PubMed

Gigliucci, Valentina; Buckley, Kathleen Niamh; Nunan, John; O'Shea, Karen; Harkin, Andrew

2010-02-01

The present study determined regional serotonin (5-HT) synthesis and metabolism changes associated with the nitric oxide synthase (NOS) inhibitor N(G)-nitro-L-arginine (L-NA) and the influence of 5-HT receptor blockade in the antidepressant-like actions of L-NA in the forced swimming test (FST). Regional effects of L-NA (5,10 and 20mg/kg i.p.) on tryptophan hydroxylase (TPH) activity, the rate limiting enzyme for 5-HT synthesis, were determined by measuring accumulation of the transient intermediate 5-hydoxytryptophan (5-HTP) following in vivo administration of the amino acid decarboxylase inhibitor, NSD 1015 (100mg/kg). L-NA (5-20mg/kg) dose dependently increased 5-HTP accumulation, particularly in the amygdaloid cortex, following exposure to the FST. L-NA also provoked an increase in regional brain 5-HIAA concentrations and in the 5-HIAA:5-HT metabolism ratio. Co-treatment with NSD-1015 failed to consistently modify the antidepressant-like effects of L-NA in the FST. Sub-active doses of L-NA (1mg/kg) and the 5-HT re-uptake inhibitor fluoxetine (2.5mg/kg) acted synergistically to increase swimming in the test. Co-treatment with the non-selective 5-HT receptor antagonist metergoline (1, 2 and 4mg/kg), attenuated the L-NA (20mg/kg)-induced reduction in immobility and increase in swimming behaviours. Metergoline alone however provoked an increase in immobility and reduction in swimming behaviours in the test. A similar response was obtained following co-treatment with the preferential 5-HT(2A) receptor antagonist ketanserin (5mg/kg) and the 5-HT(2C) receptor antagonist RO-430440 (5mg/kg). Co-treatment with the 5-HT(1A) receptor antagonist WAY 100635 (0.3mg/kg) or the 5-HT(1B) receptor antagonist GR 127935 (4mg/kg) failed to influence the antidepressant-like activity of L-NA. Taken together these data provide further support for a role for 5-HT in the antidepressant-like properties of NOS inhibitors. Copyright 2009 Elsevier Inc. All rights reserved.

Developmental intervals during the larval and juvenile stages of the Antarctic myctophid fish Electrona antarctica in relation to changes in feeding and swimming functions

NASA Astrophysics Data System (ADS)

Moteki, Masato; Tsujimura, Eri; Hulley, Percy-Alexander

2017-06-01

The Antarctic myctophid fish species Electrona antarctica is believed to play a key role in the Southern Ocean food web, but there have been few studies on its early life history. This study examined the developmental changes in the external morphology and osteology of E. antarctica from the early larva to juvenile stages through the transformation phase and inferred changes in its behaviour and feeding mode. Once the larvae reached 12-13 mm body length (BL), they adopted a primordial suction feeding mode along with the acquisition of early swimming capabilities. Thereafter, both swimming and feeding functions were enhanced through fin development and ossification and acquisition of elements of the jaw and suspensorium. These processes indicate that larvae transition from the planktonic to nektonic phase upon reaching 12-13 mm BL when they enhance their both swimming and feeding abilities with growth. Transformation occurred when larvae reached 19-21 mm BL with changes such as discontinuous increases in eye diameter and upper jaw length and the appearance of photophores and dense body pigmentation. Osteological development of swimming- and feeding-related structures were mostly complete after transformation. Rapid changes in external morphology and osteology during the transformation stage are most likely related to ontogenetic vertical migration into deep waters.

Isolated core training improves sprint performance in national-level junior swimmers.

PubMed

Weston, Matthew; Hibbs, Angela E; Thompson, Kevin G; Spears, Iain R

2015-03-01

To quantify the effects of a 12-wk isolated core-training program on 50-m front-crawl swim time and measures of core musculature functionally relevant to swimming. Twenty national-level junior swimmers (10 male and 10 female, 16±1 y, 171±5 cm, 63±4 kg) participated in the study. Group allocation (intervention [n=10], control [n=10]) was based on 2 preexisting swim-training groups who were part of the same swimming club but trained in different groups. The intervention group completed the core training, incorporating exercises targeting the lumbopelvic complex and upper region extending to the scapula, 3 times/wk for 12 wk. While the training was performed in addition to the normal pool-based swimming program, the control group maintained their usual pool-based swimming program. The authors made probabilistic magnitude-based inferences about the effect of the core training on 50-m swim time and functionally relevant measures of core function. Compared with the control group, the core-training intervention group had a possibly large beneficial effect on 50-m swim time (-2.0%; 90% confidence interval -3.8 to -0.2%). Moreover, it showed small to moderate improvements on a timed prone-bridge test (9.0%; 2.1-16.4%) and asymmetric straight-arm pull-down test (23.1%; 13.7-33.4%), and there were moderate to large increases in peak EMG activity of core musculature during isolated tests of maximal voluntary contraction. This is the first study to demonstrate a clear beneficial effect of isolated core training on 50-m front-crawl swim performance.

Toxicity assessment of polluted sediments using swimming behavior alteration test with Daphnia magna

NASA Astrophysics Data System (ADS)

Nikitin, O. V.; Nasyrova, E. I.; Nuriakhmetova, V. R.; Stepanova, N. Yu; Danilova, N. V.; Latypova, V. Z.

2018-01-01

Recently behavioral responses of organisms are increasingly used as a reliable and sensitive tool in aquatic toxicology. Behavior-related endpoints allow efficiently studying the effects of sub-lethal exposure to contaminants. At present behavioural parameters frequently are determined with the use of digital analysis of video recording by computer vision technology. However, most studies evaluate the toxicity of aqueous solutions. Due to methodological difficulties associated with sample preparation not a lot of examples of the studies related to the assessment of toxicity of other environmental objects (wastes, sewage sludges, soils, sediments etc.) by computer vision technology. This paper presents the results of assessment of the swimming behavior alterations of Daphnia magna in elutriates from both uncontaminated natural and artificially chromium-contaminated bottom sediments. It was shown, that in elutriate from chromium contaminated bottom sediments (chromium concentration 115±5.7 μg l-1) the swimming speed of daphnids was decreases from 0.61 cm s-1 (median speed over the period) to 0.50 cm s-1 (median speed at the last minute of the experiment). The relocation of Daphnia from the culture medium to the extract from the non-polluted sediments does not essential changes the swimming activity.

Scaling of swim speed and stroke frequency in geometrically similar penguins: they swim optimally to minimize cost of transport

PubMed Central

Sato, Katsufumi; Shiomi, Kozue; Watanabe, Yuuki; Watanuki, Yutaka; Takahashi, Akinori; Ponganis, Paul J.

2010-01-01

It has been predicted that geometrically similar animals would swim at the same speed with stroke frequency scaling with mass−1/3. In the present study, morphological and behavioural data obtained from free-ranging penguins (seven species) were compared. Morphological measurements support the geometrical similarity. However, cruising speeds of 1.8–2.3 m s−1 were significantly related to mass0.08 and stroke frequencies were proportional to mass−0.29. These scaling relationships do not agree with the previous predictions for geometrically similar animals. We propose a theoretical model, considering metabolic cost, work against mechanical forces (drag and buoyancy), pitch angle and dive depth. This new model predicts that: (i) the optimal swim speed, which minimizes the energy cost of transport, is proportional to (basal metabolic rate/drag)1/3 independent of buoyancy, pitch angle and dive depth; (ii) the optimal speed is related to mass0.05; and (iii) stroke frequency is proportional to mass−0.28. The observed scaling relationships of penguins support these predictions, which suggest that breath-hold divers swam optimally to minimize the cost of transport, including mechanical and metabolic energy during dive. PMID:19906666

Deformation of a micro-torque swimmer

PubMed Central

Ishikawa, Takuji; Tanaka, Tomoyuki; Imai, Yohsuke; Omori, Toshihiro; Matsunaga, Daiki

2016-01-01

The membrane tension of some kinds of ciliates has been suggested to regulate upward and downward swimming velocities under gravity. Despite its biological importance, deformation and membrane tension of a ciliate have not been clarified fully. In this study, we numerically investigated the deformation of a ciliate swimming freely in a fluid otherwise at rest. The cell body was modelled as a capsule with a hyperelastic membrane enclosing a Newtonian fluid. Thrust forces due to the ciliary beat were modelled as torques distributed above the cell body. The effects of membrane elasticity, the aspect ratio of the cell's reference shape, and the density difference between the cell and the surrounding fluid were investigated. The results showed that the cell deformed like a heart shape, when the capillary number was sufficiently large. Under the influence of gravity, the membrane tension at the anterior end decreased in the upward swimming while it increased in the downward swimming. Moreover, gravity-induced deformation caused the cells to move gravitationally downwards or upwards, which resulted in a positive or negative geotaxis-like behaviour with a physical origin. These results are important in understanding the physiology of a ciliate's biological responses to mechanical stimuli. PMID:26997893

Augmentation of the behavioural effects of desipramine by repeated immobilization stress.

PubMed

Hadweh, Nicolás; Santibañez, Marcos; González, Marcela Paz; Forray, María Inés

2010-12-25

The present report provides evidence that repeated immobilization stress (RIS) induced a noradrenergic-dependent depressive-like behaviour and an augmented behavioural response to desipramine (DMI), a noradrenaline reuptake inhibitor (NRI), in the forced swimming test (FST). The present results show that RIS decreased the baseline of climbing behaviour in the FST. Whereas subchronic administration of DMI (10mg/kg, three times in a 24h period) induced a significantly higher increase in climbing behaviour on repeatedly stressed rats compared to controls. The results also show that the concomitant administration of the low dose of DMI (3mg/Kg) during the RIS fully prevented the decrease of climbing behaviour induced by RIS, without exerting behavioural effects in control rats, further supporting an augmented response to the DMI antidepressant effects in the repeatedly stressed rats. In conclusion, our data indicate that RIS not only changes the behavioural responses in the FST but also increases the antidepressant effects of DMI. Copyright (c) 2010 Elsevier B.V. All rights reserved.

Using a multibiomarker approach and behavioural responses to assess the effects of anthracene in Palaemon serratus.

PubMed

Gravato, Carlos; Almeida, Joana R; Silva, Carlos; Oliveira, Cristiana; Soares, Amadeu M V M

2014-04-01

Polycyclic aromatic hydrocarbons (PAHs) are recognised as one of the main groups of contaminants that assume more importance in the marine environment, enhancing the need of studies concerning their adverse effects and more efficient and ecologically relevant tools for environmental monitoring purposes. This study aims to apply an integrated approach including several multi-level biological responses (accumulation levels, biochemical responses important for different physiological functions and behavioural alterations) to assess the ecological relevance of the effects induced by sub-lethal concentrations of anthracene (ANT) in Palaemon serratus (common prawn). ANT accumulation was assessed by measuring the levels of ANT-type compounds in prawn digestive gland, muscle and eye; biochemical responses were determined using biomarkers involved in biotransformation, oxidative damage, energy production and neurotransmission processes; and behavioural alterations through swimming performance after 96 h exposure bioassay (ANT:16-1,024 μg/L). The rationale behind this approach is to assess the ecologically relevant effects induced by ANT in prawn, given by the association between behavioural alterations with biochemical responses, in search for more efficient tools for environmental risk assessment. Results show a significant decrease of swimming velocity (LOEC=128 μg/L) along with increased levels of ANT-type compounds in digestive gland (LOEC=128 μg/L), muscle (LOEC=256 μg/L) and eye (LOEC=32 μg/L) in prawn exposed to ANT. Increased activities of glutathione peroxidase (GPx) and catalase (CAT), involved in anti-oxidant defence system, were also observed (LOEC=256 μg/L; 1024μg/L, respectively) in the digestive gland of prawn, induction of oxidative damage in lipids (LPO) also occurred (LOEC=32 μg/L). The inhibition of swimming velocity showed a correlation with some biochemical parameters measured, including the levels of ANT-type compounds in tissues and LPO, and thus these may be considered sensitive and ecologically relevant criteria as well as early warning endpoints for assessing polycyclic aromatic compounds exposure effects on marine organisms. Copyright © 2014 Elsevier B.V. All rights reserved.

Increased anxiety and "depressive" symptoms months after MDMA ("ecstasy") in rats: drug-induced hyperthermia does not predict long-term outcomes.

PubMed

McGregor, Iain S; Gurtman, Clint G; Morley, Kirsten C; Clemens, Kelly J; Blokland, Arjan; Li, Kong M; Cornish, Jennifer L; Hunt, Glenn E

2003-08-01

There is some uncertainty whether the acute hyperthermia caused by MDMA (ecstasy) plays a significant role in determining the long-term neurotoxic effects on brain 5-HT systems and associated changes in mood and behaviour. The present study assessed whether long-term behavioural and cognitive changes seen in MDMA-treated rats are affected by hyperthermia at the time of drug administration. Male Wistar rats were treated with MDMA (4x5 mg/kg i.p. over 4 h on 2 consecutive days) or vehicle at either a high ambient temperature (28 degrees C) or a low ambient temperature (16 degrees C). Eight to 18 weeks later, rats were tested in behavioural measures of anxiety (social interaction and emergence tests), a test of cognition (object recognition test) and the forced swim test of depression. At the conclusion of behavioural testing the rats were killed and their brains analysed using HPLC. MDMA treatment caused a clear and consistent hyperthermia at 28 degrees C and hypothermia at 16 degrees C. Months later, rats pre-treated with MDMA at either 16 or 28 degrees C displayed increased anxiety in the social interaction and emergence tests and reduced escape attempts and increased immobility in the forced swim test. MDMA pre-treatment was also associated with poorer memory on the object recognition test, but only in rats given the drug at 28 degrees C. Rats pre-treated with MDMA showed loss of 5-HT in the hippocampus, striatum, amygdala and cortex, regardless of body temperature at the time of dosing. However, 5-HIAA loss in the amygdala and hippocampus was greater in rats pre-treated at 28 degrees C. Dopamine in the striatum was also depleted in rats given MDMA. These results indicate that hyperthermia at the time of dosing with MDMA is not necessary to produce subsequent 5-HT depletion and anxiety in rats. They also extend previous findings of long-term effects of brief exposure to MDMA in rats to include apparent "depressive" symptoms in the forced swim model.

Graviresponses of Paramecium biaurelia during parabolic flights.

PubMed

Krause, Martin; Bräucker, Richard; Hemmersbach, Ruth

2006-12-01

The thresholds of graviorientation and gravikinesis in Paramecium biaurelia were investigated during the 5th DLR (German Aerospace Center) parabolic-flight campaign at Bordeaux in June 2003. Parabolic flights are a useful tool for the investigation of swimming behaviour in protists at different accelerations. At normal gravity (1 g) and hypergravity (1 g to 1.8 g), precision of orientation and locomotion rates depend linearly on the applied acceleration as seen in earlier centrifuge experiments. After transition from hypergravity to decreased gravity (minimal residual acceleration of <10(-2) g), graviorientation as well as gravikinesis show a full relaxation with different kinetics. The use of twelve independent cell samples per flight guarantees high data numbers and secures the statistical significance of the obtained data. The relatively slow change of acceleration between periods of microgravity and hypergravity (0.4 g/s) enabled us to determine the thresholds of graviorientation at 0.6 g and of gravikinesis at 0.4 g. The gravity-unrelated propulsion rate of the sample was found to be 874 microm/s, exceeding the locomotion rate of horizontally swimming cells (855 microm/s). The measured thresholds of graviresponses were compared with data obtained from earlier centrifuge experiments on the sounding rocket Maxus-2. Measured thresholds of gravireactions indicate that small energies, close to the thermal noise level, are sufficient for the gravitransduction process. Data from earlier hypergravity experiments demonstrate that mechanosensitive ion channels are functioning over a relative wide range of acceleration. From this, we may speculate that gravireceptor channels derive from mechanoreceptor channels.

Electrogenesis in the lower Metazoa and implications for neuronal integration

PubMed Central

Meech, Robert W.

2015-01-01

Electrogenic communication appears to have evolved independently in a variety of animal and plant lineages. Considered here are metazoan cells as disparate as the loose three-dimensional parenchyma of glass sponges, the two-dimensional epithelial sheets of hydrozoan jellyfish and the egg cell membranes of the ctenophore Beroe ovata, all of which are capable of generating electrical impulses. Neuronal electrogenesis may have evolved independently in ctenophores and cnidarians but the dearth of electrophysiological data relating to ctenophore nerves means that our attention is focused on the Cnidaria, whose nervous systems have been the subject of extensive study. The aim here is to show how their active and passive neuronal properties interact to give integrated behaviour. Neuronal electrogenesis, goes beyond simply relaying ‘states of excitement’ and utilizes the equivalent of a set of basic electrical ‘apps’ to integrate incoming sensory information with internally generated pacemaker activity. A small number of membrane-based processes make up these analogue applications. Passive components include the decremental spread of current determined by cellular anatomy; active components include ion channels specified by their selectivity and voltage dependence. A recurring theme is the role of inactivating potassium channels in regulating performance. Although different aspects of cnidarian behaviour are controlled by separate neuronal systems, integrated responses and coordinated movements depend on interactions between them. Integrative interactions discussed here include those between feeding and swimming, between tentacle contraction and swimming and between slow and fast swimming in the hydrozoan jellyfish Aglantha digitale. PMID:25696817

Housing conditions modulate escitalopram effects on antidepressive-like behaviour and brain neurochemistry.

PubMed

Bjørnebekk, Astrid; Mathé, Aleksander A; Gruber, Susanne H M; Brené, Stefan

2008-12-01

Despite limited understanding of the pathophysiology of depression and the underlying mechanisms mediating antidepressant effects, there are several efficient treatments. The anhedonia symptoms of depression are characterized by decreased motivation and drive and imply possible malfunctioning of the mesolimbic dopamine system, whereas cognitive deficits might reflect decreased plasticity in hippocampus. In female Flinders Sensitive Line (FSL) rats, a model of depression, we compared the effects of three long-term antidepressant treatments: voluntary running, escitalopram and the combination of both on antidepressant-like behaviour in the Porsolt swim test (PST), and on regulation of mRNA for dopamine and neuropeptides in striatal dopamine pathways and brain-derived neurotrophic factor (BDNF) in hippocampus. Escitalopram diet attenuated running behaviour in FSL rats but not in non-depressed controls rats. In the PST the running group had increased climbing activity (noradrenergic/dopaminergic response), whereas the combination of escitalopram and running-wheel access increased swimming (serotonergic response). Running elevated mRNA for dynorphin in caudate putamen and BDNF in hippocampus. The combined treatment down-regulated D1 receptor and enkephalin mRNA in accumbens. Escitalopram alone did not affect behaviour or mRNA levels. We demonstrate a novel behavioural effect of escitalopram, i.e. attenuation of running in 'depressed' rats. The antidepressant-like effect of escitalopram was dependent on the presence of a running wheel, but not actual running indicating that the environment influenced the antidepressant effect of escitalopram. Different patterns of mRNA changes in hippocampus and brain reward pathways and responses in the PST by running and escitalopram suggest that antidepressant-like responses by running and escitalopram are achieved by different mechanisms.

Stronger effects of Roundup than its active ingredient glyphosate in damselfly larvae.

PubMed

Janssens, Lizanne; Stoks, Robby

2017-12-01

Pesticides are causing strong decreases in aquatic biodiversity at concentrations assumed safe by legislation. One reason for the failing risk assessment may be strong differences in the toxicity of the active ingredient of pesticides and their commercial formulations. Sublethal effects, especially those on behaviour, have been largely ignored in this context, yet can be equally important as lethal effects at the population and ecosystem levels. Here, we compared the toxicity of the herbicide Roundup and its active ingredient glyphosate on survival, but also on ecologically relevant sublethal traits (life history, behaviour and physiology) in damselfly larvae. Roundup was more toxic than glyphosate with negative effects on survival, behaviour and most of the physiological traits being present at lower concentrations (food intake, escape swimming speed) or even only present (survival, sugar and total energy content and muscle mass) following Roundup exposure. This confirms the toxicity of the surfactant POEA. Notably, also glyphosate was not harmless: a realistic concentration of 2mg/l resulted in reduced growth rate, escape swimming speed and fat content. Our results therefore indicate that the toxicity of Roundup cannot be fully attributed to its surfactant, thereby suggesting that also the new generation of glyphosate-based herbicides with other mixtures of surfactants likely will have adverse effects on non-target aquatic organisms. Ecotoxicological studies comparing the toxicity of active ingredients and their commercial formulations typically ignore behaviour while the here observed differential effects on behaviour likely will negatively impact damselfly populations. Our data highlight that risk assessment of pesticides ignoring sublethal effects may contribute to the negative effects of pesticides on aquatic biodiversity. Copyright © 2017 Elsevier B.V. All rights reserved.

Spinal Injury: Regeneration, Recovery, and a Possible New Approach

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cohen, Avis

Spinal injury is most frequent in young healthy men, desperate to walk. Most treatments have focused on regeneration of the injured axons, but no one has as yet achieved success with this approach. However, in the lamprey, a primitive fish with a spinal cord having all the critical features of the human spinal cored, spinal injury is followed by complete regeneration of injured axons. Additionally, the animal recovers the ability to swim, and in many, the swimming is normal. Unfortunately, in most others, it is highly abnormal. This talk will review evidence from the abnormal regeneration, why it bespeaks difficultiesmore » heretofore not considered, and suggest an alternate approach for the near future. In so doing, the speaker will introduce the normal function of the spinal cord, what happens in normal and abnormal regeneration, and the new techniques that employ methods from neuromorphic engineering, a synthesis of neuroscience and engineering to engineer smart devices.« less

Spinal Injury: Regeneration, Recovery, and a Possible New Approach

ScienceCinema

Cohen, Avis [University of Maryland, College Park, Maryland, United States

2017-12-09

Spinal injury is most frequent in young healthy men, desperate to walk. Most treatments have focused on regeneration of the injured axons, but no one has as yet achieved success with this approach. However, in the lamprey, a primitive fish with a spinal cord having all the critical features of the human spinal cored, spinal injury is followed by complete regeneration of injured axons. Additionally, the animal recovers the ability to swim, and in many, the swimming is normal. Unfortunately, in most others, it is highly abnormal. This talk will review evidence from the abnormal regeneration, why it bespeaks difficulties heretofore not considered, and suggest an alternate approach for the near future. In so doing, the speaker will introduce the normal function of the spinal cord, what happens in normal and abnormal regeneration, and the new techniques that employ methods from neuromorphic engineering, a synthesis of neuroscience and engineering to engineer smart devices.

Directed collective motion of bacteria under channel confinement

NASA Astrophysics Data System (ADS)

Wioland, H.; Lushi, E.; Goldstein, R. E.

2016-07-01

Dense suspensions of swimming bacteria are known to exhibit collective behaviour arising from the interplay of steric and hydrodynamic interactions. Unconfined suspensions exhibit transient, recurring vortices and jets, whereas those confined in circular domains may exhibit order in the form of a spiral vortex. Here we show that confinement into a long and narrow macroscopic ‘racetrack’ geometry stabilises bacterial motion to form a steady unidirectional circulation. This motion is reproduced in simulations of discrete swimmers that reveal the crucial role that bacteria-driven fluid flows play in the dynamics. In particular, cells close to the channel wall produce strong flows which advect cells in the bulk against their swimming direction. We examine in detail the transition from a disordered state to persistent directed motion as a function of the channel width, and show that the width at the crossover point is comparable to the typical correlation length of swirls seen in the unbounded system. Our results shed light on the mechanisms driving the collective behaviour of bacteria and other active matter systems, and stress the importance of the ubiquitous boundaries found in natural habitats.

Effect of endurance swimming on rat cardiac myofibrillar ATPase with experimental diabetes.

PubMed

Belcastro, A N; Maybank, P; Rossiter, M; Secord, D

1985-09-01

Diabetes is characterized by depressed cardiac functional properties attributed to Ca2+-activated ATPase activity. In contrast, endurance swimming enhances the cardiac functional properties and Ca2+-activated myofibril ATPase. Thus, the purpose of this study was to observe if the changes associated with experimental diabetes can be ameliorated with training. Diabetes was induced with a single i.v. injection of streptozotocin (60 mg/kg). Blood and urine glucose concentrations were 802 +/- 44 and 6965 +/- 617 mg/dL, respectively. The training control and training diabetic animals were made to swim (+/- 2% body weight) 4 days/week for 8 weeks. Cardiac myofibril, at 10 microM free Ca2+ concentration was reduced by 54% in the sedentary diabetics compared with sedentary control animals (p less than 0.05). Swim training enhanced the Ca2+-activated myofibril ATPase activities for the normal animals. The diabetic animals, which swam for 8 weeks, had further reduced their Ca2+-activated myofibril ATPase activity when compared with sedentary diabetics (p less than 0.05). Similarly, the Mg2+-stimulated myofibril ATPase activity was depressed by 31% in diabetics following endurance swimming. It is concluded that the depressed Ca2+-activated myofibril ATPase activity of diabetic hearts is not reversible with endurance swimming.

Hydrodynamic interaction of two swimming model micro-organisms

NASA Astrophysics Data System (ADS)

Ishikawa, Takuji; Simmonds, M. P.; Pedley, T. J.

2006-12-01

In order to understand the rheological and transport properties of a suspension of swimming micro-organisms, it is necessary to analyse the fluid-dynamical interaction of pairs of such swimming cells. In this paper, a swimming micro-organism is modelled as a squirming sphere with prescribed tangential surface velocity, referred to as a squirmer. The centre of mass of the sphere may be displaced from the geometric centre (bottom-heaviness). The effects of inertia and Brownian motion are neglected, because real micro-organisms swim at very low Reynolds numbers but are too large for Brownian effects to be important. The interaction of two squirmers is calculated analytically for the limits of small and large separations and is also calculated numerically using a boundary-element method. The analytical and the numerical results for the translational rotational velocities and for the stresslet of two squirmers correspond very well. We sought to generate a database for an interacting pair of squirmers from which one can easily predict the motion of a collection of squirmers. The behaviour of two interacting squirmers is discussed phenomenologically, too. The results for the trajectories of two squirmers show that first the squirmers attract each other, then they change their orientation dramatically when they are in near contact and finally they separate from each other. The effect of bottom-heaviness is considerable. Restricting the trajectories to two dimensions is shown to give misleading results. Some movies of interacting squirmers are available with the online version of the paper.

Ahr2-dependence of PCB126 effects on the swim bladder in relation to expression of CYP1 and cox-2 genes in developing zebrafish

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jönsson, Maria E., E-mail: maria.jonsson@ebc.uu.se; Biology Department, Redfield 3-42 MS 32, Woods Hole Oceanographic Institution, Woods Hole, MA, 02543; Kubota, Akira, E-mail: akubota@whoi.edu

2012-12-01

The teleost swim bladder is assumed a homolog of the tetrapod lung. Both swim bladder and lung are developmental targets of persistent aryl hydrocarbon receptor (AHR) agonists; in zebrafish (Danio rerio) the swim bladder fails to inflate with exposure to 3,3′,4,4′,5-pentachlorobiphenyl (PCB126). The mechanism for this effect is unknown, but studies have suggested roles of cytochrome P450 1 (CYP1) and cyclooxygenase 2 (Cox-2) in some Ahr-mediated developmental effects in zebrafish. We determined relationships between swim bladder inflation and CYP1 and Cox-2 mRNA expression in PCB126-exposed zebrafish embryos. We also examined effects on β-catenin dependent transcription, histological effects, and Ahr2 dependencemore » of the effect of PCB126 on swim bladder using morpholinos targeting ahr2. One-day-old embryos were exposed to waterborne PCB126 or carrier (DMSO) for 24 h and then held in clean water until day 4, a normal time for swim bladder inflation. The effects of PCB126 were concentration-dependent with EC{sub 50} values of 1.4 to 2.0 nM for induction of the CYP1s, 3.7 and 5.1 nM (or higher) for cox-2a and cox-2b induction, and 2.5 nM for inhibition of swim bladder inflation. Histological defects included a compaction of the developing bladder. Ahr2-morpholino treatment rescued the effect of PCB126 (5 nM) on swim bladder inflation and blocked induction of CYP1A, cox-2a, and cox-2b. With 2 nM PCB126 approximately 30% of eleutheroembryos failed to inflate the swim bladder, but there was no difference in CYP1 or cox-2 mRNA expression between those embryos and embryos showing inflated swim bladder. Our results indicate that PCB126 blocks swim bladder inflation via an Ahr2-mediated mechanism. This mechanism seems independent of CYP1 or cox-2 mRNA induction but may involve abnormal development of swim bladder cells. -- Highlights: ► PCB126 caused cellular changes in the developing swim bladder. ► Swim bladder inflation was not related to expression of CYP1 or cox-2. ► Failure of swim bladder inflation is mediated via an Ahr2-dependent mechanism. ► PCB126-exposed zebrafish larvae showed upregulation of the oncogene myca.« less

The effects of marine traffic on the behaviour of Black Sea harbour porpoises (Phocoena phocoena relicta) within the Istanbul Strait, Turkey.

PubMed

Akkaya Bas, Aylin; Christiansen, Fredrik; Amaha Öztürk, Ayaka; Öztürk, Bayram; McIntosh, Caley

2017-01-01

Marine traffic is threatening cetaceans on a local and global scale. The Istanbul Strait is one of the busiest waterways, with up to 2,500 vessels present daily. This is the first study to assess the magnitude of short- and long-term behavioural changes of the endangered Black Sea harbour porpoises (Phocoena phocoena relicta) in the presence of marine vessels within the Istanbul Strait. Markov chains were used to investigate the effect of vessel presence on the transition probability between behavioural states (diving, surface-feeding and travelling), and to quantify the effect on the behavioural budget and bout length (duration of time spent in a given state) of porpoises. Further, the changes on swimming directions of porpoises in relation to vessel speed and distance was investigated using generalized linear models. In vessel presence, porpoises were less likely to remain in a given behavioural state and instead more likely to switch to another state. Because of this, the bout length of all three behavioural states decreased significantly in the presence of vessels. The vessel effect was sufficiently large to alter the behavioural budget, with surface-feeding decreasing significantly in the presence of vessels. However, when taking into account the proportion of time that porpoises were exposed to vessels (i.e. 50%), the measured effect size was not large enough to significantly alter the animals' cumulative (diurnal) behavioural budget. Additionally, vessel speed and distance had a significant effect on the probability of porpoises showing a response in their swimming directions. The southern and middle sections of the Istanbul Strait, which have the heaviest marine traffic pressure, had the lowest porpoise sightings throughout the year. Conversely, northern sections that were exposed to a lesser degree of marine traffic hold the highest porpoise sightings. The effect shown in this study in combination with increasing human impacts within the northern sections should be considered carefully and species-specific conservation actions, including establishment of protected areas, should be put in place to prevent the long-term consequences of marine traffic on the Black Sea harbour porpoise population.

The effects of marine traffic on the behaviour of Black Sea harbour porpoises (Phocoena phocoena relicta) within the Istanbul Strait, Turkey

PubMed Central

Christiansen, Fredrik; Amaha Öztürk, Ayaka; Öztürk, Bayram; McIntosh, Caley

2017-01-01

Marine traffic is threatening cetaceans on a local and global scale. The Istanbul Strait is one of the busiest waterways, with up to 2,500 vessels present daily. This is the first study to assess the magnitude of short- and long-term behavioural changes of the endangered Black Sea harbour porpoises (Phocoena phocoena relicta) in the presence of marine vessels within the Istanbul Strait. Markov chains were used to investigate the effect of vessel presence on the transition probability between behavioural states (diving, surface-feeding and travelling), and to quantify the effect on the behavioural budget and bout length (duration of time spent in a given state) of porpoises. Further, the changes on swimming directions of porpoises in relation to vessel speed and distance was investigated using generalized linear models. In vessel presence, porpoises were less likely to remain in a given behavioural state and instead more likely to switch to another state. Because of this, the bout length of all three behavioural states decreased significantly in the presence of vessels. The vessel effect was sufficiently large to alter the behavioural budget, with surface-feeding decreasing significantly in the presence of vessels. However, when taking into account the proportion of time that porpoises were exposed to vessels (i.e. 50%), the measured effect size was not large enough to significantly alter the animals’ cumulative (diurnal) behavioural budget. Additionally, vessel speed and distance had a significant effect on the probability of porpoises showing a response in their swimming directions. The southern and middle sections of the Istanbul Strait, which have the heaviest marine traffic pressure, had the lowest porpoise sightings throughout the year. Conversely, northern sections that were exposed to a lesser degree of marine traffic hold the highest porpoise sightings. The effect shown in this study in combination with increasing human impacts within the northern sections should be considered carefully and species-specific conservation actions, including establishment of protected areas, should be put in place to prevent the long-term consequences of marine traffic on the Black Sea harbour porpoise population. PMID:28296899

Anxiolytic efficacy of repeated oral capsaicin in rats with partial aberration of oral sensory relay to brain.

PubMed

Choi, Young-Jun; Kim, Jin Young; Jin, Wei-Peng; Kim, Yoon-Tae; Lee, Jong-Ho; Jahng, Jeong Won

2015-07-01

This study was conducted to examine if taste over load with oral capsaicin improves the adverse behavioural effects induced by partial aberration of oral sensory relays to brain with bilateral transections of the lingual and chorda tympani nerves. Male Sprague-Dawley rats received daily 1 ml of 0.02% capsaicin or water drop by drop into the oral cavity following the bilateral transections of the lingual and chorda tympani nerves. Rats were subjected to ambulatory activity, elevated plus maze and forced swim tests after 11th, 14th and 17th daily administration of capsaicin or water, respectively. The basal and stress-induced plasma corticosterone levels were examined after the end of behavioural tests. Ambulatory counts, distance travelled, centre zone activities and rearing were increased, and rostral grooming decreased, during the activity test in capsaicin treated rats. Behavioural scores of capsaicin rats during elevated plus maze test did not differ from control rats. Immobility during the swim test was decreased in capsaicin rats with near significance (P = 0.0547). Repeated oral capsaicin increased both the basal level and stress-induced elevation of plasma corticosterone in rats with bilateral transections of the lingual and chorda tympani nerves. It is concluded that repeated oral administration of capsaicin reduces anxiety-like behaviours in rats that received bilateral transections of the lingual and chorda tympani nerves, and that the increased corticosterone response, possibly modulating the hippocampal neural plasticity, may be implicated in the anxiolytic efficacy of oral capsaicin. Copyright © 2015 Elsevier Ltd. All rights reserved.

Elucidating the functions of brain GSK3α: Possible synergy with GSK3β upregulation and reversal by antidepressant treatment in a mouse model of depressive-like behaviour.

PubMed

Pavlov, Dmitrii; Markova, Nataliia; Bettendorff, Lucien; Chekhonin, Vladimir; Pomytkin, Igor; Lioudyno, Viktoria; Svistunov, Andrei; Ponomarev, Eugene; Lesch, Klaus-Peter; Strekalova, Tatyana

2017-09-29

Glycogen synthase kinase 3 (GSK3) has been linked to the mechanisms of stress, mood regulation, and the effects of antidepressants. The functions of the GSK3β isoform have been extensively investigated, but little is known about the α-isoform, although they may functionally related. In a recently established modified swim test with a third delayed swim exposure, brain GSK3β mRNA expression positively correlated with floating behaviour on the third test. A two-week-long pretreatment regime with imipramine (7.5mg/kg/day) or thiamine (200mg/kg/day), which is known to have antidepressant properties, reduced the GSK3β over-expression and decreased floating behaviour on Day 5. GSK3α mRNA levels were measured in the hippocampus and prefrontal cortex on Days 1, 2 and 5. GSK3α expression was decreased in the prefrontal cortex on Day 2 and increased on Day 5. In this model, GSK3α mRNA changes were prevented by imipramine or thiamine treatment. There was a significant correlation between the expression of the two isoforms in the prefrontal cortex on Day 2 in untreated group. These results provide the first evidence for the potential involvement of GSK3α in depressive-like behaviours and as a target of anti-depressant therapy. Furthermore, the correlations suggest some cross-talk may exist between the two GSK3 isoforms. Copyright © 2017. Published by Elsevier B.V.

Sound exposure changes European seabass behaviour in a large outdoor floating pen: Effects of temporal structure and a ramp-up procedure.

PubMed

Neo, Y Y; Hubert, J; Bolle, L; Winter, H V; Ten Cate, C; Slabbekoorn, H

2016-07-01

Underwater sound from human activities may affect fish behaviour negatively and threaten the stability of fish stocks. However, some fundamental understanding is still lacking for adequate impact assessments and potential mitigation strategies. For example, little is known about the potential contribution of the temporal features of sound, the efficacy of ramp-up procedures, and the generalisability of results from indoor studies to the outdoors. Using a semi-natural set-up, we exposed European seabass in an outdoor pen to four treatments: 1) continuous sound, 2) intermittent sound with a regular repetition interval, 3) irregular repetition intervals and 4) a regular repetition interval with amplitude 'ramp-up'. Upon sound exposure, the fish increased swimming speed and depth, and swam away from the sound source. The behavioural readouts were generally consistent with earlier indoor experiments, but the changes and recovery were more variable and were not significantly influenced by sound intermittency and interval regularity. In addition, the 'ramp-up' procedure elicited immediate diving response, similar to the onset of treatment without a 'ramp-up', but the fish did not swim away from the sound source as expected. Our findings suggest that while sound impact studies outdoors increase ecological and behavioural validity, the inherently higher variability also reduces resolution that may be counteracted by increasing sample size or looking into different individual coping styles. Our results also question the efficacy of 'ramp-up' in deterring marine animals, which warrants more investigation. Copyright © 2016 Elsevier Ltd. All rights reserved.

Psychotropic drugs in mixture alter swimming behaviour of Japanese medaka (Oryzias latipes) larvae above environmental concentrations.

PubMed

Chiffre, Axelle; Clérandeau, Christelle; Dwoinikoff, Charline; Le Bihanic, Florane; Budzinski, Hélène; Geret, Florence; Cachot, Jérôme

2016-03-01

Psychiatric pharmaceuticals, such as anxiolytics, sedatives, hypnotics and antidepressors, are among the most prescribed active substances in the world. The occurrence of these compounds in the environment, as well as the adverse effects they can have on non-target organisms, justifies the growing concern about these emerging environmental pollutants. This study aims to analyse the effects of six psychotropic drugs, valproate, cyamemazine, citalopram, sertraline, fluoxetine and oxazepam, on the survival and locomotion of Japanese medaka Oryzias latipes larvae. Newly hatched Japanese medaka were exposed to individual compounds for 72 h, at concentrations ranging from 10 μg L(-1) to 10 mg L(-1). Lethal concentrations 50 % (LC50) were estimated at 840, 841 and 9,136 μg L(-1) for fluoxetine, sertraline and citalopram, respectively, while other compounds did not induce any significant increase in mortality. Analysis of the swimming behaviour of larvae, including total distance moved, mobility and location, provided an estimated lowest observed effect concentration (LOEC) of 10 μg L(-1) for citalopram and oxazepam, 12.2 μg L(-1) for cyamemazine, 100 μg L(-1) for fluoxetine, 1,000 μg L(-1) for sertraline and >10,000 μg L(-1) for valproate. Realistic environmental mixture of the six psychotropic compounds induced disruption of larval locomotor behaviour at concentrations about 10- to 100-fold greater than environmental concentrations.

The foraging benefits of being fat in a highly migratory marine mammal

PubMed Central

Adachi, Taiki; Maresh, Jennifer L.; Robinson, Patrick W.; Peterson, Sarah H.; Costa, Daniel P.; Naito, Yasuhiko; Watanabe, Yuuki Y.; Takahashi, Akinori

2014-01-01

Foraging theory predicts that breath-hold divers adjust the time spent foraging at depth relative to the energetic cost of swimming, which varies with buoyancy (body density). However, the buoyancy of diving animals varies as a function of their body condition, and the effects of these changes on swimming costs and foraging behaviour have been poorly examined. A novel animal-borne accelerometer was developed that recorded the number of flipper strokes, which allowed us to monitor the number of strokes per metre swam (hereafter, referred to as strokes-per-metre) by female northern elephant seals over their months-long, oceanic foraging migrations. As negatively buoyant seals increased their fat stores and buoyancy, the strokes-per-metre increased slightly in the buoyancy-aided direction (descending), but decreased significantly in the buoyancy-hindered direction (ascending), with associated changes in swim speed and gliding duration. Overall, the round-trip strokes-per-metre decreased and reached a minimum value when seals achieved neutral buoyancy. Consistent with foraging theory, seals stayed longer at foraging depths when their round-trip strokes-per-metre was less. Therefore, neutrally buoyant divers gained an energetic advantage via reduced swimming costs, which resulted in an increase in time spent foraging at depth, suggesting a foraging benefit of being fat. PMID:25377461

Affective and cognitive effects of global deletion of alpha3-containing gamma-aminobutyric acid-A receptors.

PubMed

Fiorelli, Roberto; Rudolph, Uwe; Straub, Carolin J; Feldon, Joram; Yee, Benjamin K

2008-09-01

Gamma-aminobutyric acid (GABA)A receptors characterized by the presence of the alpha3 subunit are the major GABAA receptor subtype expressed in brain stem monoaminergic nuclei. These alpha3-GABAA receptors are therefore in a unique position to regulate monoaminergic functions. To characterize the functional properties of alpha3-GABAA receptors, we present a preliminary assessment of the expression of affective and cognitive behaviour in male mice with a targeted deletion of the Gabra3 gene encoding the alpha3 subunit [alpha3 knockout (KO) mice] on a C57BL/6Jx129X1/SvJ F1 hybrid genetic background. The alpha3 KO mice did not exhibit any gross change of anxiety-like behaviour or spontaneous locomotor behaviour. In the Porsolt forced swim test for potential antidepressant activity, alpha3 KO mice exhibited reduced floating and enhanced swimming behaviour relative to wild-type controls. Performance on a two-choice sucrose preference test, however, revealed no evidence for an increase in sucrose preference in the alpha3 KO mice that would have substantiated a potential phenotype for depression-related behaviour. In contrast, a suggestion of an enhanced negative contrast effect was revealed in a one-bottle sucrose consumption test across different sucrose concentrations. These affective phenotypes were accompanied by alterations in the balance between conditioned responding to the discrete conditioned stimulus and to the context, and a suggestion of faster extinction, in the Pavlovian conditioned freezing paradigm. Spatial learning in the water maze reference memory test, however, was largely unchanged in the alpha3 KO mice, except for a trend of preservation during reversal learning. The novel phenotypes following global deletion of the GABAA receptor alpha3 subunit identified here provided relevant insights, in addition to our earlier study, into the potential behavioural relevance of this specific receptor subtypes in the modulation of both affective and cognitive functions.

Behavioural phenotypes predict disease susceptibility and infectiousness

PubMed Central

Araujo, Alessandra; Kirschman, Lucas

2016-01-01

Behavioural phenotypes may provide a means for identifying individuals that disproportionally contribute to disease spread and epizootic outbreaks. For example, bolder phenotypes may experience greater exposure and susceptibility to pathogenic infection because of distinct interactions with conspecifics and their environment. We tested the value of behavioural phenotypes in larval amphibians for predicting ranavirus transmission in experimental trials. We found that behavioural phenotypes characterized by latency-to-food and swimming profiles were predictive of disease susceptibility and infectiousness defined as the capacity of an infected host to transmit an infection by contacts. While viral shedding rates were positively associated with transmission, we also found an inverse relationship between contacts and infections. Together these results suggest intrinsic traits that influence behaviour and the quantity of pathogens shed during conspecific interactions may be an important contributor to ranavirus transmission. These results suggest that behavioural phenotypes provide a means to identify individuals more likely to spread disease and thus give insights into disease outbreaks that threaten wildlife and humans. PMID:27555652

Behavioural phenotypes predict disease susceptibility and infectiousness.

PubMed

Araujo, Alessandra; Kirschman, Lucas; Warne, Robin W

2016-08-01

Behavioural phenotypes may provide a means for identifying individuals that disproportionally contribute to disease spread and epizootic outbreaks. For example, bolder phenotypes may experience greater exposure and susceptibility to pathogenic infection because of distinct interactions with conspecifics and their environment. We tested the value of behavioural phenotypes in larval amphibians for predicting ranavirus transmission in experimental trials. We found that behavioural phenotypes characterized by latency-to-food and swimming profiles were predictive of disease susceptibility and infectiousness defined as the capacity of an infected host to transmit an infection by contacts. While viral shedding rates were positively associated with transmission, we also found an inverse relationship between contacts and infections. Together these results suggest intrinsic traits that influence behaviour and the quantity of pathogens shed during conspecific interactions may be an important contributor to ranavirus transmission. These results suggest that behavioural phenotypes provide a means to identify individuals more likely to spread disease and thus give insights into disease outbreaks that threaten wildlife and humans. © 2016 The Author(s).

Hypericum perforatum L. treatment restored bone mass changes in swimming stressed rats.

PubMed

Seferos, Nikos; Petrokokkinos, Loukas; Kotsiou, Antonia; Rallis, George; Tesseromatis, Christine

2016-01-01

Stress, via corticosteroids release, influences bone mass density. Hypericum perforatum (Hp) a traditional remedy possess antidepressive activity (serotonin reuptake inhibitor) and wound healing properties. Hp preparation contains mainly hypericin, hyperforin, hyperoside and flavonoids exerting oestrogen-mimetic effect. Cold swimming represents an experimental model of stress associating mental strain and corporal exhaustion. This study investigates the Hp effect on femur and mandible bone mass changes in rats under cold forced swimming procedure. 30 male Wistar rats were randomized into three groups. Group A was treated with Methanolic extract of Hp (Jarsin®) via gastroesophageal catheter, and was submitted to cold swimming stress for 10 min/daily. Group B was submitted to cold stress, since group C served as control. Experiment duration was 10 days. Haematocrite and serum free fatty acids (FFA) were estimated. Furthermore volume and specific weight of each bone as well as bone mass density via dual energy X-Ray absorptiometry (DEXA) were measured. Statistic analysis by t-test. Hp treatment restores the stress injuries. Adrenals and bone mass density regain their normal values. Injuries occurring by forced swimming stress in the rats are significantly improved by Hp treatment. Estrogen-like effects of Hp flavonoids eventually may act favorable in bone remodeling.

Metabolic mapping of the effects of the antidepressant fluoxetine on the brains of congenitally helpless rats.

PubMed

Shumake, Jason; Colorado, Rene A; Barrett, Douglas W; Gonzalez-Lima, F

2010-07-09

Antidepressants require adaptive brain changes before efficacy is achieved, and they may impact the affectively disordered brain differently than the normal brain. We previously demonstrated metabolic disturbances in limbic and cortical regions of the congenitally helpless rat, a model of susceptibility to affective disorder, and we wished to test whether administration of fluoxetine would normalize these metabolic differences. Fluoxetine was chosen because it has become a first-line drug for the treatment of affective disorders. We hypothesized that fluoxetine antidepressant effects may be mediated by decreasing metabolism in the habenula and increasing metabolism in the ventral tegmental area. We measured the effects of fluoxetine on forced swim behavior and regional brain cytochrome oxidase activity in congenitally helpless rats treated for 2 weeks with fluoxetine (5mg/kg, i.p., daily). Fluoxetine reduced immobility in the forced swim test as anticipated, but congenitally helpless rats responded in an atypical manner, i.e., increasing climbing without affecting swimming. As hypothesized, fluoxetine reduced metabolism in the habenula and increased metabolism in the ventral tegmental area. In addition, fluoxetine reduced the metabolism of the hippocampal dentate gyrus and dorsomedial prefrontal cortex. This study provided the first detailed mapping of the regional brain effects of an antidepressant drug in congenitally helpless rats. All of the effects were consistent with previous studies that have metabolically mapped the effects of serotonergic antidepressants in the normal rat brain, and were in the predicted direction of metabolic normalization of the congenitally helpless rat for all affected brain regions except the prefrontal cortex. Copyright (c) 2010 Elsevier B.V. All rights reserved.

Phototactic orientation mechanism in the ciliate Fabrea salina, as inferred from numerical simulations.

PubMed

Marangoni, R; Preosti, G; Colombetti, G

2000-02-01

The marine ciliate Fabrea salina shows a clear positive phototaxis, but the mechanism by which a single cell is able to detect the direction of light and orient its swimming accordingly is still unknown. A simple model of phototaxis is that of a biased random walk, where the bias due to light can affect one or more of the parameters that characterize a random walk, i.e., the mean speed, the frequency distribution of the angles of directional changes and the frequency of directional changes. Since experimental evidence has shown no effect of light on the mean speed of Fabrea salina, we have excluded models depending on this parameter. We have, therefore, investigated the phototactic orientation of Fabrea salina by computer simulation of two simple models, the first where light affects the frequency distribution of the angles of directional changes (model M1) and the second where the light bias modifies the frequency of directional changes (model M2). Simulated M1 cells directly orient their swimming towards the direction of light, regardless of their current swimming orientation; simulated M2 cells, on the contrary, are unable to actively orient their motion, but remain locked along the light direction once they find it by chance. The simulations show that these two orientation models lead to different macroscopic behaviours of the simulated cell populations. By comparing the results of the simulations with the experimental ones, we have found that the phototactic behaviour of real cells is more similar to that of the M2 model.

Combined intervention of swimming plus metformin ameliorates the insulin resistance and impaired lipid metabolism in murine gestational diabetes mellitus

PubMed Central

Wu, Xuefei; Yu, Ting; Wang, Yang; Zhou, Ji; Kong, Derun

2018-01-01

Gestational diabetes mellitus (GDM) has short- and long- term influence on pregnant women and fetus. Swimming, as an aerobic exercise, can effectively improve the blood glucose level in GDM, but the effect of mild swimming alone was not very substantial. Metformin, as an oral antidiabetic drug, has obvious hypoglycemic effect, and is economic also, but the long-term effect on pregnant women and fetus has not been completely clear. We hypothesize that combined intervention of mild swimming and low dose of metformin, may effectively reduce blood glucose, improve the pregnancy outcomes in GDM dams, but simultaneously avoiding the adverse effects caused by overdose of drug and impotence of mild swimming. The streptozotocin was used to stimulate C57BL/6J mice to develop GDM, by which serum glucose, TC, TG, LDL-C were increased significantly, meanwhile HDL-C was decreased significantly in the GDM control (DC) group compared with the normal control group. Swimming or metformin intervention slightly or moderately improves hyperglycemia, insulin sensitivity and lipid metabolism both in liver and skeletal muscle from GDM mice, while combined therapy of swimming plus metformin markedly ameliorated hyperglycemia (FPG, decreased by 22.2–59.5% from G10 to G18 versus DC group), insulin sensitivity (2.1 and 2.8 fold increase, respectively, in AKT activity versus DC group) and de novo lipogenesis (3.2 and 7.0 fold decrease, respectively, in ACC activity, and 1.94 and 5.1 fold decrease, respectively, in SREBP2 level, versus DC group) both in liver and skeletal muscle from GDM mice. We conclude that the combined intervention by metformin plus swimming may be more effective than single action to ameliorate glucose and lipid metabolism via improving insulin sensitivity in GDM mice. PMID:29677194

Effects of exposure to water disinfection by-products in a swimming pool: A metabolome-wide association study.

PubMed

van Veldhoven, Karin; Keski-Rahkonen, Pekka; Barupal, Dinesh K; Villanueva, Cristina M; Font-Ribera, Laia; Scalbert, Augustin; Bodinier, Barbara; Grimalt, Joan O; Zwiener, Christian; Vlaanderen, Jelle; Portengen, Lützen; Vermeulen, Roel; Vineis, Paolo; Chadeau-Hyam, Marc; Kogevinas, Manolis

2018-02-01

Exposure to disinfection by-products (DBPs) in drinking water and chlorinated swimming pools are associated with adverse health outcomes, but biological mechanisms remain poorly understood. Evaluate short-term changes in metabolic profiles in response to DBP exposure while swimming in a chlorinated pool. The PISCINA-II study (EXPOsOMICS project) includes 60 volunteers swimming 40min in an indoor pool. Levels of most common DBPs were measured in water and in exhaled breath before and after swimming. Blood samples, collected before and 2h after swimming, were used for metabolic profiling by liquid-chromatography coupled to high-resolution mass-spectrometry. Metabolome-wide association between DBP exposures and each metabolic feature was evaluated using multivariate normal (MVN) models. Sensitivity analyses and compound annotation were conducted. Exposure levels of all DBPs in exhaled breath were higher after the experiment. A total of 6,471 metabolic features were detected and 293 features were associated with at least one DBP in exhaled breath following Bonferroni correction. A total of 333 metabolic features were associated to at least one DBP measured in water or urine. Uptake of DBPs and physical activity were strongly correlated and mutual adjustment reduced the number of statistically significant associations. From the 293 features, 20 could be identified corresponding to 13 metabolites including compounds in the tryptophan metabolism pathway. Our study identified numerous molecular changes following a swim in a chlorinated pool. While we could not explicitly evaluate which experiment-related factors induced these associations, molecular characterization highlighted metabolic features associated with exposure changes during swimming. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Digit-only sauropod pes trackways from China – evidence of swimming or a preservational phenomenon?

PubMed Central

Xing, Lida; Li, Daqing; Falkingham, Peter L.; Lockley, Martin G.; Benton, Michael J.; Klein, Hendrik; Zhang, Jianping; Ran, Hao; Persons, W. Scott; Dai, Hui

2016-01-01

For more than 70 years unusual sauropod trackways have played a pivotal role in debates about the swimming ability of sauropods. Most claims that sauropods could swim have been based on manus-only or manus-dominated trackways. However none of these incomplete trackways has been entirely convincing, and most have proved to be taphonomic artifacts, either undertracks or the result of differential depth of penetration of manus and pes tracks, but otherwise showed the typical pattern of normal walking trackways. Here we report an assemblage of unusual sauropod tracks from the Lower Cretaceous Hekou Group of Gansu Province, northern China, characterized by the preservation of only the pes claw traces, that we interpret as having been left by walking, not buoyant or swimming, individuals. They are interpreted as the result of animals moving on a soft mud-silt substrate, projecting their claws deeply to register their traces on an underlying sand layer where they gained more grip during progression. Other sauropod walking trackways on the same surface with both pes and manus traces preserved, were probably left earlier on relatively firm substrates that predated the deposition of soft mud and silt . Presently, there is no convincing evidence of swimming sauropods from their trackways, which is not to say that sauropods did not swim at all. PMID:26888058

Size and cell number of the utricle in kinetotically swimming fish: a parabolic aircraft flight study

NASA Astrophysics Data System (ADS)

Bäuerle, A.; Anken, R. H.; Hilbig, R.; Baumhauer, N.; Rahmann, H.

2004-01-01

Humans taking part in parabolic aircraft flights (PAFs) may suffer from space motion sickness (SMS, a kinetosis). Since it has been repeatedly shown earlier that some fish of a given batch also reveal a kinetotic behavior during PAFs (especially so-called spinning movements and looping responses) and due to the homology of the vestibular apparatus among all vertebrates, fish can be used as model systems to investigate the origin of susceptibility to motion sickness. Therefore, we examined the utricular maculae (they are responsible for the internalization of gravity in teleosteans) of fish swimming kinetotically at microgravity in comparison with animals from the same batch who swam normally. On the histological level, it was found that the total number of both sensory and supporting cells of the utricular maculae did not differ between kinetotic animals as compared to normally swimming fish. Cell density (sensory and supporting cells/100 μm 2), however, was reduced in kinetotic animals ( p < 0.0001), which seemed to be due to malformed epithelial cells (increase in cell size) of the kinetotic specimens. Susceptibility to kinetoses may therefore originate in malformed sensory epithelia.

"I think I became a swimmer rather than just someone with a disability swimming up and down:" paralympic athletes perceptions of self and identity development.

PubMed

Pack, Stephen; Kelly, Sasha; Arvinen-Barrow, Monna

2017-10-01

The purpose of this study was to explore the role of swimming on Paralympic athletes' perceptions of self and identity development. A hermeneutic phenomenological approach was taken. During semi-structured interviews, five Paralympic swimmers (aged 20-24 years) were asked questions about their swimming career, perceptions of self, integration, and impairment. Interviews were audio-recorded and transcribed verbatim. An Interpretative Phenomenological Analysis yielded three superordinate themes: (a) "One of the crowd"; none of the participants viewed themselves as disabled, nor as supercrips; these perceptions stemmed from family-, school-, and swimming-related experiences, (b) "Becoming me"; participation in swimming facilitated self- and social-acceptance, and identity development, and c) "A badge of honor"; swimming presented opportunity to present and reinforce a positive identity. Swimming experiences enabled the participants to enhance personal and social identities, integrate through pro-social mechanisms, and to develop a career path following retirement from competition. Implications for rehabilitation Offering equal sporting opportunities for people with/without physical disability can help facilitate social integration and act as a buffer against stigmatization. Our research suggests that participation in sport had afforded the participants a heightened sense of self-concept, independence, ability and corresponding pride. When working with individuals with physical disabilities, rehabilitation professionals could utilize sport as a means of increasing an individual's feelings of independence, confidence and normalization. As such, part of rehabilitation should be to ensure opportunities for sport participation for people with physical disability are available for people of all ages.

[Comparing the young asthmatics running fitness].

PubMed

Belányi, Kinga; Gyene, István; Bak, Zsuzsa; Mezei, Györgyi

2007-02-25

Nowadays, doctors strongly recommend physical activity for asthmatic children, since the resulting improved physical fitness and psychological change also raise the quality of life. The aim of this study was to compare the physical fitness of asthmatic children who regularly participate in therapeutic swimming, with asthmatic children who do not participate in this training and with non-swimming, healthy children using the 12 minute free running, Cooper test. The children from the swimmer asthmatic group (n= 51, age = 9-22 yrs) took part in a special, long term, swimming exercise program (Gyene method). Whereas, the non-swimmer asthmatics (n = 28, age = 8-22 yrs) and the healthy children (n: 179, age: 9-22 yrs) only took part in the normal school physical education classes. Fitness was measured using the Cooper test. Data was collected from 258 subjects and showed that the fitness of swimmer asthmatics is significantly better than that of the non-swimmer asthmatics and even better than that of the healthy subjects (swimmer/ non swimmer asthmatic p = 0.01; swimmer asthmatic/ healthy p < 0.0001 Chi(2) test). The difference in the fitness acquired from swimming was the most pronounced for the 8-11 years old asthmatics, presumably because of greater motivational factors. No differences were found between genders for the two asthmatic groups, whereas healthy boys were found to have significantly greater levels of fitness than healthy girls. Fitness is substantially increased with regular swimming. The favourable effects of swimming are expressed not only in comparison with the non-swimmer asthmatics but with the healthy subjects too. The regular therapeutic swimming program helps the formation of running fitness too.

Comparison of two sperm processing techniques for low complexity assisted fertilization: sperm washing followed by swim-up and discontinuous density gradient centrifugation.

PubMed

Fácio, Cássio L; Previato, Lígia F; Machado-Paula, Ligiane A; Matheus, Paulo Cs; Araújo, Edilberto

2016-12-01

This study aimed to assess and compare sperm motility, concentration, and morphology recovery rates, before and after processing through sperm washing followed by swim-up or discontinuous density gradient centrifugation in normospermic individuals. Fifty-eight semen samples were used in double intrauterine insemination procedures; 17 samples (group 1) were prepared with sperm washing followed by swim-up, and 41 (group 2) by discontinuous density gradient centrifugation. This prospective non-randomized study assessed seminal parameters before and after semen processing. A dependent t-test was used for the same technique to analyze seminal parameters before and after semen processing; an independent t-test was used to compare the results before and after processing for both techniques. The two techniques produced decreases in sample concentration (sperm washing followed by swim-up: P<0.000006; discontinuous density gradient centrifugation: P=0.008457) and increases in motility and normal morphology sperm rates after processing. The difference in sperm motility between the two techniques was not statistically significant. Sperm washing followed by swim-up had better morphology recovery rates than discontinuous density gradient centrifugation (P=0.0095); and the density gradient group had better concentration recovery rates than the swim-up group (P=0.0027). The two methods successfully recovered the minimum sperm values needed to perform intrauterine insemination. Sperm washing followed by swim-up is indicated for semen with high sperm concentration and better morphology recovery rates. Discontinuous density gradient centrifugation produced improved concentration recovery rates.

Do contamination of and exposure to chicken meat and water drive the temporal dynamics of Campylobacter cases?

PubMed

David, J M; Pollari, F; Pintar, K D M; Nesbitt, A; Butler, A J; Ravel, A

2017-11-01

Campylobacteriosis, the most frequent bacterial enteric disease, shows a clear yet unexplained seasonality. The study purpose was to explore the influence of seasonal fluctuation in the contamination of and in the behaviour exposures to two important sources of Campylobacter on the seasonality of campylobacteriosis. Time series analyses were applied to data collected through an integrated surveillance system in Canada in 2005-2010. Data included sporadic, domestically-acquired cases of Campylobacter jejuni infection, contamination of retail chicken meat and of surface water by C. jejuni, and exposure to each source through barbequing and swimming in natural waters. Seasonal patterns were evident for all variables with a peak in summer for human cases and for both exposures, in fall for chicken meat contamination, and in late fall for water contamination. Time series analyses showed that the observed campylobacteriosis summer peak could only be significantly linked to behaviour exposures rather than sources contamination (swimming rather than water contamination and barbequing rather than chicken meat contamination). The results indicate that the observed summer increase in human cases may be more the result of amplification through more frequent risky exposures rather than the result of an increase of the Campylobacter source contamination.

Giardiasis (For Parents)

MedlinePlus

... their stool. The stool can then contaminate public water supplies, community swimming pools, and water sources like lakes ... normal amounts of chlorine used to purify community water supplies, and can live for more than 2 months ...

Origin and early evolution of neural circuits for the control of ciliary locomotion.

PubMed

Jékely, Gáspár

2011-03-22

Behaviour evolved before nervous systems. Various single-celled eukaryotes (protists) and the ciliated larvae of sponges devoid of neurons can display sophisticated behaviours, including phototaxis, gravitaxis or chemotaxis. In single-celled eukaryotes, sensory inputs directly influence the motor behaviour of the cell. In swimming sponge larvae, sensory cells influence the activity of cilia on the same cell, thereby steering the multicellular larva. In these organisms, the efficiency of sensory-to-motor transformation (defined as the ratio of sensory cells to total cell number) is low. With the advent of neurons, signal amplification and fast, long-range communication between sensory and motor cells became possible. This may have first occurred in a ciliated swimming stage of the first eumetazoans. The first axons may have had en passant synaptic contacts to several ciliated cells to improve the efficiency of sensory-to-motor transformation, thereby allowing a reduction in the number of sensory cells tuned for the same input. This could have allowed the diversification of sensory modalities and of the behavioural repertoire. I propose that the first nervous systems consisted of combined sensory-motor neurons, directly translating sensory input into motor output on locomotor ciliated cells and steering muscle cells. Neuronal circuitry with low levels of integration has been retained in cnidarians and in the ciliated larvae of some marine invertebrates. This parallel processing stage could have been the starting point for the evolution of more integrated circuits performing the first complex computations such as persistence or coincidence detection. The sensory-motor nervous systems of cnidarians and ciliated larvae of diverse phyla show that brains, like all biological structures, are not irreducibly complex.

Time-dependent in-vivo effects of interleukin-2 on neurotransmitters in various cortices: relationships with depressive-related and anxiety-like behaviour.

PubMed

Karrenbauer, B D; Müller, C P; Ho, Y J; Spanagel, R; Huston, J P; Schwarting, R K W; Pawlak, C R

2011-08-15

We investigated the impact of systemically injected IL-2 (2.5 μg/kg, i.p.) on serotonergic and dopaminergic neurotransmission in various cortical areas by in-vivo microdialysis. IL-2 lastingly reduced extracellular 5-HT levels in the medial prefrontal (-75%), occipital (-70%), and temporal cortices (-45%), whereas dopamine was only moderately reduced in the medial prefrontal cortex. Based on the serotonergic time profile, we conducted further experiments to test for acute and delayed (2 h post injection) depressive-related effects of systemic IL-2 (0-5.0 μg/kg) in a forced swim test and delayed effects on anxiety-like behaviour in the elevated plus-maze. IL-2 had dose-dependent effects on depressive-related behaviour after delayed but not acute testing, but no effects on anxiety-like behaviour. Copyright © 2011 Elsevier B.V. All rights reserved.

Olfactory learning prevents MK-801-induced psychosis-like behaviour in an animal model of schizophrenia.

PubMed

Naimark, Ari; Barkai, Edi; Michael, Matar A; Kozlovsky, Nitzan; Kaplan, Zeev; Cohen, Hagit

2008-01-01

There is mounting evidence to support the concept that education is associated with the formation of a functional reserve in the brain, a process that appears to provide some protection against certain aspects of severe central nervous system disorders. The goal of this study was to examine whether learning prevents psychosis-like behaviour in an animal model of schizophrenia. A series of behavioural tasks were used to assess olfactory learning-induced protection against the effects of NMDA channel blocker, MK801. This blocker caused sensory-motor disturbances, spatial learning acquisition deficit, and swimming strategy alterations in pseudo-trained and naive rats, but had a considerably lesser effect on trained rats. In sharp contrast, olfactory learning provided no protection against d-amphetamine application. Our data support the notion that learning-induced protection against schizophrenic behaviour is maintained by non-NMDA-mediated enhanced activation of local connections in the relevant cortical networks.

Absence of opioid stress-induced analgesia in mice lacking beta-endorphin by site-directed mutagenesis.

PubMed

Rubinstein, M; Mogil, J S; Japón, M; Chan, E C; Allen, R G; Low, M J

1996-04-30

A physiological role for beta-endorphin in endogenous pain inhibition was investigated by targeted mutagenesis of the proopiomelanocortin gene in mouse embryonic stem cells. The tyrosine codon at position 179 of the proopiomelanocortin gene was converted to a premature translational stop codon. The resulting transgenic mice display no overt developmental or behavioral alterations and have a normally functioning hypothalamic-pituitary-adrenal axis. Homozygous transgenic mice with a selective deficiency of beta-endorphin exhibit normal analgesia in response to morphine, indicating the presence of functional mu-opiate receptors. However, these mice lack the opioid (naloxone reversible) analgesia induced by mild swim stress. Mutant mice also display significantly greater nonopioid analgesia in response to cold water swim stress compared with controls and display paradoxical naloxone-induced analgesia. These changes may reflect compensatory upregulation of alternative pain inhibitory mechanisms.

The foraging benefits of being fat in a highly migratory marine mammal.

PubMed

Adachi, Taiki; Maresh, Jennifer L; Robinson, Patrick W; Peterson, Sarah H; Costa, Daniel P; Naito, Yasuhiko; Watanabe, Yuuki Y; Takahashi, Akinori

2014-12-22

Foraging theory predicts that breath-hold divers adjust the time spent foraging at depth relative to the energetic cost of swimming, which varies with buoyancy (body density). However, the buoyancy of diving animals varies as a function of their body condition, and the effects of these changes on swimming costs and foraging behaviour have been poorly examined. A novel animal-borne accelerometer was developed that recorded the number of flipper strokes, which allowed us to monitor the number of strokes per metre swam (hereafter, referred to as strokes-per-metre) by female northern elephant seals over their months-long, oceanic foraging migrations. As negatively buoyant seals increased their fat stores and buoyancy, the strokes-per-metre increased slightly in the buoyancy-aided direction (descending), but decreased significantly in the buoyancy-hindered direction (ascending), with associated changes in swim speed and gliding duration. Overall, the round-trip strokes-per-metre decreased and reached a minimum value when seals achieved neutral buoyancy. Consistent with foraging theory, seals stayed longer at foraging depths when their round-trip strokes-per-metre was less. Therefore, neutrally buoyant divers gained an energetic advantage via reduced swimming costs, which resulted in an increase in time spent foraging at depth, suggesting a foraging benefit of being fat. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

Effect of boat noise and angling on lake fish behaviour.

PubMed

Jacobsen, L; Baktoft, H; Jepsen, N; Aarestrup, K; Berg, S; Skov, C

2014-06-01

The effects of disturbances from recreational activities on the swimming speed and habitat use of roach Rutilus rutilus, perch Perca fluviatilis and pike Esox lucius were explored. Disturbances were applied for 4 h as (1) boating in short intervals with a small outboard internal combustion engine or (2) boating in short intervals combined with angling with artificial lures between engine runs. The response of the fish species was evaluated by high-resolution tracking using an automatic acoustic telemetry system and transmitters with sub-minute burst rates. Rutilus rutilus swimming speed was significantly higher during disturbances [both (1) and (2)] with an immediate reaction shortly after the engine started. Perca fluviatilis displayed increased swimming activity during the first hour of disturbance but not during the following hours. Swimming activity of E. lucius was not significantly different between disturbance periods and the same periods on days without disturbance (control). Rutilus rutilus increased their use of the central part of the lake during disturbances, whereas no habitat change was observed in P. fluviatilis and E. lucius. No difference in fish response was detected between the two types of disturbances (boating with and without angling), indicating that boating was the primary source of disturbance. This study highlights species-specific responses to recreational boating and may have implications for management of human recreational activities in lakes. © 2014 The Fisheries Society of the British Isles.

Comparative axial morphology in pinnipeds and its correlation with aquatic locomotory behaviour

PubMed Central

Pierce, S E; Clack, J A; Hutchinson, J R

2011-01-01

Regional variation in the axial skeleton of pinnipeds (seals and walruses) and its correlation with aquatic locomotory behaviour is examined using vertebral functional profiles. The results demonstrate clear morpho-functional differences in the thoracolumbar region of modern pinnipeds (Phocidae, Otariidae, Odobenus) that can be strongly linked to swimming style. Phocid seals have a rigid thoracic region attached to a highly flexible lumbar region with long muscular lever arms providing the necessary mobility and leverage to perform pelvic oscillations. Conversely, otariid seals have extremely flexible inter-vertebral joints along the length of the column which should enhance manoeuvrability and turning performance. They also have greater muscular leverage in the anterior thoracic region to support pectoral oscillations. Odobenus (walrus) shows vertebral characteristics most similar to phocids, but with some otariid qualities, consistent with an intermediate or mixed form of aquatic locomotion, with pelvic oscillation dominating over pectoral oscillation. Comparison of the vertebral functional profiles in the fossil taxon Allodesmus kernensis with those of modern pinniped clades reveals that this extinct pinniped may also have used a combination of pectoral and pelvic oscillatory movements during swimming, but in a manner opposite to that of Odobenus, with pectoral oscillatory movements dominating. This study raises questions about the evolution and diversification of pinniped locomotory behaviours, but also provides the necessary framework to begin to examine axial mechanics and locomotory stages in other fossil pinnipedimorphs and their relatives in more detail. PMID:21668895

Blue whales respond to simulated mid-frequency military sonar.

PubMed

Goldbogen, Jeremy A; Southall, Brandon L; DeRuiter, Stacy L; Calambokidis, John; Friedlaender, Ari S; Hazen, Elliott L; Falcone, Erin A; Schorr, Gregory S; Douglas, Annie; Moretti, David J; Kyburg, Chris; McKenna, Megan F; Tyack, Peter L

2013-08-22

Mid-frequency military (1-10 kHz) sonars have been associated with lethal mass strandings of deep-diving toothed whales, but the effects on endangered baleen whale species are virtually unknown. Here, we used controlled exposure experiments with simulated military sonar and other mid-frequency sounds to measure behavioural responses of tagged blue whales (Balaenoptera musculus) in feeding areas within the Southern California Bight. Despite using source levels orders of magnitude below some operational military systems, our results demonstrate that mid-frequency sound can significantly affect blue whale behaviour, especially during deep feeding modes. When a response occurred, behavioural changes varied widely from cessation of deep feeding to increased swimming speed and directed travel away from the sound source. The variability of these behavioural responses was largely influenced by a complex interaction of behavioural state, the type of mid-frequency sound and received sound level. Sonar-induced disruption of feeding and displacement from high-quality prey patches could have significant and previously undocumented impacts on baleen whale foraging ecology, individual fitness and population health.

Utility of the multi-component training distress scale to monitor swimmers during periods of training overload.

PubMed

Main, Luana C; Warmington, Stuart A; Korn, Emily; Gastin, Paul B

2016-01-01

The purpose of the present study was to determine the efficacy of the multi-component training distress scale (MTDS), in monitoring swimmers prior to national competition. Twenty-one national-level adolescent swimmers completed eight weeks of testing. Once a week participants completed an 8 × 50 m sprint test, vertical jump test, sit-and-reach test, the MTDS and the Recovery-Stress Questionnaire for Athletes (REST-Q). All testing was incorporated into the swimmers' normal training programme. The REST-Q accounted for the following variances in performance: flexibility (14.6%, p = 0.009), power output (17.7%, p = 0.003), swimming speed (15.5%, p = 0.006) and swimming endurance (17.5%, p = 0.002). In comparison, the MTDS accounted for the following variances in performance: flexibility (12.1%, p = 0.095), power output (16.4%, p = 0.023), swimming speed (20.5%, p = 0.003) and swimming speed endurance (23.8%, p = 0.001). The findings of the current study suggest that both the REST-Q Sport and the MTDS have the capacity to predict performance on a range of fitness components associated with swimming.

[Nutrition, physical activity and substance use in children and adolescents : Representative results of the federal state module Thuringia in KiGGS wave 1].

PubMed

Krause, Laura; Anding, Christine; Kamtsiuris, Panagiotis

2016-08-01

The term health behaviour combines both health-promoting and health-risk components. In this study, the health behaviour of children and adolescents in Thuringia is analysed. The database was a representative subsample of the federal state module Thuringia, which was conducted by the Robert Koch Institute as part of the German Health Interview and Examination Survey for Children and Adolescents (KiGGS) wave 1 (2010-2012; n = 4,096; 3-17 years). Health behaviour was described based on nine indicators: fruit and vegetable consumption, soft drink consumption, breakfast at home, physical activity, sport, swimming ability, alcohol consumption, smoking and water pipe consumption (shisha smoking). Prevalence and mean values with 95 % confidence intervals were reported, and based on logistic or linear regression, the significance of the group differences was examined. The results show that 43.4 % of children and adolescents in Thuringia ate fruits and vegetables daily, 44.5 % consumed soft drinks less than once a week, and 67.9 % had breakfast at home every weekday. In addition, 31.0 % of children and adolescents in Thuringia were physically active at least 60 min a day, 69.8 % did sports for at least 2 h a week, and 81.5 % can swim. Additionally, 15.9 % of adolescents in Thuringia had hazardous alcohol consumption, 14.4 % currently smoked, and 20.0 % smoked a water pipe. Differences existed with regard to gender, age, socio-economic status (SES) of the family and residence (urban/rural). In summary, many of the children and adolescents in Thuringia demonstrate relatively positive health behaviour. However, the results also indicate groups at higher risk of unhealthy behaviour, such as children and adolescents from families with low SES.

Protective effects of aerobic swimming training on high-fat diet induced nonalcoholic fatty liver disease: regulation of lipid metabolism via PANDER-AKT pathway.

PubMed

Wu, Hao; Jin, Meihua; Han, Donghe; Zhou, Mingsheng; Mei, Xifan; Guan, Youfei; Liu, Chang

2015-03-20

This study aimed to investigate the mechanism by which aerobic swimming training prevents high-fat-diet-induced nonalcoholic fatty liver disease (NAFLD). Forty-two male C57BL/6 mice were randomized into normal-diet sedentary (ND; n = 8), ND exercised (n = 8), high-fat diet sedentary (HFD; n = 13), and HFD exercised groups (n = 13). After 2 weeks of training adaptation, the mice were subjected to an aerobic swimming protocol (60 min/day) 5 days/week for 10 weeks. The HFD group exhibited significantly higher mRNA levels of fatty acid transport-, lipogenesis-, and β-oxidation-associated gene expressions than the ND group. PANDER and FOXO1 expressions increased, whereas AKT expression decreased in the HFD group. The aerobic swimming program with the HFD reversed the effects of the HFD on the expressions of thrombospondin-1 receptor, liver fatty acid-binding protein, long-chain fatty-acid elongase-6, Fas cell surface death receptor, and stearoyl-coenzyme A desaturase-1, as well as PANDER, FOXO1, and AKT. In the HFD exercised group, PPARα and AOX expressions were much higher. Our findings suggest that aerobic swimming training can prevent NAFLD via the regulation of fatty acid transport-, lipogenesis-, and β-oxidation-associated genes. In addition, the benefits from aerobic swimming training were achieved partly through the PANDER-AKT-FOXO1 pathway. Copyright © 2015 Elsevier Inc. All rights reserved.

Fertility of male adult rats submitted to forced swimming stress.

PubMed

Mingoti, G Z; Pereira, R N; Monteiro, C M R

2003-05-01

We investigated whether stress interferes with fertility during adulthood. Male Wistar rats (weighing 220 g in the beginning of the experiment) were forced to swim for 3 min in water at 32 degrees C daily for 15 days. Stress was assessed by the hot-plate test after the last stressing session. To assess fertility, control and stressed males (N = 15 per group) were mated with sexually mature normal females. Males were sacrificed after copulation. Stress caused by forced swimming was demonstrated by a significant increase in the latency of the pain response in the hot-plate test (14.6 +/- 1.25 s for control males vs 26.0 +/- 1.53 s for stressed males, P = 0.0004). No changes were observed in body weight, testicular weight, seminal vesicle weight, ventral prostate weight or gross histological features of the testes of stressed males. Similarly, no changes were observed in fertility rate, measured by counting live fetuses in the uterus of normal females mated with control and stressed males; no dead or incompletely developed fetuses were observed in the uterus of either group. In contrast, there was a statistically significant decrease in spermatid production demonstrated by histometric evaluation (154.96 +/- 5.41 vs 127.02 +/- 3.95 spermatids per tubular section for control and stressed rats, respectively, P = 0.001). These data demonstrate that 15 days of forced swimming stress applied to adult male rats did not impair fertility, but significantly decreased spermatid production. This suggests that the effect of stress on fertility should not be assessed before at least the time required for one cycle of spermatogenesis.

Improving sneaky-sex in a low oxygen environment: reproductive and physiological responses of male mosquito fish to chronic hypoxia.

PubMed

Carter, Alecia J; Wilson, Robbie S

2006-12-01

Few studies have examined the adaptive significance of reversible acclimation responses. The aerobic performance and mating behaviour of the sexually coercive male eastern mosquito fish (Gambusia holbrooki) offers an excellent model system for testing the benefits of reversible acclimation responses to mating success. We exposed male mosquito fish to normoxic or hypoxic conditions for 4 weeks and tested their maximum sustained swimming performance and their ability to obtain coercive matings under both normoxic and hypoxic conditions. We predicted that hypoxia-acclimated males would possess greater swimming and mating performance in hypoxic conditions than normoxic-acclimated males, and vice versa when tested in normoxia. Supporting our predictions, we found the sustained swimming performance of male mosquito fish was greater in a hypoxic environment following long-term exposure to low partial pressures of oxygen. However, the benefits of acclimation responses to mating performance were dependent on whether they were tested in the presence or absence of male-male competition. In a non-competitive environment, male mosquito fish acclimated to hypoxic conditions spent a greater amount of time following females and obtained more copulations than normoxic-acclimated males when tested in low partial pressures of oxygen. When males were competed against each other for copulations, we found no influence of long-term exposure to different partial pressures of oxygen on mating behaviour. Thus, despite improvements in the aerobic capacity of male mosquito fish following long-term acclimation to hypoxic conditions, these benefits did not always manifest themselves in improved mating performance. This study represents one of the first experimental tests of the benefits of reversible acclimation responses, and indicates that the ecological significance of physiological plasticity may be more complicated than previously imagined.

Chronic caffeine produces sexually dimorphic effects on amphetamine-induced behavior, anxiety and depressive-like behavior in adolescent rats.

PubMed

Turgeon, Sarah M; Townsend, Shannon E; Dixon, Rushell S; Hickman, Emma T; Lee, Sabrina M

2016-04-01

Caffeine consumption has been increasing rapidly in adolescents; however, most research on the behavioral effects of caffeine has been conducted in adults. Two experiments were conducted in which adolescent male and female rats were treated with a moderate dose of caffeine (0.25 g/l) in their drinking water beginning on P26-28. In the first experiment, animals were maintained on caffeinated drinking water or normal tap water for 14 days and were then tested for behavioral and striatal c-Fos response to amphetamine (1.5 mg/kg). In the second experiment, rats were maintained on caffeinated drinking water or normal tap water beginning on P28 and were tested for novel object recognition, anxiety in the light/dark test (L/D) and elevated plus maze (EPM), and depressive like behavior in the forced swim test (FST) beginning on the 14th day of caffeine exposure. Caffeine decreased amphetamine-induced rearing in males, but had no effect in females; however, this behavioral effect was not accompanied by changes in striatal c-Fos, which was increased by amphetamine but not altered by caffeine. No effects of caffeine were observed on novel object recognition or elevated plus maze behavior. However, in the L/D test, there was a sex by caffeine interaction on time spent in the light driven by a caffeine-induced increase in light time in the males but not the females. On the pretest day of the FST, sex by caffeine interactions were observed for swimming and struggling; caffeine decreased struggling behavior and increased swimming behavior in males and caffeine-treated females demonstrated significantly more struggling and significantly less swimming than caffeine-treated males. A similar pattern was observed on the test day in which caffeine decreased immobility overall and increased swimming. These data reveal sex dependent effects of caffeine on behavior in adolescent rats. Copyright © 2016 Elsevier Inc. All rights reserved.

Behavioural alterations are independent of sickness behaviour in chronic experimental Chagas disease.

PubMed

Vilar-Pereira, Glaucia; Ruivo, Leonardo Alexandre de Souza; Lannes-Vieira, Joseli

2015-12-01

The existence of the nervous form of Chagas disease is a matter of discussion since Carlos Chagas described neurological disorders, learning and behavioural alterations in Trypanosoma cruzi-infected individuals. In most patients, the clinical manifestations of the acute phase, including neurological abnormalities, resolve spontaneously without apparent consequence in the chronic phase of infection. However, chronic Chagas disease patients have behavioural changes such as psychomotor alterations, attention and memory deficits, and depression. In the present study, we tested whether or not behavioural alterations are reproducible in experimental models. We show that C57BL/6 mice chronically infected with the Colombian strain of T. cruzi (150 days post-infection) exhibit behavioural changes as (i) depression in the tail suspension and forced swim tests, (ii) anxiety analysed by elevated plus maze and open field test sand and (iii) motor coordination in the rotarod test. These alterations are neither associated with neuromuscular disorders assessed by the grip strength test nor with sickness behaviour analysed by temperature variation sand weight loss. Therefore, chronically T. cruzi-infected mice replicate behavioural alterations (depression and anxiety) detected in Chagas disease patients opening an opportunity to study the interconnection and the physiopathology of these two biological processes in an infectious scenario.

The influence of fire-coral colony size and agonistic behaviour of territorial damselfish on associated coral reef fish communities.

PubMed

Leal, Isabela Carolina Silva; de Araújo, Maria Elisabeth; da Cunha, Simone Rabelo; Pereira, Pedro Henrique Cipresso

2015-07-01

Branching hydrocorals from the genus Millepora play an important ecological role in South Atlantic reefs, where branching scleractinian corals are absent. Previous studies have shown a high proportion of reef fish species using branching fire-coral colonies as shelter, breeding, and feeding sites. However, the effects of Millepora spp. colony size and how the agonistic behaviour of a competitive damselfish affect the associated reef fish community are still unknown. The present study examined how fire-coral colony volume and the presence of a highly territorial and aggressive damselfish (Brazilian endemic Stegastes fuscus) affects the reef fish community associated with the fire-coral Millepora alcicornis. M. alcicornis colonies were surveyed from September 2012 to April 2013 at Tamandaré Reefs off Northeast Brazil. Our results show that the abundance and richness of coral associated fish was positively correlated with M. alcicornis coral colony volume. Additionally, behaviour of S. fuscus, the most abundant reef fish species found associated with fire-coral colonies (almost 57% of the fish community), was also influenced by fire-coral colony volume. There was a clear trend of increased agonistic behaviour and feeding on coral polyps as colony volume increased. This trend was reversed for the non-occupational swimming category, which decreased as M. alcicornis colony volume increased. Behavioural ontogenetic changes were also detected for S. fuscus individuals. Juveniles mainly showed two distinct behaviours: sheltered on coral branches and feeding on coral polyps. In contrast, adults presented greater equitability among the behavioural categories, mostly non-occupational swimming around coral colonies and agonistic behaviour. Lastly, S. fuscus individuals actively defended fire-coral colonies from intruders. A large number of agonistic interactions occurred against potential food competitors, which were mainly roving herbivores, omnivores, and sessile invertebrate feeders. To our knowledge, the present study provides the first evidence that through habitat competition, the presence of S. fuscus may affect reef fish communities associated with M. alcicornis coral colonies. Our findings also indicate that S. fuscus uses M. alcicornis coral colonies as part of their territory for shelter and foraging. In conclusion, M. alcicornis fire-coral colonies are extremely important habitats for reef fishes and the size and presence of a territorial damselfish are relevant variables for associated reef fish community. Copyright © 2015 Elsevier Ltd. All rights reserved.

Comparative swimming and station-holding ability of the threatened Rocky Mountain Sculpin (Cottus sp.) from four hydrologically distinct rivers

PubMed Central

Veillard, Marie F.; Ruppert, Jonathan L.W.; Tierney, Keith; Watkinson, Douglas A.

2017-01-01

Abstract Hydrologic alterations, such as dams, culverts or diversions, can introduce new selection pressures on freshwater fishes, where they are required to adapt to novel environmental conditions. Our study investigated how species adapt to natural and altered stream flow, where we use the threatened Rocky Mountain Sculpin (Cottus sp.) as a model organism. We compared the swimming and station-holding performance of Rocky Mountain Sculpin from four different hydrologic regimes in Alberta and British Columbia, including the North Milk River, a system that experiences increased flows from a large-scale diversion. We measured the slip (Uslip) and failure (Uburst) velocities over three constant acceleration test trials. Uslip was defined as the point at which individuals required the addition of bursting or swimming to maintain position. Uburst was defined as the point at which individuals were unable to hold position in the swimming chamber through swimming, bursting or holding techniques without fully or partially resting on the electrified back plate. We found individuals from the Flathead River in British Columbia (with the highest natural flow) failed at significantly higher Uburst velocities than fish from the southern Albertan populations. However, there was no relationship between peak hydrologic flow from the natal river and Uburst or Uslip. Further, Uburst velocities decreased from 51.8 cm s−1 (7.2 BL s−1) to 45.6 cm s−1 (6.3 BL s−1) by the third consecutive test suggesting the use of anaerobic metabolism. Uslip was not different between trials suggesting the use of aerobic metabolism in station-holding behaviours (Uslip). Moreover, we found no significant differences in individuals from the altered North Milk River system. Finally, individual caudal morphological characteristics were related to both slip and failure velocities. Our study contributes to the conservation of Rocky Mountain Sculpin by providing the first documentation of swimming and station-holding abilities of this benthic fish. PMID:28480038

Comparative swimming and station-holding ability of the threatened Rocky Mountain Sculpin (Cottus sp.) from four hydrologically distinct rivers.

PubMed

Veillard, Marie F; Ruppert, Jonathan L W; Tierney, Keith; Watkinson, Douglas A; Poesch, Mark

2017-01-01

Hydrologic alterations, such as dams, culverts or diversions, can introduce new selection pressures on freshwater fishes, where they are required to adapt to novel environmental conditions. Our study investigated how species adapt to natural and altered stream flow, where we use the threatened Rocky Mountain Sculpin ( Cottus sp.) as a model organism. We compared the swimming and station-holding performance of Rocky Mountain Sculpin from four different hydrologic regimes in Alberta and British Columbia, including the North Milk River, a system that experiences increased flows from a large-scale diversion. We measured the slip ( U slip ) and failure ( U burst ) velocities over three constant acceleration test trials. U slip was defined as the point at which individuals required the addition of bursting or swimming to maintain position. U burst was defined as the point at which individuals were unable to hold position in the swimming chamber through swimming, bursting or holding techniques without fully or partially resting on the electrified back plate. We found individuals from the Flathead River in British Columbia (with the highest natural flow) failed at significantly higher U burst velocities than fish from the southern Albertan populations. However, there was no relationship between peak hydrologic flow from the natal river and U burst or U slip . Further, U burst velocities decreased from 51.8 cm s -1 (7.2 BL s -1 ) to 45.6 cm s -1 (6.3 BL s -1 ) by the third consecutive test suggesting the use of anaerobic metabolism. U slip was not different between trials suggesting the use of aerobic metabolism in station-holding behaviours ( U slip ). Moreover, we found no significant differences in individuals from the altered North Milk River system. Finally, individual caudal morphological characteristics were related to both slip and failure velocities. Our study contributes to the conservation of Rocky Mountain Sculpin by providing the first documentation of swimming and station-holding abilities of this benthic fish.

Predicting the buoyancy, equilibrium and potential swimming ability of giraffes by computational analysis.

PubMed

Henderson, Donald M; Naish, Darren

2010-07-21

Giraffes (Giraffa camelopardalis) are often stated to be unable to swim, and while few observations supporting this have ever been offered, we sought to test the hypothesis that giraffes exhibited a body shape or density unsuited for locomotion in water. We assessed the floating capability of giraffes by simulating their buoyancy with a three-dimensional mathematical/computational model. A similar model of a horse (Equus caballus) was used as a control, and its floating behaviour replicates the observed orientations of immersed horses. The floating giraffe model has its neck sub-horizontal, and the animal would struggle to keep its head clear of the water surface. Using an isometrically scaled-down giraffe model with a total mass equal to that of the horse, the giraffe's proportionally larger limbs have much higher rotational inertias than do those of horses, and their wetted surface areas are 13.5% greater relative to that of the horse, thus making rapid swimming motions more strenuous. The mean density of the giraffe model (960 gm/l) is also higher than that of the horse (930 gm/l), and closer to that causing negative buoyancy (1000 gm/l). A swimming giraffe - forced into a posture where the neck is sub-horizontal and with a thorax that is pulled downwards by the large fore limbs - would not be able to move the neck and limbs synchronously as giraffes do when moving on land, possibly further hampering the animal's ability to move its limbs effectively underwater. We found that a full-sized, adult giraffe will become buoyant in water deeper than 2.8m. While it is not impossible for giraffes to swim, we speculate that they would perform poorly compared to other mammals and are hence likely to avoid swimming if possible. (c) 2010. Published by Elsevier Ltd. All rights reserved.

[Evaluation of grip strength in normal and obese Wistar rats submitted to swimming with overload after median nerve compression].

PubMed

Coradinia, Josinéia Gresele; Kakihata, Camila Mayumi Martin; Kunz, Regina Inês; Errero, Tatiane Kamada; Bonfleur, Maria Lúcia; Bertolini, Gladson Ricardo Flor

2015-01-01

To verify the functionality through muscle grip strength in animals with obesity induced by monosodium glutamate (MSG) and in control animals, which suffered compression of the right median nerve, and treated with swimming with overload. During the first five days of life, neonatal Wistar rats received subcutaneous injections of MSG. The control group received a hypertonic saline solution. Forty-eight rats were divided into six groups: G1 (control); G2 (control + injury); G3 (control + injury + swimming); G4 (obese); G5 (obese + injury); G6 (obese + injury + swimming). The animals in groups G2, G3, G5 and G6 were submitted to compression of the median nerve and G3 and G6 groups were treated, after injury, with swimming exercise with load for three weeks. The swimming exercise had a progressive duration, according to the week, of 20, 30 and 40minutes. Muscle strength was assessed using a grip strength meter preoperatively and on the 3rd, 7th, 14th and 21st days after surgery. The results were expressed and analyzed using descriptive and inferential statistics. When the grip strength was compared among assessments regardless of group, in the second assessment the animals exhibited lower grip strength. G1 and G4 groups had greater grip strength, compared to G2, G3, G4 and G6. The swimming exercise with overload has not been effective in promoting improvement in muscle grip strength after compression injury of the right median nerve in control and in obese-MSG rats. Copyright © 2013 Elsevier Editora Ltda. All rights reserved.

Coexistence of behavioural types in an aquatic top predator: a response to resource limitation?

PubMed

Kobler, Alexander; Klefoth, Thomas; Mehner, Thomas; Arlinghaus, Robert

2009-10-01

Intra-population variation in behaviour unrelated to sex, size or age exists in a variety of species. The mechanisms behind behavioural diversification have only been partly understood, but density-dependent resource availability may play a crucial role. To explore the potential coexistence of different behavioural types within a natural fish population, we conducted a radio telemetry study, measuring habitat use and swimming activity patterns of pike (Esox lucius), a sit-and-wait predatory fish. Three behavioural types co-occurred in the study lake. While two types of fish only selected vegetated littoral habitats, the third type opportunistically used all habitats and increased its pelagic occurrence in response to decreasing resource biomasses. There were no differences in size, age or lifetime growth between the three behavioural types. However, habitat-opportunistic pike were substantially more active than the other two behavioural types, which is energetically costly. The identical growth rates exhibited by all behavioural types indicate that these higher activity costs of opportunistic behaviour were compensated for by increased prey consumption in the less favourable pelagic habitat resulting in approximately equal fitness of all pike groups. We conclude that behavioural diversification in habitat use and activity reduces intraspecific competition in preferred littoral habitats. This may facilitate the emergence of an ideal free distribution of pike along resource gradients.

Chronic treatment with 13-cis-retinoic acid changes aggressive behaviours in the resident-intruder paradigm in rats.

PubMed

Trent, Simon; Drew, Cheney J G; Mitchell, Paul J; Bailey, Sarah J

2009-12-01

Retinoids, vitamin A related compounds, have an established role in the development of the nervous system and are increasingly recognized to play a role in adult brain function. The synthetic retinoid, 13-cis-retinoic acid (13-cis-RA, Roaccutane) is widely used to treat severe acne but has been linked to an increased risk of neuropsychiatric side effects, including depression. Here we report that chronic administration with 13-cis-RA (1 mg/kg i.p. daily, 7-14 days) in adult rats reduced aggression- and increased flight-related behaviours in the resident-intruder paradigm. However, in the forced swim, sucrose consumption and open field tests treatment for up to 6 weeks with 13-cis-RA did not modify behaviour in adult or juvenile animals. The behavioural change observed in the resident-intruder paradigm is directly opposite to that observed with chronic antidepressant administration. These findings indicate that when a suitably sensitive behavioural test is employed then chronic administration of 13-cis-RA in adult rats induces behavioural changes consistent with a pro-depressant action.

Supraspinal control of spinal reflex responses to body bending during different behaviours in lampreys

PubMed Central

Hsu, Li‐Ju; Zelenin, Pavel V.; Orlovsky, Grigori N.

2016-01-01

Key points Spinal reflexes are substantial components of the motor control system in all vertebrates and centrally driven reflex modifications are essential to many behaviours, but little is known about the neuronal mechanisms underlying these modifications.To study this issue, we took advantage of an in vitro brainstem–spinal cord preparation of the lamprey (a lower vertebrate), in which spinal reflex responses to spinal cord bending (caused by signals from spinal stretch receptor neurons) can be evoked during different types of fictive behaviour.Our results demonstrate that reflexes observed during fast forward swimming are reversed during escape behaviours, with the reflex reversal presumably caused by supraspinal commands transmitted by a population of reticulospinal neurons.NMDA receptors are involved in the formation of these commands, which are addressed primarily to the ipsilateral spinal networks.In the present study the neuronal mechanisms underlying reflex reversal have been characterized for the first time. Abstract Spinal reflexes can be modified during different motor behaviours. However, our knowledge about the neuronal mechanisms underlying these modifications in vertebrates is scarce. In the lamprey, a lower vertebrate, body bending causes activation of intraspinal stretch receptor neurons (SRNs) resulting in spinal reflexes: activation of motoneurons (MNs) with bending towards either the contralateral or ipsilateral side (a convex or concave response, respectively). The present study had two main aims: (i) to investigate how these spinal reflexes are modified during different motor behaviours, and (ii) to reveal reticulospinal neurons (RSNs) transmitting commands for the reflex modification. For this purpose in in vitro brainstem–spinal cord preparation, RSNs and reflex responses to bending were recorded during different fictive behaviours evoked by supraspinal commands. We found that during fast forward swimming MNs exhibited convex responses. By contrast, during escape behaviours, MNs exhibited concave responses. We found RSNs that were activated during both stimulation causing reflex reversal without initiation of any specific behaviour, and stimulation causing reflex reversal during escape behaviour. We suggest that these RSNs transmit commands for the reflex modification. Application of the NMDA antagonist (AP‐5) to the brainstem significantly decreased the reversed reflex, suggesting involvement of NMDA receptors in the formation of these commands. Longitudinal split of the spinal cord did not abolish the reflex reversal caused by supraspinal commands, suggesting an important role for ipsilateral networks in determining this type of motor response. This is the first study to reveal the neuronal mechanisms underlying supraspinal control of reflex reversal. PMID:27589479

Bacterial populations on silicone hydrogel and hydrogel contact lenses after swimming in a chlorinated pool.

PubMed

Choo, Jennifer; Vuu, Kathy; Bergenske, Peter; Burnham, Kara; Smythe, Jennifer; Caroline, Patrick

2005-02-01

A number of reports have indicated an association between swimming with contact lenses and subsequent eye infection. This study tests whether a hydrophilic contact lens worn while swimming accumulates bacteria present in the water. It was of interest to determine whether lens type (silicone hydrogel vs. hydrogel) affected the result. Fifteen healthy noncontact lens wearers swam for 30 minutes with a silicone hydrogel lens (PureVision, Bausch & Lomb, Rochester, NY) on one eye and a hydrogel lens (Acuvue 2, Vistakon Inc., Jacksonville, FL) on the other. Lenses were removed aseptically and placed in sterile vials 10 minutes after the subjects left the water. Microbial growth was enumerated for total numbers of colonies and categorized by species present. Numbers of colonies were compared between the two lens groups and with a water sample taken from the pool at the time of the experiment. Eight of the subjects returned on a different day and wore new lenses for 50 minutes in normal room conditions. Two lenses were lost while swimming. Twenty-seven of the remaining 28 lenses worn while swimming showed colonization, principally with Staphylococcus epidermidis, which was also by far the most common species identified from the water itself. Small numbers of Staphylococcus aureus and Streptococcus salivarius were also present in the water and on the lenses. Numbers of colonies varied among subjects (range, 0 to 230), but no differences were observed between the two lens groups. Lenses removed after 30 minutes of wear without swimming were mostly sterile, with 3 of 16 lenses showing just two colonies each. It appears that wearing a hydrophilic lens while swimming allows accumulation of microbial organisms on or in the lens, regardless of lens material. Swimmers should be advised to wear tight-fitting goggles if lenses are worn while swimming, and thorough disinfection of the lenses before overnight wear seems prudent.

Concerns Girls Have about Puberty

MedlinePlus

... in activities such as swimming, horseback riding, or physical education classes. Reassure your daughter that she can take part in normal activities while menstruating. Exercise can sometimes even ease the cramps ... Physical Development in Girls: What to Expect When Puberty ...

Absence of opioid stress-induced analgesia in mice lacking beta-endorphin by site-directed mutagenesis.

PubMed Central

Rubinstein, M; Mogil, J S; Japón, M; Chan, E C; Allen, R G; Low, M J

1996-01-01

A physiological role for beta-endorphin in endogenous pain inhibition was investigated by targeted mutagenesis of the proopiomelanocortin gene in mouse embryonic stem cells. The tyrosine codon at position 179 of the proopiomelanocortin gene was converted to a premature translational stop codon. The resulting transgenic mice display no overt developmental or behavioral alterations and have a normally functioning hypothalamic-pituitary-adrenal axis. Homozygous transgenic mice with a selective deficiency of beta-endorphin exhibit normal analgesia in response to morphine, indicating the presence of functional mu-opiate receptors. However, these mice lack the opioid (naloxone reversible) analgesia induced by mild swim stress. Mutant mice also display significantly greater nonopioid analgesia in response to cold water swim stress compared with controls and display paradoxical naloxone-induced analgesia. These changes may reflect compensatory upregulation of alternative pain inhibitory mechanisms. Images Fig. 1 Fig. 2 PMID:8633004

Central nervous system activity of the ethanol leaf extract of Sida acuta in rats.

PubMed

Ibironke, G F; Umukoro, A S; Ajonijebu, D C

2014-03-01

The study investigated the pharmacological effects of ethanol extract of Sida acuta leaves on central nervous system activities in mice. Adult male mice (18 - 25g) were used for the study. The extract was administered orally in male mice and evaluated in the following tests: forced swimming, tail suspension, formalin-induced paw licking, acetic acid--induced mouse writhing and apomorphine-induced stereotypy. The results revealed a reduction in the frequency of abdominal constrictions induced by acetic acid, decreased licking times in both phases of the formalin test, reduction in immobility times in forced swimming and tail suspension tests. However, the extract produced no effect on apomorphine-induced stereotyped behaviour. These results suggest that the ethanol extract of Sida acuta contains psychoactive substances with analgesic and antidepressant-like properties which may be beneficial in the management of pain.

‘Eavesdropping’ in wild rough-toothed dolphins (Steno bredanensis)?

PubMed Central

Götz, Thomas; Verfuß, Ursula Katharina; Schnitzler, Hans-Ulrich

2005-01-01

Several authors suggest that dolphins use information obtained by eavesdropping on echoes from sonar signals of conspecifics, but there is little evidence that this strategy is used by dolphins in the wild. Travelling rough-toothed dolphins (Steno bredanensis) either exhibit asynchronous movements or an extremely synchronized swimming behaviour in tight formations, which we expect to facilitate eavesdropping. Therefore, we determined, whether either one or more dolphins were echolocating in subgroups that were travelling with asynchronous and synchronized movements. Since, the number of recording sequences in which more than one animal produced sonar signals was significantly lower during synchronized travel, we conclude that the other members of a subgroup might get information on targets ahead by eavesdropping. Synchronized swimming in tight formations might be an energetic adaptation for travelling in a pelagic dolphin species that facilitates eavesdropping. PMID:17148311

'Eavesdropping' in wild rough-toothed dolphins (Steno bredanensis)?

PubMed

Götz, Thomas; Verfuss, Ursula Katharina; Schnitzler, Hans-Ulrich

2006-03-22

Several authors suggest that dolphins use information obtained by eavesdropping on echoes from sonar signals of conspecifics, but there is little evidence that this strategy is used by dolphins in the wild. Travelling rough-toothed dolphins (Steno bredanensis) either exhibit asynchronous movements or an extremely synchronized swimming behaviour in tight formations, which we expect to facilitate eavesdropping. Therefore, we determined, whether either one or more dolphins were echolocating in subgroups that were travelling with asynchronous and synchronized movements. Since, the number of recording sequences in which more than one animal produced sonar signals was significantly lower during synchronized travel, we conclude that the other members of a subgroup might get information on targets ahead by eavesdropping. Synchronized swimming in tight formations might be an energetic adaptation for travelling in a pelagic dolphin species that facilitates eavesdropping.

The Use of Acceleration to Code for Animal Behaviours; A Case Study in Free-Ranging Eurasian Beavers Castor fiber

PubMed Central

Graf, Patricia M.; Wilson, Rory P.; Qasem, Lama; Hackländer, Klaus; Rosell, Frank

2015-01-01

Recent technological innovations have led to the development of miniature, accelerometer-containing electronic loggers which can be attached to free-living animals. Accelerometers provide information on both body posture and dynamism which can be used as descriptors to define behaviour. We deployed tri-axial accelerometer loggers on 12 free-ranging Eurasian beavers Castor fiber in the county of Telemark, Norway, and on four captive beavers (two Eurasian beavers and two North American beavers C. canadensis) to corroborate acceleration signals with observed behaviours. By using random forests for classifying behavioural patterns of beavers from accelerometry data, we were able to distinguish seven behaviours; standing, walking, swimming, feeding, grooming, diving and sleeping. We show how to apply the use of acceleration to determine behaviour, and emphasise the ease with which this non-invasive method can be implemented. Furthermore, we discuss the strengths and weaknesses of this, and the implementation of accelerometry on animals, illustrating limitations, suggestions and solutions. Ultimately, this approach may also serve as a template facilitating studies on other animals with similar locomotor modes and deliver new insights into hitherto unknown aspects of behavioural ecology. PMID:26317623

The influence of maternal condition on offspring performance in sockeye salmon Oncorhynchus nerka.

PubMed

Tierney, K B; Patterson, D A; Kennedy, C J

2009-10-01

Eggs were taken from adult sockeye salmon Oncorhynchus nerka that had reached their journey's end in spawn-ready and moribund condition, and fertilized by healthy males. Egg number, size, hatching success and offspring growth did not differ with maternal condition, which suggests the absence of any persisting physiological maternal effects. Differences were noted in the swimming behaviour and physiology of the offspring at parr stage. In a 30 min schooling test conducted using groups of five in a flume, parr from moribund females were more likely to fatigue, were not as tightly schooled, and had a diminished startle response, both in the per cent responding and the burst distance. In individual, confined swimming tests conducted within a tube, post-exercise plasma lactate concentration, which is an indicator of white muscle use, was greater for parr from moribund adult females. The moribund females also had elevated lactate following exercise (their migration), which suggests heritable differences may exist in muscle use. This study shows that juvenile O. nerka artificially propagated from females exhausted by their return migration can exhibit swimming performance differences, indicating that maternal condition may need to be considered in breeding programmes.

Consumption, supply and transport: self-organization without direct communication

NASA Technical Reports Server (NTRS)

Kessler, J. O.

1996-01-01

Swimming bacteria of the species Bacillus subtilis require and consume oxygen. In static liquid cultures the cells' swimming behaviour leads them to accumulate up oxygen concentration gradients generated by consumption and supply. Since the density of bacterial cells exceeds that of the fluid in which they live, fluid regions where cells have accumulated are denser than depleted regions. These density variations cause convection. The fluid motion is dynamically maintained by the swimming of the cells toward regions of attraction: the air-fluid interface and the fluctuating advecting attractors, gradients of oxygen concentration that are embedded in the convecting fluid. Because of the fluid dynamical conservation laws, these complex physical and biological factors generate patterns ordered over distances > 10000 bacterial cell diameters. The convection enhances long-range transport and mixing of oxygen, cells and extracellular products by orders of magnitude. Thus, through the interplay of physical and biological factors, a population of undifferentiated selfish cells creates functional dynamic patterns. Populations of bacteria that have organised themselves into regularly patterned regions of vigorous convection and varying cell concentration interact with their environment as if they were one purposeful, coherent multicellular individual. The mathematical and experimental ingredients of these remarkable phenomena are presented here.

Spiral swimming behavior due to cranial and vertebral lesions associated with Cytophaga psychrophila infections in salmonid fishes

USGS Publications Warehouse

Kent, M.L.; Groff, J.M.; Morrison, J.K.; Yasutake, W.T.; Holt, R.A.

1989-01-01

C. psychrophila infections of the cranium and anterior vertebrae in salmonid fishes were associated with ataxia, spiral swimming along the axis of the fish, and death. The syndrome was observed in 2-10% of underyearling coho salmon Oncorhynchus kisutch, rainbow troutSalmo gairdneri, and steelhead trout S. gairdneri at several private, state, and federal hatcheries in Washington and Oregon, USA, between 1963 and 1987. Affected fish did not recover and ultimately died. Histological examination consistently revealed subacute to chronic periostitis, osteitis, meningitis, and ganglioneuritis. Inflammation and periosteal proliferation of the anterior vertebrae at the junction of the vertebral column with the cranium with extension into the cranial case was a consistent feature. The adjacent nervous tissue, particularly the medulla, was often compressed by the proliferative lesion, and this may have caused the ataxia. Though bacteria were seldom observed in these lesions. C. psychrophilawas isolated in culture from the cranial cavity of all affected fish that were tested. Epidemiological observations suggested that this bacterium is the causative agent because the spiral swimming behaviour and lesions were observed only in populations that had recovered from acute C. psychrophila infections.

Effect of vitamin C on male fertility in rats subjected to forced swimming stress.

PubMed

Vijayprasad, Sanghishetti; Bb, Ghongane; Bb, Nayak

2014-07-01

Stress is defined as a general body response to initially threatening external or internal demands, involving the mobilization of physiological and psychological resources to deal with them. Recently, oxidative stress has become the focus of interest as a potential cause of male infertility. Normally, equilibrium exists between reactive oxygen species (ROS) production and antioxidant scavenging activities in the male reproductive organs. The ascorbic acid is a known antioxidant present in the testis with the precise role of protecting the latter from the oxidative damage. It also contributes to the support of spermatogensis at least in part through its capacity to maintain antioxidant in an active state. Group1: Normal Control animal received Distilled water, Group 2: Positive control (Only Stress), Group 3: Normal rats received an intermediate dose of Vitamin C (20mg/kg/day), Group 4: Stress + Low dose Vitamin C (10mg/kg/day), Group 5: Stress+ Intermediate dose Vitamin C (20mg/kg/day), Group 6: High dose Vitamin C (30mg/kg/day). On 16(th) day effect of stress on body weight, Reproductive organ weight, sperm parameters, and hormonal assay was studied. In the present context, in stress group the sperm count, motility, testicular weight declined significantly. The intermediate dose and high dose of vitamin C showed significantly increased effect on the sperm count and motility. Various physiological changes produced force swimming indicates that swimming is an effective model for producing stress in albino rats. The results suggest that Vitamin C supplementation improves the stress induced reproductive infertility due to both their testosterone increase effect and their antioxidant effect.

Hippocampal Neurogenesis and Dendritic Plasticity Support Running-Improved Spatial Learning and Depression-Like Behaviour in Stressed Rats

PubMed Central

Tong, Jian-Bin; Wong, Richard; Ching, Yick-Pang; Qiu, Guang; Tang, Siu-Wa; Lee, Tatia M. C.; So, Kwok-Fai

2011-01-01

Exercise promotes hippocampal neurogenesis and dendritic plasticity while stress shows the opposite effects, suggesting a possible mechanism for exercise to counteract stress. Changes in hippocampal neurogenesis and dendritic modification occur simultaneously in rats with stress or exercise; however, it is unclear whether neurogenesis or dendritic remodeling has a greater impact on mediating the effect of exercise on stress since they have been separately examined. Here we examined hippocampal cell proliferation in runners treated with different doses (low: 30 mg/kg; moderate: 40 mg/kg; high: 50 mg/kg) of corticosterone (CORT) for 14 days. Water maze task and forced swim tests were applied to assess hippocampal-dependent learning and depression-like behaviour respectively the day after the treatment. Repeated CORT treatment resulted in a graded increase in depression-like behaviour and impaired spatial learning that is associated with decreased hippocampal cell proliferation and BDNF levels. Running reversed these effects in rats treated with low or moderate, but not high doses of CORT. Using 40 mg/kg CORT-treated rats, we further studied the role of neurogenesis and dendritic remodeling in mediating the effects of exercise on stress. Co-labelling with BrdU (thymidine analog) /doublecortin (immature neuronal marker) showed that running increased neuronal differentiation in vehicle- and CORT-treated rats. Running also increased dendritic length and spine density in CA3 pyramidal neurons in 40 mg/kg CORT-treated rats. Ablation of neurogenesis with Ara-c infusion diminished the effect of running on restoring spatial learning and decreasing depression-like behaviour in 40 mg/kg CORT-treated animals in spite of dendritic and spine enhancement. but not normal runners with enhanced dendritic length. The results indicate that both restored hippocampal neurogenesis and dendritic remodelling within the hippocampus are essential for running to counteract stress. PMID:21935393

Solar cooling in Madrid: Available solar energy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Izquierdo, M.; Hernandez, F.; Martin, E.

1994-11-01

This paper analyzes the behaviour of an absorption chiller lithium bromide installation fed by a field of flat-plate solar collectors and condensed by swimming pool water. A method of calculation in a variable regime is developed in terms of the obtained experimental results. Starting from the meteorological variables of a clear summer day and from the project data (collector normalization curve, collector and installation mass), the minimum solar radiation level necessary to initiate the process, I[sub min], and the instantaneous available solar energy, Q[sub u] + W[sub 1] is determined. The solar radiation threshold, I[sub min], necessary to obtain themore » process temperature, t[sub ave], in each instant, is obtained by adding to the corrected Klein radiation threshold, I[sub k,c], the heat capacity effects of the collector, HCE[sub CO], and of the installation, HCE[sub ins], as well as the losses of heat of the pipes to the surroundings, Q[sub 1]. The instantaneous available solar energy, available useful heat, in addition to the wind collector losses to the surroundings, Q[sub u] + W[sub 1], is the difference, in each instant, between the radiation, I[sub g1T], and the radiation threshold, I[sub min].The integration during the day of the instantaneous available solar energy allows us to calculate the daily available function, H[sub T]. The value of H[sub T], measured in the swimming-pool water condensation installation reached 6.92 MJ/(m[sup 2] day ). The calculated values of H[sub T] for a conventional installation condensed by tower water, or air, have been 6.35 and 0.56 MJ/(m[sup 2] day). respectively.« less

Computational fluid dynamics-habitat suitability index (CFD-HSI) modelling as an exploratory tool for assessing passability of riverine migratory challenge zones for fish

USGS Publications Warehouse

Haro, Alexander J.; Chelminski, Michael; Dudley, Robert W.

2015-01-01

We developed two-dimensional computational fluid hydraulics-habitat suitability index (CFD-HSI) models to identify and qualitatively assess potential zones of shallow water depth and high water velocity that may present passage challenges for five major anadromous fish species in a 2.63-km reach of the main stem Penobscot River, Maine, as a result of a dam removal downstream of the reach. Suitability parameters were based on distribution of fish lengths and body depths and transformed to cruising, maximum sustained and sprint swimming speeds. Zones of potential depth and velocity challenges were calculated based on the hydraulic models; ability of fish to pass a challenge zone was based on the percent of river channel that the contiguous zone spanned and its maximum along-current length. Three river flows (low: 99.1 m3 sec-1; normal: 344.9 m3 sec-1; and high: 792.9 m3 sec-1) were modelled to simulate existing hydraulic conditions and hydraulic conditions simulating removal of a dam at the downstream boundary of the reach. Potential depth challenge zones were nonexistent for all low-flow simulations of existing conditions for deeper-bodied fishes. Increasing flows for existing conditions and removal of the dam under all flow conditions increased the number and size of potential velocity challenge zones, with the effects of zones being more pronounced for smaller species. The two-dimensional CFD-HSI model has utility in demonstrating gross effects of flow and hydraulic alteration, but may not be as precise a predictive tool as a three-dimensional model. Passability of the potential challenge zones cannot be precisely quantified for two-dimensional or three-dimensional models due to untested assumptions and incomplete data on fish swimming performance and behaviours.

A wild Indo-Pacific bottlenose dolphin adopts a socially and genetically distant neonate.

PubMed

Sakai, Mai; Kita, Yuki F; Kogi, Kazunobu; Shinohara, Masanori; Morisaka, Tadamichi; Shiina, Takashi; Inoue-Murayama, Miho

2016-04-06

Alloparental behaviour and adoption have been reported in many mammals and birds. Such behaviours are energetically costly, and their causes and functions remain unclear. We observed the adoption behaviour of a wild Indo-Pacific bottlenose dolphin (Tursiops aduncus) near Mikura Island, Japan. A calf was seen with its mother on six observation days. Following the mother's death, the calf was observed with a sub-adult female on all 18 observation days from May to September 2012. On three days, the calf was observed swimming with this female in the suckling position and milk was seen leaking from the female's mammary slit. A five-year dataset revealed no significant social or kin relationships between the biological mother and allomother, indicating that kinship and social relationships did not play an important role in the observed adoption.

Exogenous lactate supply affects lactate kinetics of rainbow trout, not swimming performance

PubMed Central

Omlin, Teye; Langevin, Karolanne

2014-01-01

Intense swimming causes circulatory lactate accumulation in rainbow trout because lactate disposal (Rd) is not stimulated as strongly as lactate appearance (Ra). This mismatch suggests that maximal Rd is limited by tissue capacity to metabolize lactate. This study uses exogenous lactate to investigate what constrains maximal Rd and minimal Ra. Our goals were to determine how exogenous lactate affects: 1) Ra and Rd of lactate under baseline conditions or during graded swimming, and 2) exercise performance (critical swimming speed, Ucrit) and energetics (cost of transport, COT). Results show that exogenous lactate allows swimming trout to boost maximal Rd lactate by 40% and reach impressive rates of 56 μmol·kg−1·min−1. This shows that the metabolic capacity of tissues for lactate disposal is not responsible for setting the highest Rd normally observed after intense swimming. Baseline endogenous Ra (resting in normoxic water) is not significantly reduced by exogenous lactate supply. Therefore, trout have an obligatory need to produce lactate, either as a fuel for oxidative tissues and/or from organs relying on glycolysis. Exogenous lactate does not affect Ucrit or COT, probably because it acts as a substitute for glucose and lipids rather than extra fuel. We conclude that the observed 40% increase in Rd lactate is made possible by accelerating lactate entry into oxidative tissues via monocarboxylate transporters (MCTs). This observation together with the weak expression of MCTs and the phenomenon of white muscle lactate retention show that lactate metabolism of rainbow trout is significantly constrained by transmembrane transport. PMID:25121611

A sensitive and reliable test instrument to assess swimming in rats with spinal cord injury.

PubMed

Xu, Ning; Åkesson, Elisabet; Holmberg, Lena; Sundström, Erik

2015-09-15

For clinical translation of experimental spinal cord injury (SCI) research, evaluation of animal SCI models should include several sensorimotor functions. Validated and reliable assessment tools should be applicable to a wide range of injury severity. The BBB scale is the most widely used test instrument, but similar to most others it is used to assess open field ambulation. We have developed an assessment tool for swimming in rats with SCI, with high discriminative power and sensitivity to functional recovery after mild and severe injuries, without need for advanced test equipment. We studied various parameters of swimming in four groups of rats with thoracic SCI of different severity and a control group, for 8 weeks after surgery. Six parameters were combined in a multiple item scale, the Karolinska Institutet Swim Assessment Tool (KSAT). KSAT scores for all SCI groups showed consistent functional improvement after injury, and significant differences between the five experimental groups. The internal consistency, the inter-rater and the test-retest reliability were very high. The KSAT score was highly correlated to the cross-section area of white matter spared at the injury epicenter. Importantly, even after 8 weeks of recovery the KSAT score reliably discriminated normal animals from those inflicted by the mildest injury, and also displayed the recovery of the most severely injured rats. We conclude that this swim scale is an efficient and reliable tool to assess motor activity during swimming, and an important addition to the methods available for evaluating rat models of SCI. Copyright © 2015 Elsevier B.V. All rights reserved.

Stress-induced hyperlocomotion as a confounding factor in anxiety and depression models in mice.

PubMed

Strekalova, T; Spanagel, R; Dolgov, O; Bartsch, D

2005-05-01

Chronic stress is broadly used to model anxiety and depression. However, in chronic stress models, anxiety- and depression-like behaviors might be masked by unspecific effects of stress. We tested whether chronic stress in mice can induce unspecific changes in locomotion, and whether these changes interfere with the measurement of anxiety and forced-swimming behaviors. Also, we studied these latter behaviors in relation to the duration of stress, the lighting conditions during testing, and after the injection of diazepam. We employed a 4-week chronic stress paradigm, adopted from a model of stress-induced anhedonia and a 1-week subchronic stress, both consisting of rat exposure, restraint stress and tail suspension. Chronically stressed mice, tested under bright and moderate illumination, exhibited 'anxiolytic-like' behavior along with prolonged swimming and hyperactivity. These behaviors were not detectable under weak illumination or after the injection of diazepam (0.25 mg/kg). Instead, normal locomotion, increased anxiety and inhibited swimming were revealed under these conditions. Thus, chronic stress can induce hyperlocomotion in mice, which is triggered by acute stressors such as light, and interferes with the evaluation of anxiety and forced swimming. One week of stress did not change locomotion and forced swimming, and increased anxiety irrespective of illumination applied during testing. Our data can possibly explain previously reported contradictions in the behavioral testing of mice with chronic stress models of anxiety and depression.

Antidepressant-like effects of erythropoietin: a focus on behavioural and hippocampal processes.

PubMed

Osborn, Meagan; Rustom, Nazneen; Clarke, Melanie; Litteljohn, Darcy; Rudyk, Chris; Anisman, Hymie; Hayley, Shawn

2013-01-01

Depression is a chronic and debilitating condition with a significant degree of relapse and treatment resistance that could stem, at least in part, from disturbances of neuroplasticity. This has led to an increased focus on treatment strategies that target brain derived neurotrophic factor (BDNF), synaptic plasticity and adult neurogenesis. In the current study we aimed to assess whether erythropoietin (EPO) would have antidepressant-like effects given its already established pro-trophic actions. In particular, we assessed whether EPO would diminish the deleterious effects of a social stressor in mice. Indeed, EPO induced anxiolytic and antidepressant-like responses in a forced swim test, open field, elevated-plus maze, and a novelty test, and appeared to blunt some of the negative behavioural effects of a social stressor. Furthermore, EPO promoted adult hippocampal neurogenesis, an important feature of effective antidepressants. Finally, a separate study using the mTOR inhibitor rapamycin revealed that antagonizing this pathway prevented the impact of EPO upon forced swim performance. These data are consistent with previous findings showing that the mTOR pathway and its neurogenic and synaptogenic effects might mediate the behavioral consequences of antidepressant agents. Our findings further highlight EPO as a possible adjunct treatment for affective disorders, as well as other stressor associated disorders of impaired neuroplasticity.

Fish responses to flow velocity and turbulence in relation to size, sex and parasite load

PubMed Central

Hockley, F. A.; Wilson, C. A. M. E.; Brew, A.; Cable, J.

2014-01-01

Riverine fish are subjected to heterogeneous flow velocities and turbulence and may use this to their advantage by selecting regions that balance energy expenditure for station holding while maximizing energy gain through feeding opportunities. This study investigated microhabitat selection by guppies Poecilia reticulata in terms of flow characteristics generated by hemisphere boulders in an open channel flume. Velocity and turbulence influenced the variation in swimming behaviour with respect to size, sex and parasite intensity. With increasing body length, fish swam further and more frequently between boulder regions. Larger guppies spent more time in the areas of high-velocity and low-turbulence regions beside the boulders, whereas smaller guppies frequented the low-velocity and high-turbulence regions directly behind the boulders. Male guppies selected the regions of low velocity, indicating possible reduced swimming ability owing to hydrodynamic drag imposed by their fins. With increasing Gyrodactylus turnbulli burden, fish spent more time in regions with moderate velocity and lowest turbulent kinetic energy which were the most spatially and temporally homogeneous in terms of velocity and turbulence. These findings highlight the importance of heterogeneous flow conditions in river channel design owing to the behavioural variability within a species in response to velocity and turbulence. PMID:24284893

Neuronal NOS inhibitor 1-(2-trifluoromethylphenyl)-imidazole augment the effects of antidepressants acting via serotonergic system in the forced swimming test in rats.

PubMed

Ulak, Güner; Mutlu, Oguz; Akar, Füruzan Yildiz; Komsuoğlu, F Ipek; Tanyeri, Pelin; Erden, B Faruk

2008-10-01

Treatment-resistant depression has necessitated new therapeutic strategies in augmenting the therapeutic actions of currently existing antidepressant drugs. The aim of this study was to investigate the possibility of synergistic interaction between 1-(2-trifluoromethylphenyl)-imidazole (TRIM), a novel neuronal nitric oxide synthase (nNOS) inhibitor and conventional antidepressants of different classes in the forced swimming test (FST) in rats. TRIM decreased the immobility time at 50 mg/kg doses in the FST in rats. Treatment with a behaviourally subeffective dose of TRIM (20 mg/kg) augmented the behavioural effect of tricyclic antidepressant imipramine, selective serotonin re-uptake inhibitor (SSRI) citalopram and fluoxetine or selective serotonin reuptake enhancer tianeptine but failed to augment the antidepressant effect of reboxetine, a noradrenaline re-uptake inhibitor, in this test. Therefore inhibition of NOS augments the effects of antidepressants acting on serotonergic system in the FST. Neither TRIM (10-50 mg/kg) nor other drug treatments affected the locomotor activity of animals. These findings are in agreement with the view that antidepressant effects or augmentation of these effects in the FST may be explained with inhibition of NOS activity and this may be a new approach in offering greater therapeutic efficacy of antidepressants acting via serotonergic system.

Fish responses to flow velocity and turbulence in relation to size, sex and parasite load.

PubMed

Hockley, F A; Wilson, C A M E; Brew, A; Cable, J

2014-02-06

Riverine fish are subjected to heterogeneous flow velocities and turbulence and may use this to their advantage by selecting regions that balance energy expenditure for station holding while maximizing energy gain through feeding opportunities. This study investigated microhabitat selection by guppies Poecilia reticulata in terms of flow characteristics generated by hemisphere boulders in an open channel flume. Velocity and turbulence influenced the variation in swimming behaviour with respect to size, sex and parasite intensity. With increasing body length, fish swam further and more frequently between boulder regions. Larger guppies spent more time in the areas of high-velocity and low-turbulence regions beside the boulders, whereas smaller guppies frequented the low-velocity and high-turbulence regions directly behind the boulders. Male guppies selected the regions of low velocity, indicating possible reduced swimming ability owing to hydrodynamic drag imposed by their fins. With increasing Gyrodactylus turnbulli burden, fish spent more time in regions with moderate velocity and lowest turbulent kinetic energy which were the most spatially and temporally homogeneous in terms of velocity and turbulence. These findings highlight the importance of heterogeneous flow conditions in river channel design owing to the behavioural variability within a species in response to velocity and turbulence.

Akt2 deficiency is associated with anxiety and depressive behavior in mice.

PubMed

Leibrock, Christina; Ackermann, Teresa F; Hierlmeier, Michael; Lang, Florian; Borgwardt, Stefan; Lang, Undine E

2013-01-01

The economic burden associated with major depressive disorder and anxiety disorders render both disorders the most common and debilitating psychiatric illnesses. To date, the exact cellular and molecular mechanisms underlying the pathophysiology, successful treatment and prevention of these highly associated disorders have not been identified. Akt2 is a key protein in the phosphatidylinositide-3 (PI3K) / glycogen synthase 3 kinase (GSK3) signaling pathway, which in turn is involved in brain-derived neurotrophic factor (BDNF) effects on fear memory, mood stabilisation and action of several antidepressant drugs. The present study thus explored the impact of Akt2 on behaviour of mice. Behavioural studies (Open-Field, Light-Dark box, O-Maze, Forced Swimming Test, Emergence Test, Object Exploration Test, Morris Water Maze, Radial Maze) have been performed with Akt2 knockout mice (akt(-/-)) and corresponding wild type mice (akt(+/+)). Anxiety and depressive behavior was significantly higher in akt(-/-) than in akt(+/+) mice. The akt(-/-) mice were cognitively unimpaired but displayed increased anxiety in several behavioral tests (O-Maze test, Light-Dark box, Open Field test). Moreover, akt(-/-) mice spent more time floating in the Forced Swimming test, which is a classical feature of experimental depression. Akt2 might be a key factor in the pathophysiology of depression and anxiety. © 2013 S. Karger AG, Basel.

Different patterns of metabolic cryo-damage in domestic cat (Felis catus) and cheetah (Acinonyx jubatus) spermatozoa.

PubMed

Terrell, Kimberly A; Wildt, David E; Anthony, Nicola M; Bavister, Barry D; Leibo, S P; Penfold, Linda M; Marker, Laurie L; Crosier, Adrienne E

2012-04-01

Felid spermatozoa are sensitive to cryopreservation-induced damage, but functional losses can be mitigated by post-thaw swim-up or density gradient processing methods that selectively recover motile or structurally-normal spermatozoa, respectively. Despite the importance of sperm energy production to achieving fertilization, there is little knowledge about the influence of cryopreservation or post-thaw processing on felid sperm metabolism. We conducted a comparative study of domestic cat and cheetah sperm metabolism after cryopreservation and post-thaw processing. We hypothesized that freezing/thawing impairs sperm metabolism and that swim-up, but not density gradient centrifugation, recovers metabolically-normal spermatozoa. Ejaculates were cryopreserved, thawed, and processed by swim-up, Accudenz gradient centrifugation, or conventional washing (representing the 'control'). Sperm glucose and pyruvate uptake, lactate production, motility, and acrosomal integrity were assessed. Mitochondrial membrane potential (MMP) was measured in cat spermatozoa. In both species, lactate production, motility, and acrosomal integrity were reduced in post-thaw, washed samples compared to freshly-collected ejaculates. Glucose uptake was minimal pre- and post-cryopreservation, whereas pyruvate uptake was similar between treatments due to high coefficients of variation. In the cat, swim-up, but not Accudenz processing, recovered spermatozoa with increased lactate production, pyruvate uptake, and motility compared to controls. Although confounded by differences in non-specific fluorescence among processing methods, MMP values within treatments were positively correlated to sperm motility and acrosomal integrity. Cheetah spermatozoa isolated by either selection method exhibited improved motility and/or acrosomal integrity, but remained metabolically compromised. Collectively, findings revealed a metabolically-robust subpopulation of cryopreserved cat, but not cheetah, spermatozoa, recovered by selecting for motility rather than morphology. Published by Elsevier Inc.

Active fluids at circular boundaries: swim pressure and anomalous droplet ripening.

PubMed

Jamali, Tayeb; Naji, Ali

2018-06-13

We investigate the swim pressure exerted by non-chiral and chiral active particles on convex or concave circular boundaries. Active particles are modeled as non-interacting and non-aligning self-propelled Brownian particles. The convex and concave circular boundaries are used to model a fixed inclusion immersed in an active bath and a cavity (or container) enclosing the active particles, respectively. We first present a detailed analysis of the role of convex versus concave boundary curvature and of the chirality of active particles in their spatial distribution, chirality-induced currents, and the swim pressure they exert on the bounding surfaces. The results will then be used to predict the mechanical equilibria of suspended fluid enclosures (generically referred to as 'droplets') in a bulk with active particles being present either inside the bulk fluid or within the suspended droplets. We show that, while droplets containing active particles behave in accordance with standard capillary paradigms when suspended in a normal bulk, those containing a normal fluid exhibit anomalous behaviors when suspended in an active bulk. In the latter case, the excess swim pressure results in non-monotonic dependence of the inside droplet pressure on the droplet radius; hence, revealing an anomalous regime of behavior beyond a threshold radius, in which the inside droplet pressure increases upon increasing the droplet size. Furthermore, for two interconnected droplets, mechanical equilibrium can occur also when the droplets have different sizes. We thus identify a regime of anomalous droplet ripening, where two unequal-sized droplets can reach a final state of equal size upon interconnection, in stark contrast with the standard Ostwald ripening phenomenon, implying shrinkage of the smaller droplet in favor of the larger one.

Passive and active floating torque during swimming.

PubMed

Kjendlie, Per-Ludvik; Stallman, Robert Keig; Stray-Gundersen, James

2004-10-01

The purpose of this study was to examine the effect of passive underwater torque on active body angle with the horizontal during front crawl swimming and to assess the effect of body size on passive torque and active body angle. Additionally, the effects of passive torque, body angle and hydrostatic lift on maximal sprinting performance were addressed. Ten boys [aged 11.7 (0.8) years] and 12 male adult [aged 21.4 (3.7) years] swimmers volunteered to participate. Their body angle with the horizontal was measured at maximal velocity, and at two submaximal velocities using an underwater video camera system. Passive torque and hydrostatic lift were measured during an underwater weighing procedure, and the center of mass and center of volume were determined. The results showed that passive torque correlated significantly with the body angle at a velocity 63% of v(max) ( alpha(63) r=-0.57), and that size-normalized passive torque correlated significantly with the alpha(63) and alpha(77) (77% of v(max)) with r=-0.59 and r=-0.54 respectively. Hydrostatic lift correlated with alpha(63) with r=-0.45. The negative correlation coefficients are suggested to be due to the adults having learned to overcome passive torque when swimming at submaximal velocities by correcting their body angle. It is concluded that at higher velocities the passive torque and hydrostatic lift do not influence body angle during swimming. At a velocity of 63% of v(max), hydrostatic lift and passive torque influences body angle. Passive torque and size-normalized passive torque increases with body size. When corrected for body size, hydrostatic lift and passive torque did not influence the maximal sprinting velocity.

Long-term exercise-specific neuroprotection in spinal muscular atrophy-like mice.

PubMed

Chali, Farah; Desseille, Céline; Houdebine, Léo; Benoit, Evelyne; Rouquet, Thaïs; Bariohay, Bruno; Lopes, Philippe; Branchu, Julien; Della Gaspera, Bruno; Pariset, Claude; Chanoine, Christophe; Charbonnier, Frédéric; Biondi, Olivier

2016-04-01

The real impact of physical exercise parameters, i.e. intensity, type of contraction and solicited energetic metabolism, on neuroprotection in the specific context of neurodegeneration remains poorly explored. In this study behavioural, biochemical and cellular analyses were conducted to compare the effects of two different long-term exercise protocols, high intensity swimming and low intensity running, on motor units of a type 3 spinal muscular atrophy (SMA)-like mouse model. Our data revealed a preferential SMA-induced death of intermediate and fast motor neurons which was limited by the swimming protocol only, suggesting a close relationship between neuron-specific protection and their activation levels by specific exercise. The exercise-induced neuroprotection was independent of SMN protein expression and associated with specific metabolic and behavioural adaptations with notably a swimming-induced reduction of muscle fatigability. Our results provide new insight into the motor units' adaptations to different physical exercise parameters and will contribute to the design of new active physiotherapy protocols for patient care. Spinal muscular atrophy (SMA) is a group of autosomal recessive neurodegenerative diseases differing in their clinical outcome, characterized by the specific loss of spinal motor neurons, caused by insufficient level of expression of the protein survival of motor neuron (SMN). No cure is at present available for SMA. While physical exercise might represent a promising approach for alleviating SMA symptoms, the lack of data dealing with the effects of different exercise types on diseased motor units still precludes the use of active physiotherapy in SMA patients. In the present study, we have evaluated the efficiency of two long-term physical exercise paradigms, based on either high intensity swimming or low intensity running, in alleviating SMA symptoms in a mild type 3 SMA-like mouse model. We found that 10 months' physical training induced significant benefits in terms of resistance to muscle damage, energetic metabolism, muscle fatigue and motor behaviour. Both exercise types significantly enhanced motor neuron survival, independently of SMN expression, leading to the maintenance of neuromuscular junctions and skeletal muscle phenotypes, particularly in the soleus, plantaris and tibialis of trained mice. Most importantly, both exercises significantly improved neuromuscular excitability properties. Further, all these training-induced benefits were quantitatively and qualitatively related to the specific characteristics of each exercise, suggesting that the related neuroprotection is strongly dependent on the specific activation of some motor neuron subpopulations. Taken together, the present data show significant long-term exercise benefits in type 3 SMA-like mice providing important clues for designing rehabilitation programmes in patients. © 2016 The Authors. The Journal of Physiology © 2016 The Physiological Society.

Flagellar Hook Flexibility Is Essential for Bundle Formation in Swimming Escherichia coli Cells

PubMed Central

Brown, Mostyn T.; Steel, Bradley C.; Silvestrin, Claudio; Wilkinson, David A.; Delalez, Nicolas J.; Lumb, Craig N.; Obara, Boguslaw; Berry, Richard M.

2012-01-01

Swimming Escherichia coli cells are propelled by the rotary motion of their flagellar filaments. In the normal swimming pattern, filaments positioned randomly over the cell form a bundle at the posterior pole. It has long been assumed that the hook functions as a universal joint, transmitting rotation on the motor axis through up to ∼90° to the filament in the bundle. Structural models of the hook have revealed how its flexibility is expected to arise from dynamic changes in the distance between monomers in the helical lattice. In particular, each of the 11 protofilaments that comprise the hook is predicted to cycle between short and long forms, corresponding to the inside and outside of the curved hook, once each revolution of the motor when the hook is acting as a universal joint. To test this, we genetically modified the hook so that it could be stiffened by binding streptavidin to biotinylated monomers, impeding their motion relative to each other. We found that impeding the action of the universal joint resulted in atypical swimming behavior as a consequence of disrupted bundle formation, in agreement with the universal joint model. PMID:22522898

Repeatable group differences in the collective behaviour of stickleback shoals across ecological contexts

PubMed Central

2018-01-01

Establishing how collective behaviour emerges is central to our understanding of animal societies. Previous research has highlighted how universal interaction rules shape collective behaviour, and that individual differences can drive group functioning. Groups themselves may also differ considerably in their collective behaviour, but little is known about the consistency of such group variation, especially across different ecological contexts that may alter individuals' behavioural responses. Here, we test if randomly composed groups of sticklebacks differ consistently from one another in both their structure and movement dynamics across an open environment, an environment with food, and an environment with food and shelter. Based on high-resolution tracking data of the free-swimming shoals, we found large context-associated changes in the average behaviour of the groups. But despite these changes and limited social familiarity among group members, substantial and predictable behavioural differences between the groups persisted both within and across the different contexts (group-level repeatability): some groups moved consistently faster, more cohesively, showed stronger alignment and/or clearer leadership than other groups. These results suggest that among-group heterogeneity could be a widespread feature in animal societies. Future work that considers group-level variation in collective behaviour may help understand the selective pressures that shape how animal collectives form and function. PMID:29436496

Soft active matter: a contemporary example of Edwardsian statistical mechanics

NASA Astrophysics Data System (ADS)

Liverpool, Tanniemola

Colonies of swimming bacteria, algae or spermatozoa are examples of active systems composed of interacting units that consume energy and collectively generate motion and mechanical stresses. Due to the anisotropy of their interactions, these active particles can exhibit orientational order at high concentrations and have been called ``living liquid crystals''. Biology at the cellular and multicellular scale provides numerous examples of these active systems. They provide a novel class of experimentally accessible system far from equilibrium. Their rich collective behaviour includes non-equilibrium phase transitions and pattern formation on mesoscopic scales. Interestingly however, some of the theoretical insights gained from field theories applied to equilibrium soft matter systems can be used to explain aspects of their behaviour, but with a number of surprising new twists. I will describe and summarise recent theoretical results characterising the behaviour of such soft active systems highlighting in particular the effects of their internal dynamics on their macroscopic behaviour. With support of the EPSRC Grant No. EP/G026440/1.

Blue whales respond to simulated mid-frequency military sonar

PubMed Central

Goldbogen, Jeremy A.; Southall, Brandon L.; DeRuiter, Stacy L.; Calambokidis, John; Friedlaender, Ari S.; Hazen, Elliott L.; Falcone, Erin A.; Schorr, Gregory S.; Douglas, Annie; Moretti, David J.; Kyburg, Chris; McKenna, Megan F.; Tyack, Peter L.

2013-01-01

Mid-frequency military (1–10 kHz) sonars have been associated with lethal mass strandings of deep-diving toothed whales, but the effects on endangered baleen whale species are virtually unknown. Here, we used controlled exposure experiments with simulated military sonar and other mid-frequency sounds to measure behavioural responses of tagged blue whales (Balaenoptera musculus) in feeding areas within the Southern California Bight. Despite using source levels orders of magnitude below some operational military systems, our results demonstrate that mid-frequency sound can significantly affect blue whale behaviour, especially during deep feeding modes. When a response occurred, behavioural changes varied widely from cessation of deep feeding to increased swimming speed and directed travel away from the sound source. The variability of these behavioural responses was largely influenced by a complex interaction of behavioural state, the type of mid-frequency sound and received sound level. Sonar-induced disruption of feeding and displacement from high-quality prey patches could have significant and previously undocumented impacts on baleen whale foraging ecology, individual fitness and population health. PMID:23825206

Analysis of Behavioural Characteristics Related to Unintentional Injury in Southeast Chinese Adolescents: Evidence from a School-Based Survey.

PubMed

Feng, Wei; Gong, Qinghai; Liu, Kui; Li, Hui

2017-03-01

The purpose of this study was to explore the epidemiological features of common unintentional injury-related behaviours and to identify possible factors that lead to these unsafe behaviours among adolescents. A representative sample of 10,806 students was recruited from 77 schools by using the two-stage stratified random sampling method. All participants took a self-administered questionnaires and data were analysed to estimate the prevalence of unintentional injury-related behaviours and to identify the influential factors for these behaviours. The prevalence of unsafe swimming, jaywalking, illegal bicycling and not wearing a seat belt was 6.35%, 33.08%, 18.10% and 15.73%, respectively. The proportion of students who had two, three or four unintentional injury-related behaviours was 14.59%, 4.27% and 0.57%, respectively. Multiple regression analysis showed that male adolescents, living in an urban area and attending a vocational-technical school might contribute to the occurrence of four unintentional injury-related behaviours. In addition, the marital status of parents and father with a college degree or above were negatively associated with the adolescent's behaviour of not wearing a seat belt. Considering diverse epidemiological characteristics of unintentional injury-related behaviours among adolescents, targeted interventions such as enhancing self-protection capabilities and strengthening safety consciousness by family, school and related departments should be implemented to lower the occurrence of unintentional injury-related behaviours.

Maternal exposure to environmental enrichment before and during gestation influences behaviour of rat offspring in a sex-specific manner.

PubMed

Zuena, Anna Rita; Zinni, Manuela; Giuli, Chiara; Cinque, Carlo; Alemà, Giovanni Sebastiano; Giuliani, Alessandro; Catalani, Assia; Casolini, Paola; Cozzolino, Roberto

2016-09-01

The beneficial effects of Environmental Enrichment (EE) applied immediately after weaning or even in adulthood have been widely demonstrated. Less is known about the possible changes in behaviour and brain development of the progeny following the exposure of dams to EE. In order to further investigate this matter, female rats were reared in EE for 12weeks, from weaning until delivery. After having confirmed the presence of relevant behavioural effects of EE, both control and EE females underwent mating. Maternal behaviour was observed and male and female offspring were then administered a battery of behavioural test at different ages. EE mothers showed a decreased frequency of total nursing and, during the first 2days of lactation, an increase in licking/grooming behaviour. Maternal exposure to EE affected offspring behaviour in a sex-specific manner: social play behaviour and anxiety-like behaviour were increased in males but not in females and learning ability was improved only in females. As a general trend, maternal EE had a marked influence on motility in male and female offspring in both locomotor activity and swimming speed. Overall, this study highlights the importance of environmental stimulation, not only in the animals directly experiencing EE, but for their progeny too, opening the way to new hypothesis on the heritability mechanisms of behavioural traits. Copyright © 2016 Elsevier Inc. All rights reserved.

Phenotypic screening of hepatocyte nuclear factor (HNF) 4-{gamma} receptor knockout mice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gerdin, Anna Karin; Surve, Vikas V.; Joensson, Marie

2006-10-20

Using the mouse as a model organism in pharmaceutical research presents unique advantages as its physiology in many ways resembles the human physiology, it also has a relatively short generation time, low breeding and maintenance costs, and is available in a wide variety of inbred strains. The ability to genetically modify mouse embryonic stem cells to generate mouse models that better mimic human disease is another advantage. In the present study, a comprehensive phenotypic screening protocol is applied to elucidate the phenotype of a novel mouse knockout model of hepatocyte nuclear factor (HNF) 4-{gamma}. HNF4-{gamma} is expressed in the kidneys,more » gut, pancreas, and testis. First level of the screen is aimed at general health, morphologic appearance, normal cage behaviour, and gross neurological functions. The second level of the screen looks at metabolic characteristics and lung function. The third level of the screen investigates behaviour more in-depth and the fourth level consists of a thorough pathological characterisation, blood chemistry, haematology, and bone marrow analysis. When compared with littermate wild-type mice (HNF4-{gamma}{sup +/+}), the HNF4-{gamma} knockout (HNF4-{gamma}{sup -/-}) mice had lowered energy expenditure and locomotor activity during night time that resulted in a higher body weight despite having reduced intake of food and water. HNF4-{gamma}{sup -/-} mice were less inclined to build nest and were found to spend more time in a passive state during the forced swim test.« less

Phytochemical and biological assessments on Lipidium meyenii (maca) and Epimidium sagittatum (horny goat weed).

PubMed

Qureshi, Mahmood; Mehjabeen, -; Noorjahan, -; Muhammad, Shafi; Siddiqui, Faheem Ahmed; Baig, Iftikhar; Ahmad, Mansoor

2017-01-01

The effects of Lipidium meyenii (maca, LM) and Epimidium sagittatum (horny goat weed, ES) have been investigated due to their involvement in fertilization. Both of the drugs showed good results before, during and after fertilization in male and female mice. The results revealed that the crude extract of Lipidium meyenii caused a significant decrease in the no. of writhes at 300 and 500mg/kg (p<0.05) as compare to control, Epimidium sagittatum and standard drug. The gross behavioral, open field, exploratory behaviour, forced swimming test for stress, diuretic activity, chronic toxicity with the effect on reproduction of both male and female and change in body weight were also studied. The phytochemical study showed the presence of tannin, alkaloid, carbohydrate, rich protein and absence of sterol in LM, whereas ES shows presence of sterol and less protein. LS improve in muscle activity and exploratory behaviours without any toxic effects on mice and their pups. It does not have diuretic effect for first two hour but act normally after initial phase of drug therapy. Epimidium sagittatum has dual action that is at low dose it has slight stimulation action and at high dose little depressive effect. ES also has some diuretic effect. Overall these results suggest that LM is highly effective remedy for treatment of impotency and reduces stress and depression, because of dual effect ES not only suggested as an anxiolytic medicine but also effective in female hormonal disorder.

Glancing angle metal evaporation synthesis of catalytic swimming Janus colloids with well defined angular velocity.

PubMed

Archer, R J; Campbell, A I; Ebbens, S J

2015-09-14

The ability to control the degree of spin, or rotational velocity, for catalytic swimming devices opens up the potential to access well defined spiralling trajectories, enhance cargo binding rate, and realise theoretically proposed behaviour such as chiral diffusion. Here we assess the potential to impart a well-defined spin to individual catalytic Janus swimmers by using glancing angle metal evaporation onto a colloidal crystal to break the symmetry of the catalytic patch due to shadowing by neighbouring colloids. Using this approach we demonstrate a well-defined relationship between the glancing angle and the ratio of rotational to translational velocity. This allows batches of colloids with well-defined spin rates in the range 0.25 to 2.5 Hz to be produced. With reference to the shape and thickness variations across the catalytically active shapes, and their propulsion mechanism we discuss the factors that can lead to the observed variations in rotational propulsion.

Behavioural and physiological effects of the trophically transmitted cestode parasite, Cyathocephalus truncatus, on its intermediate host, Gammarus pulex.

PubMed

Franceschi, N; Rigaud, T; Moret, Y; Hervant, F; Bollache, L

2007-11-01

Some parasites with complex life-cycles are able to manipulate the behaviour of their intermediate hosts in a way that increases their transmission to the next host. Gammarids infected by the tapeworm Cyathocephalus truncatus (Cestoda: Spathebothriidea) are known to be more predated by fish than uninfected ones, but potential behavioural manipulation by the parasite has never been investigated. In this study, we tested the hypothesis that C. truncatus is able to manipulate the behaviour of one of its intermediate hosts, Gammarus pulex (Crustacea: Amphipoda). To assess if any behavioural change was linked to other phenotypic alterations, we also measured the immunity of infected and uninfected individuals and investigated the pathogenic effects of the parasite. Infected gammarids were significantly less photophobic than uninfected ones, but no effect of infection on the level of immune defence was found. The results on survival, swimming activity and oxygen consumption suggest that the parasite also has various pathogenic effects. However, the alteration in host phototaxis was not correlated to some of these pathogenic effects. Therefore, we propose that the modification in host reaction to light is a behavioural manipulation, explaining the previously observed increase of gammarid predation rate.

Effect of Chronic Training on Heart Rate Variability, Salivary IgA and Salivary Alpha-Amylase in Elite Swimmers with a Disability

PubMed Central

Edmonds, Rohan

2015-01-01

The purpose of this study was to a) determine the heart rate variability (HRV) and saliva markers of immunity (salivary immunoglobulin A; sIgA) and stress (salivary alpha-amylase; sAA) responses to chronic training in elite swimmers with a disability; and b) identify the relationships between HRV, sIgA, sAA and training volume. Eight members of a high performance Paralympic swimming program were monitored for their weekly resting HRV, sIgA and sAA levels in the 14 weeks leading up to a major international competition. The 14 week training program included aerobic, anaerobic, power and speed, and taper training phases, while also incorporating two swimming step tests and two swimming competitions. Specific time (root mean square of the successive differences; RMSSD) and frequency (high frequency normalized units [HFnu]) domain measures, along with non-linear indices (standard deviation of instantaneous RR variability; SD1 and short term fractal scaling exponent; α1) of HRV were used for all analyses with effects examined using magnitude-based inferences. Relationships between HRV and saliva markers were identified by Spearman rank rho (ρ) correlation coefficients. Compared with week 1, SD1 was very likely lower (96/4/0, ES = -2.21), while sAA was very likely elevated (100/0/0, ES = 2.32) at the beginning of week 7 for all athletes. The training program did not alter HRV or saliva whereas competition did. There were also no apparent differences observed for HRV, sIgA and sAA between each of the training phases during the 14 week swimming program. Correlations were observed between sAA and SD1 (ρ = -0.212, p<0.05), along with sAA and mean HR (ρ = 0.309, p<0.05). These results show that high level national competition influences depresses HRV (SD1) and increases saliva biomarkers of stress (sAA). It appears that a well-managed and periodised swimming program can maintain these indices within normal baseline levels. The study also highlighted the parasympathetic nervous system influence on sAA. PMID:26043224

Effect of chronic training on heart rate variability, salivary IgA and salivary alpha-amylase in elite swimmers with a disability.

PubMed

Edmonds, Rohan; Burkett, Brendan; Leicht, Anthony; McKean, Mark

2015-01-01

The purpose of this study was to a) determine the heart rate variability (HRV) and saliva markers of immunity (salivary immunoglobulin A; sIgA) and stress (salivary alpha-amylase; sAA) responses to chronic training in elite swimmers with a disability; and b) identify the relationships between HRV, sIgA, sAA and training volume. Eight members of a high performance Paralympic swimming program were monitored for their weekly resting HRV, sIgA and sAA levels in the 14 weeks leading up to a major international competition. The 14 week training program included aerobic, anaerobic, power and speed, and taper training phases, while also incorporating two swimming step tests and two swimming competitions. Specific time (root mean square of the successive differences; RMSSD) and frequency (high frequency normalized units [HFnu]) domain measures, along with non-linear indices (standard deviation of instantaneous RR variability; SD1 and short term fractal scaling exponent; α1) of HRV were used for all analyses with effects examined using magnitude-based inferences. Relationships between HRV and saliva markers were identified by Spearman rank rho (ρ) correlation coefficients. Compared with week 1, SD1 was very likely lower (96/4/0, ES = -2.21), while sAA was very likely elevated (100/0/0, ES = 2.32) at the beginning of week 7 for all athletes. The training program did not alter HRV or saliva whereas competition did. There were also no apparent differences observed for HRV, sIgA and sAA between each of the training phases during the 14 week swimming program. Correlations were observed between sAA and SD1 (ρ = -0.212, p<0.05), along with sAA and mean HR (ρ = 0.309, p<0.05). These results show that high level national competition influences depresses HRV (SD1) and increases saliva biomarkers of stress (sAA). It appears that a well-managed and periodised swimming program can maintain these indices within normal baseline levels. The study also highlighted the parasympathetic nervous system influence on sAA.

Swimming training prevents metabolic imprinting induced by hypernutrition during lactation.

PubMed

Fischer, Stefani Valeria; Capriglioni Cancian, Cláudia Regina; Montes, Elisangela Gueiber; de Carvalho Leite, Nayara; Grassiolli, Sabrina

2015-02-01

Reduction in litter size during lactation induces hypernutrition of the offspring culminating with altered metabolic programming during adult life. Overnourished rats present alterations in the endocrine pancreas and major predisposition to the development of type 2 diabetes. Our study evaluated the impact of swimming training on insulin secretion control in overnourished rats. At postnatal day 3 male rat pup litters were redistributed randomly into Small Litters (SL, 3 pups) or Normal Litters (NL, 9 pups) to induce early overfeeding during lactation. Both groups were subjected to swimming training (3 times/week/30 min) post-weaning (21 days) for 72 days. At 92 days of life pancreatic islets were isolated using collagenase technique and incubated with glucose in the presence or absence of acetylcholine (Ach, 0.1-1000 μM) or glucagon-like peptide 1 (GLP1, 10 nM). Adipose tissue depots (white and brown) and endocrine pancreas samples were examined by histological analysis. Food intake and body weight were measured. Blood biochemical parameters were also evaluated. Swimming training prevented metabolic program alteration by hypernutrition during lactation. Exercise reduced obesity and hyperglycemia in overnourished rats. Pancreatic islets isolated from overnourished rats showed a reduction in glucose-induced insulin secretion and cholinergic responses while the insulinotropic action of GLP1 was increased. Physical training effectively restored glucose-induced insulin secretion and GLP1-stimulated action in pancreatic islets from overnourished rats. However, swimming training did not correct the weak cholinergic response in pancreatic islets isolated from overnourished rats. Swimming training avoids obesity development, corrects glucose-induced insulin secretion, as well as, GLP1 insulinotropic response in overnourished rats. Copyright © 2014 European Society for Clinical Nutrition and Metabolism. Published by Elsevier Ltd. All rights reserved.

Bergamot Essential Oil Attenuates Anxiety-Like Behaviour in Rats.

PubMed

Rombolà, Laura; Tridico, Laura; Scuteri, Damiana; Sakurada, Tsukasa; Sakurada, Shinobu; Mizoguchi, Hirokazu; Avato, Pinarosa; Corasaniti, Maria Tiziana; Bagetta, Giacinto; Morrone, Luigi Antonio

2017-04-11

Preclinical studies have recently highlighted that bergamot essential oil (BEO) is endowed with remarkable neurobiolological effects. BEO can affect synaptic transmission, modulate electroencephalographic activity and it showed neuroprotective and analgesic properties. The phytocomplex, along with other essential oils, is also widely used in aromatherapy to minimize symptoms of stress-induced anxiety and mild mood disorders. However, only limited preclinical evidences are actually available. This study examined the anxiolytic/sedative-like effects of BEO using an open field task (OFT), an elevated plus-maze task (EPM), and a forced swimming task (FST) in rats. This study further compared behavioural effects of BEO to those of the benzodiazepine diazepam. Analysis of data suggests that BEO induces anxiolytic-like/relaxant effects in animal behavioural tasks not superimposable to those of the DZP. The present observations provide further insight to the pharmacological profile of BEO and support its rational use in aromatherapy.

Consistent Selection towards Low Activity Phenotypes When Catchability Depends on Encounters among Human Predators and Fish

PubMed Central

Alós, Josep; Palmer, Miquel; Arlinghaus, Robert

2012-01-01

Together with life-history and underlying physiology, the behavioural variability among fish is one of the three main trait axes that determines the vulnerability to fishing. However, there are only a few studies that have systematically investigated the strength and direction of selection acting on behavioural traits. Using in situ fish behaviour revealed by telemetry techniques as input, we developed an individual-based model (IBM) that simulated the Lagrangian trajectory of prey (fish) moving within a confined home range (HR). Fishers exhibiting various prototypical fishing styles targeted these fish in the model. We initially hypothesised that more active and more explorative individuals would be systematically removed under all fished conditions, in turn creating negative selection differentials on low activity phenotypes and maybe on small HR. Our results partly supported these general predictions. Standardised selection differentials were, on average, more negative on HR than on activity. However, in many simulation runs, positive selection pressures on HR were also identified, which resulted from the stochastic properties of the fishes’ movement and its interaction with the human predator. In contrast, there was a consistent negative selection on activity under all types of fishing styles. Therefore, in situations where catchability depends on spatial encounters between human predators and fish, we would predict a consistent selection towards low activity phenotypes and have less faith in the direction of the selection on HR size. Our study is the first theoretical investigation on the direction of fishery-induced selection of behaviour using passive fishing gears. The few empirical studies where catchability of fish was measured in relation to passive fishing techniques, such as gill-nets, traps or recreational fishing, support our predictions that fish in highly exploited situations are, on average, characterised by low swimming activity, stemming, in part, from negative selection on swimming activity. PMID:23110164

Reduced efficacy of fluoxetine following MDMA ("Ecstasy")-induced serotonin loss in rats.

PubMed

Durkin, Sarah; Prendergast, Alison; Harkin, Andrew

2008-12-12

Long-term serotonin (5-HT) neuronal loss is currently a major cause of concern associated with recreational use of the substituted amphetamine 3,4 methylenedioxymethamphetamine (MDMA; "Ecstasy"). Such loss may be problematic considering that psychiatric disorders such as depression and anxiety and responses to first line treatments for these disorders are associated with 5-HT. In this study the effects of prior exposure to MDMA on behavioural and central neurochemical changes induced by the serotonin (5-HT) re-uptake inhibitor and antidepressant fluoxetine were examined in rats. Animals were administered MDMA (10 mg/kg. i.p.) four times daily for two consecutive days. One week later the animals were subjected to treatment with fluoxetine (10 mg/kg, i.p.). Fluoxetine treatment groups received either acute (saline injections for 20 days followed by 3 fluoxetine treatments over 24 h) or chronic (once daily fluoxetine for 21 days) drug administration. Prior exposure to MDMA resulted in an attenuation of fluoxetine-induced swimming behaviour in the modified forced swimming test (FST); a behavioural test of antidepressant action. In parallel MDMA treatment resulted in significant regional depletions of 5-HT and its metabolite 5-hydroxyindoleacetic acid (5-HIAA) accompanied by a reduction in cortical [3H] paroxetine binding to nerve terminal 5-HT transporters. MDMA-induced 5-HT loss was enhanced in animals following chronic fluoxetine administration. Elimination of fluoxetine and its metabolite norfluoxetine from the brain abolished this interaction between MDMA and fluoxetine treatment. Fluoxetine administration reduced both 5-HIAA and the 5-HIAA:5-HT metabolism ratio, which was attenuated in animals pre-treated with MDMA. Overall the results show that MDMA induces long-term 5-HT loss in the rodent brain and consequently diminishes behaviour and reductions in 5-HT metabolism induced by the antidepressant fluoxetine. These results have potential clinical relevance, suggesting that 5-HT re-uptake inhibitors such as fluoxetine may be less effective at treating depression in chronic abusers of MDMA.

Behavioural studies on BR-16A (Mentat), a herbal psychotropic formulation.

PubMed

Bhattacharya, S K

1994-01-01

The anxiolytic, antidepressant and anti-aggression activities of Mentat were investigated in rats and mice, using standard behavioural paradigms. Single acute administration of Mentat, up to a dose of 200 mg/kg, ip, induced insignificant behavioural effects on the test parameters. However, when Mentat was administered subchronically for 7 days at two dose levels (50 and 100 mg/kg, intragastrically), the drug induced dose-related behavioural effects. Thus, it exhibited anxiolytic effect, as assessed by paradigms like the open-field test and elevated plus-maze tests in mice, and the social interaction test and Vogel's drink conflict test in rats. Furthermore, Mentat attenuated the increase in rat brain tribulin, a putative endocoid marker of anxiety, levels induced by pentylenetetrazole (20 mg/kg, sc), a known anxiogenic agent. Mentat attenuated footshock-induced aggressive behaviour in paired rats but failed to affect clonidine-induced automutilative behaviour. The observed aggression-attenuating effect of Mentat may be related to its anxiolytic activity. Mentat exhibited significant antidepressant effect as indicated by its ability to reduce swim stress induced immobility in Porsolt's behavioural despair test, reduction in escape failures concomitant with an increase in avoidance response in the learned helplessness test, and attenuation of muricidal behaviour, in rats. The observed behavioural effects are consonant with the reported clinical utility of Mentat as an adjuvant in the treatment of anxiety and depression.

A study of the effect of dietary factors and various exercises on the swimming performance of the albino rat.

PubMed

Frenkl, R; Györe, A

1979-01-01

In Experiment 1 a double-phase test diet (high-protein low-carbohydrate phase (HP): 5 days, high-carbohydrate phase (HC): 2 days) was compared to a normal diet by measuring all-out performance in rats trained by steady or interval swimming exercise. The tests carried out on the 8th day showed the swimming performance to be improved to a similar extent by the two training procedures, to be further improved by the test diet in the exercised animals; changes in liver glycogen, blood glucose and serum corticosterone reflected especially in the influence of exercise which in some cases was potentiated by the test diet. In Experiment 2 the 5 days of high protein intake were treated separately from the effect of the double-phase test diet as a whole in order to study the mechanism. These aminals were exercised by treadmill running of 7 days. Cytochrome P450 content of the liver rose under the effect of exercise as well as the HP phase, thus supplying additional evidence for the enzyme inducer effect of physical exertion. Glycogen decreased both in the muscle and liver during the HP phase and returned to normal after the HC phase. Liver glycogen rose to an even higher level than normal in the trained groups, but muscle glycogen values remained lower, this may be related to the shortness of training and to an accelerated rate of turnover. High protein intake associated with a depletion of carbohydrate stores was found to have an effect of its own which, when followed by replenishment of calories reserves, might be used to advantage in improving physical performance.

Intracyclic Velocity Variation of the Center of Mass and Hip in Breaststroke Swimming With Maximal Intensity.

PubMed

Gourgoulis, Vassilios; Koulexidis, Stylianos; Gketzenis, Panagiotis; Tzouras, Grigoris

2018-03-01

Gourgoulis, V, Koulexidis, S, Gketzenis, P, and Tzouras, G. Intra-cyclic velocity variation of the center of mass and hip in breaststroke swimming with maximal intensity. J Strength Cond Res 32(3): 830-840, 2018-The aim of the study was to compare the center of mass (CM) and hip (HIP) intracyclic velocity variation in breaststroke swimming using 3-dimensional kinematic analysis. Nine male breaststrokes, of moderate performance level, swam 25-m breaststroke with maximal intensity, and their movements were recorded, both under and above the water surface, using 8 digital cameras. Their CM and HIP velocities and their intracyclic variations were estimated after manual digitization of 28 selected points on the body in a complete arm and leg breaststroke cycle. Paired sample t-tests or Wilcoxon tests, when the assumption of normality was broken, were used for statistical analyses. In both, CM and HIP velocity-time curves, the results revealed a similar pattern of 2 clear peaks associated with the leg and arm propulsive phases and 2 minimal velocities that corresponded to the arm and leg recovery phase and the lag time between the leg and arm propulsive phases, respectively. However, despite this similar general pattern, the HIP minimum resultant velocity was significantly lower, whereas its maximal value was significantly greater, than the corresponding CM values. Consequently, the HIP intracyclic swimming velocity fluctuation significantly overestimates the actual variation of the swimmer's velocity in breaststroke swimming.

Winter-swimming as a building-up body resistance factor inducing adaptive changes in the oxidant/antioxidant status.

PubMed

Lubkowska, Anna; Dołęgowska, Barbara; Szyguła, Zbigniew; Bryczkowska, Iwona; Stańczyk-Dunaj, Małgorzata; Sałata, Daria; Budkowska, Marta

2013-01-01

The aim of our research was to examine whether winter-swimming for five consecutive months results in adaptational changes improving tolerance to stress induced by exposure to cryogenic temperatures during whole-body cryostimulation (WBC). The research involved 15 healthy men, with normal bodyweight, who had never been subjected to either WBC or cold water immersion. During the experiment, the participants were twice subjected to WBC (3 min/- 130°C), namely before the winter-swimming season and after the season. Blood was taken seven times: In the morning before each cryostimulation, 30 min after each cryostimulation and the next morning. Additionally, control blood was collected in the middle of the winter season, in February. Our analysis concerned changes in hematological parameters as well as in reduced glutathione and oxidized glutathione, total oxidant status, total antioxidant status and in components of the antioxidant system: Superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, glutathione S-transferase and 8-Isoprostanes as a sensitive indicator of oxidative stress. We found significant changes in hemoglobin concentration, the number of red blood cells, the hematocrit index and mean corpuscular volume of red blood cell and the percentage of monocytes and granulocytes after the winter swimming season. The response to cryogenic temperatures was milder after five months of winter-swimming. The obtained results may indicate positive adaptive changes in the antioxidant system of healthy winter-swimmers. These changes seem to increase the readiness of the human body to stress factors.

Behavioural analysis of four mouse strains in an anxiety test battery.

PubMed

van Gaalen, M M; Steckler, T

2000-10-01

Differences in locomotor activity, exploratory activity and anxiety-like behaviour of C57BL/6ChR,C57BL/6J, Swiss Webster/J and A/J strain were investigated in an anxiety battery. The battery consisted of paradigms studying spontaneous behaviour after a mild stressor, tasks of innate anxiety (light-dark box, elevated plus maze, novel object exploration), response to a conflict situation (Vogel conflict), conditioned fear and response to inescapable swim stress. Locomotor activity was studied in an open field and compared with locomotion in the other tests. Exploratory behaviour was studied in a 16-hole board task. The data confirm previous studies suggesting that A/J mice are a relatively anxious strain. Also, the data indicated that locomotor activity was independent of the paradigm employed, while the rank order of strain-dependent effects on anxiety-related behaviour changed as a function of the task under study. Our data provide further support for the notion that choice of strain is essential in studies of anxiety-related behaviour. Influence of strain should be considered in pharmacological and lesion studies, as well as in studies with mutant mice. In addition, the data indicate that different anxiety paradigms tax different aspects of anxiety, suggesting that a battery of different tests should be used in studies of anxiety-related behaviour.

Automated tracking and classification of the settlement behaviour of barnacle cyprids

PubMed Central

Aldred, Nick; Clare, Anthony S.

2017-01-01

A focus on the development of nontoxic coatings to control marine biofouling has led to increasing interest in the settlement behaviour of fouling organisms. Barnacles pose a significant fouling challenge and accordingly the behaviour of their settlement-stage cypris larva (cyprid) has attracted much attention, yet remains poorly understood. Tracking technologies have been developed that quantify cyprid movement, but none have successfully automated data acquisition over the prolonged periods necessary to capture and identify the full repertoire of behaviours, from alighting on a surface to permanent attachment. Here we outline a new tracking system and a novel classification system for identifying and quantifying the exploratory behaviour of cyprids. The combined system enables, for the first time, tracking of multiple larvae, simultaneously, over long periods (hours), followed by automatic classification of typical cyprid behaviours into swimming, wide search, close search and inspection events. The system has been evaluated by comparing settlement behaviour in the light and dark (infrared illumination) and tracking one of a group of 25 cyprids from the water column to settlement over the course of 5 h. Having removed a significant technical barrier to progress in the field, it is anticipated that the system will accelerate our understanding of the process of surface selection and settlement by barnacles. PMID:28356538

Activation of the NLRP3 inflammasome in lipopolysaccharide-induced mouse fatigue and its relevance to chronic fatigue syndrome.

PubMed

Zhang, Zi-Teng; Du, Xiu-Ming; Ma, Xiu-Juan; Zong, Ying; Chen, Ji-Kuai; Yu, Chen-Lin; Liu, Yan-Gang; Chen, Yong-Chun; Zhao, Li-Jun; Lu, Guo-Cai

2016-04-05

The NLRP3 inflammasome (NOD-like receptor family, pyrin domain containing 3) is an intracellular protein complex that plays an important role in innate immune sensing. Its activation leads to the maturation of caspase-1 and regulates the cleavage of interleukin (IL)-1β and IL-18. Various studies have shown that activation of the immune system plays a pivotal role in the development of fatigue. However, the mechanisms underlying the association between immune activation and fatigue remained elusive, and few reports have described the involvement of NLRP3 inflammasome activation in fatigue. We established a mouse fatigue model with lipopolysaccharide (LPS, 3 mg/kg) challenge combined with swim stress. Both behavioural and biochemical parameters were measured to illustrate the characteristics of this model. We also assessed NLRP3 inflammasome activation in the mouse diencephalon, which is the brain region that has been suggested to be responsible for fatigue sensation. To further identify the role of NLRP3 inflammasome activation in the pathogenesis of chronic fatigue syndrome (CFS), NLRP3 KO mice were also subjected to LPS treatment and swim stress, and the same parameters were evaluated. Mice challenged with LPS and subjected to the swim stress test showed decreased locomotor activity, decreased fall-off time in a rota-rod test and increased serum levels of IL-1β and IL-6 compared with untreated mice. Serum levels of lactic acid and malondialdehyde (MDA) were not significantly altered in the treated mice. We demonstrated increased NLRP3 expression, IL-1β production and caspase-1 activation in the diencephalons of the treated mice. In NLRP3 KO mice, we found remarkably increased locomotor activity with longer fall-off times and decreased serum IL-1β levels compared with those of wild-type (WT) mice after LPS challenge and the swim stress test. IL-1β levels in the diencephalon were also significantly decreased in the NLRP3 KO mice. By contrast, IL-6 levels were not significantly altered. These findings suggest that LPS-induced fatigue is an IL-1β-dependent process and that the NLRP3/caspase-1 pathway is involved in the mechanisms of LPS-induced fatigue behaviours. NLRP3/caspase-1 inhibition may be a promising therapy for fatigue treatment.

First satellite tracks of South Atlantic sea turtle ‘lost years’: seasonal variation in trans-equatorial movement

PubMed Central

Mendilaharsu, Milagros L.; dei Marcovaldi, Maria A. G.; Sacco, Alexander E.; Lopez, Gustave; Pires, Thais; Swimmer, Yonat

2017-01-01

In the South Atlantic Ocean, few data exist regarding the dispersal of young oceanic sea turtles. We characterized the movements of laboratory-reared yearling loggerhead turtles from Brazilian rookeries using novel telemetry techniques, testing for differences in dispersal during different periods of the sea turtle hatching season that correspond to seasonal changes in ocean currents. Oceanographic drifters deployed alongside satellite-tagged turtles allowed us to explore the mechanisms of dispersal (passive drift or active swimming). Early in the hatching season turtles transited south with strong southward currents. Late in the hatching season, when currents flowed in the opposite direction, turtles uniformly moved northwards across the Equator. However, the movement of individuals differed from what was predicted by surface currents alone. Swimming velocity inferred from track data and an ocean circulation model strongly suggest that turtles' swimming plays a role in maintaining their position within frontal zones seaward of the continental shelf. The long nesting season of adults and behaviour of post-hatchlings exposes young turtles to seasonally varying ocean conditions that lead some individuals further into the South Atlantic and others into the Northern Hemisphere. Such migratory route diversity may ultimately buffer the population against environmental changes or anthropologic threats, fostering population resiliency. PMID:29212722

Running, swimming and diving modifies neuroprotecting globins in the mammalian brain

PubMed Central

Williams, Terrie M; Zavanelli, Mary; Miller, Melissa A; Goldbeck, Robert A; Morledge, Michael; Casper, Dave; Pabst, D. Ann; McLellan, William; Cantin, Lucas P; Kliger, David S

2007-01-01

The vulnerability of the human brain to injury following just a few minutes of oxygen deprivation with submergence contrasts markedly with diving mammals, such as Weddell seals (Leptonychotes weddellii), which can remain underwater for more than 90 min while exhibiting no neurological or behavioural impairment. This response occurs despite exposure to blood oxygen levels concomitant with human unconsciousness. To determine whether such aquatic lifestyles result in unique adaptations for avoiding ischaemic–hypoxic neural damage, we measured the presence of circulating (haemoglobin) and resident (neuroglobin and cytoglobin) oxygen-carrying globins in the cerebral cortex of 16 mammalian species considered terrestrial, swimming or diving specialists. Here we report a striking difference in globin levels depending on activity lifestyle. A nearly 9.5-fold range in haemoglobin concentration (0.17–1.62 g Hb 100 g brain wet wt−1) occurred between terrestrial and deep-diving mammals; a threefold range in resident globins was evident between terrestrial and swimming specialists. Together, these two globin groups provide complementary mechanisms for facilitating oxygen transfer into neural tissues and the potential for protection against reactive oxygen and nitrogen groups. This enables marine mammals to maintain sensory and locomotor neural functions during prolonged submergence, and suggests new avenues for averting oxygen-mediated neural injury in the mammalian brain. PMID:18089537

Does behaviour affect the dispersal of flatback post-hatchlings in the Great Barrier Reef?

PubMed Central

Critchell, Kay; Fuentes, Mariana M. P. B.; Limpus, Colin J.; Wolanski, Eric; Hamann, Mark

2017-01-01

The ability of individuals to actively control their movements, especially during the early life stages, can significantly influence the distribution of their population. Most marine turtle species develop oceanic foraging habitats during different life stages. However, flatback turtles (Natator depressus) are endemic to Australia and are the only marine turtle species with an exclusive neritic development. To explain the lack of oceanic dispersal of this species, we predicted the dispersal of post-hatchlings in the Great Barrier Reef (GBR), Australia, using oceanographic advection-dispersal models. We included directional swimming in our models and calibrated them against the observed distribution of post-hatchling and adult turtles. We simulated the dispersal of green and loggerhead turtles since they also breed in the same region. Our study suggests that the neritic distribution of flatback post-hatchlings is favoured by the inshore distribution of nesting beaches, the local water circulation and directional swimming during their early dispersal. This combination of factors is important because, under the conditions tested, if flatback post-hatchlings were entirely passively transported, they would be advected into oceanic habitats after 40 days. Our results reinforce the importance of oceanography and directional swimming in the early life stages and their influence on the distribution of a marine turtle species. PMID:28573024

Elevated corticosterone levels during the first postpartum period influence subsequent pregnancy outcomes and behaviours of the dam.

PubMed

Wong, J H K; Brummelte, S; Galea, L A M

2011-11-01

Postpartum depression affects 15% of new mothers and previous depressive episodes increase the risk for postpartum depression. Chronic administration of corticosterone (CORT) to dams during the postpartum period causes depressive-like behaviour and has been used as a model of postpartum depression. To better understand the subsequent progress of this model, we examined whether there were persistent effects of CORT treatment during the dam's first postpartum period on maternal care and mood following a subsequent pregnancy. Sprague-Dawley female rats received either sesame oil (control) or CORT (40 mg/kg) injections for 22 days during their first postpartum period. Subsequently, all females were re-mated for a second time and neither group received treatment during the second postpartum period. Maternal care was observed from days 2-8 of each postpartum period and dams were tested in the forced-swim test on days 21 and 22 of the first and days 4 and 21 of the second postpartum period. As expected, the amount of time spent immobile in the forced-swim test was increased in CORT dams at the end of the first postpartum period; however, the amount of time spent immobile was decreased at the end of the second postpartum period relative to oil dams. Furthermore, dams treated with CORT in first postpartum period gave birth to a smaller litter with a larger male/female sex ratio after their second pregnancy. This implies that elevated stress hormone levels during the first postpartum period have a substantial influence on subsequent postpartum behaviour and litter characteristics. Further investigations are necessary to fully understand the effect of parity, experience during first motherhood, and hypothalamic-pituitary-adrenal axis regulation on postpartum depression. © 2011 The Authors. Journal of Neuroendocrinology © 2011 Blackwell Publishing Ltd.

Behavioural and neurotoxic effects of ayahuasca infusion (Banisteriopsis caapi and Psychotria viridis) in female Wistar rat.

PubMed

Pic-Taylor, Aline; da Motta, Luciana Gueiros; de Morais, Juliana Alves; Junior, Willian Melo; Santos, Alana de Fátima Andrade; Campos, Leandro Ambrósio; Mortari, Marcia Renata; von Zuben, Marcus Vinicius; Caldas, Eloisa Dutra

2015-09-01

Ayahuasca, a psychoactive beverage used by indigenous and religious groups, is generally prepared by the coction of Psychotria viridis and Banisteriopsis caapi plants containing N,N-dimethyltryptamine (DMT) and β-carboline alkaloids, respectively. To investigate the acute toxicity of ayahuasca, the infusion was administered by gavage to female Wistar rats at doses of 30X and 50X the dose taken during a religious ritual, and the animals observed for 14 days. Behavioural functions were investigated one hour after dosing at 15X and 30X using the open field, elevated plus maze, and forced swimming tests. Neuronal activation (c-fos marked neurons) and toxicity (Fluoro-Jade B and Nissl/Cresyl staining) were investigated in the dorsal raphe nuclei (DRN), amygdaloid nucleus, and hippocampal formation brain areas of rats treated with a 30X ayahuasca dose. The actual lethal oral dose in female Wistar rats could not be determined in this study, but was shown to be higher than the 50X (which corresponds to 15.1mg/kg bw DMT). The ayahuasca and fluoxetine treated groups showed a significant decrease in locomotion in the open field and elevated plus-maze tests compared to controls. In the forced swimming test, ayahuasca treated animals swam more than controls, a behaviour that was not significant in the fluoxetine group. Treated animals showed higher neuronal activation in all brain areas involved in serotoninergic neurotransmission. Although this led to some brain injury, no permanent damage was detected. These results suggest that ayahuasca has antidepressant properties in Wistar female at high doses, an effect that should be further investigated. Copyright © 2015 Elsevier B.V. All rights reserved.

Prenatal stress affects insulin-like growth factor-1 (IGF-1) level and IGF-1 receptor phosphorylation in the brain of adult rats.

PubMed

Basta-Kaim, Agnieszka; Szczesny, Ewa; Glombik, Katarzyna; Stachowicz, Katarzyna; Slusarczyk, Joanna; Nalepa, Irena; Zelek-Molik, Agnieszka; Rafa-Zablocka, Katarzyna; Budziszewska, Boguslawa; Kubera, Marta; Leskiewicz, Monika; Lason, Wladyslaw

2014-09-01

It has been shown that stressful events occurring in early life have a powerful influence on the development of the central nervous system. Insulin-like growth factor-1 (IGF-1) promotes the growth, differentiation and survival of both neurons and glial cells and is thought to exert antidepressant-like activity. Thus, it is possible that disturbances in the function of the IGF-1 system may be responsible for disturbances observed over the course of depression. Prenatal stress was used as a valid model of depression. Adult male offspring of control and stressed rat dams were subjected to behavioural testing (forced swim test). The level of IGF-1 in the blood and the expression of IGF-1, IGF-1R, and IRS-1/2 in the hippocampus and frontal cortex using RT-PCR, ELISA and western blotting were measured. In addition the effect of intracerebroventricularly administered IGF-1 and/or the IGF-1R receptor antagonist JB1 in the forced swim test was studied. Prenatally stressed rats showed depressive like behaviour, including increased immobility time as well as decreased mobility and climbing. Intracerebroventricular administration of IGF-1 reversed these effects in stressed animals, whereas concomitant administration of the IGF-1R antagonist JB1 completely blocked the effects. Biochemical analysis of homogenates from the hippocampus and frontal cortex revealed decreases in IGF-1 level and IGF-1R phosphorylation along with disturbances in IRS-1 phosphorylation. These findings reveal that prenatal stress alters IGF-1 signalling, which may contribute to the behavioural changes observed in depression. Copyright © 2014 Elsevier B.V. and ECNP. All rights reserved.

Assessing hydrodynamic space use of brown trout, Salmo trutta, in a complex flow environment: a return to first principles.

PubMed

Kerr, James R; Manes, Costantino; Kemp, Paul S

2016-11-01

It is commonly assumed that stream-dwelling fish should select positions where they can reduce energetic costs relative to benefits gained and enhance fitness. However, the selection of appropriate hydrodynamic metrics that predict space use is the subject of recent debate and a cause of controversy. This is for three reasons: (1) flow characteristics are often oversimplified, (2) confounding variables are not always controlled and (3) there is limited understanding of the explanatory mechanisms that underpin the biophysical interactions between fish and their hydrodynamic environment. This study investigated the space use of brown trout, Salmo trutta, in a complex hydrodynamic flow field created using an array of different sized vertically oriented cylinders in a large open-channel flume in which confounding variables were controlled. A hydrodynamic drag function (D) based on single-point time-averaged velocity statistics that incorporates the influence of turbulent fluctuations was used to infer the energetic cost of steady swimming. Novel hydrodynamic preference curves were developed and used to assess the appropriateness of D as a descriptor of space use compared with other commonly used metrics. Zones in which performance-enhancing swimming behaviours (e.g. Kármán gaiting, entraining and bow riding) that enable fish to hold position while reducing energetic costs (termed 'specialised behaviours') were identified and occupancy was recorded. We demonstrate that energy conservation strategies play a key role in space use in an energetically taxing environment with the majority of trout groups choosing to frequently occupy areas in which specialised behaviours may be adopted or by selecting low-drag regions. © 2016. Published by The Company of Biologists Ltd.

Opposing behavioural alterations in male and female transgenic TGF alpha mice: association with tumour susceptibility.

PubMed Central

Hilakivi-Clarke, L. A.; Arora, P. K.; Clarke, R.; Wright, A.; Lippman, M. E.; Dickson, R. B.

1993-01-01

Psychosocial factors are thought to influence risk and survival from cancer. We have previously studied specific behaviours in transgenic male CD-1 MT42 mice, which overexpress the gene encoding human transforming growth factor alpha (TGF alpha) in multiple tissues, and which develop a high incidence of spontaneous hepatocellular carcinoma. The male TGF alpha mice spent a lengthened time immobile in the swim test, were highly aggressive, had increased plasma levels of 17 beta-estradiol (E2), and reduced natural killer (NK) cell activity. The female transgenic MT42 TGF alpha mice do not develop an increased rate of tumours at any site. We hypothesised that if the alterations in male TGF alpha mice are associated with their development of hepatocellular carcinomas, female TGF alpha should not show these alterations. The data in the present study indicate that female TGF alpha mice display shortened immobility in the swim test, suggesting an improved ability to cope with stress, and appear less aggressive in the resident-intruder test than non-transgenic female CD-1 mice. The female TGF alpha mice also exhibit a 3-fold increase in the plasma levels of E2, and a 3-fold increase in NK cell activity. These findings suggest that the elevated expression of TGF alpha in the transgenic mice is associated with gender-specific behavioural alterations, and the development of spontaneous hepatocellular tumours in the males. Furthermore, TGF alpha alters hormonal and immune parameters similarly in both sexes. It remains to be determined whether the development of hepatocarcinoma in the male TGF alpha animals is associated with an impaired ability to cope with stress and elevated aggressive tendencies and/or whether manipulations leading to an impaired ability to cope with stress will promote tumourigenesis in female TGF alpha mice. PMID:8494695

Anthropogenic chemical cues can alter the swimming behaviour of juvenile stages of a temperate fish.

PubMed

Díaz-Gil, Carlos; Cotgrove, Lucy; Smee, Sarah Louise; Simón-Otegui, David; Hinz, Hilmar; Grau, Amalia; Palmer, Miquel; Catalán, Ignacio A

2017-04-01

Human pressure on coastal areas is affecting essential ecosystems including fish nursery habitats. Among these anthropogenic uses, the seasonal increment in the pressure due to leisure activities such as coastal tourism and yachting is an important environmental stressor in many coastal zones. These pressures may elicit understudied impacts due to, for example, sunscreens or other seasonal pollutants. The island of Majorca, northwest Mediterranean Sea, experiences one of the highest number of tourist visits per capita in the world, thus the surrounding coastal habitat is subject to high anthropogenic seasonal stress. Studies on early stages of fishes have observed responses to coastal chemical cues for the selection or avoidance of habitats. However, the potential interferences of human impacts on these signals are largely unknown. A choice chamber was used to determine water type preference and behaviour in naïve settled juvenile gilt-head sea bream (Sparus aurata), a temperate species of commercial interest. Fish were tested individually for behavioural changes with respect to water types from potential beneficial habitats, such as seawater with extract of the endemic seagrass Posidonia oceanica, anthropogenically influenced habitats such as water extracted from a commercial and recreational harbour and seawater mixed with sunscreen at concentrations observed in coastal waters. Using a Bayesian approach, we investigated a) water type preference; b) mean speed; and c) variance in the movement (as an indicator of burst swimming activity, or "sprint" behaviour) as behavioural descriptors with respect to water type. Fish spent similar percentage of time in treatment and control water types. However, movement descriptors showed that fish in sunscreen water moved slower (98.43% probability of being slower) and performed fewer sprints (90.1% probability of having less burst in speed) compared to control water. Less evident increases in sprints were observed in harbour water (73.56% more sprints), and seagrass (79.03% more) in comparison to control water. When seagrass water was tested against harbour water, the latter elicited a higher number of sprints (91.66% increase). We show that juvenile gilt-head seabream are able to react to a selection of naturally occurring chemically different odourscapes, including the increasingly important presence of sunscreen products, and provide a plausible interpretation of the observed behavioural patterns. Copyright © 2017 Elsevier Ltd. All rights reserved.

Predicting the effectiveness of depth-based technologies to prevent salmon lice infection using a dispersal model.

PubMed

Samsing, Francisca; Johnsen, Ingrid; Stien, Lars Helge; Oppedal, Frode; Albretsen, Jon; Asplin, Lars; Dempster, Tim

2016-07-01

Salmon lice is one of the major parasitic problems affecting wild and farmed salmonid species. The planktonic larval stages of these marine parasites can survive for extended periods without a host and are transported long distances by water masses. Salmon lice larvae have limited swimming capacity, but can influence their horizontal transport by vertical positioning. Here, we adapted a coupled biological-physical model to calculate the distribution of farm-produced salmon lice (Lepeophtheirus salmonis) during winter in the southwest coast of Norway. We tested 4 model simulations to see which best represented empirical data from two sources: (1) observed lice infection levels reported by farms; and (2) experimental data from a vertical exposure experiment where fish were forced to swim at different depths with a lice-barrier technology. Model simulations tested were different development time to the infective stage (35 or 50°-days), with or without the presence of temperature-controlled vertical behaviour of lice early planktonic stages (naupliar stages). The best model fit occurred with a 35°-day development time to the infective stage, and temperature-controlled vertical behaviour. We applied this model to predict the effectiveness of depth-based preventive lice-barrier technologies. Both simulated and experimental data revealed that hindering fish from swimming close to the surface efficiently reduced lice infection. Moreover, while our model simulation predicted that this preventive technology is widely applicable, its effectiveness will depend on environmental conditions. Low salinity surface waters reduce the effectiveness of this technology because salmon lice avoid these conditions, and can encounter the fish as they sink deeper in the water column. Correctly parameterized and validated salmon lice dispersal models can predict the impact of preventive approaches to control this parasite and become an essential tool in lice management strategies. Copyright © 2016 Elsevier B.V. All rights reserved.

Loggerhead Turtles (Caretta caretta) Use Vision to Forage on Gelatinous Prey in Mid-Water

PubMed Central

Narazaki, Tomoko; Sato, Katsufumi; Abernathy, Kyler J.; Marshall, Greg J.; Miyazaki, Nobuyuki

2013-01-01

Identifying characteristics of foraging activity is fundamental to understanding an animals’ lifestyle and foraging ecology. Despite its importance, monitoring the foraging activities of marine animals is difficult because direct observation is rarely possible. In this study, we use an animal-borne imaging system and three-dimensional data logger simultaneously to observe the foraging behaviour of large juvenile and adult sized loggerhead turtles (Caretta caretta) in their natural environment. Video recordings showed that the turtles foraged on gelatinous prey while swimming in mid-water (i.e., defined as epipelagic water column deeper than 1 m in this study). By linking video and 3D data, we found that mid-water foraging events share the common feature of a marked deceleration phase associated with the capture and handling of the sluggish prey. Analysis of high-resolution 3D movements during mid-water foraging events, including presumptive events extracted from 3D data using deceleration in swim speed as a proxy for foraging (detection rate = 0.67), showed that turtles swam straight toward prey in 171 events (i.e., turning point absent) but made a single turn toward the prey an average of 5.7±6.0 m before reaching the prey in 229 events (i.e., turning point present). Foraging events with a turning point tended to occur during the daytime, suggesting that turtles primarily used visual cues to locate prey. In addition, an incident of a turtle encountering a plastic bag while swimming in mid-water was recorded. The fact that the turtle’s movements while approaching the plastic bag were analogous to those of a true foraging event, having a turning point and deceleration phase, also support the use of vision in mid-water foraging. Our study shows that integrated video and high-resolution 3D data analysis provides unique opportunities to understand foraging behaviours in the context of the sensory ecology involved in prey location. PMID:23776603

Behavioural and endocrine effects of chronic cola intake.

PubMed

Celec, P; Behuliak, M

2010-10-01

Consumption of cola beverages is very high worldwide. The health effects of cola intake are not clear, although epidemiological studies point toward associations with obesity, kidney diseases and osteoporosis. Experimental studies are surprisingly rare. In this study, we substituted drinking water of adult male Wistar rats with three different cola beverages for 3 months. Behavioural phenotyping, measurement of sex steroids in plasma and oxidative stress in testes were performed at the end of the study. A light-dark box showed increased locomotor activity and anxiety in all groups with cola intake. A subtle anti-depressive effect was seen in the forced swim test. Chronic cola intake increased both oestradiol and testosterone levels suggesting an additional mechanism of action beyond the known effects of caffeine on adenosine receptors.

Automated swimming activity monitor for examining temporal patterns of toxicant effects on individual Daphnia magna.

PubMed

Bahrndorff, Simon; Michaelsen, Thomas Yssing; Jensen, Anne; Marcussen, Laurits Faarup; Nielsen, Majken Elley; Roslev, Peter

2016-07-01

Aquatic pollutants are often biologically active at low concentrations and impact on biota in combination with other abiotic stressors. Traditional toxicity tests may not detect these effects, and there is a need for sensitive high-throughput methods for detecting sublethal effects. We have evaluated an automated infra-red (IR) light-based monitor for recording the swimming activity of Daphnia magna to establish temporal patterns of toxicant effects on an individual level. Activity was recorded for 48 h and the sensitivity of the monitor was evaluated by exposing D. magna to the reference chemicals K2 Cr2 O7 at 15, 20 and 25 °C and 2,4-dichlorophenol at 20 °C. Significant effects (P < 0.001) of toxicant concentrations, exposure time and incubation temperatures were observed. At 15 °C, the swimming activity remained unchanged for 48 h at sublethal concentrations of K2 Cr2 O7 whereas activity at 20 and 25 °C was more biphasic with decreases in activity occurring after 12-18 h. A similar biphasic pattern was observed after 2,4-dichlorophenol exposure at 20 °C. EC50 values for 2,4-dichlorophenol and K2 Cr2 O7 determined from automated recording of swimming activity showed increasing toxicity with time corresponding to decreases in EC50 of 0.03-0.07 mg l(-1) h(-1) . EC50 values determined after 48 h were comparable or lower than EC50 values based on visual inspection according to ISO 6341. The results demonstrated that the swimming activity monitor is capable of detecting sublethal behavioural effects that are toxicant and temperature dependent. The method allows EC values to be established at different time points and can serve as a high-throughput screening tool in toxicity testing. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

Biological implications of the hydrodynamics of swimming at or near the surface and in shallow water.

PubMed

Blake, R W

2009-03-01

The origins and effects of wave drag at and near the surface and in shallow water are discussed in terms of the dispersive waves generated by streamlined technical bodies of revolution and by semi-aquatic and aquatic animals with a view to bearing on issues regarding the design and function of autonomous surface and underwater vehicles. A simple two-dimensional model based on energy flux, allowing assessment of drag and its associated wave amplitude, is applied to surface swimming in Lesser Scaup ducks and is in good agreement with measured values. It is argued that hydrodynamic limitations to swimming at speeds associated with the critical Froude number ( approximately 0.5) and hull speed do not necessarily set biological limitations as most behaviours occur well below the hull speed. From a comparative standpoint, the need for studies on the hull displacement of different forms is emphasized. For forms in surface proximity, drag is a function of both Froude and Reynolds numbers. Whilst the depth dependence of wave drag is not particularly sensitive to Reynolds number, its magnitude is, with smaller and slower forms subject to relatively less drag augmentation than larger, faster forms that generate additional resistance due to ventilation and spray. A quasi-steady approach to the hydrodynamics of swimming in shallow water identifies substantial drag increases relative to the deeply submerged case at Froude numbers of about 0.9 that could limit the performance of semi-aquatic and aquatic animals and autonomous vehicles. A comparative assessment of fast-starting trout and upside down catfish shows that the energy losses of fast-starting fish are likely to be less for fish in surface proximity in deep water than for those in shallow water. Further work on unsteady swimming in both circumstances is encouraged. Finally, perspectives are offered as to how autonomous surface and underwater vehicles in surface proximity and shallow water could function to avoid prohibitive hydrodynamic resistance, thereby increasing their operational life.

Mechanism of colour discrimination by a bacterial sensory rhodopsin

NASA Technical Reports Server (NTRS)

Spudich, J. L.; Bogomolni, R. A.

1984-01-01

A photosensitive protein resembling the visual pigments of invertebrates enables phototactic archaebacteria to distinguish color. This protein exists in two spectrally-distinct forms, one of which is a transient photoproduct of the other and each of which undergoes photochemical reactions controlling the cell's swimming behaviour. Activation of a single pigment molecule in the cell is sufficient to signal the flagellar motor. This signal-transduction mechanism makes evident a color-sensing capability inherent in the retinal/protein chromophore.

Dietary magnesium deficiency alters gut microbiota and leads to depressive-like behaviour.

PubMed

Winther, Gudrun; Pyndt Jørgensen, Betina M; Elfving, Betina; Nielsen, Denis Sandris; Kihl, Pernille; Lund, Sten; Sørensen, Dorte Bratbo; Wegener, Gregers

2015-06-01

Gut microbiota (GM) has previously been associated with alterations in rodent behaviour, and since the GM is affected by the diet, the composition of the diet may be an important factor contributing to behavioural changes. Interestingly, a magnesium restricted diet has been shown to induce anxiety and depressive-like behaviour in humans and rodents, and it could be suggested that magnesium deficiency may mediate the effects through an altered GM. The present study therefore fed C57BL/6 mice with a standard diet or a magnesium deficient diet (MgD) for 6 weeks, followed by behavioural testing in the forced swim test (FST) to evaluate depressive-like behaviour. An intraperitoneal glucose tolerance test (GTT) was performed 2 day after the FST to assess metabolic alterations. Neuroinflammatory markers were analysed from hippocampus. GM composition was analysed and correlated to the behaviour and hippocampal markers. It was found that mice exposed to MgD for 6 weeks were more immobile than control mice in the FST, suggesting an increased depressive-like behaviour. No significant difference was detected in the GTT. GM composition correlated positively with the behaviour of undisturbed C57BL/6 mice, feeding MgD diet altered the microbial composition. The altered GM correlated positively to the hippocampal interleukin-6. In conclusion, we hypothesise that imbalances of the microbiota-gut-brain axis induced by consuming a MgD diet, contributes to the development of depressive-like behaviour.

Nervous system disruption and concomitant behavioral abnormality in early hatched pufferfish larvae exposed to heavy oil.

PubMed

Kawaguchi, Masahumi; Sugahara, Yuki; Watanabe, Tomoe; Irie, Kouta; Ishida, Minoru; Kurokawa, Daisuke; Kitamura, Shin-Ichi; Takata, Hiromi; Handoh, Itsuki C; Nakayama, Kei; Murakami, Yasunori

2011-08-01

Spills of heavy oil (HO) over the oceans have been proven to have an adverse effect on marine life. It has been hypothesized that exposure of early larvae of sinking eggs to HO leads largely to normal morphology, whereas abnormal organization of the developing neural scaffold is likely to be found. HO-induced disruption of the nervous system, which controls animal behavior, may in turn cause abnormalities in the swimming behavior of hatched larvae. To clarify the toxicological effects of HO, we performed exposure experiments and morphological and behavioral analyses in pufferfish (Takifugu rubripes) larvae. Fertilized eggs of pufferfish were exposed to 50 mg/L of HO for 8 days and transferred to fresh seawater before hatching. The hatched larvae were observed for their swimming behavior, morphological appearance, and construction of muscles and nervous system. In HO-exposed larvae, we did not detect any anomaly of body morphology. However, they showed an abnormal swimming pattern and disorganized midbrain, a higher center controlling movement. Our results suggest that HO-exposed fishes suffer developmental disorder of the brain that triggers an abnormal swimming behavior and that HO may be selectively toxic to the brain and cause physical disability throughout the life span of these fishes.

NUCLEAR REACTOR CONTROL SYSTEM

DOEpatents

Epler, E.P.; Hanauer, S.H.; Oakes, L.C.

1959-11-01

A control system is described for a nuclear reactor using enriched uranium fuel of the type of the swimming pool and other heterogeneous nuclear reactors. Circuits are included for automatically removing and inserting the control rods during the course of normal operation. Appropriate safety circuits close down the nuclear reactor in the event of emergency.

Noise characteristics of the Escherichia coli rotary motor

PubMed Central

2011-01-01

Background The chemotaxis pathway in the bacterium Escherichia coli allows cells to detect changes in external ligand concentration (e.g. nutrients). The pathway regulates the flagellated rotary motors and hence the cells' swimming behaviour, steering them towards more favourable environments. While the molecular components are well characterised, the motor behaviour measured by tethered cell experiments has been difficult to interpret. Results We study the effects of sensing and signalling noise on the motor behaviour. Specifically, we consider fluctuations stemming from ligand concentration, receptor switching between their signalling states, adaptation, modification of proteins by phosphorylation, and motor switching between its two rotational states. We develop a model which includes all signalling steps in the pathway, and discuss a simplified version, which captures the essential features of the full model. We find that the noise characteristics of the motor contain signatures from all these processes, albeit with varying magnitudes. Conclusions Our analysis allows us to address how cell-to-cell variation affects motor behaviour and the question of optimal pathway design. A similar comprehensive analysis can be applied to other two-component signalling pathways. PMID:21951560

Voltage-gated calcium channels of Paramecium cilia

PubMed Central

Lodh, Sukanya; Valentine, Megan S.; Van Houten, Judith L.

2016-01-01

ABSTRACT Paramecium cells swim by beating their cilia, and make turns by transiently reversing their power stroke. Reversal is caused by Ca2+ entering the cilium through voltage-gated Ca2+ (CaV) channels that are found exclusively in the cilia. As ciliary Ca2+ levels return to normal, the cell pivots and swims forward in a new direction. Thus, the activation of the CaV channels causes cells to make a turn in their swimming paths. For 45 years, the physiological characteristics of the Paramecium ciliary CaV channels have been known, but the proteins were not identified until recently, when the P. tetraurelia ciliary membrane proteome was determined. Three CaVα1 subunits that were identified among the proteins were cloned and confirmed to be expressed in the cilia. We demonstrate using RNA interference that these channels function as the ciliary CaV channels that are responsible for the reversal of ciliary beating. Furthermore, we show that Pawn (pw) mutants of Paramecium that cannot swim backward for lack of CaV channel activity do not express any of the three CaV1 channels in their ciliary membrane, until they are rescued from the mutant phenotype by expression of the wild-type PW gene. These results reinforce the correlation of the three CaV channels with backward swimming through ciliary reversal. The PwB protein, found in endoplasmic reticulum fractions, co-immunoprecipitates with the CaV1c channel and perhaps functions in trafficking. The PwA protein does not appear to have an interaction with the channel proteins but affects their appearance in the cilia. PMID:27707864

Stress-related behavioral alterations accompanying cocaine toxicity: the effects of mixed opioid drugs.

PubMed

Hayase, T; Yamamoto, Y; Yamamoto, K

2000-12-01

The present study evaluated the effects of mixed opioid drugs on the severity of cocaine (COCA) toxicity by examining stress-related behavioral alterations in mice. In order to ascertain the strength of the stress, the continuous observation of the behavioral symptoms in the cage and the forced swimming test (Porsolt test) were performed in the COCA (75 mg/kg, i.p.)-treated groups, with or without the mixed mu-kappa receptor-related opioid drugs, buprenorphine (BUP) and pentazocine (PEN). Using the high-sensitivity activity measuring instrument Supermex, both the spontaneous behaviors in the cage and the forced swimming behaviors in the water were assessed as activity counts. The behavioral alterations in the COCA-treated groups were compared with a group of mice given a 10 min immobilization stress (IM group). In the COCA-only group, a prolonged increase in the spontaneous behaviors accompanied by convulsive seizures was observed even in the surviving mice, unlike in the IM group. However, an acceleration of behavioral despair in the Porsolt test similar to that observed in the IM group was observed in the COCA group after the disappearance of the acute toxic symptoms (5 hours after the COCA treatment). Among the opioid-treated groups, the mortality rate was attenuated only in the COCA-BUP (0.25 mg/kg, i.p.) group. In the COCA-BUP group, a prolonged suppression of the morbid hyperactivity in the cage except for the convulsive seizures, and a normalization of the swimming behavior in the Porsolt test were observed in the survivors. On the other hand, in the COCA-PEN (5 mg/kg, i.p.) group, the swimming behavior in the Porsolt test was abnormally increased in addition to the prolonged morbid hyperactivity in the cage. Therefore, the COCA-induced stress-related behaviors were normalized in the group of mice treated with BUP, a group with a good prognosis.

ASIC1A in neurons is critical for fear-related behaviors.

PubMed

Taugher, R J; Lu, Y; Fan, R; Ghobbeh, A; Kreple, C J; Faraci, F M; Wemmie, J A

2017-11-01

Acid-sensing ion channels (ASICs) have been implicated in fear-, addiction- and depression-related behaviors in mice. While these effects have been attributed to ASIC1A in neurons, it has been reported that ASICs may also function in nonneuronal cells. To determine if ASIC1A in neurons is indeed required, we generated neuron-specific knockout (KO) mice with floxed Asic1a alleles disrupted by Cre recombinase driven by the neuron-specific synapsin I promoter (SynAsic1a KO mice). We confirmed that Cre expression occurred in neurons, but not all neurons, and not in nonneuronal cells including astrocytes. Consequent loss of ASIC1A in some but not all neurons was verified by western blotting, immunohistochemistry and electrophysiology. We found ASIC1A was disrupted in fear circuit neurons, and SynAsic1a KO mice exhibited prominent deficits in multiple fear-related behaviors including Pavlovian fear conditioning to cue and context, predator odor-evoked freezing and freezing responses to carbon dioxide inhalation. In contrast, in the nucleus accumbens ASIC1A expression was relatively normal in SynAsic1a KO mice, and consistent with this observation, cocaine conditioned place preference (CPP) was normal. Interestingly, depression-related behavior in the forced swim test, which has been previously linked to ASIC1A in the amygdala, was also normal. Together, these data suggest neurons are an important site of ASIC1A action in fear-related behaviors, whereas other behaviors likely depend on ASIC1A in other neurons or cell types not targeted in SynAsic1a KO mice. These findings highlight the need for further work to discern the roles of ASICs in specific cell types and brain sites. © 2017 John Wiley & Sons Ltd and International Behavioural and Neural Genetics Society.

Effects of bisphenol A (BPA) on brain-specific expression of cyp19a1b gene in swim-up fry of Labeo rohita.

PubMed

Gupta, Shreyasi; Guha, Payel; Majumder, Suravi; Pal, Puja; Sen, Koushik; Chowdhury, Piyali; Chakraborty, Arindam; Panigrahi, Ashis Kumar; Mukherjee, Dilip

2018-07-01

Estrogen regulates numerous developmental and physiological processes and effects are mediated mainly by estrogenic receptors (ERs), which function as ligand-regulated transcription factor. ERs can be activated by many different types endocrine disrupting chemicals (EDCs) and interfere with behaviour and reproductive potential of living organism. Estrogenic regulation of membrane associated G protein-coupled estrogen receptor, GPER activity has also been reported. Bisphenol A (BPA), a ubiquitous endocrine disruptor is present in many household products, has been linked to many adverse effect on sexual development and reproductive potential of wild life species. The present work is aimed to elucidate how an environmentally pervasive chemical BPA affects in vivo expression of a known estrogen target gene, cyp19a1b in the brain, and a known estrogenic biomarker, vitellogenin (Vg) in the whole body homogenate of 30 days post fertilization (dpf) swim-up fry of Labeo rohita. We confirm that, like estrogen, the xenoestrogen BPA exposure for 5-15 days induces strong overexpression of cyp19a1b, but not cyp19a1a mRNA in the brain and increase concentration of vitellogenin in swim-up fry. BPA also induces strong overexpression of aromatase B protein and aromatase activity in brain. Experiments using selective modulators of classical ERs and GPER argue that this induction is largely through nuclear ERs, not through GPER. Thus, BPA has the potential to elevate the levels of aromatase and thereby, levels of endogenous estrogen in developing brain. These results indicate that L. rohita swim-up fry can be used to detect environmental endocrine disruptors either using cyp19a1b gene expression or vitellogenin induction. Copyright © 2018 Elsevier Inc. All rights reserved.

Behavioural abnormalities of the hyposulphataemic Nas1 knock-out mouse.

PubMed

Dawson, Paul Anthony; Steane, Sarah Elizabeth; Markovich, Daniel

2004-10-05

We recently generated a sodium sulphate cotransporter knock-out mouse (Nas1-/-) which has increased urinary sulphate excretion and hyposulphataemia. To examine the consequences of disturbed sulphate homeostasis in the modulation of mouse behavioural characteristics, Nas1-/- mice were compared with Nas1+/- and Nas1+/+ littermates in a series of behavioural tests. The Nas1-/- mice displayed significantly (P < 0.001) decreased marble burying behaviour (4.33 +/- 0.82 buried) when compared to Nas1+/+ (7.86 +/- 0.44) and Nas1+/- (8.40 +/- 0.37) animals, suggesting that Nas1-/- mice may have decreased object-induced anxiety. The Nas1-/- mice also displayed decreased locomotor activity by moving less distance (1.53 +/- 0.27 m, P < 0.05) in an open-field test when compared to Nas1+/+ (2.31 +/- 0.24 m) and Nas1+/- (2.15 +/- 0.19 m) mice. The three genotypes displayed similar spatiotemporal and ethological behaviours in the elevated-plus maze and open-field test, with the exception of a decreased defecation frequency by the Nas1-/- mice (40% reduction, P < 0.01). There were no significant differences between Nas1-/- and Nas1+/+ mice in a rotarod performance test of motor coordination and in the forced swim test assessing (anti-)depressant-like behaviours. This is the first study to demonstrate behavioural abnormalities in the hyposulphataemic Nas1-/- mice.

Hydrogen Water Drinking Exerts Antifatigue Effects in Chronic Forced Swimming Mice via Antioxidative and Anti-Inflammatory Activities

PubMed Central

Ara, Jesmin; Lee, Sung Pyo; Jung, Jin Young

2018-01-01

Purpose This study was performed to evaluate antifatigue effect of hydrogen water (HW) drinking in chronic forced exercise mice model. Materials and Methods Twelve-week-old C57BL6 female mice were divided into nonstressed normal control (NC) group and stressed group: (purified water/PW-treated group and HW-treated group). Stressed groups were supplied with PW and HW, respectively, ad libitum and forced to swim for the stress induction every day for 4 consecutive weeks. Gross antifatigue effects of HW were assessed by swimming endurance capacity (once weekly for 4 wk), metabolic activities, and immune-redox activities. Metabolic activities such as blood glucose, lactate, glycogen, blood urea nitrogen (BUN), and lactate dehydrogenase (LDH) as well as immune-redox activities such as reactive oxygen species (ROS), nitric oxide (NO), glutathione peroxidase (GPx), catalase, and the related cytokines were evaluated to elucidate underlying mechanism. Blood glucose and lactate were measured at 0 wk (before swimming) and 4 wk (after swimming). Results HW group showed a higher swimming endurance capacity (p < 0.001) than NC and PW groups. Positive metabolic effects in HW group were revealed by the significant reduction of blood glucose, lactate, and BUN in serum after 4 wk (p < 0.01, resp.), as well as the significant increase of liver glycogen (p < 0.001) and serum LDH (p < 0.05) than PW group. In parallel, redox balance was represented by lower NO in serum (p < 0.01) and increased level of GPx in both serum and liver (p < 0.05) than PW group. In line, the decreased levels of serum TNF-α (p < 0.01), IL-6, IL-17, and liver IL-1β (p < 0.05) in HW group revealed positive cytokine profile compared to PW and NC group. Conclusion This study shows antifatigue effects of HW drinking in chronic forced swimming mice via metabolic coordination and immune-redox balance. In that context, drinking HW could be applied to the alternative and safety fluid remedy for chronic fatigue control. PMID:29850492

Acute changes in serum immune markers due to swimming in a chlorinated pool.

PubMed

Vlaanderen, Jelle; van Veldhoven, Karin; Font-Ribera, Laia; Villanueva, Cristina M; Chadeau-Hyam, Marc; Portengen, Lützen; Grimalt, Joan O; Zwiener, Christian; Heederik, Dick; Zhang, Xiangru; Vineis, Paolo; Kogevinas, Manolis; Vermeulen, Roel

2017-08-01

Exposure to disinfectants and disinfection byproducts (DBPs) due to swimming in chlorinated water has been associated with allergic and respiratory health effects, including asthma. Biological mechanisms contributing to these associations are largely unknown. We hypothesized a potential pathway involving modulation of the immune system. We assessed levels of immune markers (CCL11, CCL22, CXCL10, CRP, EGF, GCSF, IL-8, IL-17, IL-1RA, MPO, VEGF, Periostin) in serum collected from 30 women and 29 men before and after 40min of swimming in a chlorinated pool. Exposure to DBPs was assessed by measuring bromodichloromethane, bromoform, chloroform, and dibromochloromethane in exhaled breath before and after swimming. Covariate data including information on physical activity was available through questionnaires and measurements. We assessed the association between indicators of swimming in a chlorinated pool and changes in serum immune marker concentrations using linear regression with bivariate normal distributions and adjusted for multiple comparisons by applying the Benjamini-Hochberg procedure. We observed a significant decrease in serum concentrations of IL-8 (-12.53%; q=2.00e-03), CCL22 (-7.28%; q=4.00e-04), CCL11 (-7.15%; q=9.48e-02), CRP (-7.06%; q=4.68e-05), and CXCL10 (-13.03%; q=6.34e-14) and a significant increase in IL-1RA (20.16%; q=4.18e-06) from before to after swimming. Associations with quantitative measurements of DBPs or physical activity were similar in direction and strength. Most of the observed associations became non-significant when we adjusted the effects of exposure to DBPs for physical activity or vice-versa. Our study indicates that swimming in a chlorinated pool induces perturbations of the immune response through acute alterations of patterns of cytokine and chemokine secretion. The observed effects could not be uniquely attributed to either exposure to DBPs or physical activity. Evidence in the literature suggests that observed decreases in immune markers are possibly due to an immunosuppressive effect of DBPs, while the increase in IL-1RA might be due to physical activity. Copyright © 2017 Elsevier Ltd. All rights reserved.

Hydrodynamic schooling of flapping swimmers

NASA Astrophysics Data System (ADS)

Becker, Alexander D.; Masoud, Hassan; Newbolt, Joel W.; Shelley, Michael; Ristroph, Leif

2015-10-01

Fish schools and bird flocks are fascinating examples of collective behaviours in which many individuals generate and interact with complex flows. Motivated by animal groups on the move, here we explore how the locomotion of many bodies emerges from their flow-mediated interactions. Through experiments and simulations of arrays of flapping wings that propel within a collective wake, we discover distinct modes characterized by the group swimming speed and the spatial phase shift between trajectories of neighbouring wings. For identical flapping motions, slow and fast modes coexist and correspond to constructive and destructive wing-wake interactions. Simulations show that swimming in a group can enhance speed and save power, and we capture the key phenomena in a mathematical model based on memory or the storage and recollection of information in the flow field. These results also show that fluid dynamic interactions alone are sufficient to generate coherent collective locomotion, and thus might suggest new ways to characterize the role of flows in animal groups.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Becker, Alexander D.; Masoud, Hassan; Newbolt, Joel W.

Fish schools and bird flocks are fascinating examples of collective behaviours in which many individuals generate and interact with complex flows. Motivated by animal groups on the move, here we explore how the locomotion of many bodies emerges from their flow-mediated interactions. Through experiments and simulations of arrays of flapping wings that propel within a collective wake, we discover distinct modes characterized by the group swimming speed and the spatial phase shift between trajectories of neighbouring wings. For identical flapping motions, slow and fast modes coexist and correspond to constructive and destructive wing–wake interactions. Simulations show that swimming in amore » group can enhance speed and save power, and we capture the key phenomena in a mathematical model based on memory or the storage and recollection of information in the flow field. Lastly, these results also show that fluid dynamic interactions alone are sufficient to generate coherent collective locomotion, and thus might suggest new ways to characterize the role of flows in animal groups.« less

Spatial ecology of coastal Atlantic cod Gadus morhua associated with parasite load.

PubMed

Aalvik, I M; Moland, E; Olsen, E M; Stenseth, N C

2015-08-01

Acoustic tags and receivers were used to investigate the spatial ecology of coastal Atlantic cod Gadus morhua (n = 32, mean fork length: 50 cm, range: 33-80 cm) on the Norwegian Skagerrak coast in 2012. Monthly home ranges (HR), swimming activity and depth use varied considerably among individuals and through the months of June, July and August. HR sizes for the period ranged from 0.25 to 5.20 km2 (mean = 2.30 km2. Two thirds of the tagged G. morhua were infected with black spot disease Cryptocotyle lingua parasites; these fish had larger HRs and occupied deeper water compared with non-infected fish. The infected fish also tended to be more active in terms of horizontal swimming. From an ecological and evolutionary perspective, any environmental change that modifies G. morhua behaviour may therefore also alter the parasite load of the population, and its conservation and fishery status. © 2015 The Fisheries Society of the British Isles.

Involvement of Melatonin in Changing Depression-Like and Aggressive Behaviour in Rats Under Moderate Electromagnetic Shielding

NASA Astrophysics Data System (ADS)

Temuryants, N. A.; Tumanyants, K. N.; Khusainov, D. R.; Cheretaev, I. V.; Tumanyants, E. N.

2017-12-01

It was found that moderate electromagnetic shielding, which attenuates constant and variable components of the geomagnetic field (19 h per day for 10 days), induces in male rats the development of depression-like behavior. This behavior is diagnosed on the basis of increased passive swimming time and a decreased duration of active swimming in the Porsolt test. These behaviors reach their peak on days 3-4 of the experiment. The daily administration of 1 mg/kg exogenous melatonin reduces these depression-like behaviors as soon as day 1 of the experiment, and this effect persists throughout all stages of the experiment. Electromagnetic shielding and the administration of 1 mg/kg exogenous melatonin do not change the levels of intraspecies aggressiveness. An increase in melatonin dosage to 5 mg/kg even further reduces depression-like symptoms and stops the increase in intraspecies aggressiveness during the experiment. The conclusion is made that melatonin plays an important role in the mechanisms of physiological effects of a weakened electromagnetic geomagnetic field.

Acquired versus innate prey capturing skills in super-precocial live-bearing fish.

PubMed

Lankheet, Martin J; Stoffers, Twan; van Leeuwen, Johan L; Pollux, Bart J A

2016-07-13

Live-bearing fish start hunting for mobile prey within hours after birth, an example of extreme precociality. Because prenatal, in utero, development of this behaviour is constrained by the lack of free-swimming sensory-motor interactions, immediate success after birth depends on innate, evolutionarily acquired patterns. Optimal performance however requires flexible adjustment to an unpredictable environment. To distinguish innate from postnatally developing patterns we analysed over 2000 prey capture events for 28 metallic livebearers (Girardinus metallicus; Poeciliidae), during their first 3 days after birth. We show that the use of synchronous pectoral fin beats for final acceleration and ingestion is fixed and presumably innate. It allows for direct, symmetrical control of swimming speed and direction, while avoiding head yaw. Eye movements and body curvatures, however, change considerably in the first few days, showing that eye-tail coordination requires postnatal development. The results show how successful prey captures for newborn, live-bearing fish are based on a combination of fixed motor programmes and rapid, postnatal development. © 2016 The Author(s).

Hydrodynamic schooling of flapping swimmers

DOE PAGES

Becker, Alexander D.; Masoud, Hassan; Newbolt, Joel W.; ...

2015-10-06

Fish schools and bird flocks are fascinating examples of collective behaviours in which many individuals generate and interact with complex flows. Motivated by animal groups on the move, here we explore how the locomotion of many bodies emerges from their flow-mediated interactions. Through experiments and simulations of arrays of flapping wings that propel within a collective wake, we discover distinct modes characterized by the group swimming speed and the spatial phase shift between trajectories of neighbouring wings. For identical flapping motions, slow and fast modes coexist and correspond to constructive and destructive wing–wake interactions. Simulations show that swimming in amore » group can enhance speed and save power, and we capture the key phenomena in a mathematical model based on memory or the storage and recollection of information in the flow field. Lastly, these results also show that fluid dynamic interactions alone are sufficient to generate coherent collective locomotion, and thus might suggest new ways to characterize the role of flows in animal groups.« less

Dimensions of human ejaculated spermatozoa in Papanicolaou-stained seminal and swim-up smears obtained from the Integrated Semen Analysis System (ISAS®)

PubMed Central

Bellastella, Giuseppe; Cooper, Trevor G.; Battaglia, Marina; Ströse, Anda; Torres, Inma; Hellenkemper, Barbara; Soler, Carles; Sinisi, Antonio A.

2010-01-01

Objective measurements are required for computer-aided sperm morphometric analysis (CASMA) machines to distinguish normal from abnormal sperm heads. The morphometric characteristics of spermatozoa in 72 samples of semen and of spermatozoa from 72 other semen samples after swim-up were quantified by the semi-automated Integrated Sperm Analysis System (ISAS) computer-aided system, which measured the sperm head parameters length (L), width (W), area (A), perimeter (P), acrosomal area (Ac), and the derived values L/W and P/A. For each man a homogeneous population of distributions characterized seminal spermatozoa (7 942 cells: median values L 4.4 μm, W 2.8 μm, A 9.8 μm2, P 12.5 μm, Ac 47.5%, L/W 1.57, P/A 1.27), and there was no significant difference in within- and among-individual variation. Different men could have spermatozoa of significantly different dimensions. Head dimensions for swim-up spermatozoa from different men (4 812 cells) were similar to those in semen, differing only by 2%–5%. The values of L, W and L/W fell within the limits given by the World Health Organization (WHO). Although these samples were not biologically matched, linear mixed-effects statistical analyses permitted valid comparison of the groups. A subpopulation of 404 spermatozoa considered to fit the stringent criteria of WHO 'normal' seminal spermatozoa from both semen and swim-up were characterized by median values (and 95% confidence intervals) of L, 4.3 μm (3.8–4.9), W, 2.9 μm (2.6–3.3), A, 10.2 μm2 (8.5–12.2), P, 12.4 μm (11.3–13.9), Ac, 49% (36–60), L/W, 1.49 (1.32–1.67) and P/A, 1.22 (1.11–1.35). These median values fall within the 95th centile confidence limits given by WHO, but the confidence intervals for L and W were larger. Although these differences in head dimensions among men and after swim-up could be detected by CASMA, the small differences make it unlikely that technicians would be able to distinguish them. The values could be used as default sperm head values for the CASMA machine used here. PMID:20852650

Dimensions of human ejaculated spermatozoa in Papanicolaou-stained seminal and swim-up smears obtained from the Integrated Semen Analysis System (ISAS(®)).

PubMed

Bellastella, Giuseppe; Cooper, Trevor G; Battaglia, Marina; Ströse, Anda; Torres, Inma; Hellenkemper, Barbara; Soler, Carles; Sinisi, Antonio A

2010-11-01

Objective measurements are required for computer-aided sperm morphometric analysis (CASMA) machines to distinguish normal from abnormal sperm heads. The morphometric characteristics of spermatozoa in 72 samples of semen and of spermatozoa from 72 other semen samples after swim-up were quantified by the semi-automated Integrated Sperm Analysis System (ISAS) computer-aided system, which measured the sperm head parameters length (L), width (W), area (A), perimeter (P), acrosomal area (Ac), and the derived values L/W and P/A. For each man a homogeneous population of distributions characterized seminal spermatozoa (7 942 cells: median values L 4.4 μm, W 2.8 μm, A 9.8 μm(2), P 12.5 μm, Ac 47.5%, L/W 1.57, P/A 1.27), and there was no significant difference in within- and among-individual variation. Different men could have spermatozoa of significantly different dimensions. Head dimensions for swim-up spermatozoa from different men (4 812 cells) were similar to those in semen, differing only by 2%-5%. The values of L, W and L/W fell within the limits given by the World Health Organization (WHO). Although these samples were not biologically matched, linear mixed-effects statistical analyses permitted valid comparison of the groups. A subpopulation of 404 spermatozoa considered to fit the stringent criteria of WHO 'normal' seminal spermatozoa from both semen and swim-up were characterized by median values (and 95% confidence intervals) of L, 4.3 μm (3.8-4.9), W, 2.9 μm (2.6-3.3), A, 10.2 μm(2) (8.5-12.2), P, 12.4 μm (11.3-13.9), Ac, 49% (36-60), L/W, 1.49 (1.32-1.67) and P/A, 1.22 (1.11-1.35). These median values fall within the 95th centile confidence limits given by WHO, but the confidence intervals for L and W were larger. Although these differences in head dimensions among men and after swim-up could be detected by CASMA, the small differences make it unlikely that technicians would be able to distinguish them. The values could be used as default sperm head values for the CASMA machine used here.

Redescription of Strombidium oculatum Gruber 1884 (Ciliophora, Oligotrichia).

PubMed

Montagnes, David J S; Lowe, Chris D; Poultonb, Alex; Jonsson, Per R

2002-01-01

The marine, tide pool-dwelling ciliate Stombidium oculatum was redescribed using live, stained, SEM, and TEM material prepared from samples collected from pools on the Isle of Man (Irish Sea) and Brittany (France). Also, we reviewed the older German and French works that reported on ciliates collected in the Mediterranean and Brittany, respectively. The Brittany and Isle of Man populations of the ciliate were considered identical. Some morphological and behavioural differences exist between the Brittany-Isle of Man populations and the Mediterranean populations, but they were insufficient to distinguish different taxa. Thus, taxa from all three locations were considered to be conspecific. Key features used to describe the ciliate were: morphology and ultrastructure of the free-swimming ciliate; cyst morphology; presence of mixotrophic-chloroplasts; presence of an eye spot composed of stigma obtained from chlorophyte prey; division, morphogenesis, and nuclear structure; live observations and behaviour, including the encystment-excystment cycle. Based on morphological and behavioural characteristics the taxon was distinguished from other similar species, and a neotype has been designated as no type material exists.

High surface adsorption properties of carbon-based nanomaterials are responsible for mortality, swimming inhibition, and biochemical responses in Artemia salina larvae.

PubMed

Mesarič, Tina; Gambardella, Chiara; Milivojević, Tamara; Faimali, Marco; Drobne, Damjana; Falugi, Carla; Makovec, Darko; Jemec, Anita; Sepčić, Kristina

2015-06-01

We investigated the effects of three different carbon-based nanomaterials on brine shrimp (Artemia salina) larvae. The larvae were exposed to different concentrations of carbon black, graphene oxide, and multiwall carbon nanotubes for 48 h, and observed using phase contrast and scanning electron microscopy. Acute (mortality) and behavioural (swimming speed alteration) responses and cholinesterase, glutathione-S-transferase and catalase enzyme activities were evaluated. These nanomaterials were ingested and concentrated in the gut, and attached onto the body surface of the A. salina larvae. This attachment was responsible for concentration-dependent inhibition of larval swimming, and partly for alterations in the enzyme activities, that differed according to the type of tested nanomaterials. No lethal effects were observed up to 0.5mg/mL carbon black and 0.1mg/mL multiwall carbon nanotubes, while graphene oxide showed a threshold whereby it had no effects at 0.6 mg/mL, and more than 90% mortality at 0.7 mg/mL. Risk quotients calculated on the basis of predicted environmental concentrations indicate that carbon black and multiwall carbon nanotubes currently do not pose a serious risk to the marine environment, however if uncontrolled release of nanomaterials continues, this scenario can rapidly change. Copyright © 2015 Elsevier B.V. All rights reserved.

Bacteria exploit a polymorphic instability of the flagellar filament to escape from traps.

PubMed

Kühn, Marco J; Schmidt, Felix K; Eckhardt, Bruno; Thormann, Kai M

2017-06-13

Many bacterial species swim by rotating single polar helical flagella. Depending on the direction of rotation, they can swim forward or backward and change directions to move along chemical gradients but also to navigate their obstructed natural environment in soils, sediments, or mucus. When they get stuck, they naturally try to back out, but they can also resort to a radically different flagellar mode, which we discovered here. Using high-speed microscopy, we monitored the swimming behavior of the monopolarly flagellated species Shewanella putrefaciens with fluorescently labeled flagellar filaments at an agarose-glass interface. We show that, when a cell gets stuck, the polar flagellar filament executes a polymorphic change into a spiral-like form that wraps around the cell body in a spiral-like fashion and enables the cell to escape by a screw-like backward motion. Microscopy and modeling suggest that this propagation mode is triggered by an instability of the flagellum under reversal of the rotation and the applied torque. The switch is reversible and bacteria that have escaped the trap can return to their normal swimming mode by another reversal of motor direction. The screw-type flagellar arrangement enables a unique mode of propagation and, given the large number of polarly flagellated bacteria, we expect it to be a common and widespread escape or motility mode in complex and structured environments.

Antifatigue Effect of Luteolin-6-C-Neohesperidoside on Oxidative Stress Injury Induced by Forced Swimming of Rats through Modulation of Nrf2/ARE Signaling Pathways.

PubMed

Duan, Fang-Fang; Guo, Ying; Li, Jing-Wan; Yuan, Ke

2017-01-01

Luteolin-6-C-neohesperidoside (LN) is a flavonoid isolated from moso bamboo leaf. This study was performed to evaluate the antifatigue effect of LN on a rat model undergoing the weight-loaded forced swimming test (FST). Briefly, male Sprague-Dawley rats (20-22 weeks old) were forced to undertake exhaustive swimming every other day for 3 weeks. Each swimming session was followed by the administration of distilled water, LN (25-75 mg/kg), or ascorbic acid (100 mg/kg) 1 h later. Oral administration of LN significantly improved exercise endurance; normalized alterations in energy metabolic markers; and decreased serum lactic acid, lactate dehydrogenase, and blood urea nitrogen levels of rats that underwent FST. Moreover, LN enhanced the activities of antioxidant enzymes and antioxidant capacity, as measured by enzyme activity assays, RT-PCR, and Western blotting, as well as decreasing the levels of proinflammatory cytokines such as tumor necrosis factor- α , interleukin-1 β (IL-1 β ), and IL-6 and increasing the level of anti-inflammatory (IL-10) in the liver and skeletal muscle. These results suggested that LN reduces both physical and mental effects of chronic fatigue, probably by attenuating oxidative stress injury and inflammatory responses in the liver and skeletal muscle. This study thus supports the use of LN in functional foods for antifatigue and antioxidant effects.

Stereotypic behaviour in standard non-enriched cages is an alternative to depression-like responses in C57BL/6 mice.

PubMed

Fureix, Carole; Walker, Michael; Harper, Laura; Reynolds, Kathryn; Saldivia-Woo, Amanda; Mason, Georgia

2016-05-15

Depressive-like forms of waking inactivity have been recently observed in laboratory primates and horses. We tested the hypotheses that being awake but motionless within the home-cage is a depression-like symptom in mice, and that in impoverished housing, it represents an alternative response to stereotypic behaviour. We raised C57BL/6 ('C57') and DBA/2 ('DBA') females to adulthood in non-enriched (n=62 mice) or enriched (n=60 mice) cages, observing home-cage behaviour during the active (dark) phases. We predicted that being still but awake would be reduced by environmental enrichment; more pronounced in C57s, as the strain most prone to learned helplessness; negatively related to stereotypic behaviour; and positively related to immobility in Forced Swim Tests (FST). Compared to enriched mice, non-enriched subjects did spend more time spent being inactive but awake, especially if they displayed relatively little stereotypic behaviour. C57 mice also spent more time awake but motionless than DBAs. Furthermore, even after statistically controlling for housing type and strain, this behaviour very strongly tended to predict increased immobility in the FST, while high levels of stereotypic behaviours in contrast predicted low immobility in the FST. Being awake but motionless is thus a reaction to non-enriched housing that seems to be an alternative to stereotypic behaviour, and could reflect depression-like states. Copyright © 2016 Elsevier B.V. All rights reserved.

Impacts of the antidepressant fluoxetine on the anti-predator behaviours of wild guppies (Poecilia reticulata).

PubMed

Saaristo, Minna; McLennan, Alisha; Johnstone, Christopher P; Clarke, Bradley O; Wong, Bob B M

2017-02-01

Chemical pollution from pharmaceuticals is increasingly recognised as a major threat to aquatic communities. One compound of great concern is fluoxetine, which is one of the most widely prescribed psychoactive drugs in the world and frequently detected in the environment. The aim of this study was to investigate the effects of 28-d fluoxetine exposure at two environmentally relevant levels (measured concentrations: 4ng/L and 16ng/L) on anti-predator behaviour in wild guppies (Poecilia reticulata). This was achieved by subjecting fluoxetine-exposed and unexposed guppies to a simulated bird strike and recording their subsequent behavioural responses. We found that exposure to fluoxetine affected the anti-predator behaviour of guppies, with exposed fish remaining stationary for longer (i.e. 'freezing' behaviour) after the simulated strike and also spending more time under plant cover. By contrast, control fish were significantly more active and explored the tank more, as indicated by the distance covered per minute over the period fish spent swimming. Furthermore, behavioural shifts were sex-dependent, with evidence of a non-monotonic dose-response among the fluoxetine-exposed fish. This is one of the first studies to show that exposure to environmentally relevant concentrations of fluoxetine can alter the anti-predator behaviour of adult fish. In addition to the obvious repercussions for survival, impaired anti-predator behaviour can have direct impacts on fitness and influence the overall population dynamics of species. Copyright © 2016 Elsevier B.V. All rights reserved.

Anti-fatigue activity of sea cucumber peptides prepared from Stichopus japonicus in an endurance swimming rat model.

PubMed

Ye, Jing; Shen, Caihong; Huang, Yayan; Zhang, Xueqin; Xiao, Meitian

2017-10-01

Sea cucumber (Stichopus japonicus) is a well-known nutritious and luxurious seafood in Asia which has attracted increasing attention because of its nutrition and bioactivities in recent years. In this study, the anti-fatigue activity of sea cucumber peptides (SCP) prepared from S. japonicus was evaluated in a load-induced endurance swimming model. The SCP prepared in this study was mainly made up of low-molecular-weight peptides (<2 kDa). The analysis result of amino acid composition revealed that SCP was rich in glycine, glutamic acid and proline. The endurance capability of rats to fatigue was significantly improved by SCP treatment. Meanwhile, the remarkable alterations of energy metabolic markers, antioxidant enzymes, antioxidant capacity and oxidative stress biomarkers were normalized. Moreover, administration of SCP could modulate alterations of inflammatory cytokines and downregulate the overexpression of TRL4 and NF-κB. SCP has anti-fatigue activity and it exerted its anti-fatigue effect probably through normalizing energy metabolism as well as alleviating oxidative damage and inflammatory responses. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Shear-induced orientational dynamics and spatial heterogeneity in suspensions of motile phytoplankton

PubMed Central

Barry, Michael T.; Rusconi, Roberto; Guasto, Jeffrey S.; Stocker, Roman

2015-01-01

Fluid flow, ubiquitous in natural and man-made environments, has the potential to profoundly impact the transport of microorganisms, including phytoplankton in aquatic habitats and bioreactors. Yet, the effect of ambient flow on the swimming behaviour of phytoplankton has remained poorly understood, largely owing to the difficulty of observing cell–flow interactions at the microscale. Here, we present microfluidic experiments where we tracked individual cells for four species of motile phytoplankton exposed to a spatially non-uniform fluid shear rate, characteristic of many flows in natural and artificial environments. We observed that medium-to-high mean shear rates (1–25 s−1) produce heterogeneous cell concentrations in the form of regions of accumulation and regions of depletion. The location of these regions relative to the flow depends on the cells' propulsion mechanism, body shape and flagellar arrangement, as captured by an effective aspect ratio. Species having a large effective aspect ratio accumulated in the high-shear regions, owing to shear-induced alignment of the swimming orientation with the fluid streamlines. Species having an effective aspect ratio close to unity exhibited little preferential accumulation at low-to-moderate flow rates, but strongly accumulated in the low-shear regions under high flow conditions, potentially owing to an active, behavioural response of cells to shear. These observations demonstrate that ambient fluid flow can strongly affect the motility and spatial distribution of phytoplankton and highlight the rich dynamics emerging from the interaction between motility, morphology and flow. PMID:26538558

Voltage-gated calcium channels of Paramecium cilia.

PubMed

Lodh, Sukanya; Yano, Junji; Valentine, Megan S; Van Houten, Judith L

2016-10-01

Paramecium cells swim by beating their cilia, and make turns by transiently reversing their power stroke. Reversal is caused by Ca 2+ entering the cilium through voltage-gated Ca 2+ (Ca V ) channels that are found exclusively in the cilia. As ciliary Ca 2+ levels return to normal, the cell pivots and swims forward in a new direction. Thus, the activation of the Ca V channels causes cells to make a turn in their swimming paths. For 45 years, the physiological characteristics of the Paramecium ciliary Ca V channels have been known, but the proteins were not identified until recently, when the P. tetraurelia ciliary membrane proteome was determined. Three Ca V α1 subunits that were identified among the proteins were cloned and confirmed to be expressed in the cilia. We demonstrate using RNA interference that these channels function as the ciliary Ca V channels that are responsible for the reversal of ciliary beating. Furthermore, we show that Pawn (pw) mutants of Paramecium that cannot swim backward for lack of Ca V channel activity do not express any of the three Ca V 1 channels in their ciliary membrane, until they are rescued from the mutant phenotype by expression of the wild-type PW gene. These results reinforce the correlation of the three Ca V channels with backward swimming through ciliary reversal. The PwB protein, found in endoplasmic reticulum fractions, co-immunoprecipitates with the Ca V 1c channel and perhaps functions in trafficking. The PwA protein does not appear to have an interaction with the channel proteins but affects their appearance in the cilia. © 2016. Published by The Company of Biologists Ltd.

Vestibular lesion-induced developmental plasticity in spinal locomotor networks during Xenopus laevis metamorphosis.

PubMed

Beyeler, Anna; Rao, Guillaume; Ladepeche, Laurent; Jacques, André; Simmers, John; Le Ray, Didier

2013-01-01

During frog metamorphosis, the vestibular sensory system remains unchanged, while spinal motor networks undergo a massive restructuring associated with the transition from the larval to adult biomechanical system. We investigated in Xenopus laevis the impact of a pre- (tadpole stage) or post-metamorphosis (juvenile stage) unilateral labyrinthectomy (UL) on young adult swimming performance and underlying spinal locomotor circuitry. The acute disruptive effects on locomotion were similar in both tadpoles and juvenile frogs. However, animals that had metamorphosed with a preceding UL expressed restored swimming behavior at the juvenile stage, whereas animals lesioned after metamorphosis never recovered. Whilst kinematic and electrophysiological analyses of the propulsive system showed no significant differences in either juvenile group, a 3D biomechanical simulation suggested that an asymmetry in the dynamic control of posture during swimming could account for the behavioral restoration observed in animals that had been labyrinthectomized before metamorphosis. This hypothesis was subsequently supported by in vivo electromyography during free swimming and in vitro recordings from isolated brainstem/spinal cord preparations. Specifically, animals lesioned prior to metamorphosis at the larval stage exhibited an asymmetrical propulsion/posture coupling as a post-metamorphic young adult. This developmental alteration was accompanied by an ipsilesional decrease in propriospinal coordination that is normally established in strict left-right symmetry during metamorphosis in order to synchronize dorsal trunk muscle contractions with bilateral hindlimb extensions in the swimming adult. Our data thus suggest that a disequilibrium in descending vestibulospinal information during Xenopus metamorphosis leads to an altered assembly of adult spinal locomotor circuitry. This in turn enables an adaptive compensation for the dynamic postural asymmetry induced by the vestibular imbalance and the restoration of functionally-effective behavior.

Long‐term exercise‐specific neuroprotection in spinal muscular atrophy‐like mice

PubMed Central

Chali, Farah; Desseille, Céline; Houdebine, Léo; Benoit, Evelyne; Rouquet, Thaïs; Bariohay, Bruno; Lopes, Philippe; Branchu, Julien; Della Gaspera, Bruno; Pariset, Claude; Chanoine, Christophe; Charbonnier, Frédéric

2016-01-01

Key points The real impact of physical exercise parameters, i.e. intensity, type of contraction and solicited energetic metabolism, on neuroprotection in the specific context of neurodegeneration remains poorly explored.In this study behavioural, biochemical and cellular analyses were conducted to compare the effects of two different long‐term exercise protocols, high intensity swimming and low intensity running, on motor units of a type 3 spinal muscular atrophy (SMA)‐like mouse model.Our data revealed a preferential SMA‐induced death of intermediate and fast motor neurons which was limited by the swimming protocol only, suggesting a close relationship between neuron‐specific protection and their activation levels by specific exercise.The exercise‐induced neuroprotection was independent of SMN protein expression and associated with specific metabolic and behavioural adaptations with notably a swimming‐induced reduction of muscle fatigability.Our results provide new insight into the motor units’ adaptations to different physical exercise parameters and will contribute to the design of new active physiotherapy protocols for patient care. Abstract Spinal muscular atrophy (SMA) is a group of autosomal recessive neurodegenerative diseases differing in their clinical outcome, characterized by the specific loss of spinal motor neurons, caused by insufficient level of expression of the protein survival of motor neuron (SMN). No cure is at present available for SMA. While physical exercise might represent a promising approach for alleviating SMA symptoms, the lack of data dealing with the effects of different exercise types on diseased motor units still precludes the use of active physiotherapy in SMA patients. In the present study, we have evaluated the efficiency of two long‐term physical exercise paradigms, based on either high intensity swimming or low intensity running, in alleviating SMA symptoms in a mild type 3 SMA‐like mouse model. We found that 10 months’ physical training induced significant benefits in terms of resistance to muscle damage, energetic metabolism, muscle fatigue and motor behaviour. Both exercise types significantly enhanced motor neuron survival, independently of SMN expression, leading to the maintenance of neuromuscular junctions and skeletal muscle phenotypes, particularly in the soleus, plantaris and tibialis of trained mice. Most importantly, both exercises significantly improved neuromuscular excitability properties. Further, all these training‐induced benefits were quantitatively and qualitatively related to the specific characteristics of each exercise, suggesting that the related neuroprotection is strongly dependent on the specific activation of some motor neuron subpopulations. Taken together, the present data show significant long‐term exercise benefits in type 3 SMA‐like mice providing important clues for designing rehabilitation programmes in patients. PMID:26915343

Compensation for environmental change by complementary shifts of thermal sensitivity and thermoregulatory behaviour in an ectotherm.

PubMed

Glanville, E J; Seebacher, F

2006-12-01

Thermoregulating animals are thought to have evolved a preferred body temperature at which thermally sensitive performance is optimised. Even during thermoregulation, however, many animals experience pronounced variability in body temperature, and may regulate to different body temperatures depending on environmental conditions. Here we test the hypothesis that there is a trade-off between regulating to lower body temperatures in cooler conditions and locomotory and metabolic performance. Animals (estuarine crocodiles, Crocodylus porosus) acclimated to cold (N=8) conditions had significantly lower maximum and mean daily body temperatures after 33 days than warm-acclimated animals (N=9), despite performing characteristic thermoregulatory behaviours. Concomitant with behavioural changes, maximum sustained swimming speed (U(crit)) shifted to the respective mean body temperatures during acclimation (cold=20 degrees C, warm=29 degrees C), but there was no difference in the maxima between acclimation groups. Mitochondrial oxygen consumption changed significantly during acclimation, and maximum respiratory control ratios coincided with mean body temperatures in liver, muscle and heart tissues. There were significant changes in the activities of regulatory metabolic enzymes (lactate dehydrogenase, citrate synthase, cytochrome c oxidase) and these were tissue specific. The extraordinary shift in behaviour and locomotory and metabolic performance shows that within individuals, behaviour and physiology covary to maximise performance in different environments.

A Mixture of Persistent Organic Pollutants and Perfluorooctanesulfonic Acid Induces Similar Behavioural Responses, but Different Gene Expression Profiles in Zebrafish Larvae

PubMed Central

Khezri, Abdolrahman; Fraser, Thomas W. K.; Nourizadeh-Lillabadi, Rasoul; Kamstra, Jorke H.; Berg, Vidar; Zimmer, Karin E.; Ropstad, Erik

2017-01-01

Persistent organic pollutants (POPs) are widespread in the environment and some may be neurotoxic. As we are exposed to complex mixtures of POPs, we aimed to investigate how a POP mixture based on Scandinavian human blood data affects behaviour and neurodevelopment during early life in zebrafish. Embryos/larvae were exposed to a series of sub-lethal doses and behaviour was examined at 96 h post fertilization (hpf). In order to determine the sensitivity window to the POP mixture, exposure models of 6 to 48 and 48 to 96 hpf were used. The expression of genes related to neurological development was also assessed. Results indicate that the POP mixture increases the swimming speed of larval zebrafish following exposure between 48 to 96 hpf. This behavioural effect was associated with the perfluorinated compounds, and more specifically with perfluorooctanesulfonic acid (PFOS). The expression of genes related to the stress response, GABAergic, dopaminergic, histaminergic, serotoninergic, cholinergic systems and neuronal maintenance, were altered. However, there was little overlap in those genes that were significantly altered by the POP mixture and PFOS. Our findings show that the POP mixture and PFOS can have a similar effect on behaviour, yet alter the expression of genes relevant to neurological development differently. PMID:28146072

Efficient swimming of a plunging elastic plate in a viscous fluid

NASA Astrophysics Data System (ADS)

Yeh, Peter; Alexeev, Alexander

2014-03-01

We use three dimensional computer simulations to examine the combined hydrodynamics and structural response of a plunging elastic plate submerged in a viscous fluid with Reynolds number of 250. The plate is actuated at the root with a prescribed vertical sinusoidal displacement and a zero slope (clamped) boundary condition. We explore the steady state swimming velocity and the associated input power as a function of driving frequency, added mass, and aspect ratio. We find a universal bending pattern independent of geometry and added mass that maximizes the distance traveled per unit applied work. This bending pattern is associated with minimizing center of mass oscillations normal to the direction of travel. Subsequently, the flow around the sides of the swimmer, which does not aid in propulsion, is minimized, thereby reducing viscous losses.

Detecting the gravitational sensitivity of Paramecium caudatum using magnetic forces

NASA Astrophysics Data System (ADS)

Guevorkian, Karine; Valles, James M., Jr.

2006-03-01

Under normal conditions, Paramecium cells regulate their swimming speed in response to the pN level mechanical force of gravity. This regulation, known as gravikinesis, is more pronounced when the external force is increased by methods such as centrifugation. Here we present a novel technique that simulates gravity fields using the interactions between strong inhomogeneous magnetic fields and cells. We are able to achieve variable gravities spanning from 10xg to -8xg; where g is earth's gravity. Our experiments show that the swimming speed regulation of Paramecium caudatum to magnetically simulated gravity is a true physiological response. In addition, they reveal a maximum propulsion force for paramecia. This advance establishes a general technique for applying continuously variable forces to cells or cell populations suitable for exploring their force transduction mechanisms.

Morphological differences between habitats are associated with physiological and behavioural trade-offs in stickleback (Gasterosteus aculeatus)

PubMed Central

Seebacher, Frank; Webster, Mike M.; James, Rob S.; Tallis, Jason; Ward, Ashley J. W.

2016-01-01

Local specialization can be advantageous for individuals and may increase the resilience of the species to environmental change. However, there may be trade-offs between morphological responses and physiological performance and behaviour. Our aim was to test whether habitat-specific morphology of stickleback (Gasterosteus aculeatus) interacts with physiological performance and behaviour at different salinities. We rejected the hypothesis that deeper body shape of fish from habitats with high predation pressure led to decreases in locomotor performance. However, there was a trade-off between deeper body shape and muscle quality. Muscle of deeper-bodied fish produced less force than that of shallow-bodied saltmarsh fish. Nonetheless, saltmarsh fish had lower swimming performance, presumably because of lower muscle mass overall coupled with smaller caudal peduncles and larger heads. Saltmarsh fish performed better in saline water (20 ppt) relative to freshwater and relative to fish from freshwater habitats. However, exposure to salinity affected shoaling behaviour of fish from all habitats and shoals moved faster and closer together compared with freshwater. We show that habitat modification can alter phenotypes of native species, but local morphological specialization is associated with trade-offs that may reduce its benefits. PMID:27429785

Morphological differences between habitats are associated with physiological and behavioural trade-offs in stickleback (Gasterosteus aculeatus).

PubMed

Seebacher, Frank; Webster, Mike M; James, Rob S; Tallis, Jason; Ward, Ashley J W

2016-06-01

Local specialization can be advantageous for individuals and may increase the resilience of the species to environmental change. However, there may be trade-offs between morphological responses and physiological performance and behaviour. Our aim was to test whether habitat-specific morphology of stickleback (Gasterosteus aculeatus) interacts with physiological performance and behaviour at different salinities. We rejected the hypothesis that deeper body shape of fish from habitats with high predation pressure led to decreases in locomotor performance. However, there was a trade-off between deeper body shape and muscle quality. Muscle of deeper-bodied fish produced less force than that of shallow-bodied saltmarsh fish. Nonetheless, saltmarsh fish had lower swimming performance, presumably because of lower muscle mass overall coupled with smaller caudal peduncles and larger heads. Saltmarsh fish performed better in saline water (20 ppt) relative to freshwater and relative to fish from freshwater habitats. However, exposure to salinity affected shoaling behaviour of fish from all habitats and shoals moved faster and closer together compared with freshwater. We show that habitat modification can alter phenotypes of native species, but local morphological specialization is associated with trade-offs that may reduce its benefits.

Induced clustering of Escherichia coli by acoustic fields.

PubMed

Gutiérrez-Ramos, Salomé; Hoyos, Mauricio; Ruiz-Suárez, J C

2018-03-16

Brownian or self-propelled particles in aqueous suspensions can be trapped by acoustic fields generated by piezoelectric transducers usually at frequencies in the megahertz. The obtained confinement allows the study of rich collective behaviours like clustering or spreading dynamics in microgravity-like conditions. The acoustic field induces the levitation of self-propelled particles and provides secondary lateral forces to capture them at nodal planes. Here, we give a step forward in the field of confined active matter, reporting levitation experiments of bacterial suspensions of Escherichia coli. Clustering of living bacteria is monitored as a function of time, where different behaviours are clearly distinguished. Upon the removal of the acoustic signal, bacteria rapidly spread, impelled by their own swimming. Nevertheless, long periods of confinement result in irreversible bacteria entanglements that could act as seeds for levitating bacterial aggregates.

Sex differences on the competitive place task in the water maze: The influence of peripheral pool time on spatial navigation performance in rats.

PubMed

Devan, Bryan D; Tobin, Elizabeth L; Dunn, Emily N; Magalis, Christopher

2016-11-01

This study investigated sex differences on the competitive place version of the Morris water maze task to determine whether potential strategy differences would emerge during any phase of the study but in particular on the competitive place phase. Previous findings indicate that this version of the task is highly sensitive to measures that disrupt NMDA-dependent synaptic plasticity within the hippocampus during memory consolidation (McDonald et al., 2005). The present findings revealed significant sex differences during all phases of the study, including Phase I with standard place training to located a hidden platform/goal, Phase II mass training to a new place with the platform/goal relocated to the diagonally opposite quadrant and Phase III, competitive place probe test with the platform removed to measure spatial behaviour directed at either location. The findings showed no sex difference in escape latency and other standard performance measures during the first two phases, initial place acquisition and mass training to a new location. A very subtle male advantage in visiting both Old and New place locations during the third phase place competition test was observed, however, in the time spent swimming in the periphery of the pool, the pool wall (Zone C - outer third radial distance) was increased for females during all phases of the study, suggesting a general effect may have influenced place location search behaviour of the females. Increased peripheral pool time may represent a female preference for approaching the wall, a local cue. Alternatively, the possibility that increased peripheral swimming/thigmotaxis may represent hormonal influences interacting with strategic preferences were discussed, though no definitive conclusions about sex differences in cognitive-spatial performance or memory consolidation were inferred from the present findings. The findings suggest that mixed results reported in the literature by others may be due in part to an interaction with a persistent peripheral pool swimming response demonstrated in female rats. Copyright © 2016 Elsevier B.V. All rights reserved.

Restoring normal eating behaviour in adolescents with anorexia nervosa: A video analysis of nursing interventions.

PubMed

Beukers, Laura; Berends, Tamara; de Man-van Ginkel, Janneke M; van Elburg, Annemarie A; van Meijel, Berno

2015-12-01

An important part of inpatient treatment for adolescents with anorexia nervosa is to restore normal eating behaviour. Health-care professionals play a significant role in this process, but little is known about their interventions during patients' meals. The purpose of the present study was to describe nursing interventions aimed at restoring normal eating behaviour in patients with anorexia nervosa. The main research question was: 'Which interventions aimed at restoring normal eating behaviour do health-care professionals in a specialist eating disorder centre use during meal times for adolescents diagnosed with anorexia nervosa? The present study was a qualitative, descriptive study that used video recordings made during mealtimes. Thematic data analysis was applied. Four categories of interventions emerged from the data: (i) monitoring and instructing; (ii) encouraging and motivating; (iii) supporting and understanding; and (iv) educating. The data revealed a directive attitude aimed at promoting behavioural change, but always in combination with empathy and understanding. In the first stage of clinical treatment, health-care professionals focus primarily on changing patients' eating behaviour. However, they also address the psychosocial needs that become visible in patients as they struggle to restore normal eating behaviour. The findings of the present study can be used to assist health-care professionals, and improve multidisciplinary guidelines and health-care professionals' training programmes. © 2015 Australian College of Mental Health Nurses Inc.

The C-2 derivatives of salvinorin A, ethoxymethyl ether Sal B and β-tetrahydropyran Sal B, have anti-cocaine properties with minimal side effects.

PubMed

Ewald, Amy W M; Bosch, Peter J; Culverhouse, Aimee; Crowley, Rachel Saylor; Neuenswander, Benjamin; Prisinzano, Thomas E; Kivell, Bronwyn M

2017-08-01

Kappa-opioid receptor (KOPr) agonists have pre-clinical anti-cocaine and analgesic effects. However, side effects including sedation, dysphoria, aversion, anxiety and depression limit their therapeutic development. The unique structure of salvinorin A has been used to develop longer acting KOPr agonists. We evaluate two novel C-2 analogues of salvinorin A, ethoxymethyl ether Sal B (EOM Sal B) and β-tetrahydropyran Sal B (β-THP Sal B) alongside U50,488 for their ability to modulate cocaine-induced behaviours and side effects, pre-clinically. Anti-cocaine properties of EOM Sal B were evaluated using the reinstatement model of drug seeking in self-administering rats. EOM Sal B and β-THP Sal B were evaluated for effects on cocaine-induced hyperactivity, spontaneous locomotor activity and sucrose self-administration. EOM Sal B and β-THP Sal B were evaluated for aversive, anxiogenic and depressive-like effects using conditioned place aversion (CPA), elevated plus maze (EPM) and forced swim tests (FSTs), respectively. EOM Sal B (0.1, 0.3 mg/kg, intraperitoneally (i.p.)) dose dependently attenuated drug seeking, and EOM Sal B (0.1 mg/kg, i.p.) and β-THP Sal B (1 mg/kg, i.p.) attenuated cocaine-induced hyperactivity. No effects on locomotor activity, open arm times (EPM) or swimming behaviours (FST) were seen with EOM (0.1 or 0.3 mg/kg, i.p.) or β-THP Sal B (1 or 2 mg/kg, i.p.). However, β-THP Sal B decreased time spent in the drug-paired chamber. EOM Sal B is more potent than Sal A and β-THP Sal B in reducing drug-seeking behaviour with fewer side effects. EOM Sal B showed no effects on sucrose self-administration (0.1 mg/kg), locomotor, depressive-like, aversive-like or anxiolytic effects.

Thiamine and benfotiamine improve cognition and ameliorate GSK-3β-associated stress-induced behaviours in mice.

PubMed

Markova, Nataliia; Bazhenova, Nataliia; Anthony, Daniel C; Vignisse, Julie; Svistunov, Andrey; Lesch, Klaus-Peter; Bettendorff, Lucien; Strekalova, Tatyana

2017-04-03

Thiamine (vitamin B1) deficiency in the brain has been implicated in the development of dementia and symptoms of depression. Indirect evidence suggests that thiamine may contribute to these pathologies by controlling the activities of glycogen synthase kinase (GSK)-3β. While decreased GSK-3β activity appears to impair memory, increased GSK-3β activity is associated with the distressed/depressed state. However, hitherto direct evidence for the effects of thiamine on GSK-3β function has not been reported. Here, we administered thiamine or, the more bioavailable precursor, benfotiamine at 200mg/kg/day for 2weeks to C57BL/6J mice, to determine whether treatment might affect behaviours that are known to be sensitive to GSK-3β activity and whether such administration impacts on GSK-3β expression within the brain. The mice were tested in models of contextual conditioning and extinction, a 5-day rat exposure stress test, and a modified swim test with repeated testing. The tricyclic antidepressant imipramine (7.5mg/kg/day), was administered as a positive control for the effects of thiamine or benfotiamine. As for imipramine, both compounds inhibited the upregulation of GSK-3β induced by predator stress or repeated swimming, and reduced floating scores and the predator stress-induced behavioural changes in anxiety and exploration. Coincident, thiamine and benfotiamine improved learning and extinction of contextual fear, and the acquisition of the step-down avoidance task. Our data indicate that thiamine and benfotiamine have antidepressant/anti-stress effects in naïve animals that are associated with reduced GSK-3β expression and conditioning of adverse memories. Thus thiamine and benfotiamine may modulate GSK-3β functions in a manner that is dependent on whether the contextual conditioning is adaptive or maladaptive. Copyright © 2016 Elsevier Inc. All rights reserved.

Simultaneous infection of Schistosoma mansoni and S. rodhaini in Biomphalaria glabrata: impact on chronobiology and cercarial behaviour

PubMed Central

Norton, Alice; Rollinson, David; Richards, Louisa; Webster, Joanne

2008-01-01

Background The chances of a schistosome cercaria encountering a suitable definitive host may be enhanced by emergence from the molluscan intermediate host with maximal glycogen stores and by an appropriate chronobiological rhythm. This study aimed to identify and characterize the effects of potential competitive interactions in the snail host Biomphalaria glabrata, between the closely-related Schistosoma mansoni and S. rodhaini, on phenotypic behavioural traits. It was predicted that inter-specific competition would affect chronobiological emergence rhythms and reduce the activity of schistosome swimming behavioural traits. Biomphalaria glabrata snails (120) were exposed to either S. mansoni or S. rodhaini single infections, or a mixed infection of both species simultaneously and the resulting cercarial phenotypic traits were characterised. Cercariae were identified from co-exposed snails by amplification and sequencing of the mitochondrial cytochrome oxidase subunit 1 (CO1). Results S. mansoni and S. rodhaini largely maintained their distinct chronobiological rhythms after mixed exposures and infections. However, inter-specific competition appeared to result in a restriction of the shedding pattern of S. rodhaini and slight shift in the shedding pattern of S. mansoni. Inter-specific competition also significantly lowered hourly cercarial production for both parasite species in comparison to single exposures and infections and reduced cercarial swimming activity. Conclusion Inter-specific competition was shown to influence cercarial production, chronobiology and activity and should therefore be investigated further in field situations to determine the effects of these changes on parasite fitness (incorporating both host finding and infectivity) where these two species overlap. Importantly this competition did not result in a large change in chronobiological emergence of cercariae for either species indicating that it would not have a large influence on the species of hosts available for infection at time of emergence. This study has furthermore demonstrated the potential for phenotypic measures to provide markers for species-specific identification even in conditions of co-infection. PMID:19055722

Chronic icv oxytocin attenuates the pathological high anxiety state of selectively bred Wistar rats.

PubMed

Slattery, D A; Neumann, I D

2010-01-01

Central oxytocin (OXT) has been shown to promote numerous social behaviours, to attenuate hormonal stress responsiveness of the HPA axis and to decrease anxiety. Wistar rats selectively bred for high (HAB) and low (LAB) anxiety-related behaviour, respectively, have been shown to represent a suitable animal model to study the underlying aetiology of psychopathologies like anxiety- and depression-related disorders. The goal of the present studies was to assess the effects of central OXT on anxiety- and depression-related behaviour in male and female HAB and LAB rats. Acute icv OXT (1 microg) or OXT receptor antagonist (OXT-A; 0.75 microg) administration did not affect anxiety-related behaviour in male or female HAB and LAB rats as assessed in the light-dark box. In contrast, chronic icv OXT infusion (10 ng/h; 6 d) attenuated the high level of anxiety-related behaviour in female, but not male, HAB rats, whereas chronic OXT-A infusion (7.5 ng/h; 6 d) increased anxiety-related behaviour in female, but not male, LAB rats. Neither acute nor chronic manipulation of the OXT system altered depression-related behaviour as assessed by the forced swim test. Combined, these results suggest that pharmacological manipulation of the brain OXT system is effective to attenuate extremes in trait anxiety in an animal model of psychopathological anxiety. Moreover, the data indicate that differences in the activity of the brain OXT systems between HAB and LAB rats may, at least partially, contribute to the opposing anxiety but not depression-related behaviour.

Neuropeptide S alters anxiety, but not depression-like behaviour in Flinders Sensitive Line rats: a genetic animal model of depression.

PubMed

Wegener, Gregers; Finger, Beate C; Elfving, Betina; Keller, Kirsten; Liebenberg, Nico; Fischer, Christina W; Singewald, Nicolas; Slattery, David A; Neumann, Inga D; Mathé, Aleksander A

2012-04-01

Neuropeptide S (NPS) and its receptor (NPSR) have been implicated in the mediation of anxiolytic-like behaviour in rodents. However, little knowledge is available regarding the NPS system in depression-related behaviours, and whether NPS also exerts anxiolytic effects in an animal model of psychopathology. Therefore, the aim of this work was to characterize the effects of NPS on depression- and anxiety-related parameters, using male and female rats in a well-validated animal model of depression: the Flinders Sensitive Line (FSL), their controls, the Flinders Resistant Line (FRL), and Sprague-Dawley (SD) rats. We found that FSL showed greater immobility in the forced swim test (FST) than FRL, confirming their phenotype. However, NPS did not affect depression-related behaviour in any rat line. No significant differences in baseline anxiety levels between the FSL and FRL strains were observed, but FSL and FRL rats displayed less anxiety-like behaviour compared to SD rats. NPS decreased anxiety-like behaviour on the elevated plus-maze in all strains. The expression of the NPSR in the amygdala, periventricular hypothalamic nucleus, and hippocampus was equal in all male strains, although a trend towards reduced expression within the amygdala was observed in FSL rats compared to SD rats. In conclusion, NPS had a marked anxiolytic effect in FSL, FRL and SD rats, but did not modify the depression-related behaviour in any strain, in spite of the significant differences in innate level between the strains. These findings suggest that NPS specifically modifies anxiety behaviour but cannot overcome/reverse a genetically mediated depression phenotype.

Antifatigue Effect of Luteolin-6-C-Neohesperidoside on Oxidative Stress Injury Induced by Forced Swimming of Rats through Modulation of Nrf2/ARE Signaling Pathways

PubMed Central

Duan, Fang-fang; Guo, Ying; Li, Jing-wan

2017-01-01

Luteolin-6-C-neohesperidoside (LN) is a flavonoid isolated from moso bamboo leaf. This study was performed to evaluate the antifatigue effect of LN on a rat model undergoing the weight-loaded forced swimming test (FST). Briefly, male Sprague-Dawley rats (20–22 weeks old) were forced to undertake exhaustive swimming every other day for 3 weeks. Each swimming session was followed by the administration of distilled water, LN (25–75 mg/kg), or ascorbic acid (100 mg/kg) 1 h later. Oral administration of LN significantly improved exercise endurance; normalized alterations in energy metabolic markers; and decreased serum lactic acid, lactate dehydrogenase, and blood urea nitrogen levels of rats that underwent FST. Moreover, LN enhanced the activities of antioxidant enzymes and antioxidant capacity, as measured by enzyme activity assays, RT-PCR, and Western blotting, as well as decreasing the levels of proinflammatory cytokines such as tumor necrosis factor-α, interleukin-1β (IL-1β), and IL-6 and increasing the level of anti-inflammatory (IL-10) in the liver and skeletal muscle. These results suggested that LN reduces both physical and mental effects of chronic fatigue, probably by attenuating oxidative stress injury and inflammatory responses in the liver and skeletal muscle. This study thus supports the use of LN in functional foods for antifatigue and antioxidant effects. PMID:28588747

Electric potentiation of gravikinesis in Paramecium is possibly mediated by filaments.

PubMed

Machemer, H

1998-01-01

Sensitivity of Paramecium to mechanical stress including gravitational force is organized along two opposing gradients of membrane channel distribution: depolarizing Ca channels and hyperpolarizing K channels. Mechanoreceptor channels reside in the membrane of the cell soma and are activated, when the weight of the cytoplasm deforms the "lower" plasma membrane. Channel distribution is such as to generate ciliary activation which can counteract sedimentation of the cells: a reduction in downward swimming rate and an augmentation in upward swimming rate. Application of weak DC fields does not only induce the well-known cathodal orientation and swimming of Paramecium toward the cathode (galvano-taxis). We document that swimming velocity is augmented up to 175% as a function of the voltage gradient between 0.3 V/cm and 0.8 V/cm (galvanokinesis). A gradient of 0.3 V/cm was highly effective in raising the common negative gravikinesis of downward swimmers threefold. The gravikinesis of upward swimmers reversed polarity under field stimulation inducing cells to augment sedimentation effects (positive gravikinesis). Both effects of electric-field stimulation on ciliary activation are of the depolarizing type: reduction in the frequency of normally beating cilia. Analysis of the data shows that a voltage-sensitivity of gravireceptor channels would not account for the observed potentiation of negative gravikinesis. It is suggested that a previously described voltage-dependent Ca channel of the soma membrane interferes with a Ca(2+)-sensitive, peripheral filament system, which directly connects to gravireceptor channels.

Possible involvement of corticosterone and serotonin in antidepressant and antianxiety effects of chromium picolinate in chronic unpredictable mild stress induced depression and anxiety in rats.

PubMed

Dubey, Vivek Kumar; Ansari, Faraha; Vohora, Divya; Khanam, Razia

2015-01-01

In the present study, we investigated the effects of chromium picolinate (CrP) on behavioural and biochemical parameters in chronic unpredictable mild stress (CUMS) induced depression and anxiety in rats. The normal and stressed male Swiss albino rats were administered CrP (8 and 16μg/mL in drinking water), they received stressors for seven days (each day one stressor) and this cycle was repeated three times for 21 days. On 22nd day, behaviour assessments followed by biochemical estimations were conducted. The results showed that treatment of CrP produced significant antidepressant effect, which has been evidenced by decrease in immobility time in modified forced swimming test (FST) in chronic unpredictable mild stress (CUMS) induced depression in rats. In elevated plus maze (EPM), CrP (16μg/mL) showed significant reduction in time spent in open arm. CrP (8μg/mL and 16μg/mL) also showed significant decrease in number of entries in open arm that shows antianxiety effect of CrP in CUMS rats. It was also found that CrP (8 and 16μg/mL) significantly increased 5-HT concentration in the discrete regions of brain (cortex and cerebellum). On the other hand, the plasma corticosterone level was significantly decreased with CrP (16μg/mL). The results suggested that increase in the concentration of 5-HT and decrease in plasma corticosterone levels could be responsible for improvement in symptoms of depression and anxiety in CUMS induced depression and anxiety in rats. Copyright © 2014 Elsevier GmbH. All rights reserved.

Developmental effects of simulated microgravity on zebrafish, (Danio rerio)

NASA Astrophysics Data System (ADS)

Stoyek, Matthew; Edsall, Sara; Franz-Odendaal, Tamara; Smith, Frank; Croll, Roger

Zebrafish are widely used model vertebrates in research and recently this species has been used to study the effects of microgravity on fundamental biological processes. In this study we used a NASA-designed rotating wall vessel (RWV) to investigate the effects of simulated microgravity (SMG) on zebrafish development up to 14 days post fertilization (dpf). At developmental stages beyond the 3-4 somite stage we found SMG-exposed embryos reached key developmental stag-ing points more rapidly than fish raised within a non-rotating vessel. By the 21 somite stage, both groups were again synchronized in their developmental staging. However, SMG-exposed embryos eventually exhibited a delay in hatching time compared to controls. Otolith and to-tal body size were observed to be greater in larvae raised in SMG. In addition, pigmentation patterns in SMG exposed fish differed, with larger and differentially aggregated melanocytes . Heart development was slowed in SMG exposed fish, but no change in nervous system de-velopment was detected. Ongoing research will focus on differences in heart and respiration rates. Finally, by developing a method to extend the duration of SMG exposure, we found the swimming behaviour of SMG-exposed animals was altered with time in the RWV. Initially SMG-exposed animals swam in the direction of RWV rotation (5-9dpf) but older (9+dpf) fish swam against rotation and demonstrated righting behaviour with each rotation. These results suggest that vestibular reflexes may develop normally and be maintained in animals exposed to SMG. Together, our data provide insights into how zebrafish may develop when flown in space, permitting better formulation of experiments to test mechanisms by which microgravity may affect ontogeny of this model organism. Keywords: microgravity, zebrafish, growth, development

The impact of glide phases on the trackability of hydrodynamic trails in harbour seals (Phoca vitulina).

PubMed

Wieskotten, S; Dehnhardt, G; Mauck, B; Miersch, L; Hanke, W

2010-11-01

The mystacial vibrissae of harbour seals (Phoca vitulina) constitute a highly sensitive hydrodynamic receptor system enabling the seals to detect and follow hydrodynamic trails. In the wild, hydrodynamic trails, as generated by swimming fish, consist of cyclic burst-and-glide phases, associated with various differences in the physical parameters of the trail. Here, we investigated the impact of glide phases on the trackability of differently aged hydrodynamic trails in a harbour seal. As fish are not easily trained to swim certain paths with predetermined burst-and-glide phases, the respective hydrodynamic trails were generated using a remote-controlled miniature submarine. Gliding phases in hydrodynamic trails had a negative impact on the trackability when trails were 15 s old. The seal lost the generated trails more often within the transition zones, when the submarine switched from a burst to a glide moving pattern. Hydrodynamic parameter analysis (particle image velocimetry) revealed that the smaller dimensions and faster decay of hydrodynamic trails generated by the gliding submarine are responsible for the impaired success of the seal tracking the gliding phase. Furthermore, the change of gross water flow generated by the submarine from a rearwards-directed stream in the burst phase to a water flow passively dragged behind the submarine during gliding might influence the ability of the seal to follow the trail as this might cause a weaker deflection of the vibrissae. The possible ecological implications of intermittent swimming behaviour in fish for piscivorous predators are discussed.

Novel Methods for Analysing Bacterial Tracks Reveal Persistence in Rhodobacter sphaeroides

PubMed Central

Rosser, Gabriel; Fletcher, Alexander G.; Wilkinson, David A.; de Beyer, Jennifer A.; Yates, Christian A.; Armitage, Judith P.; Maini, Philip K.; Baker, Ruth E.

2013-01-01

Tracking bacteria using video microscopy is a powerful experimental approach to probe their motile behaviour. The trajectories obtained contain much information relating to the complex patterns of bacterial motility. However, methods for the quantitative analysis of such data are limited. Most swimming bacteria move in approximately straight lines, interspersed with random reorientation phases. It is therefore necessary to segment observed tracks into swimming and reorientation phases to extract useful statistics. We present novel robust analysis tools to discern these two phases in tracks. Our methods comprise a simple and effective protocol for removing spurious tracks from tracking datasets, followed by analysis based on a two-state hidden Markov model, taking advantage of the availability of mutant strains that exhibit swimming-only or reorientating-only motion to generate an empirical prior distribution. Using simulated tracks with varying levels of added noise, we validate our methods and compare them with an existing heuristic method. To our knowledge this is the first example of a systematic assessment of analysis methods in this field. The new methods are substantially more robust to noise and introduce less systematic bias than the heuristic method. We apply our methods to tracks obtained from the bacterial species Rhodobacter sphaeroides and Escherichia coli. Our results demonstrate that R. sphaeroides exhibits persistence over the course of a tumbling event, which is a novel result with important implications in the study of this and similar species. PMID:24204227

Long-lasting potassium channel inactivation in myoepithelial fibres is related to characteristics of swimming in diphyid siphonophores.

PubMed

Inoue, Isao; Tsutsui, Izuo; Bone, Quentin

2005-12-01

Diphyid siphonophores swim using bursts of propulsive jets, which are produced by contractions of a monolayer of subumbrellar myoepithelial fibres lining the nectophore. This swimming behaviour is characterised by successive increases in the force generating the jets during the initial jets of the burst. Action potentials that generate the contractions propagate throughout the myoepithelial layer: both their amplitude and duration successively increase during the first part of the burst. To investigate the ionic mechanism of this action potential augmentation, single myoepithelial cells were enzymatically dissociated and whole-cell voltage clamped. Na+, Ca2+ and K+ currents were recorded under different internal and external salt compositions. The Na+ current was blocked by a relatively high concentration (4 micromol l-1 or higher) of tetrodotoxin (TTX), indicating that the Na+ channel belongs to a group of TTX-resistant Na+ channels. The Ca2+ current was blocked by nifedipine (10 micromol l-1) and Co2+ (5 mmol l-1), indicating that the Ca2+ channel is L-type. The K+ current possessed a unique property of long-lasting inactivation. The K+ current fully inactivated during a depolarisation to +30 mV with a time-constant of approximately 9 ms, and the time constant of recovery from inactivation at -70 mV was 13.2 s. This long-lasting inactivation of the K+ channel was the major factor in the augmentation of both action potentials and contractions of the myoepithelial sheet during the initial part of the burst.

Investigation of antidepressant-like and anxiolytic-like actions and cognitive and motor side effects of four N-methyl-D-aspartate receptor antagonists in mice.

PubMed

Refsgaard, Louise K; Pickering, Darryl S; Andreasen, Jesper T

2017-02-01

Evidence suggests that N-methyl-D-aspartate receptor (NMDAR) antagonists could be efficacious in treating depression and anxiety, but side effects constitute a challenge. This study evaluated the antidepressant-like and anxiolytic-like actions, and cognitive and motor side effects of four NMDAR antagonists. MK-801, ketamine, S-ketamine, RO 25-6981 and the positive control, citalopram, were tested for antidepressant-like and anxiolytic-like effects in mice using the forced-swim test, the elevated zero maze and the novelty-induced hypophagia test. Side effects were assessed using a locomotor activity test, the modified Y-maze and the rotarod test. All compounds increased swim distance in the forced-swim test. In the elevated zero maze, the GluN2B subtype-selective RO 25-6981 affected none of the measured parameters, whereas all other compounds showed anxiolytic-like effects. In the novelty-induced hypophagia test, citalopram and MK-801 showed anxiogenic-like action. All NMDAR antagonists induced hyperactivity. The high doses of ketamine and MK-801 impaired performance in the modified Y-maze test, whereas S-ketamine and RO 25-6891 showed no effects in this test. Only MK-801 impaired rotarod performance. The study supports that NMDARs could be a possible therapeutic target for treating depression and anxiety. However, selective antagonism of GluN2B subunit-containing NMDARs showed no effect on anxiety-like behaviours in this study.

Review of the dynamic behaviour of sports balls during normal and oblique impacts

NASA Astrophysics Data System (ADS)

Haron, Muhammad Adli; Jailani, Azrol; Abdullah, Nik Ahmad Faris Nik; Ismail, Rafis Suizwan; Rahim, Shayfull Zamree Abd; Ghazali, Mohd Fathullah

2017-09-01

In this paper are review of impact experiment to study the dynamic behaviour of sports ball during oblique and normal impacts. In previous studies, the investigation was done on the dynamic behaviour of a sports ball during oblique and normal impacts from experimental, numerical, and theoretical viewpoints. The experimental results are analysed and compared with the theories, in order to understand the dynamics behaviours based on the phenomenological occurrence. Throughout the experimental studies previously, there are results of dynamics behaviours examined by many researchers such as the coefficient of restitution, tangential coefficient, local deformation, dynamic impact force, contact time, angle of impact (inbound and rebound), spin rate of the ball, ball stiffness and damping coefficient which dependable of the initial or impact velocity.

Optimum swimming pathways of fish spawning migrations in rivers

USGS Publications Warehouse

McElroy, Brandon; DeLonay, Aaron; Jacobson, Robert

2012-01-01

Fishes that swim upstream in rivers to spawn must navigate complex fluvial velocity fields to arrive at their ultimate locations. One hypothesis with substantial implications is that fish traverse pathways that minimize their energy expenditure during migration. Here we present the methodological and theoretical developments necessary to test this and similar hypotheses. First, a cost function is derived for upstream migration that relates work done by a fish to swimming drag. The energetic cost scales with the cube of a fish's relative velocity integrated along its path. By normalizing to the energy requirements of holding a position in the slowest waters at the path's origin, a cost function is derived that depends only on the physical environment and not on specifics of individual fish. Then, as an example, we demonstrate the analysis of a migration pathway of a telemetrically tracked pallid sturgeon (Scaphirhynchus albus) in the Missouri River (USA). The actual pathway cost is lower than 105 random paths through the surveyed reach and is consistent with the optimization hypothesis. The implication—subject to more extensive validation—is that reproductive success in managed rivers could be increased through manipulation of reservoir releases or channel morphology to increase abundance of lower-cost migration pathways.

Swimming and cycling overloaded training in triathlon has no effect on running kinematics and economy.

PubMed

Palazzetti, S; Margaritis, I; Guezennec, C Y

2005-04-01

The aim of the study was to verify whether an overloaded training (OT) in triathlon deteriorates running kinematics (RK) and running economy (RE). Thirteen well-trained male long-distance triathletes (age: 28.1 +/- 4.3 yrs; V.O (2max): 65.0 +/- 3.1 ml O (2) . min (-1) . kg (-1)) were divided into two groups: completed an individualized OT program (OG; n = 7) or maintained a normal level of training (NT) (CG; n = 6) for a duration of 3 weeks. Every week, each triathlete completed a standardized questionnaire to quantify the influence of training loads on mood state. To reach OT, total training load (h . 3 wk (-1)) was increased by 24 %; swimming and cycling total volumes were increased by 46 and 57 %, respectively, but the distance run was not modified in order to limit the risk of injuries. RK and RE were determined on treadmill test at 12 km . h (-1) before and after the 3 weeks. The 3-week swimming and cycling OT in triathlon was sufficiently stressful to alter mood state but not to deteriorate the running kinematics and economy parameters in our previously well-trained male long-distance triathletes.

A behavioural analysis of spatial localization following electrolytic, kainate- or colchicine-induced damage to the hippocampal formation in the rat.

PubMed

Sutherland, R J; Whishaw, I Q; Kolb, B

1983-02-01

This experiment examines the notion that in the rat the hippocampal formation is an essential structure in the neurological representation of spatial abilities. Spatial localization by rats with different types of hippocampal damage, including bilateral electrolytic lesions, unilateral and bilateral kainic acid-induced CA3-CA4 lesions, and unilateral and bilateral colchicine-induced dentate gyrus lesions, was compared with vehicle-injected and normal control groups in the Morris water task. The task required the rats to escape from cold water by finding a submerged and hidden platform located at a fixed place within the room. The start point was varied randomly from trial to trial and there were no local cues available to indicate the position of the hidden platform. After training, the platform was moved. Escape latencies and the initial swimming headings revealed that all lesion groups, except the unilateral CA3-damaged group, were impaired at finding the platform: the dentate-damaged rats exhibited the greatest deficit. When the platform was moved the control rats swam mainly in the part of the pool that had previously contained the platform and, on finding it in the new location, they showed a marked dishabituation of rearing. None of the bilateral lesion groups showed these effects.

Ciliary propulsion of objects in tubes: wall drag on swimming Tetrahymena (Ciliata) in the presence of mucin and other long-chain polymers.

PubMed

Winet, H

1976-04-01

The lubrication effect of three long-chain polymers - mucin, methylcellulose and Ficoll - on ciliary propulsion in tubes is measured by plotting the relative velocities of swimming cilitates as a function of the tube bore diameter. Mucin shows the most unequivocal lubrication, which is found at concentrations between 0% and 9.1% (w/v). This observation, coupled with viscometric measurements which show that ciliary tip shear rates are sufficient to solate mucin, serve as the groundwork for a model of mucin lubrication which explains the optimized lubrication behaviour of thixotropic gelating polymers as an expression of the response to shear by the various stages of polymer clustering during the gelatin process. In addition to the lubricative effect, another wall drag reduction effect by mucin was measured in the clearance region beyond the lubrication layer. This apparent viscosity reduction is optimized in the concentration range between I.7% and 4.I% mucin and may also be explained in terms of the properties of gel clustering.

Hydrodynamic interaction between two trapped swimming model micro-organisms.

PubMed

Matas Navarro, R; Pagonabarraga, I

2010-09-01

We present a theoretical study of the behaviour of two active particles under the action of harmonic traps kept at a fixed distance away from each other. We classify the steady configurations the squirmers develop as a function of their self-propelling velocity and the active stresses the swimmers induce around them. We have further analyzed the stability of such configurations, and have found that the ratio between their self-propelling velocity and the apolar flow generated through active stresses determines whether collinear parallel squirmers or perpendicularly swimming particles moving away from each other are stable. Therefore, there is a close connection between the stable configurations and the active mechanisms leading to the particle self-propulsion. The trap potential does not affect the stability of the configurations; it only modifies some of their relevant time scales. We have also observed the development of characteristic frequencies which should be observable. Finally, we show that the development of the hydrodynamic flows induced by the active particles may be relevant even when its time scale orders of magnitude smaller than the other present characteristic time scales and may destabilize the stable configurations.

Dynamic modulation of visual and electrosensory gains for locomotor control

PubMed Central

Sutton, Erin E.; Demir, Alican; Stamper, Sarah A.; Fortune, Eric S.; Cowan, Noah J.

2016-01-01

Animal nervous systems resolve sensory conflict for the control of movement. For example, the glass knifefish, Eigenmannia virescens, relies on visual and electrosensory feedback as it swims to maintain position within a moving refuge. To study how signals from these two parallel sensory streams are used in refuge tracking, we constructed a novel augmented reality apparatus that enables the independent manipulation of visual and electrosensory cues to freely swimming fish (n = 5). We evaluated the linearity of multisensory integration, the change to the relative perceptual weights given to vision and electrosense in relation to sensory salience, and the effect of the magnitude of sensory conflict on sensorimotor gain. First, we found that tracking behaviour obeys superposition of the sensory inputs, suggesting linear sensorimotor integration. In addition, fish rely more on vision when electrosensory salience is reduced, suggesting that fish dynamically alter sensorimotor gains in a manner consistent with Bayesian integration. However, the magnitude of sensory conflict did not significantly affect sensorimotor gain. These studies lay the theoretical and experimental groundwork for future work investigating multisensory control of locomotion. PMID:27170650

Verification of epigenetic inheritance in a unicellular model system: multigenerational effects of hormonal imprinting.

PubMed

Kőhidai, László; Lajkó, Eszter; Pállinger, Eva; Csaba, György

2012-10-01

The unicellular Tetrahymena has receptors for hormones of higher vertebrates, produces these hormones, and their signal pathways are similar. The first encounter with a hormone in higher dose provokes the phenomenon of hormonal imprinting, by which the reaction of the cell is quantitatively modified. This modification is transmitted to the progeny generations. The duration of the single imprinter effect of two representative signal molecules, insulin and 5-HT (5-hydroxytryptamine), in two concentrations (10(-6) and 10(-15) M) were studied. The effects of imprinting were followed in 5 physiological indices: (i) insulin binding, (ii) 5-HT synthesis, (iii) swimming behaviour, (iv) cell growth and (v) chemotaxis in progeny generations 500 and 1000. The result of each index was different from the non-imprinted control functions, growth rate, swimming behaviour and chemotactic activity to insulin being enhanced, while others, e.g. synthesis and chemotactic responsiveness of 5-HT and the binding of insulin were reduced. This means that a function-specific heritable epigenetic change during imprinting occurs, and generally a single encounter with a femtomolar hormone concentration is enough for provoking durable and heritable imprinting in Tetrahymena. The experiments demonstrate the possibility of epigenetic effects at a unicellular level and call attention to the possibility that the character of unicellular organisms has changed through to the present day due to an enormous amount of non-physiological imprinter substances in their environment. The results - together with results obtained earlier in mammals - point to the validity of epigenetic imprinting effects throughout the animal world.

Neuropharmacological effects of oleamide in male and female mice.

PubMed

Akanmu, Moses A; Adeosun, Samuel O; Ilesanmi, Olapade R

2007-08-22

Oleamide, a fatty acid amide accumulates selectively in the cerebrospinal fluid of sleep deprived cats and rats. Oleamide has been reported to have effects on a wide range of receptors and neurotransmitter systems especially the centrally acting ones for example, dopamine acetylcholine, serotonin, gamma aminobutyric acid (GABA), cannabinoid and vanilloid among others. This suggests a wide range of central nervous system effects of the compound. The effects of intraperitoneal administered oleamide on Novelty-induced behaviours, learning and memory and forced swimming-induced depression were studied. The relative effects of the compound on the male and female mice were also noted. Oleamide dose-dependently reduced (p<0.05) novelty induced rearing, grooming and locomotion. The effects on the all NIBs started within the first 10 min of the test and the peak of the effects was observed during the third 10 min period of the test. Effect of oleamide on short-term working memory was significantly (p<0.05) affected only with the dose of 5mg/kg while the other dose of 10mg/kg had no effect. In the forced swimming test, acute triple intraperitoneal administration of oleamide at 10mg/kg induced a significant reduction in the immobility duration in mice signifying an antidepressant effect. Sex differences in the effects of oleamide (10mg/kg, i.p.) were clearly evident in active behaviours in FST. These results confirm the multiplicity of central nervous system receptors and neurotransmitters that oleamide interacts with hence its numerous and diverse neuropharmacological effects. Most importantly, the present study suggests that oleamide has antidepressant-like property.

Pramipexole but not imipramine or fluoxetine reverses the "depressive-like" behaviour in a rat model of preclinical stages of Parkinson's disease.

PubMed

Berghauzen-Maciejewska, Klemencja; Kuter, Katarzyna; Kolasiewicz, Wacław; Głowacka, Urszula; Dziubina, Anna; Ossowska, Krystyna; Wardas, Jadwiga

2014-09-01

Depression is a frequent comorbid disorder in Parkinson's disease and may antedate its motor symptoms. However, mechanisms underlying Parkinson's disease-associated depression are unknown and its current medication is insufficient. The aim of the present study was to compare antidepressant-like effects of imipramine, fluoxetine and pramipexole in a model of preclinical stages of Parkinson's disease in rats. 6-Hydroxydopamine was bilaterally injected into the ventrolateral region of the caudate-putamen in rats. This treatment induced moderate decreases in the levels of dopamine and its metabolites in the caudate-putamen, nucleus accumbens and frontal cortex and reduced the density of tyrosine hydroxylase-immunoreactive neurons in the substantia nigra pars compacta and ventral tegmental area. The lesion increased immobility measured in the forced swimming test without influencing locomotor activity. Chronic (13 days) administration of pramipexole (1mg/kg sc/twice a day) reversed prolongation of the immobility time in lesioned animals but did not stimulate their locomotion. Chronic pramipexole activated dopaminergic transmission in the brain structures which might contribute to its effectiveness in the forced swimming test. In contrast, the 13-day administration of imipramine (10mg/kg ip/day) and fluoxetine (10mg/kg ip/day) did not shorten the immobility time in lesioned rats but reduced their locomotion. The present study indicates that already a moderate lesion of dopaminergic neurons induces "depressive-like" behaviour in animals which is reversed by chronic administration of the antiparkinsonian drug, pramipexole. Copyright © 2014 Elsevier B.V. All rights reserved.

Gastroprotective Effect of Ginger Rhizome (Zingiber officinale) Extract: Role of Gallic Acid and Cinnamic Acid in H+, K+-ATPase/H. pylori Inhibition and Anti-Oxidative Mechanism

PubMed Central

Nanjundaiah, Siddaraju M.; Annaiah, Harish Nayaka Mysore; Dharmesh, Shylaja M.

2011-01-01

Zinger officinale has been used as a traditional source against gastric disturbances from time immemorial. The ulcer-preventive properties of aqueous extract of ginger rhizome (GRAE) belonging to the family Zingiberaceae is reported in the present study. GRAE at 200 mg kg−1 b.w. protected up to 86% and 77% for the swim stress-/ethanol stress-induced ulcers with an ulcer index (UI) of 50 ± 4.0/46 ± 4.0, respectively, similar to that of lansoprazole (80%) at 30 mg kg−1 b.w. Increased H+, K+-ATPase activity and thiobarbituric acid reactive substances (TBARS) were observed in ulcer-induced rats, while GRAE fed rats showed normalized levels and GRAE also normalized depleted/amplified anti-oxidant enzymes in swim stress and ethanol stress-induced animals. Gastric mucin damage was recovered up to 77% and 74% in swim stress and ethanol stress, respectively after GRAE treatment. GRAE also inhibited the growth of H. pylori with MIC of 300 ± 38 μg and also possessed reducing power, free radical scavenging ability with an IC50 of 6.8 ± 0.4 μg mL−1 gallic acid equivalent (GAE). DNA protection up to 90% at 0.4 μg was also observed. Toxicity studies indicated no lethal effects in rats fed up to 5 g kg−1 b.w. Compositional analysis favored by determination of the efficacy of individual phenolic acids towards their potential ulcer-preventive ability revealed that between cinnamic (50%) and gallic (46%) phenolic acids, cinnamic acid appear to contribute to better H+, K+-ATPase and Helicobacter pylori inhibitory activity, while gallic acid contributes significantly to anti-oxidant activity. PMID:19570992

Pleurodeles waltl, amphibian, Urodele, is a suitable biological model for embryological and physiological space experiments on a vertebrate

NASA Astrophysics Data System (ADS)

Gualandris-Parisot, L.; Husson, D.; Foulquier, F.; Kan, P.; Davet, J.; Aimar, C.; Dournon, C.; Duprat, A. M.

2001-01-01

Pleurodeles waltl (amphibian, Urodele) is an appropriate biological model for space experiments on a vertebrate. One reason for interest in this animal concerns the study of the effects of absence of gravity on embryonic development. First, after mating (on Earth) the females retain live, functional sperm in their cloacum for up to 5 months, allowing normal in vivo fertilisation after hormonal stimulation. Second, their development is slow, which allows analyses of all the key stages of ontogenesis from the oocyte to swimming tailbud embryos or larvae. We have performed detailed studies and analyses of the effects of weightlessness on amphibian Pleurodeles embryos, fertilised and allowed to develop until the swimming larvae stage. These experiments were performed in space during three missions on the MIR-station: FERTILE I, FERTILE II and NEUROGENESIS respectively in 1996, 1998 and 1999. We show that in microgravity abnormalities appeared at specific stages of development compared to 1g-centrifuge control embryos and 1g-ground control embryos. In this report we describe abnormalities occurring in the central nervous system. These modifications occur during the neurulation process (delay in the closure of the neural tube and failure of closure of this tube in the cephalic area) and at the early tailbud stage (microcephaly observed in 40% of the microgravity-embryos). However, if acephalic and microcephalic embryos are not taken into account, these abnormalities did not disturb further morphological, biochemical and functional development and the embryos were able to regulate and a majority of normal hatching and swimming larvae were obtained in weightlessness with a developmental time-course equivalent to that of 1g-centrifuge control embryos (on the MIR station) and 1g-ground control embryos.

Sleep patterning and behaviour in cats with pontine lesions creating REM without atonia.

PubMed

Sanford; Morrison; Mann; Harris; Yoo; Ross

1994-12-01

Lesions of the dorsal pontine tegmentum release muscle tone and motor behaviour, much of it similar to orienting during wakefulness, into rapid eye movement sleep (REM), a state normally characterized by paralysis. Sleep after pontine lesions may be altered, with more REM-A episodes of shorter duration compared to normal REM. We examined behaviour, ponto-geniculo-occipital (PGO) waves (which may be central markers of orienting) and sleep in lesioned cats: (i) to characterize the relationship of PGO waves to behaviour in REM-A; (ii) to determine whether post-lesion changes in the timing and duration of REM-A episodes were due to activity-related awakenings: and (iii) to determine whether alterations in sleep changed the circadian sleep/wake cycle in cats. Behavioural release in REM-A was generally related to episode length, but episode length was not necessarily shorter than normal REM in cats capable of full locomotion in REM-A. PGO wave frequency was reduced overall during REM-A, but was higher during REM-A with behaviour than during quiet REM-A without overt behaviour. Pontine lesions did not significantly alter the circadian sleep/wake cycle: REM-A had approximately the same Light/Dark distribution as normal REM. Differences in the patterning of normal REM and REM-A within sleep involve more than mere movement-induced awakenings. Brainstem lesions that eliminate the atonia of REM may damage neural circuitry involved in REM initiation and maintenance; this circuitry is separate from circadian control mechanisms.

Adaptation of the pituitary-adrenal axis to daily repeated forced swim exposure in rats is dependent on the temperature of water.

PubMed

Rabasa, Cristina; Delgado-Morales, Raúl; Gómez-Román, Almudena; Nadal, Roser; Armario, Antonio

2013-11-01

Comparison of exposure to certain predominantly emotional stressors reveals a qualitatively similar neuroendocrine response profile as well as a reduction of physiological responses after daily repeated exposure (adaptation). However, particular physical components of the stressor may interfere with adaptation. As defective adaptation to stress can enhance the probability to develop pathologies, we studied in adult male rats (n = 10/group) swimming behavior (struggling, immobility and mild swim) and physiological responses (ACTH, corticosterone and rectal temperature) to daily repeated exposure to forced swim (20 min, 13 d) at 25 or 36 °C (swim25 or swim36). Rats were repeatedly blood-sampled by tail-nick and hormones measured by radioimmunoassay. Some differences were observed between the two swim temperature groups after the first exposure to forced swim: (a) active behaviors were greater in swim25 than swim36 groups; (b) swim25 but not swim36 caused hypothermia; and (c) swim36 elicited the same ACTH response as swim25, but plasma corticosterone concentration was lower for swim36 at 30 min post-swim. After daily repeated exposure, adaptation in ACTH secretion was observed with swim36 already on day 4, whereas with swim25 adaptation was not observed until day 13 and was of lower magnitude. Nevertheless, after repeated exposure to swim25 a partial protection from hypothermia was observed and the two swim conditions resulted in progressive reduction of active behaviors. Thus, daily repeated swim at 25 °C impairs adaptation of the hypothalamic-pituitary-adrenal axis as compared to swim at 36 °C, supporting the hypothesis that certain physical components of predominantly emotional stressors can interfere with the process of adaptation.

A stochastic vision-based model inspired by zebrafish collective behaviour in heterogeneous environments

PubMed Central

Collignon, Bertrand; Séguret, Axel; Halloy, José

2016-01-01

Collective motion is one of the most ubiquitous behaviours displayed by social organisms and has led to the development of numerous models. Recent advances in the understanding of sensory system and information processing by animals impels one to revise classical assumptions made in decisional algorithms. In this context, we present a model describing the three-dimensional visual sensory system of fish that adjust their trajectory according to their perception field. Furthermore, we introduce a stochastic process based on a probability distribution function to move in targeted directions rather than on a summation of influential vectors as is classically assumed by most models. In parallel, we present experimental results of zebrafish (alone or in group of 10) swimming in both homogeneous and heterogeneous environments. We use these experimental data to set the parameter values of our model and show that this perception-based approach can simulate the collective motion of species showing cohesive behaviour in heterogeneous environments. Finally, we discuss the advances of this multilayer model and its possible outcomes in biological, physical and robotic sciences. PMID:26909173

Escape behaviour elicited by a visual stimulus. A comparison between lateralised and non-lateralised female topminnows.

PubMed

Agrillo, Christian; Dadda, Marco; Bisazza, Angelo

2009-05-01

Studies over the past 30 years suggest that functional lateralisation occurs in many animal species. Preferential eye use is ubiquitous among fish, and recently some advantages of being lateralised have been reported in the golden topminnow, Girardinus falcatus, using fish from lines selected for high or low degrees of behavioural lateralisation. In the present paper we investigated whether non-lateralised fish differed from lateralised fish in escape behaviour elicited by a potentially dangerous stimulus. A total of 56 female topminnows were observed when swimming in an unknown environment in which the shape of a predator was presented on either the right or the left side of the visual field. We found no side differences in latency and efficiency of escape reaction and on the whole non-lateralised fish escaped as quickly as lateralised individuals. We discuss our results in the light of recent findings suggesting that the development of lateralisation in the fast escape response in fish may be controlled by a mechanism distinct from that controlling the asymmetric placement of most other cognitive functions.

Vestibular evidence for the evolution of aquatic behaviour in early cetaceans.

PubMed

Spoor, F; Bajpai, S; Hussain, S T; Kumar, K; Thewissen, J G M

2002-05-09

Early cetaceans evolved from terrestrial quadrupeds to obligate swimmers, a change that is traditionally studied by functional analysis of the postcranial skeleton. Here we assess the evolution of cetacean locomotor behaviour from an independent perspective by looking at the semicircular canal system, one of the main sense organs involved in neural control of locomotion. Extant cetaceans are found to be unique in that their canal arc size, corrected for body mass, is approximately three times smaller than in other mammals. This reduces the sensitivity of the canal system, most plausibly to match the fast body rotations that characterize cetacean behaviour. Eocene fossils show that the new sensory regime, incompatible with terrestrial competence, developed quickly and early in cetacean evolution, as soon as the taxa are associated with marine environments. Dedicated agile swimming of cetaceans thus appeared to have originated as a rapid and fundamental shift in locomotion rather than as the gradual transition suggested by postcranial evidence. We hypothesize that the unparalleled modification of the semicircular canal system represented a key 'point of no return' event in early cetacean evolution, leading to full independence from life on land.

Disinfection by-products and microbial contamination in the treatment of pool water with granular activated carbon.

PubMed

Uhl, W; Hartmann, C

2005-01-01

For swimming pools, it is generally agreed that free chlorine levels have to be maintained to guarantee adequate disinfection. Recommended free chlorine levels can vary between 0.3 and 0.6 mg/L in Germany and up to 3 mg/L in other countries. Bathers introduce considerable amounts of organic matter, mainly in the form of such as urine and sweat, into the pool water. As a consequence, disinfection byproducts (DBPs) are formed. Regulations in Germany recommend levels of combined chlorine of less than 0.2 mg/L and levels of trihalomethanes (THMs) of less than 20 microg/L. Haloacetic acids (HAAs), haloacetonitriles (HANs), chloropicrin and chloral hydrate are also detected in considerable amounts. However, these compounds are not regulated yet. Swimming pool staff and swimmers, especially athletes, are primarily exposed to these byproducts by inhalation and/or dermal uptake. In Germany, new regulations for swimming pool water treatment generally require the use of activated carbon. In this project, three different types of granular activated carbon (GAC) (one standard GAC, two catalytic GACs) are compared for their long time behaviour in pool water treatment. In a pilot plant operated with real swimming pool water, production and removal of disinfection byproducts (THMs, HAAs, AOXs), of biodegradable substances (AOC), of bacteria (Pseudomonas aeruginosa, Legionella, coliforms, HPC) as well as the removal of chlorine and chloramines are monitored as function of GAC bed depth. Combined chlorine penetrates deeper in the filter bed than free chlorine does. However, both, free and combined chlorine removal efficiencies decrease over the time of filter operation. The decreases of removal efficiencies are also observed for parameters such as dissolved organic carbon, spectral absorption coefficient, adsorbable organic carbon and most of the disinfection byproducts. However, THMs, especially chloroform are produced in the filter bed. The GAC beds were contaminated microbially, especially with P. aeruginosa. The contamination was not removable by backwashing with chlorine concentrations up to 2 mg/l free chlorine.

Swimming gaits, passive drag and buoyancy of diving sperm whales Physeter macrocephalus.

PubMed

Miller, Patrick J O; Johnson, Mark P; Tyack, Peter L; Terray, Eugene A

2004-05-01

Drag and buoyancy are two primary external forces acting on diving marine mammals. The strength of these forces modulates the energetic cost of movement and may influence swimming style (gait). Here we use a high-resolution digital tag to record depth, 3-D orientation, and sounds heard and produced by 23 deep-diving sperm whales in the Ligurian Sea and Gulf of Mexico. Periods of active thrusting versus gliding were identified through analysis of oscillations measured by a 3-axis accelerometer. Accelerations during 382 ascent glides of five whales (which made two or more steep ascents and for which we obtained a measurement of length) were strongly affected by depth and speed at Reynold's numbers of 1.4-2.8x10(7). The accelerations fit a model of drag, air buoyancy and tissue buoyancy forces with an r(2) of 99.1-99.8% for each whale. The model provided estimates (mean +/- S.D.) of the drag coefficient (0.00306+/-0.00015), air carried from the surface (26.4+/-3.9 l kg(-3) mass), and tissue density (1030+/-0.8 kg m(-3)) of these five animals. The model predicts strong positive buoyancy forces in the top 100 m of the water column, decreasing to near neutral buoyancy at 250-850 m. Mean descent speeds (1.45+/-0.19 m s(-1)) were slower than ascent speeds (1.63+/-0.22 m s(-1)), even though sperm whales stroked steadily (glides 5.3+/-6.3%) throughout descents and employed predominantly stroke-and-glide swimming (glides 37.7+/-16.4%) during ascents. Whales glided more during portions of dives when buoyancy aided their movement, and whales that glided more during ascent glided less during descent (and vice versa), supporting the hypothesis that buoyancy influences behavioural swimming decisions. One whale rested at approximately 10 m depth for more than 10 min without fluking, regulating its buoyancy by releasing air bubbles.

Do intracoelomic telemetry transmitters alter the post-release behaviour of migratory fish?

USGS Publications Warehouse

Wilson, Alexander D.M.; Hayden, Todd A.; Vandergoot, Christopher S.; Kraus, Richard T.; Dettmers, John M.; Cooke, Steven J.; Charles C. Krueger,

2016-01-01

Electronic tags have become a common tool in fish research, enhancing our understanding of how fish interact with their environment and move among different habitats, for estimating mortality and recording internal physiological states. An often-untested assumption of electronic tagging studies is that tagged fish are representative of untagged conspecifics and thus show ‘normal’ behaviour (e.g. movement rates, swimming activity, feeding). Here, we use a unique data set for potamadromous walleye (Sander vitreus) in Lake Huron and Lake Erie tributaries to assess whether the lack of appropriate controls in electronic tagging could seriously affect behavioural data. We used fish tagged in previous years and compared their migratory behaviour during the spawning season to fish tagged in a current year at the same location. The objective of the study was to determine whether intracoelomic acoustic tag implantation altered downstream movement of walleye after spawning. Fish tagged in a given season travelled slower downstream from two river spawning sites than fish tagged in previous years. Fish tagged one or two years earlier showed no differences between each other in downstream travel time, in contrast to fish tagged in a given year. Our results support notions that standard collection and intracoelomic tagging procedures can alter short-term behaviour (i.e. days, weeks, months), and as such, researchers should use caution when interpreting data collected over such time periods. Further, whenever possible, researchers should also explicitly evaluate post-tagging effects on behaviour as part of their experimental objectives.

The Effect of Swimming Experience on Acquisition and Retention of Swimming-Based Taste Aversion Learning in Rats

ERIC Educational Resources Information Center

Masaki, Takahisa; Nakajima, Sadahiko

2010-01-01

Swimming endows rats with an aversion to a taste solution consumed before swimming. The present study explored whether the experience of swimming before or after the taste-swimming trials interferes with swimming-based taste aversion learning. Experiment 1 demonstrated that a single preexposure to 20 min of swimming was as effective as four or…

Micro-navigation in complex periodic environments

NASA Astrophysics Data System (ADS)

Chamolly, Alexander; Ishikawa, Takuji; Lauga, Eric

2017-11-01

Natural and artificial small-scale swimmers may often self-propel in environments subject to complex geometrical constraints. While most past theoretical work on low-Reynolds number locomotion addressed idealised geometrical situations, not much is known on the motion of swimmers in heterogeneous environments. We investigate theoretically and numerically the behaviour of a single spherical micro-swimmer located in an infinite, periodic body-centred cubic lattice consisting of rigid inert spheres of the same size as the swimmer. We uncover a surprising and complex phase diagram of qualitatively different trajectories depending on the lattice packing density and swimming actuation strength. These results are then rationalised using hydrodynamic theory. In particular we show that the far-field nature of the swimmer (pusher vs. puller) governs the behaviour even at high volume fractions. ERC Grant PhyMeBa (682754, EL); JSPS Grant-in-Aid for Scientific Research (A) (17H00853, TI).

Using goal attainment scaling to evaluate a needs-led exercise programme for people with severe and profound intellectual disabilities.

PubMed

Jones, Martyn C; Walley, Robert M; Leech, Amanda; Paterson, Marion; Common, Stephanie; Metcalf, Charlotte

2006-12-01

The aim of this study was to evaluate whether involvement in a 16 week exercise programme improved goal attainment in areas of behaviour, access to community-based experiences, health and physical competence. Participants were women with severe intellectual disability and associated challenging behaviour (setting A,N = 14) and male/female service users with profound physical and intellectual disabilities (setting B,N = 8). The exercise programme included active and passive exercise, walking, swimming, hydrotherapy, team games and rebound therapy. Significant gains in aggregated goal attainment were demonstrated by week 16. The reliability and validity of our goal attainment procedures were demonstrated with inter-rater reliabilities exceeding 80 percent. Changes in goal attainment were concurrent with global clinical impression scores in a series of single case studies. Continuing care settings should dedicate care staff to provide routinized, continuing exercise programmes.

Social behaviour and collective motion in plant-animal worms.

PubMed

Franks, Nigel R; Worley, Alan; Grant, Katherine A J; Gorman, Alice R; Vizard, Victoria; Plackett, Harriet; Doran, Carolina; Gamble, Margaret L; Stumpe, Martin C; Sendova-Franks, Ana B

2016-02-24

Social behaviour may enable organisms to occupy ecological niches that would otherwise be unavailable to them. Here, we test this major evolutionary principle by demonstrating self-organizing social behaviour in the plant-animal, Symsagittifera roscoffensis. These marine aceol flat worms rely for all of their nutrition on the algae within their bodies: hence their common name. We show that individual worms interact with one another to coordinate their movements so that even at low densities they begin to swim in small polarized groups and at increasing densities such flotillas turn into circular mills. We use computer simulations to: (i) determine if real worms interact socially by comparing them with virtual worms that do not interact and (ii) show that the social phase transitions of the real worms can occur based only on local interactions between and among them. We hypothesize that such social behaviour helps the worms to form the dense biofilms or mats observed on certain sun-exposed sandy beaches in the upper intertidal of the East Atlantic and to become in effect a super-organismic seaweed in a habitat where macro-algal seaweeds cannot anchor themselves. Symsagittifera roscoffensis, a model organism in many other areas in biology (including stem cell regeneration), also seems to be an ideal model for understanding how individual behaviours can lead, through collective movement, to social assemblages. © 2016 The Author(s).

Minocycline reduces mechanical allodynia and depressive-like behaviour in type-1 diabetes mellitus in the rat.

PubMed

Amorim, Diana; Puga, Sónia; Bragança, Rui; Braga, António; Pertovaara, Antti; Almeida, Armando; Pinto-Ribeiro, Filipa

2017-06-01

A common and devastating complication of diabetes mellitus is painful diabetic neuropathy (PDN) that can be accompanied by emotional disorders such as depression. A few studies have suggested that minocycline that inhibits microglia may attenuate pain hypersensitivity in PDN. Moreover, a recent study reported that minocycline has an acute antidepressive-like effect in diabetic animals. Here we studied whether (i) prolonged minocycline treatment suppresses pain behaviour in PDN, (ii) the minocycline effect varies with submodality of pain, and (iii) the suppression of pain behaviour by prolonged minocycline treatment is associated with antidepressive-like effect. The experiments were performed in streptozotocin-induced rat model of type-1 diabetes. Pain behaviour was evoked by innocuous (monofilaments) and noxious (paw pressure) mechanical stimulation, innocuous cold (acetone drops) and noxious heat (radiant heat). Depression-like behaviour was assessed using forced swimming test. Minocycline treatment (daily 80mg/kg per os) of three-week duration started four weeks after induction of diabetes. Diabetes induced mechanical allodynia and hyperalgesia, cold allodynia, heat hypoalgesia, and depression-like behaviour. Minocycline treatment significantly attenuated mechanical allodynia and depression-like behaviour, while it failed to produce significant changes in mechanical hyperalgesia, cold allodynia or heat hypoalgesia. The results indicate that prolonged per oral treatment with minocycline has a sustained mechanical antiallodynic and antidepressive-like effect in PDN. These results support the proposal that minocycline might provide a treatment option for attenuating sensory and comorbid emotional symptoms in chronic PDN. Copyright © 2017 Elsevier B.V. All rights reserved.

Can you really swim? Validation of self and parental reports of swim skill with an inwater swim test among children attending community pools in Washington State.

PubMed

Mercado, Melissa C; Quan, Linda; Bennett, Elizabeth; Gilchrist, Julie; Levy, Benjamin A; Robinson, Candice L; Wendorf, Kristen; Gangan Fife, Maria Aurora; Stevens, Mark R; Lee, Robin

2016-08-01

Drowning is the second leading cause of unintentional injury death among US children. Multiple studies describe decreased drowning risk among children possessing some swim skills. Current surveillance for this protective factor is self/proxy-reported swim skill rather than observed inwater performance; however, children's self-report or parents' proxy report of swim skill has not been validated. This is the first US study to evaluate whether children or parents can validly report a child's swim skill. It also explores which swim skill survey measure(s) correlate with children's inwater swim performance. For this cross-sectional convenience-based sample, pilot study, child/parent dyads (N=482) were recruited at three outdoor public pools in Washington State. Agreement between measures of self-reports and parental-reports of children's swim skill was assessed via paired analyses, and validated by inwater swim test results. Participants were representative of pool's patrons (ie, non-Hispanic White, highly educated, high income). There was agreement in child/parent dyads' reports of the following child swim skill measures: 'ever taken swim lessons', perceived 'good swim skills' and 'comfort in water over head'. Correlation analyses suggest that reported 'good swim skills' was the best survey measure to assess a child's swim skill-best if the parent was the informant (r=0.25-0.47). History of swim lessons was not significantly correlated with passing the swim test. Reported 'good swim skills' was most correlated with observed swim skill. Reporting 'yes' to 'ever taken swim lessons' did not correlate with swim skill. While non-generalisable, findings can help inform future studies. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Behaviour problems and cortisol levels in very-low-birth-weight children.

PubMed

Wadsby, Marie; Nelson, Nina; Ingemansson, Fredrik; Samuelsson, Stefan; Leijon, Ingemar

2014-11-01

Abstract Background. There are still diverging results concerning the behaviour of children with very-low-birth-weight (VLBW) and they have been questioned to display different levels of stress hormone than normal-birth-weight (NBW) children. Aims. This study examined behaviour and the stress hormone cortisol in children with VLBW at the ages of 7 and 9 years compared with children with NBW. Results. Fifty-one VLBW and 50 NBW children were studied with the Child Behavior Checklist. Cortisol rhythm was measured through saliva samples three times a day for 2 days. VLBW children displayed more behavioural problems than NBW children, specifically social and attention problems, although still within normal ranges. They showed lower cortisol levels both at 7 and 9 years of age. No strong association between behaviour and cortisol levels was shown. Conclusion. VLBW children display more behaviour problems compared with NBW children but both groups score are within the normal range. Down-regulation of their hypothalamic-pituitary-adrenal (HPA) function in terms of lower cortisol levels is also noted.

Tidal amplitude and fish abundance in the mouth region of a small estuary.

PubMed

Becker, A; Whitfield, A K; Cowley, P D; Cole, V J; Taylor, M D

2016-09-01

Using an acoustic underwater camera (Dual Frequency IDentification SONar, DIDSON), the abundance and direction of movement of fishes > 80 mm total length (LT ) in the mouth of a small South African estuary during spring and neap tidal cycles were observed. While the sizes of fishes recorded were consistent across both tide cycles, the number of fishes passing the camera was significantly greater during the smaller neap tides. Schooling behaviour was more pronounced for fishes that were travelling into the estuary compared to fishes swimming towards the ocean. © 2016 The Fisheries Society of the British Isles.

Genes and proteins involved in bacterial magnetic particle formation.

PubMed

Matsunaga, Tadashi; Okamura, Yoshiko

2003-11-01

Magnetic bacteria synthesize intracellular magnetosomes that impart a cellular swimming behaviour referred to as magnetotaxis. The magnetic structures aligned in chains are postulated to function as biological compass needles allowing the bacterium to migrate along redox gradients through the Earth's geomagnetic field lines. Despite the discovery of this unique group of microorganisms 28 years ago, the mechanisms of magnetic crystal biomineralization have yet to be fully elucidated. This review describes the current knowledge of the genes and proteins involved in magnetite formation in magnetic bacteria and the biotechnological applications of biomagnetites in the interdisciplinary fields of nanobiotechnology, medicine and environmental management.

Deaths in triathletes: immersion pulmonary oedema as a possible cause

PubMed Central

Moon, Richard E; Martina, Stefanie D; Peacher, Dionne F; Kraus, William E

2016-01-01

Background/aim To address the question as to whether immersion pulmonary oedema (IPO) may be a common cause of death in triathlons, markers of swimming-induced pulmonary oedema (SIPO) susceptibility were sought in triathletes' postmortem examinations. Methods Deaths while training for or during triathlon events in the USA and Canada from October 2008 to November 2015 were identified, and postmortem reports requested. We assessed obvious causes of death; the prevalence of left ventricular hypertrophy (LVH); comparison with healthy triathletes. Results We identified 58 deaths during the time period of the review, 42 (72.4%) of which occurred during a swim. Of these, 23 postmortem reports were obtained. Five individuals had significant (≥70%) coronary artery narrowing; one each had coronary stents; retroperitoneal haemorrhage; or aortic dissection. 9 of 20 (45%) with reported heart mass exceeded 95th centile values. LV free wall and septal thickness were reported in 14 and 9 cases, respectively; of these, 6 (42.9%) and 4 (44.4%) cases exceeded normal values. 6 of 15 individuals (40%) without an obvious cause of death had excessive heart mass. The proportion of individuals with LVH exceeded the prevalence in the general triathlete population. Conclusions LVH—a marker of SIPO susceptibility—was present in a greater than the expected proportion of triathletes who died during the swim portion. We propose that IPO may be a significant aetiology of death during the swimming phase in triathletes. The importance of testing for LVH in triathletes as a predictor of adverse outcomes should be explored further. PMID:27900191

A high throughput passive dosing format for the Fish Embryo Acute Toxicity test.

PubMed

Vergauwen, Lucia; Schmidt, Stine N; Stinckens, Evelyn; Maho, Walid; Blust, Ronny; Mayer, Philipp; Covaci, Adrian; Knapen, Dries

2015-11-01

High throughput testing according to the Fish Embryo Acute Toxicity (FET) test (OECD Testing Guideline 236) is usually conducted in well plates. In the case of hydrophobic test substances, sorptive and evaporative losses often result in declining and poorly controlled exposure conditions. Therefore, our objective was to improve exposure conditions in FET tests by evaluating a passive dosing format using silicone O-rings in standard 24-well polystyrene plates. We exposed zebrafish embryos to a series of phenanthrene concentrations until 120h post fertilization (hpf), and obtained a linear dilution series. We report effect values for both mortality and sublethal morphological effects based on (1) measured exposure concentrations, (2) (lipid normalized) body residues and (3) chemical activity. The LC50 for 120hpf was 310μg/L, CBR50 (critical body residue) was 2.72mmol/kg fresh wt and La50 (lethal chemical activity) was 0.047. All values were within ranges expected for baseline toxicity. Impaired swim bladder inflation was the most pronounced morphological effect and swimming activity was reduced in all exposure concentrations. Further analysis showed that the effect on swimming activity was not attributed to impaired swim bladder inflation, but rather to baseline toxicity. We conclude that silicone O-rings (1) produce a linear dilution series of phenanthrene in the 120hpf FET test, (2) generate and maintain aqueous concentrations for reliable determination of effect concentrations, and allow for obtaining mechanistic toxicity information, and (3) cause no toxicity, demonstrating its potential as an extension of the FET test when testing hydrophobic chemicals. Copyright © 2015 Elsevier Ltd. All rights reserved.

Response of Euphausia pacifica to small-scale shear in turbulent flow over a sill in a fjord

PubMed Central

Ianson, Debby; Allen, Susan E.; Mackas, David L.; Trevorrow, Mark V.; Benfield, Mark C.

2011-01-01

Zooplankton in the ocean respond to visual and hydro-mechanical cues such as small-scale shear in turbulent flow. In addition, they form strong aggregations where currents intersect sloping bottoms. Strong and predictable tidal currents over a sill in Knight Inlet, Canada, make it an ideal location to investigate biological behaviour in turbulent cross-isobath flow. We examine acoustic data (38, 120 and 200 kHz) collected there during the daylight hours, when the dominant zooplankters, Euphausia pacifica have descended into low light levels at ∼90 m. As expected, these data reveal strong aggregations at the sill. However, they occur consistently 10–20 m below the preferred light depth of the animals. We have constructed a simple model of the flow to investigate this phenomenon. Tracks of individual animals are traced in the flow and a variety of zooplankton behaviours tested. Our results indicate that the euphausiids must actively swim downward when they encounter the bottom boundary layer (bbl) to reproduce the observed downward shift in aggregation patterns. We suggest that this behaviour is cued by the small-scale shear in the bbl. Furthermore, this behaviour is likely to enhance aggregations found in strong flows at sills and on continental shelves. PMID:21954320

Sex Differences in World-Record Performance: The Influence of Sport Discipline and Competition Duration.

PubMed

Sandbakk, Øyvind; Solli, Guro Strøm; Holmberg, Hans-Christer

2018-01-01

The current review summarizes scientific knowledge concerning sex differences in world-record performance and the influence of sport discipline and competition duration. In addition, the way that physiological factors relate to sex dimorphism is discussed. While cultural factors played a major role in the rapid improvement of performance of women relative to men up until the 1990s, sex differences between the world's best athletes in most events have remained relatively stable at approximately 8-12%. The exceptions are events in which upper-body power is a major contributor, where this difference is more than 12%, and ultraendurance swimming, where the gap is now less than 5%. The physiological advantages in men include a larger body size with more skeletal-muscle mass, a lower percentage of body fat, and greater maximal delivery of anaerobic and aerobic energy. The greater strength and anaerobic capacity in men normally disappear when normalized for fat-free body mass, whereas the higher hemoglobin concentrations lead to 5-10% greater maximal oxygen uptake in men with such normalization. The higher percentage of muscle mass in the upper body of men results in a particularly large sex difference in power production during upper-body exercise. While the exercise efficiency of men and women is usually similar, women have a better capacity to metabolize fat and demonstrate better hydrodynamics and more even pacing, which may be advantageous, in particular during long-lasting swimming competitions.

Early Life Stress Differentially Modulates Distinct Forms of Brain Plasticity in Young and Adult Mice

PubMed Central

Reichardt, Wilfried; Clark, Kristin; Geiger, Julia; Gross, Claus M.; Heyer, Andrea; Neagu, Valentin; Bhatia, Harsharan; Atas, Hasan C.; Fiebich, Bernd L.; Bischofberger, Josef; Haas, Carola A.; Normann, Claus

2012-01-01

Background Early life trauma is an important risk factor for many psychiatric and somatic disorders in adulthood. As a growing body of evidence suggests that brain plasticity is disturbed in affective disorders, we examined the short-term and remote effects of early life stress on different forms of brain plasticity. Methodology/Principal Findings Mice were subjected to early deprivation by individually separating pups from their dam in the first two weeks after birth. Distinct forms of brain plasticity were assessed in the hippocampus by longitudinal MR volumetry, immunohistochemistry of neurogenesis, and whole-cell patch-clamp measurements of synaptic plasticity. Depression-related behavior was assessed by the forced swimming test in adult animals. Neuropeptides and their receptors were determined by real-time PCR and immunoassay. Early maternal deprivation caused a loss of hippocampal volume, which returned to normal in adulthood. Adult neurogenesis was unaffected by early life stress. Long-term synaptic potentiation, however, was normal immediately after the end of the stress protocol but was impaired in adult animals. In the forced swimming test, adult animals that had been subjected to early life stress showed increased immobility time. Levels of substance P were increased both in young and adult animals after early deprivation. Conclusion Hippocampal volume was affected by early life stress but recovered in adulthood which corresponded to normal adult neurogenesis. Synaptic plasticity, however, exhibited a delayed impairment. The modulation of synaptic plasticity by early life stress might contribute to affective dysfunction in adulthood. PMID:23071534

Visual resolution and contrast sensitivity in two benthic sharks.

PubMed

Ryan, Laura A; Hart, Nathan S; Collin, Shaun P; Hemmi, Jan M

2016-12-15

Sharks have long been described as having 'poor' vision. They are cone monochromats and anatomical estimates suggest they have low spatial resolution. However, there are no direct behavioural measurements of spatial resolution or contrast sensitivity. This study estimates contrast sensitivity and spatial resolution of two species of benthic sharks, the Port Jackson shark, Heterodontus portusjacksoni, and the brown-banded bamboo shark, Chiloscyllium punctatum, by recording eye movements in response to optokinetic stimuli. Both species tracked moving low spatial frequency gratings with weak but consistent eye movements. Eye movements ceased at 0.38 cycles per degree, even for high contrasts, suggesting low spatial resolution. However, at lower spatial frequencies, eye movements were elicited by low contrast gratings, 1.3% and 2.9% contrast in H portusjacksoni and C. punctatum, respectively. Contrast sensitivity was higher than in other vertebrates with a similar spatial resolving power, which may reflect an adaptation to the relatively low contrast encountered in aquatic environments. Optokinetic gain was consistently low and neither species stabilised the gratings on their retina. To check whether restraining the animals affected their optokinetic responses, we also analysed eye movements in free-swimming C. punctatum We found no eye movements that could compensate for body rotations, suggesting that vision may pass through phases of stabilisation and blur during swimming. As C. punctatum is a sedentary benthic species, gaze stabilisation during swimming may not be essential. Our results suggest that vision in sharks is not 'poor' as previously suggested, but optimised for contrast detection rather than spatial resolution. © 2016. Published by The Company of Biologists Ltd.

Developmental changes in spatial learning in the Morris water-maze in young meadow voles, Microtus pennsylvanicus.

PubMed

Galea, L A; Ossenkopp, K P; Kavaliers, M

1994-01-31

Spatial learning in pre- and postweaning meadow voles, (Microtus pennsylvanicus) was examined in a Morris water-maze task. The learning performance of 10-day-old (preweaning) and 15-, 20- and 25-day-old (postweaning) male and female voles was assessed by measuring the latency to reach a hidden platform by each animal twice a day for 5 days. Voles of all age groups were able to learn the spatial task with Day 10 and Day 15 voles acquiring the task more slowly than did Day 20 and Day 25 voles. There were no significant sex differences in task acquisition in any of the four age groups. In addition, although swimming speed was related to age, with older animals swimming faster than younger ones, differences in swim speed did not account for the faster acquisition by the older animals. These results show that both preweaning and postweaning voles can successfully learn a spatial task. This is in contrast to preweaning laboratory rats which cannot successfully acquire a similar spatial task. These findings indicate that there are species differences in the ontogeny of spatial learning, which are likely related to the ecological and behavioural developmental characteristics of the species. Furthermore, in contrast to the sex difference in water-maze performance obtained in adult, breeding meadow voles who demonstrate a sex difference, there were no significant sex differences in the spatial performance of the juvenile voles. This suggests that sex differences in spatial learning in the meadow vole do not appear until voles reach reproductive adulthood.

A consistent muscle activation strategy underlies crawling and swimming in Caenorhabditis elegans

PubMed Central

Butler, Victoria J.; Branicky, Robyn; Yemini, Eviatar; Liewald, Jana F.; Gottschalk, Alexander; Kerr, Rex A.; Chklovskii, Dmitri B.; Schafer, William R.

2015-01-01

Although undulatory swimming is observed in many organisms, the neuromuscular basis for undulatory movement patterns is not well understood. To better understand the basis for the generation of these movement patterns, we studied muscle activity in the nematode Caenorhabditis elegans. Caenorhabditis elegans exhibits a range of locomotion patterns: in low viscosity fluids the undulation has a wavelength longer than the body and propagates rapidly, while in high viscosity fluids or on agar media the undulatory waves are shorter and slower. Theoretical treatment of observed behaviour has suggested a large change in force–posture relationships at different viscosities, but analysis of bend propagation suggests that short-range proprioceptive feedback is used to control and generate body bends. How muscles could be activated in a way consistent with both these results is unclear. We therefore combined automated worm tracking with calcium imaging to determine muscle activation strategy in a variety of external substrates. Remarkably, we observed that across locomotion patterns spanning a threefold change in wavelength, peak muscle activation occurs approximately 45° (1/8th of a cycle) ahead of peak midline curvature. Although the location of peak force is predicted to vary widely, the activation pattern is consistent with required force in a model incorporating putative length- and velocity-dependence of muscle strength. Furthermore, a linear combination of local curvature and velocity can match the pattern of activation. This suggests that proprioception can enable the worm to swim effectively while working within the limitations of muscle biomechanics and neural control. PMID:25551155

Rheoceptive mediators of graviperception in a water flea: Morphological implications of antennal-socket setae in daphnia magna

NASA Technical Reports Server (NTRS)

Meyers, D. G.

1984-01-01

Aquatic microcrustaceans of the genus Daphnia are known to orient to light during the day. At night, in the absence of visual cues, daphnids were suspected of maintaining equilibrium by monitoring the direction of gravity through their swimming antennae. Recent investigations using simulated, weightlessness conditions coupled with absence of illumination revealed hair like structures or setae on the basal, articulating socket of the antennae that, when surgically removed, resulted in disorientation. Given the simulated weightlessness or neutrally buoyant condition that eliminated sinking of the normally negatively buoyant Daphnia, it was proposed that the antennal socket setae function as rheoceptors stimulated by the upward rush of water currents during gravity induced, sinking phase of daphnid swimming movements. This rheoceptively mediated, gravity perception hypothesis is further supported by morphological investigations. Scanning electron micrographs indicate that antennal socket setae are anatomically similar to proprioceptors used by higher crustaceans to monitor gravitational direction.

Forebrain-Specific Loss of BMPRII in Mice Reduces Anxiety and Increases Object Exploration.

PubMed

McBrayer, Zofeyah L; Dimova, Jiva; Pisansky, Marc T; Sun, Mu; Beppu, Hideyuki; Gewirtz, Jonathan C; O'Connor, Michael B

2015-01-01

To investigate the role of Bone Morphogenic Protein Receptor Type II (BMPRII) in learning, memory, and exploratory behavior in mice, a tissue-specific knockout of BMPRII in the post-natal hippocampus and forebrain was generated. We found that BMPRII mutant mice had normal spatial learning and memory in the Morris water maze, but showed significantly reduced swimming speeds with increased floating behavior. Further analysis using the Porsolt Swim Test to investigate behavioral despair did not reveal any differences in immobility between mutants and controls. In the Elevated Plus Maze, BMPRII mutants and Smad4 mutants showed reduced anxiety, while in exploratory tests, BMPRII mutants showed more interest in object exploration. These results suggest that loss of BMPRII in the mouse hippocampus and forebrain does not disrupt spatial learning and memory encoding, but instead impacts exploratory and anxiety-related behaviors.

Forebrain-Specific Loss of BMPRII in Mice Reduces Anxiety and Increases Object Exploration

PubMed Central

McBrayer, Zofeyah L.; Dimova, Jiva; Pisansky, Marc T.; Sun, Mu; Beppu, Hideyuki; Gewirtz, Jonathan C.; O’Connor, Michael B.

2015-01-01

To investigate the role of Bone Morphogenic Protein Receptor Type II (BMPRII) in learning, memory, and exploratory behavior in mice, a tissue-specific knockout of BMPRII in the post-natal hippocampus and forebrain was generated. We found that BMPRII mutant mice had normal spatial learning and memory in the Morris water maze, but showed significantly reduced swimming speeds with increased floating behavior. Further analysis using the Porsolt Swim Test to investigate behavioral despair did not reveal any differences in immobility between mutants and controls. In the Elevated Plus Maze, BMPRII mutants and Smad4 mutants showed reduced anxiety, while in exploratory tests, BMPRII mutants showed more interest in object exploration. These results suggest that loss of BMPRII in the mouse hippocampus and forebrain does not disrupt spatial learning and memory encoding, but instead impacts exploratory and anxiety-related behaviors. PMID:26444546

Different stability of social-communication problems and negative demanding behaviour from infancy to toddlerhood in a large Dutch population sample

PubMed Central

2014-01-01

Background Little is known about the stability of behavioural and developmental problems as children develop from infants to toddlers in the general population. Therefore, we investigated behavioural profiles at two time points and determined whether behaviours are stable during early development. Methods Parents of 4,237 children completed questionnaires with 62 items about externalizing, internalizing, and social-communicative behaviour when the children were 14–15 and 36–37 months old. Factor mixture modelling identified five homogeneous profiles at both time points: three with relatively normal behaviour or with mild/moderate problems, one with clear communication and interaction problems, and another with pronounced negative and demanding behaviour. Results More than 85% of infants with normal behaviour or mild problems at 14–15 months were reported to behave relatively typically as toddlers at 36–37 months. A similar percentage of infants with moderate communication problems outgrew their problems by the time they were toddlers. However, infants with severe problems had mild to severe problems as toddlers, and did not show completely normal behaviour. Improvement over time occurred more often in children with negative and demanding behaviour than in children with communication and interaction problems. The former showed less homotypic continuity than the latter. Conclusions Negative and demanding behaviour is more often transient and a less specific predictor of problems in toddlerhood than communication and interaction problems. PMID:25061477

Toward robust phase-locking in Melibe swim central pattern generator models

NASA Astrophysics Data System (ADS)

Jalil, Sajiya; Allen, Dane; Youker, Joseph; Shilnikov, Andrey

2013-12-01

Small groups of interneurons, abbreviated by CPG for central pattern generators, are arranged into neural networks to generate a variety of core bursting rhythms with specific phase-locked states, on distinct time scales, which govern vital motor behaviors in invertebrates such as chewing and swimming. These movements in lower level animals mimic motions of organs in higher animals due to evolutionarily conserved mechanisms. Hence, various neurological diseases can be linked to abnormal movement of body parts that are regulated by a malfunctioning CPG. In this paper, we, being inspired by recent experimental studies of neuronal activity patterns recorded from a swimming motion CPG of the sea slug Melibe leonina, examine a mathematical model of a 4-cell network that can plausibly and stably underlie the observed bursting rhythm. We develop a dynamical systems framework for explaining the existence and robustness of phase-locked states in activity patterns produced by the modeled CPGs. The proposed tools can be used for identifying core components for other CPG networks with reliable bursting outcomes and specific phase relationships between the interneurons. Our findings can be employed for identifying or implementing the conditions for normal and pathological functioning of basic CPGs of animals and artificially intelligent prosthetics that can regulate various movements.

Effect of forced swimming stress on in-vivo fertilization capacity of rat and subsequent offspring quality

PubMed Central

Saki, Ghasem; Rahim, Fakher; Vaysi, Ozra Allah

2010-01-01

AIMS: This study aimed to determine the effect of 50 days of forced swimming stress on fertilization capacity of rat and subsequent offspring quality. SETTING AND DESIGN: The prospective study designed in vivo. MATERIALS AND METHODS: Total 90 Wistar rats including 30 adult male (3 months of age, weighing 210 ± 10.6 g) and 60 female rats (3 months of age, weighing 230 ± 12.2 g) were engaged in this study. Male rats were randomly divided in two equal groups (n = 15): Control and experimental groups. Animals of the experimental group were submitted to forced swimming stress for 3 min in water at 32°C daily for 50 days. Then all adult male rats were mated with normal females (2 per each male) for 7 days. Female rats were sacrificed and autopsy was performed on day 20 of pregnancy when uterus and ovaries were examined for the number of corpora lutea, dead and live fetuses, embryo resorption, implantation sites, and fetus weight. CONCLUSION: Results of this study have important implications for families attempting pregnancy. Stress pursuant to life events may have a negative impact on in vivo fertilization capacity of male rats and subsequent offspring quality. PMID:20607006

Syndecan-4 Signaling Is Required for Exercise-Induced Cardiac Hypertrophy

PubMed Central

Xie, Jun; He, Guixin; Chen, Qinhua; Sun, Jiayin; Dai, Qin; Lu, Jianrong; Li, Guannan; Wu, Han; Li, Ran; Chen, Jianzhou; Xu, Wei; Xu, Biao

2016-01-01

Cardiac hypertrophy can be broadly classified as either physiological or pathological. Physiological stimuli such as exercise cause adaptive cardiac hypertrophy and normal heart function. Pathological stimuli including hypertension and aortic valvular stenosis cause maladaptive cardiac remodeling and ultimately heart failure. Syndecan-4 (synd4) is a transmembrane proteoglycan identified as being involved in cardiac adaptation after injury, but whether it takes part in physiological cardiac hypertrophy is unclear. We observed upregulation of synd4 in exercise-induced hypertrophic myocardium. To evaluate the role of synd4 in the physiological form of cardiac hypertrophy, mice lacking synd4 (synd4–/–) were exercised by swimming for 4 wks. Ultrasonic cardiogram (UCG) and histological analysis revealed that swimming induced the hypertrophic phenotype but was blunted in synd4–/– compared with wild-type (WT) mice. The swimming-induced activation of Akt, a key molecule in physiological hypertrophy was also more decreased than in WT controls. In cultured cardiomyocytes, synd4 overexpression could induce cell enlargement, protein synthesis and distinct physiological molecular alternation. Akt activation also was observed in synd4-overexpressed cardiomyocytes. Furthermore, inhibition of protein kinase C (PKC) prevented the synd4-induced hypertrophic phenotype and Akt phosphorylation. This study identified an essential role of synd4 in mediation of physiological cardiac hypertrophy. PMID:26835698

Use of chiral cell shape to ensure highly directional swimming in trypanosomes

PubMed Central

2017-01-01

Swimming cells typically move along a helical path or undergo longitudinal rotation as they swim, arising from chiral asymmetry in hydrodynamic drag or propulsion bending the swimming path into a helix. Helical paths are beneficial for some forms of chemotaxis, but why asymmetric shape is so prevalent when a symmetric shape would also allow highly directional swimming is unclear. Here, I analyse the swimming of the insect life cycle stages of two human parasites; Trypanosoma brucei and Leishmania mexicana. This showed quantitatively how chirality in T. brucei cell shape confers highly directional swimming. High speed videomicrographs showed that T. brucei, L. mexicana and a T. brucei RNAi morphology mutant have a range of shape asymmetries, from wild-type T. brucei (highly chiral) to L. mexicana (near-axial symmetry). The chiral cells underwent longitudinal rotation while swimming, with more rapid longitudinal rotation correlating with swimming path directionality. Simulation indicated hydrodynamic drag on the chiral cell shape caused rotation, and the predicted geometry of the resulting swimming path matched the directionality of the observed swimming paths. This simulation of swimming path geometry showed that highly chiral cell shape is a robust mechanism through which microscale swimmers can achieve highly directional swimming at low Reynolds number. It is insensitive to random variation in shape or propulsion (biological noise). Highly symmetric cell shape can give highly directional swimming but is at risk of giving futile circular swimming paths in the presence of biological noise. This suggests the chiral T. brucei cell shape (associated with the lateral attachment of the flagellum) may be an adaptation associated with the bloodstream-inhabiting lifestyle of this parasite for robust highly directional swimming. It also provides a plausible general explanation for why swimming cells tend to have strong asymmetries in cell shape or propulsion. PMID:28141804

Amitriptyline reverses hyperalgesia and improves associated mood-like disorders in a model of experimental monoarthritis.

PubMed

Amorim, D; David-Pereira, A; Pertovaara, A; Almeida, A; Pinto-Ribeiro, F

2014-05-15

Affective disorders are common comorbidities of chronic inflammatory pain that are often overlooked in primary care. As the impact of inflammatory pain upon mood-like disorders in animal models is not well known, our objective was to assess whether prolonged experimental monoarthritis (ARTH) induced the development of anxiety and depressive-like behaviours in rodents and if amitriptyline, an antidepressant commonly used in the treatment of chronic pain, could reverse both nociceptive and mood-like impairments. Experimental ARTH was induced through an injection of kaolin/carrageenan into the right knee joint with control (SHAM) animals injected with saline. Four weeks after induction, ARTH animals displayed mechanical hyperalgesia and a depressive-like phenotype as they showed a significant increase in immobility and a decrease in the latency to immobility in the forced-swimming test at the expense of the time spent climbing/swimming. ARTH animals also displayed a decreased sucrose preference, an index of anhedonia and anxiety-like behaviour as time spent exploring the open arms of the elevated-plus-maze was decreased when compared to controls. The anxiety-like phenotype was also supported by an increase in the number of fecal boli left in the open field. In ARTH animals, the administration of amitriptyline decreased mechanical hyperalgesia and increased sucrose preference and the time spent climbing, although it had a deleterious effect in the performance of control animals. Our data show that this model of ARTH can be useful for the study of chronic pain-mood disorders comorbidities and that amitriptyline is able to partly reverse the associated nociceptive and emotional impairments. Copyright © 2014 Elsevier B.V. All rights reserved.

Contribution of hippocampal area CA1 to acetone cyanohydrin-induced loss of motor coordination in rats.

PubMed

Rivadeneyra-Domínguez, E; Vázquez-Luna, A; Díaz-Sobac, R; Briones-Céspedes, E E; Rodríguez-Landa, J F

2017-05-01

Some vegetable foodstuffs contain toxic compounds that, when consumed, favour the development of certain diseases. Cassava (Manihot esculenta Crantz) is an important food source, but it contains cyanogenic glucosides (linamarin and lotaustralin) that have been associated with the development of tropical ataxic neuropathy and konzo. In rats, intraperitoneal administration of acetone cyanohydrin (a metabolite of linamarin) produces neurological disorders and neuronal damage in the hippocampus. However, it is unknown whether hippocampal area CA1 plays a role in neurological disorders associated with acetone cyanohydrin. A total of 32 male Wistar rats 3 months old were assigned to 4 groups (n=8 per group) as follows: vehicle (1μl physiological saline), and 3 groups with acetone cyanohydrin (1μl of 10, 15, and 20mM solution, respectively). The substances were microinjected intrahippocampally every 24hours for 7 consecutive days, and their effects on locomotor activity, rota-rod and swim tests were assessed daily. On the fifth day post-treatment, rats underwent further assessment with behavioural tests to identify or rule out permanent damage induced by acetone cyanohydrin. Microinjection of acetone cyanohydrin 20mM resulted in hyperactivity, motor impairment, and reduced exploration from the third day of treatment. All concentrations of acetone cyanohydrin produced rotational behaviour in the swim test from the first day of microinjection. The hippocampal area CA1 is involved in motor alterations induced by microinjection of acetone cyanohydrin, as has been reported for other cassava compounds. Copyright © 2015 Sociedad Española de Neurología. Publicado por Elsevier España, S.L.U. All rights reserved.

The vestibuloocular reflex of tadpoles (Xenopus laevis) after knock-down of the isthmus-related transcription factor XTcf-4.

PubMed

Horn, Eberhard R; El-Yamany, Nabil A; Gradl, Dietmar

2013-02-15

Development of the amphibian vestibular organ is regulated by molecular and neuronal mechanisms and by environmental input. The molecular component includes inductive signals derived from neural tissue of the hindbrain and from the surrounding mesoderm. The integrity of hindbrain patterning, on the other hand, depends on instructive signals from the isthmus organizer of the midbrain, including the transcription factor XTcf-4. If the development of the vestibular system depends on the integrity of the isthmus as the organizing centre, suppression of isthmus maintenance should modify vestibular morphology and function. We tested this hypothesis by downregulation of the transcription factor XTcf-4. 10 pmol l(-1) XTcf-4-specific antisense morpholino oligonucleotide was injected in one blastomere of two-cell-stage embryos of Xenopus laevis. For reconstitution experiments, 500 pg mRNA of the repressing XTcf-4A isoform or the activating XTcf-4C isoform were co-injected. Overexpression experiments were included using the same isoforms. Otoconia formation and vestibular controlled behaviour such as the roll-induced vestibuloocular reflex (rVOR) and swimming were recorded two weeks later. In 50% of tadpoles, downregulation of XTcf-4 induced (1) a depression of otoconia formation accompanied by a reduction of the rVOR, (2) abnormal tail development and (3) loop swimming behaviour. (4) All effects were rescued by co-injection of XTcf-4C but not, or only partially, by XTcf-4A. (5) Overexpression of XTcf-4A caused similar morphological and rVOR modifications as XTcf-4 depletion, while overexpression of XTcf-4C had no effect. Because XTcf-4C has been described as an essential factor for isthmus development, we postulate that the isthmus is strongly involved in vestibular development.

Synergistic impacts by an invasive amphipod and an invasive fish explain native gammarid extinction.

PubMed

Beggel, S; Brandner, J; Cerwenka, A F; Geist, J

2016-07-14

Worldwide freshwater ecosystems are increasingly affected by invasive alien species. In particular, Ponto-Caspian gobiid fishes and amphipods are suspected to have pronounced effects on aquatic food webs. However, there is a lack of systematic studies mechanistically testing the potential synergistic effects of invasive species on native fauna. In this study we investigated the interrelations between the invasive amphipod Dikerogammarus villosus and the invasive fish species Neogobius melanostomus in their effects on the native amphipod Gammarus pulex. We hypothesized selective predation by the fish as a driver for displacement of native species resulting in potential extinction of G. pulex. The survival of G. pulex in the presence of N. melanostomus in relation to the presence of D. villosus and availability of shelter was analyzed in the context of behavioural differences between the amphipod species. Gammarus pulex had a significantly higher susceptibility to predation by N. melanostomus compared to D. villosus in all experiments, suggesting preferential predation by this fish on native gammarids. Furthermore, the presence of D. villosus significantly increased the vulnerability of G. pulex to fish predation. Habitat structure was an important factor for swimming activity of amphipods and their mortality, resulting in a threefold decrease in amphipods consumed with shelter habitat structures provided. Behavioral differences in swimming activity were additionally responsible for higher predation rates on G. pulex. Intraguild predation could be neglected within short experimental durations. The results of this study provide evidence for synergistic effects of the two invasive Ponto-Caspian species on the native amphipod as an underlying process of species displacements during invasion processes. Prey behaviour and monotonous habitat structures additionally contribute to the decline of the native gammarid fauna in the upper Danube River and elsewhere.

Arctigenin Attenuates Learning and Memory Deficits through PI3k/Akt/GSK-3β Pathway Reducing Tau Hyperphosphorylation in Aβ-Induced AD Mice.

PubMed

Qi, Yue; Dou, De-Qiang; Jiang, Hong; Zhang, Bing-Bing; Qin, Wen-Yan; Kang, Kai; Zhang, Na; Jia, Dong

2017-01-01

Arctigenin is a phenylpropanoid dibenzylbutyrolactone lignan compound possessing antitumor, anti-inflammatory, anti-influenza, antioxidant, antibacterial, and hypoglycaemic activities. Our previous study demonstrated that arctigenin exerts neuroprotective effects both in vitro and in vivo in a Parkinson's disease model. However, the exact mechanism through which arctigenin improves amyloid beta-induced memory impairment by inhibiting the production of the hyperphosphorylated tau protein is unknown. Amyloid β 1-42 was slowly administered via the intracerebroventricular route in a volume of 3 µL (≈ 410 pmmol/mouse) to mice. The mice were administered arctigenin (10, 40, or 150 mg/kg) or vehicle starting from the second day after amyloid β 1-42 injection to the end of the experiment. Behavioural tests were performed from days 9 to 15. On day 16 after the intracerebroventricular administration of amyloid β 1-42 , the mice were sacrificed for biochemical analysis. Arctigenin (10-150 mg/kg) significantly attenuated the impairment of spontaneous alternation behaviours in the Y-maze task, decreased the escape latency in the Morris water maze test, and increased the swimming times and swimming distances to the platform located in the probe test. Arctigenin attenuated the level of phosphorylated tau at the Thr-181, Thr-231, and Ser-404 sites in the hippocampus, and increased the phosphorylation levels of phosphatidylinositol-3-kinase, threonine/serine protein kinase B, and glycogen synthase kinase-3 β . Arctigenin effectively provides protection against learning and memory deficits and in inhibits hyperphosphorylated tau protein expression in the hippocampus. The possible mechanism may occur via the phosphatidylinositol-3-kinase/protein kinase B-dependent glycogen synthase kinase-3 β signalling pathway. Georg Thieme Verlag KG Stuttgart · New York.

Ballistic movements of jumping legs implemented as variable components of cricket behaviour.

PubMed

Hustert, R; Baldus, M

2010-12-01

Ballistic accelerations of a limb or the whole body require special joint mechanisms in many animals. Specialized joints can be moved by stereotypic or variable motor control during motor patterns with and without ballistic components. As a model of variable motor control, the specialized femur-tibia (knee) joints of cricket (Acheta domesticus) hindlegs were studied during ballistic kicking, jumping and swimming and in non-ballistic walking. In this joint the tendons of the antagonistic flexor and the extensor muscles attach at different distances from the pivot and the opposed lever arms form an angle of 120 deg. A 10:1 ratio of their effective lever arms at full knee flexion helps to prepare for most ballistic extensions: the tension of the extensor can reach its peak while it is restrained by flexor co-contraction. In kicks, preparatory flexion is rapid and the co-contraction terminates just before knee extensions. Therefore, mainly the stored tension of the extensor muscle accelerates the small mass of the tibia. Jumps are prepared with slower extensor-flexor co-contractions that flex both knees simultaneously and then halt to rotate both legs outward to a near horizontal level. From there, catapult extension of both knees accelerates the body, supported by continued high frequency motor activity to their tibia extensor muscles during the ongoing push-off from the substrate. Premature extension of one knee instantly takes load from the lagging leg that extends and catches up, which finally results in a straight jump. In swimming, synchronous ballistic power strokes of both hindlegs drive the tibiae on a ventral-to-posterior trajectory through the water, well coordinated with the swimming patterns of all legs. In walking, running and climbing the steps of the hindlegs range between 45 deg flexion and 125 deg extension and use non-ballistic, alternating activity of knee flexor and extensor muscles. Steep climbing requires longer bursts from the extensor tibiae muscles when they support the extended hindlegs against gravity forces when the body hangs over. All ballistic movements of cricket knees are elicited by a basic but variable motor pattern: knee flexions by co-contraction of the antagonists prepare catapult extensions with speeds and forces as required in the different behaviours.

Behavioural responses of sardines Sardina pilchardus to simulated purse-seine capture and slipping.

PubMed

Marçalo, A; Araújo, J; Pousão-Ferreira, P; Pierce, G J; Stratoudakis, Y; Erzini, K

2013-09-01

The behavioural effects of confinement of sardine Sardina pilchardus in a purse seine were evaluated through three laboratory experiments simulating the final stages of purse seining; the process of slipping (deliberately allowing fishes to escape) and subsequent exposure to potential predators. Effects of holding time (the time S. pilchardus were held or entangled in the simulation apparatus) and S. pilchardus density were investigated. Experiment 1 compared the effect of a mild fishing stressor (20 min in the net and low S. pilchardus density) with a control (fishing not simulated) while the second and third experiments compared the mild stressor with a severe stressor (40 min in the net and high S. pilchardus density). In all cases, sea bass Dicentrarchus labrax were used as potential predators. Results indicated a significant effect of crowding time and density on the survival and behaviour of slipped S. pilchardus. After simulated fishing, S. pilchardus showed significant behavioural changes including lower swimming speed, closer approaches to predators and higher nearest-neighbour distances (wider school area) than controls, regardless of stressor severity. These results suggest that, in addition to the delayed and unobserved mortality caused by factors related to fishing operations, slipped pelagic fishes can suffer behavioural impairments that may increase vulnerability to predation. Possible sub-lethal effects of behavioural impairment on fitness are discussed, with suggestions on how stock assessment might be modified to account for both unobserved mortality and sub-lethal effects, and possible approaches to provide better estimates of unobserved mortality in the field are provided. © 2013 The Fisheries Society of the British Isles.

Increased anxiety-related behaviour in Hint1 knockout mice.

PubMed

Varadarajulu, Jeeva; Lebar, Maria; Krishnamoorthy, Gurumoorthy; Habelt, Sonja; Lu, Jia; Bernard Weinstein, I; Li, Haiyang; Holsboer, Florian; Turck, Christoph W; Touma, Chadi

2011-07-07

Several reports have implicated a role for the histidine triad nucleotide-binding protein-1 (Hint1) in psychiatric disorders. We have studied the emotional behaviour of male Hint1 knockout (Hint1 KO) mice in a battery of tests and performed biochemical analyses on brain tissue. The behavioural analysis revealed that Hint1 KO mice exhibit an increased emotionality phenotype compared to wildtype (WT) mice, while no significant differences in locomotion or general exploratory activity were noted. In the elevated plus-maze (EPM) test, the Hint1 KO animals entered the open arms of the apparatus less often than WT littermates. Similarly, in the dark-light box test, Hint1 KO mice spent less time in the lit compartment and the number of entries were reduced, which further confirmed an increased anxiety-related behaviour. Moreover, the Hint1 KO animals showed significantly more struggling and less floating behaviour in the forced swim test (FST), indicating an increased emotional arousal in aversive situations. Hint1 is known as a protein kinase C (PKC) interacting protein. Western blot analysis showed that PKCγ expression was elevated in Hint1 KO compared to WT mice. Interestingly, PKCγ mRNA levels of the two groups did not show a significant difference, implying a post-transcriptional PKCγ regulation. In addition, PKC enzymatic activity was increased in Hint1 KO compared to WT mice. In summary, our results indicate a role for Hint1 and PKCγ in modulating anxiety-related and stress-coping behaviour in mice. Copyright © 2011 Elsevier B.V. All rights reserved.

Early life experience contributes to the developmental programming of depressive-like behaviour, neuroinflammation and oxidative stress.

PubMed

Réus, Gislaine Z; Fernandes, Gabrielly C; de Moura, Airam B; Silva, Ritele H; Darabas, Ana Caroline; de Souza, Thays G; Abelaira, Helena M; Carneiro, Celso; Wendhausen, Diogo; Michels, Monique; Pescador, Bruna; Dal-Pizzol, Felipe; Macêdo, Danielle S; Quevedo, João

2017-12-01

This study used an animal model of depression induced by maternal care deprivation (MCD) to investigate whether depressive behaviour, neuroinflammation and oxidative stress were underlying factors in developmental programming after early life stress. At postnatal days (PND) 20, 30, 40, and 60, individual subsets of animals were evaluated in behavioural tests and then euthanized to assess cytokine levels and oxidative stress parameters in the prefrontal cortex (PFC), hippocampus and serum. The results showed that MCD did not induce behavioural changes at PND 30 and 40. However, at PND 20 and 60, the rats displayed a depressive-like behaviour in the forced swimming test, without changes in locomotor spontaneous activity. In the brain and serum, the levels of pro-inflammatory cytokines (interleukin-1β (IL-1β), interleukin-6 (IL-6) and tumour necrosis factor-α (TNF-α)) were increased, and the anti-inflammatory cytokine (interleukin-10) level was reduced throughout developmental programming (PND 20, 30, 40 and 60). Protein carbonyl levels increased in the brain at PND 30, 40 and 60. Superoxide dismutase (SOD) activity was decreased during all developmental programming phases evaluated in the brain. Catalase (CAT) activity was decreased at PND 20, 40 and 60 in the brain. Our results revealed that "critical episodes" in early life stressful events are able to induce behavioural alterations that persist into adulthood and can stimulate inflammation and oxidative damage in both central and peripheral systems, which are required for distinct patterns of resilience against psychiatric disorders later in life. Copyright © 2017 Elsevier Ltd. All rights reserved.

Knockdown of desmin in zebrafish larvae affects interfilament spacing and mechanical properties of skeletal muscle.

PubMed

Li, Mei; Andersson-Lendahl, Monika; Sejersen, Thomas; Arner, Anders

2013-03-01

Skeletal muscle was examined in zebrafish larvae in order to address questions related to the function of the intermediate filament protein desmin and its role in the pathogenesis of human desminopathy. A novel approach including mechanical and structural studies of 4-6-d-old larvae was applied. Morpholino antisense oligonucleotides were used to knock down desmin. Expression was assessed using messenger RNA and protein analyses. Histology and synchrotron light-based small angle x-ray diffraction were applied. Functional properties were analyzed with in vivo studies of swimming behavior and with in vitro mechanical examinations of muscle. The two desmin genes normally expressed in zebrafish could be knocked down by ~50%. This resulted in a phenotype with disorganized muscles with altered attachments to the myosepta. The knockdown larvae were smaller and had diminished swimming activity. Active tension was lowered and muscles were less vulnerable to acute stretch-induced injury. X-ray diffraction revealed wider interfilament spacing. In conclusion, desmin intermediate filaments are required for normal active force generation and affect vulnerability during eccentric work. This is related to the role of desmin in anchoring sarcomeres for optimal force transmission. The results also show that a partial lack of desmin, without protein aggregates, is sufficient to cause muscle pathology resembling that in human desminopathy.

Universality, Limits and Predictability of Gold-Medal Performances at the Olympic Games

PubMed Central

Radicchi, Filippo

2012-01-01

Inspired by the Games held in ancient Greece, modern Olympics represent the world’s largest pageant of athletic skill and competitive spirit. Performances of athletes at the Olympic Games mirror, since 1896, human potentialities in sports, and thus provide an optimal source of information for studying the evolution of sport achievements and predicting the limits that athletes can reach. Unfortunately, the models introduced so far for the description of athlete performances at the Olympics are either sophisticated or unrealistic, and more importantly, do not provide a unified theory for sport performances. Here, we address this issue by showing that relative performance improvements of medal winners at the Olympics are normally distributed, implying that the evolution of performance values can be described in good approximation as an exponential approach to an a priori unknown limiting performance value. This law holds for all specialties in athletics–including running, jumping, and throwing–and swimming. We present a self-consistent method, based on normality hypothesis testing, able to predict limiting performance values in all specialties. We further quantify the most likely years in which athletes will breach challenging performance walls in running, jumping, throwing, and swimming events, as well as the probability that new world records will be established at the next edition of the Olympic Games. PMID:22808137

Fine-Scale Movements of the Broadnose Sevengill Shark and Its Main Prey, the Gummy Shark

PubMed Central

Barnett, Adam; Abrantes, Kátya G.; Stevens, John D.; Bruce, Barry D.; Semmens, Jayson M.

2010-01-01

Information on the fine-scale movement of predators and their prey is important to interpret foraging behaviours and activity patterns. An understanding of these behaviours will help determine predator-prey relationships and their effects on community dynamics. For instance understanding a predator's movement behaviour may alter pre determined expectations of prey behaviour, as almost any aspect of the prey's decisions from foraging to mating can be influenced by the risk of predation. Acoustic telemetry was used to study the fine-scale movement patterns of the Broadnose Sevengill shark Notorynchus cepedianus and its main prey, the Gummy shark Mustelus antarcticus, in a coastal bay of southeast Tasmania. Notorynchus cepedianus displayed distinct diel differences in activity patterns. During the day they stayed close to the substrate (sea floor) and were frequently inactive. At night, however, their swimming behaviour continually oscillated through the water column from the substrate to near surface. In contrast, M. antarcticus remained close to the substrate for the entire diel cycle, and showed similar movement patterns for day and night. For both species, the possibility that movement is related to foraging behaviour is discussed. For M. antarcticus, movement may possibly be linked to a diet of predominantly slow benthic prey. On several occasions, N. cepedianus carried out a sequence of burst speed events (increased rates of movement) that could be related to chasing prey. All burst speed events during the day were across the substrate, while at night these occurred in the water column. Overall, diel differences in water column use, along with the presence of oscillatory behaviour and burst speed events suggest that N. cepedianus are nocturnal foragers, but may opportunistically attack prey they happen to encounter during the day. PMID:21151925

Altered gravity affects ventral root activity during fictive swimming and the static vestibuloocular reflex in young tadpoles (Xenopus laevis).

PubMed

Böser, S; Dournon, C; Gualandris-Parisot, L; Horn, E

2008-03-01

During early periods of life, modifications of the gravitational environment affect the development of sensory, neuronal and motor systems. The vestibular system exerts significant effects on motor networks that control eye and body posture as well as swimming. The objective of the present study was to study whether altered gravity (AG) affects vestibuloocular and spinal motor systems in a correlated manner. During the French Soyuz taxi flight Andromède to the International Space Station ISS (launch: October 21, 2001; landing: October 31, 2001) Xenopus laevis embryos were exposed for 10 days to microgravity (microg). In addition, a similar experiment with 3g-hypergravity (3g) was performed in the laboratory. At onset of AG, embryos had reached developmental stages 24 to 27. After exposure to AG, each tadpole was tested for its roll-induced vestibuloocular reflex (rVOR) and 3 hours later it was tested for the neuronal activity recorded from the ventral roots (VR) during fictive swimming. During the post-AG recording periods tadpoles had reached developmental stages 45 to 47. It was observed that microgravity affected VR activity during fictive swimming and rVOR. In particular, VR activity changes included a significant decrease of the rostrocaudal delay and a significant increase of episode duration. The rVOR-amplitude was transiently depressed. Hypergravity was less effective on the locomotor pattern; occurring effects on fictive swimming were the opposite of microg effects. As after microgravity, the rVOR was depressed after 3g-exposure. All modifications of the rVOR and VR-activity recovered to normal levels within 4 to 7 days after termination of AG. Significant correlations between the rVOR amplitude and VR activity of respective tadpoles during the recording period have been observed in both tadpoles with or without AG experience. The data are consistent with the assumptions that during this period of life which is characterized by a progressive development of vestibuloocular and vestibulospinal projections (i) microgravity retards the development of VR activity while hypergravity weakly accelerates it; (ii) that microgravity retards the rVOR development while hypergravity caused a sensitization, and that (iii) AG-induced changes of VR activity during fictive swimming have a vestibular origin.

The Physiology and Mechanics of Undulatory Swimming: A Student Laboratory Exercise Using Medicinal Leeches

ERIC Educational Resources Information Center

Ellerby, David J.

2009-01-01

The medicinal leech is a useful animal model for investigating undulatory swimming in the classroom. Unlike many swimming organisms, its swimming performance can be quantified without specialized equipment. A large blood meal alters swimming behavior in a way that can be used to generate a discussion of the hydrodynamics of swimming, muscle…

Hydrodynamic advantages of swimming by salp chains.

PubMed

Sutherland, Kelly R; Weihs, Daniel

2017-08-01

Salps are marine invertebrates comprising multiple jet-propelled swimming units during a colonial life-cycle stage. Using theory, we show that asynchronous swimming with multiple pulsed jets yields substantial hydrodynamic benefit due to the production of steady swimming velocities, which limit drag. Laboratory comparisons of swimming kinematics of aggregate salps ( Salpa fusiformis and Weelia cylindrica ) using high-speed video supported that asynchronous swimming by aggregates results in a smoother velocity profile and showed that this smoother velocity profile is the result of uncoordinated, asynchronous swimming by individual zooids. In situ flow visualizations of W. cylindrica swimming wakes revealed that another consequence of asynchronous swimming is that fluid interactions between jet wakes are minimized. Although the advantages of multi-jet propulsion have been mentioned elsewhere, this is the first time that the theory has been quantified and the role of asynchronous swimming verified using experimental data from the laboratory and the field. © 2017 The Author(s).

Entropy-driven motility of Sinorhizobium meliloti on a semi-solid surface

PubMed Central

Dilanji, Gabriel E.; Teplitski, Max; Hagen, Stephen J.

2014-01-01

Sinorhizobium meliloti growing on soft agar can exhibit an unusual surface spreading behaviour that differs from other bacterial surface motilities. Bacteria in the colony secrete an exopolysaccharide-rich mucoid fluid that expands outward on the surface, carrying within it a suspension of actively dividing cells. The moving slime disperses the cells in complex and dynamic patterns indicative of simultaneous bacterial growth, swimming and aggregation. We find that while flagellar swimming is required to maintain the cells in suspension, the spreading and the associated pattern formation are primarily driven by the secreted exopolysaccharide EPS II, which creates two entropy-increasing effects: an osmotic flow of water from the agar to the mucoid fluid and a crowding or depletion attraction between the cells. Activation of these physical/chemical phenomena may be a useful function for the high molecular weight EPS II, a galactoglucan whose biosynthesis is tightly regulated by the ExpR/SinI/SinR quorum-sensing system: unlike bacterial colonies that spread via bacterium-generated, physical propulsive forces, S. meliloti under quorum conditions may use EPS II to activate purely entropic forces within its environment, so that it can disperse by passively ‘surfing’ on those forces. PMID:24741008

Case studies of spinal deformities in ornamental koi, Cyprinus carpio L.

PubMed

Chin, H N; Loh, R; Hong, Y C; Gibson-Kueh, S

2017-01-01

This is a study of vertebral deformities in ornamental koi based on computed radiography and skeletons cleaned by dermestid beetles (Dermestes maculatus). All koi developed gradual onset of swimming abnormalities as adults. Extensive intervertebral osteophyte formation correlated with age of fish and was associated with hindquarter paresis in one koi. Vertebral compression and fusion were the most common spinal deformities occurring at multiple sites, similar to findings in other farmed fish. Site-specific spinal deformities were thought to develop due to differences in swimming behaviour and rates of vertebral growth. One koi had offspring with spinal deformities. Spinal deformities are significant problems in both European and Australian food fish hatcheries. The heritability of vertebral deformities in farmed fish is reportedly low unless there is concurrent poor husbandry or nutritional deficiencies. The specific aetiologies for vertebral deformities in koi in this study could not be ascertained. Current knowledge on spinal deformities in the better studied European food fish species suggests multifactorial aetiologies. Future research should include prospective longitudinal studies of larger numbers of koi from hatch and consideration of all potential risk factors such as husbandry, nutrition, temperature, photoperiod and genetics. © 2016 John Wiley & Sons Ltd.

Effects of palmitoylethanolamide and luteolin in an animal model of anxiety/depression.

PubMed

Crupi, Rosalia; Paterniti, Irene; Ahmad, Akbar; Campolo, Michela; Esposito, Emanuela; Cuzzocrea, Salvatore

2013-11-01

The antidepressant effect of a compound formed by co-ultramicronized palmitoylethanolamide (PEA) and luteolin (PEA+luteolin) was investigated in a mouse model of anxiety/depressive-like behavior. 129Sv/Ev mice were subjected to 6 weeks of corticosterone administration, and then behavior, neurogenesis, neuroplasticity, neurotrophic and apoptotic proteins expression were evaluated. The effect of PEA+luteolin compound treatment (1mg/kg, i.p.), on depression-like behaviour was assessed using different paradigms such as open field, novelty suppressed feeding, forced swim test and elevated plus maze. In particular in the open field, novelty suppressed feeding and elevated plus maze the time spent in the open arm was employed as an indicator of anxiety; forced swim test was used to evaluate the antidepressant capacity of PEA+luteolin on immobility time as an indicator of depression. Adult hippocampal neurogenesis and neuroplasticity were evaluated by immunohistochemical techniques; brain-derived neurotrophic factor and apoptotic protein (Bax and Bcl2) expression were studied by immunostaining and Western blot analysis. For the first time we demonstrated that PEA+luteolin compound exerts a significant antidepressant effect a low dose and may be considered as a novel therapeutic strategy in depression.

Flagellum synchronization inhibits large-scale hydrodynamic instabilities in sperm suspensions

NASA Astrophysics Data System (ADS)

Schöller, Simon F.; Keaveny, Eric E.

2016-11-01

Sperm in suspension can exhibit large-scale collective motion and form coherent structures. Our picture of such coherent motion is largely based on reduced models that treat the swimmers as self-locomoting rigid bodies that interact via steady dipolar flow fields. Swimming sperm, however, have many more degrees of freedom due to elasticity, have a more exotic shape, and generate spatially-complex, time-dependent flow fields. While these complexities are known to lead to phenomena such as flagellum synchronization and attraction, how these effects impact the overall suspension behaviour and coherent structure formation is largely unknown. Using a computational model that captures both flagellum beating and elasticity, we simulate suspensions on the order of 103 individual swimming sperm cells whose motion is coupled through the surrounding Stokesian fluid. We find that the tendency for flagella to synchronize and sperm to aggregate inhibits the emergence of the large-scale hydrodynamic instabilities often associated with active suspensions. However, when synchronization is repressed by adding noise in the flagellum actuation mechanism, the picture changes and the structures that resemble large-scale vortices appear to re-emerge. Supported by an Imperial College PhD scholarship.

A theory of how active behavior stabilises neural activity: Neural gain modulation by closed-loop environmental feedback

PubMed Central

2018-01-01

During active behaviours like running, swimming, whisking or sniffing, motor actions shape sensory input and sensory percepts guide future motor commands. Ongoing cycles of sensory and motor processing constitute a closed-loop feedback system which is central to motor control and, it has been argued, for perceptual processes. This closed-loop feedback is mediated by brainwide neural circuits but how the presence of feedback signals impacts on the dynamics and function of neurons is not well understood. Here we present a simple theory suggesting that closed-loop feedback between the brain/body/environment can modulate neural gain and, consequently, change endogenous neural fluctuations and responses to sensory input. We support this theory with modeling and data analysis in two vertebrate systems. First, in a model of rodent whisking we show that negative feedback mediated by whisking vibrissa can suppress coherent neural fluctuations and neural responses to sensory input in the barrel cortex. We argue this suppression provides an appealing account of a brain state transition (a marked change in global brain activity) coincident with the onset of whisking in rodents. Moreover, this mechanism suggests a novel signal detection mechanism that selectively accentuates active, rather than passive, whisker touch signals. This mechanism is consistent with a predictive coding strategy that is sensitive to the consequences of motor actions rather than the difference between the predicted and actual sensory input. We further support the theory by re-analysing previously published two-photon data recorded in zebrafish larvae performing closed-loop optomotor behaviour in a virtual swim simulator. We show, as predicted by this theory, that the degree to which each cell contributes in linking sensory and motor signals well explains how much its neural fluctuations are suppressed by closed-loop optomotor behaviour. More generally we argue that our results demonstrate the dependence of neural fluctuations, across the brain, on closed-loop brain/body/environment interactions strongly supporting the idea that brain function cannot be fully understood through open-loop approaches alone. PMID:29342146

A theory of how active behavior stabilises neural activity: Neural gain modulation by closed-loop environmental feedback.

PubMed

Buckley, Christopher L; Toyoizumi, Taro

2018-01-01

During active behaviours like running, swimming, whisking or sniffing, motor actions shape sensory input and sensory percepts guide future motor commands. Ongoing cycles of sensory and motor processing constitute a closed-loop feedback system which is central to motor control and, it has been argued, for perceptual processes. This closed-loop feedback is mediated by brainwide neural circuits but how the presence of feedback signals impacts on the dynamics and function of neurons is not well understood. Here we present a simple theory suggesting that closed-loop feedback between the brain/body/environment can modulate neural gain and, consequently, change endogenous neural fluctuations and responses to sensory input. We support this theory with modeling and data analysis in two vertebrate systems. First, in a model of rodent whisking we show that negative feedback mediated by whisking vibrissa can suppress coherent neural fluctuations and neural responses to sensory input in the barrel cortex. We argue this suppression provides an appealing account of a brain state transition (a marked change in global brain activity) coincident with the onset of whisking in rodents. Moreover, this mechanism suggests a novel signal detection mechanism that selectively accentuates active, rather than passive, whisker touch signals. This mechanism is consistent with a predictive coding strategy that is sensitive to the consequences of motor actions rather than the difference between the predicted and actual sensory input. We further support the theory by re-analysing previously published two-photon data recorded in zebrafish larvae performing closed-loop optomotor behaviour in a virtual swim simulator. We show, as predicted by this theory, that the degree to which each cell contributes in linking sensory and motor signals well explains how much its neural fluctuations are suppressed by closed-loop optomotor behaviour. More generally we argue that our results demonstrate the dependence of neural fluctuations, across the brain, on closed-loop brain/body/environment interactions strongly supporting the idea that brain function cannot be fully understood through open-loop approaches alone.

Effect of fastskin suits on performance, drag, and energy cost of swimming.

PubMed

Chatard, Jean-Claude; Wilson, Barry

2008-06-01

To investigate the effect of fastskin suits on 25- to 800-m performances, drag, and energy cost of swimming. The performances, stroke rate and distance per stroke, were measured for 14 competitive swimmers in a 25-m pool, when wearing a normal suit (N) and when wearing a full-body suit (FB) or a waist-to-ankle suit (L). Passive drag, oxygen uptake, blood lactate, and the perceived exertion were measured in a flume. There was a 3.2% +/- 2.4% performance benefit for all subjects over the six distances covered at maximal speed wearing FB and L when compared with N. When wearing L, the gain was significantly lower (1.8% +/- 2.5%, P < 0.01) than when wearing FB compared with N. The exercise perception was significantly lower when wearing FB than N, whereas there was no statistical difference when wearing L. The distance per stroke was significantly higher when wearing FB and L, whereas the differences in stroke rate were not statistically significant. There was a significant reduction in drag when wearing FB and L of 6.2% +/- 7.9% and 4.7% +/- 4.4%, respectively (P < 0.01), whereas the energy cost of swimming was significantly reduced when wearing FB and L by 4.5% +/- 5.4% and 5.5% +/- 3.1%, respectively (P < 0.01). However, the differences between FB and L were not statistically significant for drag and oxygen uptake. FB and L significantly reduced passive drag, and this was associated with a decreased energy cost of submaximal swimming and an increased distance per stroke, at the same stroke rates, and reduced freestyle performance time.

Maternal neglect with reduced depressive-like behavior and blunted c-fos activation in Brattleboro mothers, the role of central vasopressin.

PubMed

Fodor, Anna; Klausz, Barbara; Pintér, Ottó; Daviu, Nuria; Rabasa, Cristina; Rotllant, David; Balazsfi, Diana; Kovacs, Krisztina B; Nadal, Roser; Zelena, Dóra

2012-09-01

Early mother-infant relationships exert important long-term effects in offspring and are disturbed by factors such as postpartum depression. We aimed to clarify if lack of vasopressin influences maternal behavior paralleled by the development of a depressive-like phenotype. We compared vasopressin-deficient Brattleboro mothers with heterozygous and homozygous normal ones. The following parameters were measured: maternal behavior (undisturbed and separation-induced); anxiety by the elevated plus maze; sucrose and saccharin preference and forced swim behavior. Underlying brain areas were examined by c-fos immunocytochemistry among rest and after swim-stress. In another group of rats, vasopressin 2 receptor agonist was used peripherally to exclude secondary changes due to diabetes insipidus. Results showed that vasopressin-deficient rats spend less time licking-grooming their pups through a centrally driven mechanism. There was no difference between genotypes during the pup retrieval test. Vasopressin-deficient mothers tended to explore more the open arms of the plus maze, showed more preference for sucrose and saccharin and struggled more in the forced swim test, suggesting that they act as less depressive. Under basal conditions, vasopressin-deficient mothers had more c-fos expression in the medial preoptic area, shell of nucleus accumbens, paraventricular nucleus of the hypothalamus and amygdala, but not in other structures. In these areas the swim-stress-induced activation was smaller. In conclusion, vasopressin-deficiency resulted in maternal neglect due to a central effect and was protective against depressive-like behavior probably as a consequence of reduced activation of some stress-related brain structures. The conflicting behavioral data underscores the need for more sex specific studies. Copyright © 2012 Elsevier Inc. All rights reserved.

Attenuation of Ca2+ homeostasis, oxidative stress, and mitochondrial dysfunctions in diabetic rat heart: insulin therapy or aerobic exercise?

PubMed

da Silva, Márcia F; Natali, Antônio J; da Silva, Edson; Gomes, Gilton J; Teodoro, Bruno G; Cunha, Daise N Q; Drummond, Lucas R; Drummond, Filipe R; Moura, Anselmo G; Belfort, Felipe G; de Oliveira, Alessandro; Maldonado, Izabel R S C; Alberici, Luciane C

2015-07-15

We tested the effects of swimming training and insulin therapy, either alone or in combination, on the intracellular calcium ([Ca(2+)]i) homeostasis, oxidative stress, and mitochondrial functions in diabetic rat hearts. Male Wistar rats were separated into control, diabetic, or diabetic plus insulin groups. Type 1 diabetes mellitus was induced by streptozotocin (STZ). Insulin-treated groups received 1 to 4 UI of insulin daily for 8 wk. Each group was divided into sedentary or exercised rats. Trained groups were submitted to swimming (90 min/day, 5 days/wk, 8 wk). [Ca(2+)]i transient in left ventricular myocytes (LVM), oxidative stress in LV tissue, and mitochondrial functions in the heart were assessed. Diabetes reduced the amplitude and prolonged the times to peak and to half decay of the [Ca(2+)]i transient in LVM, increased NADPH oxidase-4 (Nox-4) expression, decreased superoxide dismutase (SOD), and increased carbonyl protein contents in LV tissue. In isolated mitochondria, diabetes increased Ca(2+) uptake, susceptibility to permeability transition pore (MPTP) opening, uncoupling protein-2 (UCP-2) expression, and oxygen consumption but reduced H2O2 release. Swimming training corrected the time course of the [Ca(2+)]i transient, UCP-2 expression, and mitochondrial Ca(2+) uptake. Insulin replacement further normalized [Ca(2+)]i transient amplitude, Nox-4 expression, and carbonyl content. Alongside these benefits, the combination of both therapies restored the LV tissue SOD and mitochondrial O2 consumption, H2O2 release, and MPTP opening. In conclusion, the combination of swimming training with insulin replacement was more effective in attenuating intracellular Ca(2+) disruptions, oxidative stress, and mitochondrial dysfunctions in STZ-induced diabetic rat hearts. Copyright © 2015 the American Physiological Society.

The evolution of phenotypic plasticity in fish swimming

PubMed Central

Oufiero, Christopher E.; Whitlow, Katrina R.

2016-01-01

Abstract Fish have a remarkable amount of variation in their swimming performance, from within species differences to diversity among major taxonomic groups. Fish swimming is a complex, integrative phenotype and has the ability to plastically respond to a myriad of environmental changes. The plasticity of fish swimming has been observed on whole-organismal traits such as burst speed or critical swimming speed, as well as underlying phenotypes such as muscle fiber types, kinematics, cardiovascular system, and neuronal processes. Whether the plastic responses of fish swimming are beneficial seems to depend on the environmental variable that is changing. For example, because of the effects of temperature on biochemical processes, alterations of fish swimming in response to temperature do not seem to be beneficial. In contrast, changes in fish swimming in response to variation in flow may benefit the fish to maintain position in the water column. In this paper, we examine how this plasticity in fish swimming might evolve, focusing on environmental variables that have received the most attention: temperature, habitat, dissolved oxygen, and carbon dioxide variation. Using examples from previous research, we highlight many of the ways fish swimming can plastically respond to environmental variation and discuss potential avenues of future research aimed at understanding how plasticity of fish swimming might evolve. We consider the direct and indirect effects of environmental variation on swimming performance, including changes in swimming kinematics and suborganismal traits thought to predict swimming performance. We also discuss the role of the evolution of plasticity in shaping macroevolutionary patterns of diversity in fish swimming. PMID:29491937

Factors affecting swimming performance of fasted rainbow trout with implications of exhaustive exercise on overwinter mortality

USGS Publications Warehouse

Simpkins, D.G.; Hubert, W.A.; Del Rio, C.M.; Rule, D.C.

2004-01-01

We evaluated the effects of body size, water temperature, and sustained swimming activity on swimming performance and the effects of exhaustive exercise on mortality of fasted juvenile rainbow trout. Fasting caused swimming performance to decline more rapidly for small fish than large fish, and warmer water temperatures and sustained swimming activity further decreased swimming performance. Exhaustive exercise increased mortality among fasted fish. Our observations suggest that juvenile rainbow trout with little or no food intake during winter can swim for long periods of time with little effect on mortality, but swimming to exhaustion can enhance mortality, especially among the smallest juveniles.

Swimming Performance and Metabolism of Golden Shiners

USDA-ARS?s Scientific Manuscript database

The swimming ability and metabolism of golden shiners, Notemigonus crysoleucas, was examined using swim tunnel respirometery. The oxygen consumption and tail beat frequencies at various swimming speeds, an estimation of the standard metabolic rate, and the critical swimming speed (Ucrit) was determ...

Sericin and swimming on histomorphometric parameters of denervated plantar muscle in Wistar rats.

PubMed

Santana, André Junior; Debastiani, Jean Carlos; Buratti, Pâmela; Peretti, Ana Luiza; Kunz, Regina Inês; Brancalhão, Rose Meire Costa; Ribeiro, Lucinéia de Fátima Chasko; Torrejais, Márcia Miranda; Bertolini, Gladson Ricardo Flor

2018-01-01

Objective To analyze the combined effects of the silk protein sericin and swimming exercise on histomorphometry of the plantar muscle in Wistar rats. Methods Forty adult rats were randomly allocated into 5 groups comprising 8 animals each, as follows: Control, Injury, Sericin, Swim, and Swim plus Sericin. Three days after crushing of the sciatic nerve the rats in the Swim and Swim plus Sericin Groups were submitted to swimming exercise for 21 days. Rats were then euthanized and the plantar muscle harvested and processed. Results Cross-sectional area, peripheral nuclei and muscle fiber counts, nucleus/fiber ratio and smallest muscle fiber width did not differ significantly between groups. Morphological analysis revealed hypertrophic fibers in the Swim Group and evident muscle damage in the Swim plus Sericin and Injury Groups. The percentage of intramuscular collagen was apparently maintained in the Swim Group compared to remaining groups. Conclusion Combined treatment with sericin and swimming exercise did not improve muscle properties. However, physical exercise alone was effective in maintaining intramuscular connective tissue and preventing progression of deleterious effects of peripheral nerve injury.

Flagella and motility behaviour of square bacteria.

PubMed Central

Alam, M; Claviez, M; Oesterhelt, D; Kessel, M

1984-01-01

Square bacteria are shown to have right-handed helical (RH) flagella. They swim forward by clockwise (CW), and backwards by counterclockwise (CCW) rotation of their flagella. They are propelled by several or single filaments arising at several or single points on the cell surface. When there are several filaments a stable bundle is formed that does not fly apart during the change from clockwise to counterclockwise rotation or vice versa. In addition to the flagella attached to the cells, large amounts of detached flagella aggregated into thick super-flagella, can be observed at all phases of growth. Images Fig. 1. Fig. 2. Fig. 3. Fig. 4. Fig. 5. Fig. 6. PMID:6526006

Microswimmers - From Single Particle Motion to Collective Behavior

NASA Astrophysics Data System (ADS)

Gompper, Gerhard; Bechinger, Clemens; Herminghaus, Stephan; Isele-Holder, Rolf; Kaupp, U. Benjamin; Löwen, Hartmut; Stark, Holger; Winkler, Roland G.

2016-11-01

Locomotion of autonomous microswimmers is a fascinating field at the cutting edge of science. It combines the biophysics of self-propulsion via motor proteins, artificial propulsion mechanisms, swimming strategies at low Reynolds numbers, the hydrodynamic interaction of swimmers, and the collective motion and synchronisation of large numbers of agents. The articles of this Special Issue are based on the lecture notes of an international summer school, which was organized by the DFG Priority Programme 1726 "Microswimmers - From Single Particle Motion to Collective Behaviour" in the fall of 2015. The minireviews provide a broad overview of the field, covering both elementary and advanced material, as well as selected areas from current research.

Substratum location and zoospore behaviour in the fouling alga Enteromorpha.

PubMed

Callow, M E; Callow, J A

2000-01-01

The green alga Enteromorpha is the most important macroalga that fouls ships, submarines and underwater structures. Major factors in its success in colonising new substrata are the production of enormous numbers of swimming spores and their ability to locate surfaces on which to settle. Factors facilitating the settlement and adhesion of asexual zoospores are examined in this article. Settlement and adhesion may be regulated by topographical, biological, chemical and physico-chemical cues, all of which are modified by the presence of microbial biofilm. The level of gregarious zoospore settlement is related to spore density and may be mediated by a number of external cues including fatty acids and 'detritus'.

Morning Exercise: Enhancement of Afternoon Sprint-Swimming Performance.

PubMed

McGowan, Courtney J; Pyne, David B; Thompson, Kevin G; Raglin, John S; Rattray, Ben

2017-05-01

An exercise bout completed several hours prior to an event may improve competitive performance later that same day. To examine the influence of morning exercise on afternoon sprint-swimming performance. Thirteen competitive swimmers (7 male, mean age 19 ± 3 y; 6 female, mean age 17 ± 3 y) completed a morning session of 1200 m of variedintensity swimming (SwimOnly), a combination of varied-intensity swimming and a resistance-exercise routine (SwimDry), or no morning exercise (NoEx). After a 6-h break, swimmers completed a 100-m time trial. Time-trial performance was faster in SwimOnly (1.6% ± 0.6, mean ± 90% confidence limit, P < .01) and SwimDry (1.7% ± 0.7%, P < .01) than in NoEx. Split times for the 25- to 50-m distance were faster in both SwimOnly (1.7% ± 1.2%, P = .02) and SwimDry (1.5% ± 0.8%, P = .01) than in NoEx. The first 50-m stroke rate was higher in SwimOnly (0.70 ± 0.21 Hz, mean ± SD, P = .03) and SwimDry (0.69 ± 0.18 Hz, P = .05) than in NoEx (0.64 ± 0.16 Hz). Before the afternoon session, core (0.2°C ± 0.1°C [mean ± 90% confidence limit], P = .04), body (0.2°C ± 0.1°C, P = .02), and skin temperatures (0.3°C ± 0.3°C, P = .02) were higher in SwimDry than in NoEx. Completion of a morning swimming session alone or together with resistance exercise can substantially enhance sprint-swimming performance completed later the same day.

Benefits and Enjoyment of a Swimming Intervention for Youth With Cerebral Palsy: An RCT Study.

PubMed

Declerck, Marlies; Verheul, Martine; Daly, Daniel; Sanders, Ross

2016-01-01

To investigate enjoyment and specific benefits of a swimming intervention for youth with cerebral palsy (CP). Fourteen youth with CP (aged 7 to 17 years, Gross Motor Function Classification System levels I to III) were randomly assigned to control and swimming groups. Walking ability, swimming skills, fatigue, and pain were assessed at baseline, after a 10-week swimming intervention (2/week, 40-50 minutes) or control period, after a 5-week follow-up and, for the intervention group, after a 20-week follow-up period. The level of enjoyment of each swim-session was assessed. Levels of enjoyment were high. Walking and swimming skills improved significantly more in the swimming than in the control group (P = .043; P = .002, respectively), whereas fatigue and pain did not increase. After 20 weeks, gains in walking and swimming skills were retained (P = .017; P = .016, respectively). We recommend a swimming program for youth with CP to complement a physical therapy program.

Effect of Hypergravity on Carbonanhydrase Reactivity in inner Ear Ioncytes of developing Cichlid Fish

NASA Astrophysics Data System (ADS)

Beier, M.; Anken, R.; Rahmann, H.

It has been shown earlier that hypergravity slows down inner ear otolith growth in developing fish. Otolith growth in terms of mineralisation mainly depends on the enzyme carboanhydrase (CAH), which is responsible for the provision of the pH- value necessary for calcium carbonate deposition and thus also is presumed to play a prominent role in Ménière's disease (a sensory - motor disorder inducing vertigo and kinetosis). Larval siblings of cichlid fish (Oreochromis mossambicus) were subjected to hypergravity (3g; 6 hours) during development and separated into normally and kinetotically swimming individuals following the transfer to 1g (i.e., stopping the centrifuge; kinetotically behaving fish performed spinning movements). Subsequently, CAH was histochemically demonstrated in inner ear ionocytes (cells involved in the endolymphatic ion exchange) and enzyme reactivity was determined densitometrically. The results showed that CAH-reactivity was significantly increased in normally behaving hyper-g specimens as compared to controls kept at 1g, whereas no difference in enzyme reactivity was evident between the controls and kinetotically behaving fish. On the background of earlier studies, according to which (1) hypergravity induces a decrease of otolith growth and (2) the otolithic calcium incorporation (visualized using the calcium -tracer alizarin complexone) of kinetotically swimming hyper - g fish was lower as compared to normally behaving hyper - g animals, the present study strongly supports the concept that an increase in CAH-reactivity may result in a decrease of otolithic calcium deposition. The mechanism regulating CAH-activity hitherto remains to be determined. Acknowledgement: This work was financially supported by the German Aerospace Center (DLR) (FKZ: 50 WB 9997).

Swimming Performance of Adult Asian Carp: Field Assessment Using a Mobile Swim Tunnel

DTIC Science & Technology

2016-08-01

The effect of temperature on swimming performance and oxygen consumption in adult sockeye (Oncorhynchus nerka) and coho (O. kisutch) salmon stocks...tunnel to determine the critical swim speed (Ucrit), oxygen consumption (VO2), and endurance at a single velocity. Tunnel Type Tunnel Size (L...specially designed mobile swim tunnel indicated that it might be used effectively with other large, active, free-swimming planktivores, including bigheaded

Swimming Stroke Mechanical Efficiency and Physiological Responses of 100-m Backstroke with and without the use of paddles

PubMed Central

Messinis, Spilios; Beidaris, Nikos; Messinis, Spyros; Soultanakis, Helen; Botonis, Petros; Platanou, Theodoros

2014-01-01

The use of swimming aids during training contributes to greater swimming efficiency by the improvement of the swimming specific power of the athlete. The purpose of this study was to compare the swimming stroke technical characteristics and the physiological responses of swimming 100-m backstroke, with and without the use of paddles at maximum and sub-maximum intensities at the same swimming speed. Eight swimmers competing at the national level participated in this study. The measurements took place at 4 different sessions. At every session, each participant swam individually one 100-m backstroke swimming trial with or without paddles at the same speed and two levels of intensity (100% and 85% of maximum speed). The results revealed lower stroke length, greater stroke number and gliding length without the use of swimming paddles at both intensities. Blood lactate concentration (10.03±2.96 vs. 5.85±2.23 mmol/l) and Rating of Perceived Exertion (17.43±2.07 vs. 12±2.82) were greater without the use of swimming paddles only at 100% of maximum speed. Thus, swimming backstroke with paddles compared to unaided swimming, at a similar speed, showed a greater efficiency at maximal but not at sub-maximal intensity. PMID:25031685

Swimming Stroke Mechanical Efficiency and Physiological Responses of 100-m Backstroke with and without the use of paddles.

PubMed

Messinis, Spilios; Beidaris, Nikos; Messinis, Spyros; Soultanakis, Helen; Botonis, Petros; Platanou, Theodoros

2014-03-27

The use of swimming aids during training contributes to greater swimming efficiency by the improvement of the swimming specific power of the athlete. The purpose of this study was to compare the swimming stroke technical characteristics and the physiological responses of swimming 100-m backstroke, with and without the use of paddles at maximum and sub-maximum intensities at the same swimming speed. Eight swimmers competing at the national level participated in this study. The measurements took place at 4 different sessions. At every session, each participant swam individually one 100-m backstroke swimming trial with or without paddles at the same speed and two levels of intensity (100% and 85% of maximum speed). The results revealed lower stroke length, greater stroke number and gliding length without the use of swimming paddles at both intensities. Blood lactate concentration (10.03±2.96 vs. 5.85±2.23 mmol/l) and Rating of Perceived Exertion (17.43±2.07 vs. 12±2.82) were greater without the use of swimming paddles only at 100% of maximum speed. Thus, swimming backstroke with paddles compared to unaided swimming, at a similar speed, showed a greater efficiency at maximal but not at sub-maximal intensity.

Repeated weekly exposure to MDMA, methamphetamine or their combination: long-term behavioural and neurochemical effects in rats.

PubMed

Clemens, Kelly J; Cornish, Jennifer L; Hunt, Glenn E; McGregor, Iain S

2007-01-12

In recent work we have documented lasting adverse neurochemical and behavioural effects in rats given short-term 'binge' dosing with methylenedioxymethamphetamine (MDMA, Ecstasy), methamphetamine (METH) or their combination. Here we investigated whether similar effects persist in rats given 16 weekly injections followed by a 10 week period of abstinence. Female rats received MDMA (8 mg/kg, i.p.), METH (8 mg/kg), or a MDMA/METH combination (4 mg/kg MDMA + 4 mg/kg METH), once a week for 16 weeks, with locomotor activity and body temperature measured on weeks 1, 8 and 16. The MDMA and MDMA/METH groups showed acute drug-induced hyperthermia on week 1 only. MDMA-treated rats demonstrated an acute hyperactivity while METH and MDMA/METH treated rats showed pronounced stereotypy. Seven weeks after drug-treatment concluded, a decrease in social interaction was observed in all chronically drug-treated rats. No group differences were evident on the emergence, object recognition or forced swim tests. Neurochemical analysis revealed modest noradrenaline and serotonin depletion in chronically treated rats that was not evident following a single equivalent administration. These results indicate that although chronic, intermittent exposure to MDMA, METH or their combination, may not lead to significant long-term monoamine depletion, lasting adverse behavioural effects may persist, especially those related to social behaviour.

Tethered swimming can be used to evaluate force contribution for short-distance swimming performance.

PubMed

Morouço, Pedro G; Marinho, Daniel A; Keskinen, Kari L; Badillo, Juan J; Marques, Mário C

2014-11-01

The purpose of this study was two-fold: (a) to compare stroke and the physiological responses between maximal tethered and free front crawl swimming and (b) to evaluate the contribution of force exertion for swimming performance over short distances. A total of 34 male swimmers, representing various levels of competitive performance, participated in this study. Each participant was tested in both a 30-second maximal tethered swimming test and a 50-m free swimming test. The tethered force parameters, the swimming speed, stroke (stroke rate [SR]), and the physiological responses (increase in blood lactate concentration [ΔBLa], heart rate, and rate of perceived exertion) were recorded and calculated. The results showed no differences in stroke and the physiological responses between tethered and free swimming, with a high level of agreement for the SR and ΔBLa. A strong correlation was obtained between the maximum impulse of force per stroke and the speed (r = 0.91; p < 0.001). Multiple regression analysis revealed that the maximum impulse and SR in the tethered condition explained 84% of the free swimming performance. The relationship between the swimming speed and maximum force tended to be nonlinear, whereas linear relationships were observed with the maximum impulse. This study demonstrates that tethered swimming does not significantly alter stroke and the physiological responses compared with free swimming, and that the maximum impulse per stroke should be used to evaluate the balance between force and the ability to effectively apply force during sprint swimming. Consequently, coaches can rely on tethered forces to identify strength deficits and improve swimming performance over short distances.

Ocean enemy's lasting sting: chronic cutaneous reaction after Cnidarian attack.

PubMed

Naumann, D; Hejmadi, R K; Evriviades, D

2013-01-01

Cnidaria stings cause a wide range of cutaneous and systemic symptoms, normally occurring shortly after the venomous insult (1). We report a case of worsening cutaneous reaction over an eight-year period following a Cnidaria attack sustained whilst maritime swimming. The lesion was characterised by severe, ulcerating chronic inflammation that required wide local excision and skin grafting. Prevention and early identification of Cnidaria envenomation is important for those treating maritime swimmers.

Swimming Pools for Schools.

ERIC Educational Resources Information Center

Neilson, Donald W.; Nixon, John E.

The increasing interest in swimming instruction and recreation for elementary and secondary school children has resulted in the development of this guide for swimming pool use, design, and construction. Introductory material discussed the need for swimming in the educational program and the organization of swimming programs in the school. Design…

Cryptic female choice enhances fertilization success and embryo survival in chinook salmon

PubMed Central

2016-01-01

In this study, we investigated two potentially important intersexual postcopulatory gametic interactions in a population of chinook salmon (Oncorhynchus tshawytscha): (i) the effect of female ovarian fluid (OF) on the behaviour of spermatozoa during fertilization and (ii) the effects of multilocus heterozygosity (MLH) (as an index of male quality) and female–male genetic relatedness on sperm behaviour and male fertilization success when there is sperm competition in the presence of that OF. To do this, we conducted a series of in vitro competitive fertilization experiments and found that, when ejaculates from two males are competing for access to a single female's unfertilized eggs, fertilization success was significantly biased towards the male whose sperm swam fastest in the female's OF. Embryo survival—a measure of fitness—was also positively correlated with both sperm swimming speed in OF and male MLH, providing novel evidence that cryptic female choice is adaptive for the female, enhancing the early survival of her offspring and potentially influencing her fitness. PMID:27009221

Male swordtails court with an audience in mind.

PubMed

Fisher, Heidi S; Rosenthal, Gil G

2007-02-22

Females are usually considered to be the target of male courtship behaviour. In nature, however, social interactions rarely occur without other observers; thus, it is conceivable that some male courtship behaviours are directed not towards females, but rather towards male rivals. The northern swordtail, Xiphophorus birchmanni, is a freshwater fish found in high densities in natural streams. Males court by swimming close to and in parallel with the female, raising their large sail-like dorsal fin, and quivering briefly. Here, we show that females prefer males that display small dorsal fins to those with large ones, and that males are less aggressive to other males with large dorsal fins. Male swordtails also raise their dorsal fins more frequently when courting in the presence of other males. These results suggest that, despite female avoidance of large dorsal fins, males that raise their fin during courtship benefit by intimidating potential competitors; the intended receivers of this signal are thus males, not females. Intrasexual selection can therefore offset the forces of intersexual selection, even in a courtship display.

Cryptic female choice enhances fertilization success and embryo survival in chinook salmon.

PubMed

Rosengrave, Patrice; Montgomerie, Robert; Gemmell, Neil

2016-03-30

In this study, we investigated two potentially important intersexual postcopulatory gametic interactions in a population of chinook salmon (Oncorhynchus tshawytscha): (i) the effect of female ovarian fluid (OF) on the behaviour of spermatozoa during fertilization and (ii) the effects of multilocus heterozygosity (MLH) (as an index of male quality) and female-male genetic relatedness on sperm behaviour and male fertilization success when there is sperm competition in the presence of that OF. To do this, we conducted a series of in vitro competitive fertilization experiments and found that, when ejaculates from two males are competing for access to a single female's unfertilized eggs, fertilization success was significantly biased towards the male whose sperm swam fastest in the female's OF. Embryo survival--a measure of fitness--was also positively correlated with both sperm swimming speed in OF and male MLH, providing novel evidence that cryptic female choice is adaptive for the female, enhancing the early survival of her offspring and potentially influencing her fitness. © 2016 The Author(s).

Increasing ocean temperatures reduce activity patterns of a large commercially important coral reef fish.

PubMed

Johansen, J L; Messmer, V; Coker, D J; Hoey, A S; Pratchett, M S

2014-04-01

Large-bodied fish are critical for sustaining coral reef fisheries, but little is known about the vulnerability of these fish to global warming. This study examined the effects of elevated temperatures on the movement and activity patterns of the common coral trout Plectropomus leopardus (Serranidae), which is an important fishery species in tropical Australia and throughout the Indo West-Pacific. Adult fish were collected from two locations on Australia's Great Barrier Reef (23°S and 14°S) and maintained at one of four temperatures (24, 27, 30, 33 °C). Following >4 weeks acclimation, the spontaneous swimming speeds and activity patterns of individuals were recorded over a period of 12 days. At 24-27 °C, spontaneous swimming speeds of common coral trout were 0.43-0.45 body lengths per second (bls(-1)), but dropped sharply to 0.29 bls(-1) at 30 °C and 0.25 bls(-1) at 33 °C. Concurrently, individuals spent 9.3-10.6% of their time resting motionless on the bottom at 24-27 °C, but this behaviour increased to 14.0% at 30 °C and 20.0% of the time at 33 °C (mean ± SE). The impact of temperature was greatest for smaller individuals (<45 cm TL), showing significant changes to swimming speeds across every temperature tested, while medium (45-55 cm TL) and large individuals (>55 cm TL) were first affected by 30 °C and 33 °C, respectively. Importantly, there was some indication that populations can adapt to elevated temperature if presented with adequate time, as the high-latitude population decreased significantly in swimming speeds at both 30 °C and 33 °C, while the low-latitude population only showed significant reductions at 33 °C. Given that movement and activity patterns of large mobile species are directly related to prey encounter rates, ability to capture prey and avoid predators, any reductions in activity patterns are likely to reduce overall foraging and energy intake, limit the energy available for growth and reproduction, and affect the fitness and survival of individuals and populations. © 2013 John Wiley & Sons Ltd.

Contrasting effects of nitrogenous pollution on fitness and swimming performance of Iberian waterfrog, Pelophylax perezi (Seoane, 1885), larvae in mesocosms and field enclosures.

PubMed

Egea-Serrano, A; Tejedo, M

2014-01-01

Amphibians are declining worldwide and pollutants have been implicated as a major contributor to these declines. To understand these declines, many studies have assessed the impact of pollutants on amphibian behaviour. However, information regarding their effect on locomotor abilities, as well as the intra-specific variation of the tolerance to pollutants, is extremely rare. Further, the majority of studies examining the impact of pollutants on amphibians have been conducted in simplified laboratory settings. Given the complexity of natural systems, determining whether amphibian responses in laboratory studies can be generalized to more realistic natural scenarios is critical. Towards this goal, this study assessed the impact of nitrogenous pollution on survival and fitness-related larval traits (growth, mass and swimming performance) for three populations of the frog Pelophylax perezi, exposed to different degrees of eutrophication in two different and complementary experiments: (1) pond mesocosms, with NH4Cl isolated or combined with NaNO2 and NaNO3, and (2) field enclosures placed in natural streams differing in their degree of pollution. For both mesocosm and field enclosure experiments, larval mortality was unaffected by nitrogenous pollution. However, in the mesocosm experiment, exposure to nitrogenous compounds reduced final larvae mass and growth. In contrast, in the enclosure experiment, polluted locations facilitated final mass and growth of surviving tadpoles. Population-level variation in the effect of pollution was observed for final larval mass in the mesocosm but not in the field enclosure experiment. In addition, although nitrogenous compounds in both mesocosm and natural conditions had no direct effect on absolute larval swimming performance, they may impact the viability of larvae by affecting the relationships between growth and the swimming abilities. The differential pattern found in the impacts of nitrogenous compounds on larvae of P. perezi when raised in different experimental venues (mesocosms and field conditions) points to the convenience of considering more realistic natural scenarios in assessing the impact of pollutants on amphibians. Copyright © 2013 Elsevier B.V. All rights reserved.

78 FR 35798 - Safety Zones; Swim Around Charleston; Charleston, SC

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-14

...-AA00 Safety Zones; Swim Around Charleston; Charleston, SC AGENCY: Coast Guard, DHS. ACTION: Notice of... the Swim Around Charleston, a swimming race occurring on the Wando River, the Cooper River, Charleston Harbor, and the Ashley River, in Charleston, South Carolina. The Swim Around Charleston is scheduled on...

The effects of low-speed swimming following exhaustive exercise on metabolic recovery and swimming performance in brook trout (Salvelinus fontinalis).

PubMed

Kieffer, James D; Kassie, Roshini S; Taylor, Susan G

2011-01-01

Experiments were conducted to determine whether low-speed swimming during recovery from exhaustive exercise improved both metabolic recovery and performance during a swimming challenge. For these experiments, brook trout were allowed to recover from exhaustive exercise for 2 h while swimming at 0, 0.5, 1.0, or 1.5 body length (BL) s(-1) or allowed to recover from exhaustive exercise for 1, 2, or 3 h while swimming at 1.0 BL s(-1). At the appropriate interval, either (i) muscle and blood samples were removed from the fish or (ii) fish were assessed for performance (i.e., fatigue time) during a fixed-interval swimming test. Low-speed swimming during recovery from exhaustive exercise resulted in significantly longer fatigue times compared with fish recovering in still water (i.e., 0 BL s(-1)). However, swimming during recovery did not expedite recovery of muscle lactate or blood variables (e.g., lactate, osmolarity, glucose). These observations suggest that metabolic recovery and subsequent swimming performance may not be directly linked and that other factors play a role in swimming recovery in brook trout.

Creatine supplementation and swim performance: a brief review.

PubMed

Hopwood, Melissa J; Graham, Kenneth; Rooney, Kieron B

2006-03-01

Nutritional supplements are popular among athletes participating in a wide variety of sports. Creatine is one of the most commonly used dietary supplements, as it has been shown to be beneficial in improving performance during repeated bouts of high-intensity anaerobic activity. This review examines the specific effects of creatine supplementation on swimming performance, and considers the effects of creatine supplementation on various measures of power development in this population. Research performed on the effect of creatine supplementation on swimming performance indicates that whilst creatine supplementation is ineffective in improving performance during a single sprint swim, dietary creatine supplementation may benefit repeated interval swim set performance. Considering the relationship between sprint swimming performance and measurements of power, the effect of creatine supplementation on power development in swimmers has also been examined. When measured on a swim bench ergometer, power development does show some improvement following a creatine supplementation regime. How this improvement in power output transfers to performance in the pool is uncertain. Although some evidence exists to suggest a gender effect on the performance improvements seen in swimmers following creatine supplementation, the majority of research indicates that male and female swimmers respond equally to supplementation. A major limitation to previous research is the lack of consideration given to the possible stroke dependant effect of creatine supplementation on swimming performance. The majority of the research conducted to date has involved examination of the freestyle swimming stroke only. The potential for performance improvements in the breaststroke and butterfly swimming strokes is discussed, with regards to the biomechanical differences and differences in efficiency between these strokes and freestyle. Key PointsCreatine supplementation does not improve single sprint swimming performance.Creatine supplementation does improve repeated interval swim set performance.Creatine supplementation does improve power development in swimmers when measured on a swim bench ergometer.As a result of the high energy demands of the butterfly and breaststroke competitive swimming styles, potentially, the benefits associated with creatine supplementation and swimming performance could be greater when swimming butterfly or breaststroke, compared to the commonly examined freestyle swimming stroke.

Sperm chemotaxis in siphonophores. II. Calcium-dependent asymmetrical movement of spermatozoa induced by the attractant.

PubMed

Cosson, M P; Carré, D; Cosson, J

1984-06-01

Spermatozoa from siphonophores have been shown to be attracted towards an extracellular structure, the cupule, which covers the predetermined site of fertilization of the egg. Observations on sperm behaviour during the chemotactic response show that spermatozoa describe trajectories of large diameter (700-1000 micron) while far from the cupule, and of smaller diameter (200 micron) in the cupule area. The transition between the two types of swimming occurs progressively when spermatozoa cross a 3 mm wide area around the cupule. After a few minutes 99% of the spermatozoa keep swimming around the attractant source, following circular paths 150-200 micron in diameter. In the absence of the attractant, comparable modifications of sperm trajectories are observed in the presence of the ionophore A23187 and high calcium concentrations. In the presence of 10(-2) M calcium ions, A23187-treated spermatozoa describe trajectories 200 micron in diameter, which increase up to 800 micron at lower calcium concentrations (10(-6) M). In the absence of calcium ions, spermatozoa swim across the cupule area without modification of their trajectories and no sperm accumulation can be detected. This requirement of the chemotactic response for calcium ions is observed either with fresh cupules stuck on the eggs, with cupules separated from the eggs, or with cupule extracts. Moreover, a soluble component fractionated from the cupule induces, when diluted in sea water, a reduction in the size of the sperm trajectories and this also requires calcium ions. The present data show that the chemotactic response of siphonophore sperm, which requires millimolar concentrations of calcium ions, occurs through a non-transient induction of increased asymmetry of the flagellar waveform. It is proposed that the natural attractant operates to produce an increase in the intraaxonemal calcium concentration.

Shewanella oneidensis MR-1 chemotaxis proteins and electron-transport chain components essential for congregation near insoluble electron acceptors.

PubMed

Harris, H Wayne; El-Naggar, Mohamed Y; Nealson, Kenneth H

2012-12-01

Shewanella oneidensis MR-1 cells utilize a behaviour response called electrokinesis to increase their speed in the vicinity of IEAs (insoluble electron acceptors), including manganese oxides, iron oxides and poised electrodes [Harris, El-Naggar, Bretschger, Ward, Romine, Obraztsova and Nealson (2010) Proc. Natl. Acad. Sci. U.S.A. 107, 326-331]. However, it is not currently understood how bacteria remain in the vicinity of the IEA and accumulate both on the surface and in the surrounding medium. In the present paper, we provide results indicating that cells that have contacted the IEAs swim faster than those that have not recently made contact. In addition, fast-swimming cells exhibit an enhancement of swimming reversals leading to rapid non-random accumulation of cells on, and adjacent to, mineral particles. We call the observed accumulation near IEAs 'congregation'. Congregation is eliminated by the loss of a critical gene involved with EET (extracellular electron transport) (cymA, SO_4591) and is altered or eliminated in several deletion mutants of homologues of genes that are involved with chemotaxis or energy taxis in Escherichia coli. These genes include chemotactic signal transduction protein (cheA-3, SO_3207), methyl-accepting chemotaxis proteins with the Cache domain (mcp_cache, SO_2240) or the PAS (Per/Arnt/Sim) domain (mcp_pas, SO_1385). In the present paper, we report studies of S. oneidensis MR-1 that lend some insight into how microbes in this group can 'sense' the presence of a solid substrate such as a mineral surface, and maintain themselves in the vicinity of the mineral (i.e. via congregation), which may ultimately lead to attachment and biofilm formation.

International travelers and unintentional fatal drowning in Australia--a 10 year review 2002-12.

PubMed

Peden, Amy E; Franklin, Richard C; Leggat, Peter A

2016-02-01

. Drowning deaths of travelers are commonly reported in the media, creating a perception that they are at a higher risk of drowning than residents. This may be true, due in part to unfamiliarity with the risks posed by the hazard, however there is limited information about drowning deaths of travelers in Australia. This study aims to identify the incidence of drowning among international travelers in Australia and examine the risk factors to inform prevention strategies. . Data on unintentional fatal drowning in Australian waterways of victims with a residential postcode from outside Australia were extracted from the Royal Life Saving Society-Australia National Fatal Drowning Database. . Between 1 July 2002 and 30 June 2012 drowning deaths among people known to be international travelers accounted for 4.3% (N = 123) of the 2870 drowning deaths reported in Australian waterways. Key locations for drowning deaths included beaches (39.0%), ocean/harbour (22.0%) and swimming pools (12.2%). Leading activities prior to drowning included swimming (52.0%), diving (17.9%) and watercraft incidents (13.0%). . International travelers pose a unique challenge from a drowning prevention perspective. The ability to exchange information on water safety is complicated due to potential language barriers, possible differences in swimming ability, different attitudes to safety in the traveler's home country and culture, a lack of opportunities to discuss safety, a relaxed attitude to safety which may result in an increase in risk taking behaviour and alcohol consumption. . Prevention is vital both to reduce loss of life in the aquatic environment and promote Australia as a safe and enjoyable holiday destination for international travelers. © International Society of Travel Medicine, 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Performance of four different rat strains in the autoshaping, two-object discrimination, and swim maze tests of learning and memory.

PubMed

Andrews, J S; Jansen, J H; Linders, S; Princen, A; Broekkamp, C L

1995-04-01

The performance of four strains of rats commonly used in behavioural research was assessed in three different tests of learning and memory. The four strains included three outbred lines (Long-Evans, Sprague-Dawley, Wistar) and one inbred strain (S3). Learning and memory were tested using three different paradigms: autoshaping of a lever press, a two-object discrimination test, and performance in a two-island swim maze task. The pigmented strains showed better performance in the autoshaping procedure: the majority of the Long-Evans and the S3 rats acquired the response, and the majority of the Wistar and Sprague-Dawley failed to acquire the response in the set time. The albino strains were slightly better in the swim maze than the pigmented strains. There appeared to be a speed/accuracy trade-off in the strategy used to solve the task. This was also evident following treatment with the cholinergic-depleting agent hemicholinium-3. The performance of the Long-Evans rats was most affected by the treatment in terms of accuracy and the Wistar and Sprague-Dawleys in terms of speed. In the two-object discrimination test only the Long-Evans showed satisfactory performance and were able to discriminate a novel from a known object a short interval after initial exposure. These results show large task- and strain-dependent differences in performance in tests of learning and memory. Some of the performance variation may be due to emotional differences between the strains and may be alleviated by extra training. However, the response to pharmacological manipulation may require more careful evaluation.(ABSTRACT TRUNCATED AT 250 WORDS)

Excessive nest building is a unique behavioural phenotype in the deer mouse model of obsessive-compulsive disorder.

PubMed

Wolmarans, De Wet; Stein, Dan J; Harvey, Brian H

2016-09-01

Obsessive-compulsive disorder (OCD) is a phenotypically heterogeneous condition characterised by time-consuming intrusive thoughts and/or compulsions. Irrespective of the symptom type diagnosed, the severity of OCD is characterised by heterogeneity in symptom presentation that complicates diagnosis and treatment. Heterogeneity of symptoms would be invaluable in an animal model. Nest building behaviour forms part of the normal behavioural repertoire of rodents and demonstrates profound between-species differences. However, it has been proposed that within-species differences in nest building behaviour (i.e. aberrant vs. normal nest building) may resemble obsessive-compulsive-like symptoms. In an attempt to investigate whether other obsessive-compulsive-like behaviours are present in an animal model of OCD, or if aberrant nest building behaviour may represent a unique obsessive-compulsive phenotype in such a model, the current study assessed nest building behaviour in high (H, viz obsessive-compulsive) and non (N, viz normal) stereotypical deer mice. Subsequently, 12 N and H animals, respectively, were provided with an excess of cotton wool daily for one week prior to and following four weeks of high-dose oral escitalopram treatment (50 mg/kg/day). Data from the current investigation demonstrate daily nesting activity to be highly variable in deer mice, with stereotypy and nest building being independent behaviours. However, we identified unique aberrant large nest building behaviour in 30% of animals from both cohorts that was attenuated by escitalopram to pre-treatment nesting scores of the larger group. In summary, behavioural and drug-treatment evidence confirms that deer mouse behaviour does indeed resemble symptom heterogeneity related to OCD, and as such expands its face and predictive validity for the disorder. © The Author(s) 2016.

Influence of temperature and sperm preparation on the quality of spermatozoa.

PubMed

Thijssen, Annelies; Klerkx, Elke; Huyser, Carin; Bosmans, Eugene; Campo, Rudi; Ombelet, Willem

2014-04-01

This study investigated the effects of long-term (24h) in-vitro sperm incubation at room temperature (RT; 23°C) versus testis temperature (35°C) on various sperm-quality parameters. Semen samples (n=41) were prepared both by density-gradient centrifugation (DGC) and the swim-up technique in order to compare the influence of sperm preparation on sperm quality after incubation. Progressive motility and morphology were significantly higher after incubation at RT compared with 35°C (P<0.001 and P<0.01, respectively). The proportions of acrosome-reacted, apoptotic and dead spermatozoa were significantly lower in samples incubated for 24h at RT compared with 35°C (P<0.001, P=0.01 and P<0.001, respectively). The number of motile, morphologically normal, non-acrosome-reacted and nonapoptotic spermatozoa recovered after sperm preparation was significantly higher in DGC compared with swim-up samples (P<0.001). However, spermatozoa prepared by swim-up showed better survival after incubation compared with DGC-prepared spermatozoa, especially when incubated at 35°C. In conclusion, this study indicates a significantly better and longer preservation of sperm quality when incubation is performed at RT. These findings may convince laboratories to change the routinely used sperm storage conditions in order to maximize the quality of the prepared sperm sample. Copyright © 2014 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.

Simulated front crawl swimming performance related to critical speed and critical power.

PubMed

Toussaint, H M; Wakayoshi, K; Hollander, A P; Ogita, F

1998-01-01

Competitive pool swimming events range in distance from 50 to 1500 m. Given the difference in performance times (+/- 23-1000 s), the contribution of the aerobic and anaerobic energy systems changes considerably with race distance. In training practice the regression line between swimming distance and time (Distance = critical velocity x time + anaerobic swimming capacity) is used to determine the individual capacity of the aerobic and anaerobic metabolic pathways. Although there is confidence that critical velocity and anaerobic swimming capacity are fitness measures that separate aerobic and anaerobic components, a firm theoretical basis for the interpretation of these results does not exist. The purpose of this study was to evaluate the critical power concept and anaerobic swimming capacity as measures of the aerobic and anaerobic capacity using a modeling approach. A systems model was developed that relates the mechanics and energetics involved in front crawl swimming performance. From actual swimming flume measurements, the time dependent aerobic and anaerobic energy release was modeled. Data derived from the literature were used to relate the energy cost of front crawl swimming to swimming velocity. A balance should exist between the energy cost to swim a distance in a certain time and the concomitant aerobic and anaerobic energy release. The ensuing model was used to predict performance times over a range of distances (50-1500 m) and to calculate the regression line between swimming distance and time. Using a sensitivity analysis, it was demonstrated that the critical velocity is indicative for the capacity of the aerobic energy system. Estimates of the anaerobic swimming capacity, however, were influenced by variations in both anaerobic and aerobic energy release. Therefore, it was concluded that the anaerobic swimming capacity does not provide a reliable estimate of the anaerobic capacity.

Biochemical and hematological changes following the 120-km open-water marathon swim.

PubMed

Drygas, Wojciech; Rębowska, Ewa; Stępień, Ewa; Golański, Jacek; Kwaśniewska, Magdalena

2014-09-01

Data on physiological effects and potential risks of a ultraendurance swimming are scarce. This report presents the unique case of a 61-year old athlete who completed a non-stop open-water 120-km ultramarathon swim on the Warta River, Poland. Pre-swimming examinations revealed favorable conditions (blood pressure, 110/70 mmHg; rest heart rate, 54 beats/minute, ejection fraction, 60%, 20.2 metabolic equivalents in a maximal exercise test). The swimming time and distance covered were 27 h 33 min and 120 km, respectively. Blood samples for hematological and biochemical parameters were collected 30 min, 4 hrs, 10 hrs and 8 days after the swim. The body temperature of the swimmer was 36.7°C before and 35.1°C after the swim. The hematological parameters remained within the reference range in the postexercise period except for leucocytes (17.5 and 10.6 x G/l noted 30 minutes and 4 hours after the swim, respectively). Serum urea, aspartate aminotransferase and C-reactive protein increased above the reference range reaching 11.3 mmol/l, 1054 nmol/l/s and 25.9 mg/l, respectively. Symptomatic hyponatremia was not observed. Although the results demonstrate that an experienced athlete is able to complete an ultra-marathon swim without negative health consequences, further studies addressing the potential risks of marathon swimming are required. Key pointsData on biochemical changes due to long-distance swimming are scarce.This report presents the unique case of a 61-year old athlete who completed a non-stop open-water 120-km ultramarathon swim.An experienced athlete is able to complete an ultra-marathon swim without serious health consequences.Regarding the growing popularity of marathon swimming further studies addressing the potential risks of such exhaustive exercise are required.

Changes in c-Fos Expression in the Forced Swimming Test: Common and Distinct Modulation in Rat Brain by Desipramine and Citalopram

PubMed Central

Choi, Sun Hye; Chung, Sung; Cho, Jin Hee; Cho, Yun Ha; Kim, Jin Wook; Kim, Jeong Min; Kim, Hee Jeong; Kim, Hyun Ju

2013-01-01

Rodents exposed to a 15-min pretest swim in the forced swimming test (FST) exhibit prolonged immobility in a subsequent 5-min test swim, and antidepressant treatment before the test swim reduces immobility. At present, neuronal circuits recruited by antidepressant before the test swim remain unclear, and also less is known about whether antidepressants with different mechanisms of action could influence neural circuits differentially. To reveal the neural circuits associated with antidepressant effect in the FST, we injected desipramine or citalopram 0.5 h, 19 h, and 23 h after the pretest swim and observed changes in c-Fos expression in rats before the test swim, namely 24 h after the pretest swim. Desipramine treatment alone in the absence of pretest swim was without effect, whereas citalopram treatment alone significantly increased the number of c-Fos-like immunoreactive cells in the central nucleus of the amygdala and bed nucleus of the stria terminalis, where this pattern of increase appears to be maintained after the pretest swim. Both desipramine and citalopram treatment after the pretest swim significantly increased the number of c-Fos-like immunoreactive cells in the ventral lateral septum and ventrolateral periaqueductal gray before the test swim. These results suggest that citalopram may affect c-Fos expression in the central nucleus of the amygdala and bed nucleus of the stria terminalis distinctively and raise the possibility that upregulation of c-Fos in the ventral lateral septum and ventrolateral periaqueductal gray before the test swim may be one of the probable common mechanisms underlying antidepressant effect in the FST. PMID:23946692

Using open source accelerometer analysis to assess physical activity and sedentary behaviour in overweight and obese adults.

PubMed

Innerd, Paul; Harrison, Rory; Coulson, Morc

2018-04-23

Physical activity and sedentary behaviour are difficult to assess in overweight and obese adults. However, the use of open-source, raw accelerometer data analysis could overcome this. This study compared raw accelerometer and questionnaire-assessed moderate-to-vigorous physical activity (MVPA), walking and sedentary behaviour in normal, overweight and obese adults, and determined the effect of using different methods to categorise overweight and obesity, namely body mass index (BMI), bioelectrical impedance analysis (BIA) and waist-to-hip ratio (WHR). One hundred twenty adults, aged 24-60 years, wore a raw, tri-axial accelerometer (Actigraph GT3X+), for 3 days and completed a physical activity questionnaire (IPAQ-S). We used open-source accelerometer analyses to estimate MVPA, walking and sedentary behaviour from a single raw accelerometer signal. Accelerometer and questionnaire-assessed measures were compared in normal, overweight and obese adults categorised using BMI, BIA and WHR. Relationships between accelerometer and questionnaire-assessed MVPA (Rs = 0.30 to 0.48) and walking (Rs = 0.43 to 0.58) were stronger in normal and overweight groups whilst sedentary behaviour were modest (Rs = 0.22 to 0.38) in normal, overweight and obese groups. The use of WHR resulted in stronger agreement between the questionnaire and accelerometer than BMI and BIA. Finally, accelerometer data showed stronger associations with BMI, BIA and WHR (Rs = 0.40 to 0.77) than questionnaire data (Rs = 0.24 to 0.37). Open-source, raw accelerometer data analysis can be used to estimate MVPA, walking and sedentary behaviour from a single acceleration signal in normal, overweight and obese adults. Our data supports the use of WHR to categorise overweight and obese adults. This evidence helps researchers obtain more accurate measures of physical activity and sedentary behaviour in overweight and obese populations.

77 FR 14700 - Safety Zones; Swim Around Charleston, Charleston, SC

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-13

... the Swim Around Charleston, a swimming race occurring on the Wando River, the Cooper River, Charleston... 23, 2012, the Swim Around Charleston is scheduled to take place on the Wando River, the Cooper River...-AA00 Safety Zones; Swim Around Charleston, Charleston, SC AGENCY: Coast Guard, DHS. ACTION: Notice of...

76 FR 38586 - Safety Zone; Swim Around Charleston, Charleston, SC

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-01

... the Swim Around Charleston, a swimming race occurring on waters of the Wando River, the Cooper River... officially associated with the swim on the waters of the Wando River, the Cooper River, Charleston Harbor...-AA00 Safety Zone; Swim Around Charleston, Charleston, SC AGENCY: Coast Guard, DHS. ACTION: Notice of...

36 CFR 3.17 - What regulations apply to swimming areas and beaches?

Code of Federal Regulations, 2010 CFR

2010-07-01

... swimming areas and beaches? 3.17 Section 3.17 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR BOATING AND WATER USE ACTIVITIES § 3.17 What regulations apply to swimming areas and beaches? (a) The superintendent may designate areas as swimming areas or swimming beaches in...

Mental state attribution in schizophrenia: what distinguishes patients with "poor" from patients with "fair" mentalising skills?

PubMed

Brüne, M; Schaub, D

2012-07-01

Although many patients with schizophrenia are impaired in mental states attribution abilities, a significant number perform within normal or near-normal ranges in mental state attribution tasks. No studies have analysed cognitive or behavioural differences between patients with - to some extent - preserved mental state attribution skills and those with poor mentalising abilities. To examine characteristics of "poor" and "fair" mentalisers, 58 patients with schizophrenia performed a mental state attribution task, a test of general intelligence, and two executive functioning tests. "Poor" and "fair" mentalising skills were defined according to a median-split procedure; the median score in the patient group was also within two standard deviations of the control group. In addition, patients' social behavioural skills and psychopathological profiles were rated. Patients performing within normal or near normal ranges on the mental state attribution task had fewer social behavioural abnormalities than patients with poor mentalising abilities (even when controlled for intelligence), but did not differ in executive functioning. Fair mental state performers showed less disorganisation and excitement symptoms than poor performers. The degree of disorganisation mediated the influence of mental state attribution on social behavioural skills. Schizophrenia patients with (partially) preserved mentalising skills have fewer behavioural problems in the social domain than patients with poor mentalising abilities. Conceptual disorganisation mediates the prediction of social behavioural skills through mentalising skills, suggesting that disorganised patients may require special attention regarding social-cognitive skills training. Copyright © 2010 Elsevier Masson SAS. All rights reserved.

The effect of inertia, viscous damping, temperature and normal stress on chaotic behaviour of the rate and state friction model

NASA Astrophysics Data System (ADS)

Sinha, Nitish; Singh, Arun K.; Singh, Trilok N.

2018-04-01

A fundamental understanding of frictional sliding at rock surfaces is of practical importance for nucleation and propagation of earthquakes and rock slope stability. We investigate numerically the effect of different physical parameters such as inertia, viscous damping, temperature and normal stress on the chaotic behaviour of the two state variables rate and state friction (2sRSF) model. In general, a slight variation in any of inertia, viscous damping, temperature and effective normal stress reduces the chaotic behaviour of the sliding system. However, the present study has shown the appearance of chaos for the specific values of normal stress before it disappears again as the normal stress varies further. It is also observed that magnitude of system stiffness at which chaotic motion occurs, is less than the corresponding value of critical stiffness determined by using the linear stability analysis. These results explain the practical observation why chaotic nucleation of an earthquake is a rare phenomenon as reported in literature.