Serotonergic mediation of the effects of fluoxetine, but not desipramine, in the rat forced swimming test.

PubMed

Page, M E; Detke, M J; Dalvi, A; Kirby, L G; Lucki, I

1999-11-01

The forced swimming test (FST) is a behavioral test in rodents that predicts the clinical efficacy of many types of antidepressant treatments. Recently, a behavior sampling technique was developed that scores individual response categories, including swimming, climbing and immobility. Although all antidepressant drugs reduce immobility in the FST, at least two distinct active behavioral patterns are produced by pharmacologically selective antidepressant drugs. Serotonin-selective reuptake inhibitors increase swimming behavior, while drugs acting primarily to increase extracellular levels of norepinephrine or dopamine increase climbing behavior. Distinct patterns of active behaviors in the FST may be mediated by distinct neurotransmitters, but this has not been shown directly. The present study examined the role of serotonin in mediating active behaviors in the forced swimming test after treatment with two antidepressant drugs, the selective serotonin reuptake inhibitor, fluoxetine and the selective norepinephrine reuptake inhibitor, desipramine. Endogenous serotonin was depleted by administering para-cholorophenylalanine (PCPA, 150 mg/kg, IP.) to rats 72 h and 48 h prior to the swim test. Fluoxetine (10 mg/kg, SC) or desipramine (10 mg/kg, SC) was given three times over a 24-h period prior to the FST. Behavioral responses, including immobility, swimming and climbing, were counted during the 5-min test. Pretreatment with PCPA blocked fluoxetine-induced reduction in immobility and increase in swimming behavior during the FST. In contrast, PCPA pretreatment did not interfere with the ability of desipramine to reduce immobility and increase climbing behavior. Depletion of serotonin prevented the behavioral effects of the selective serotonin reuptake inhibitor fluoxetine in the rat FST. Furthermore, depletion of serotonin had no impact on the behavioral effects induced by the selective norepinephrine reuptake inhibitor, desipramine. The effects of antidepressant drugs

Tipepidine, a non-narcotic antitussive, exerts an antidepressant-like effect in the forced swimming test in adrenocorticotropic hormone-treated rats.

PubMed

Kawaura, Kazuaki; Ogata, Yukino; Honda, Sokichi; Soeda, Fumio; Shirasaki, Tetsuya; Takahama, Kazuo

2016-04-01

We investigated whether tipepidine exerts an antidepressant-like effect in the forced swimming test in adrenocorticotropic hormone (ACTH)-treated rats, which is known as a treatment-resistant depression model, and we studied the pharmacological mechanisms of the effects of tipepidine. Male Wistar rats (5-7 weeks old) were used in this study. Tipepidine (20 and 40 mg/kg, i.p.) decreased the immobility time in the forced swimming test in ACTH-treated rats. The anti-immobility effect of tipepidine was blocked by a catecholamine-depleting agent, alpha-methyl-p-tyrosine (300 mg/kg, s.c.), but not by a serotonin-depleting agent, p-chlorophenylalanine. The anti-immobility effect of tipepidine was also blocked by a dopamine D1 receptor antagonist, SCH23390 (0.02 mg/kg, s.c.) and an adrenaline α2 receptor antagonist, yohimbine (2 mg/kg, i.p.). In microdialysis technique, tipepidine (40 mg/kg, i.p.) increased the extracellular dopamine level of the nucleus accumbens (NAc) in ACTH-treated rats. These results suggest that tipepidine exerts an antidepressant-like effect in the forced swimming test in ACTH-treated rats, and that the effect of tipepidine is mediated by the stimulation of dopamine D1 receptors and adrenaline α2 receptors. The results also suggest that an increase in the extracellular dopamine level in the NAc may be involved in the antidepressant-like effect of tipepidine in ACTH-treated rats. Copyright © 2016. Published by Elsevier B.V.

Effect of ginsenoside Rg3 on tyrosine hydroxylase and related mechanisms in the forced swimming-induced fatigue rats.

PubMed

Xu, Yuxia; Zhang, Peng; Wang, Chu; Shan, Ye; Wang, Dandan; Qian, Fenglei; Sun, Mengwei; Zhu, Cuiqing

2013-10-28

Ginsenoside Rg3 has shown multiple pharmacological activities and been considered as one of the most promising approaches for fatigue treatment. However, little is known about the cellular and molecular mechanisms of Rg3 on anti-fatigue and the effect of Rg3 on dopaminergic system has not been reported yet. The major aim of this study is to investigate the effect of Rg3 on TH expression and the related biochemical parameters, such as PKAα, ERK1/2, Akt and α-synuclein in brain of fatigue rats. Weight-loaded forced swimming was performed to establish an animal model of fatigue. Rg3 (10mg/kg, 50mg/kg and 100mg/kg) was intragastrically administrated before swimming. The effect of Rg3 on the expression and phosphorylation of TH and TH-related proteins in fatigue rats or in SH-SY5Y cells was assessed with western blotting. HPLC was used to examine the level of DA and DOPAC in the fatigue rats tissues. TH and phosphorylated TH were decreased in different brain regions of which ventral midbrain were less affected in weight-loaded forced swimming rats. Pretreatment with Rg3 significantly suppressed fatigue-induced decrease expression of TH and TH phosphorylation. Also treatment with Rg3 reversed the decrease expression of PKAα as well as the phosphorylation of ERK1/2 and Akt which were induced by weight-loaded forced swimming. Moreover, weight-loaded swimming could induce the increase expression of α-synuclein in hippocampus and midbrain, while suppressed α-synuclein expression in striatum and prefrontal cortex. Furthermore, Rg3 could induce the increase of TH expression and phosphorylation which was accompanied with elevated expression and phosphorylation of related kinase proteins in vitro, while the inhibitors of kinase proteins could suppress these effects of Rg3. In addition, HPLC results showed that Rg3 could reverse the weight-loaded swimming-induced increase of DOPAC/DA ratio. Our data suggest that fatigue can induce the decrease of DA which might partially

Impact of melatonin supplementation in the rat spermatogenesis subjected to forced swimming exercise.

PubMed

Moayeri, A; Mokhtari, T; Hedayatpour, A; Abbaszadeh, H-A; Mohammadpour, S; Ramezanikhah, H; Shokri, S

2018-04-01

Oxygen consumption increases many times during exercise, which can increase reactive oxygen species. It negatively affects fertility in male athletes. Melatonin is exerting a regulatory role at different levels of the hypothalamic-pituitary-gonadal axis. However, there is no evidence that the protective effects of melatonin persist after long duration exercise on the spermatogenesis. Therefore, this study was conducted to examine the impacts of melatonin on the testis following the administration of swimming exercise. Rats were separated into five different groups, including Control, sham M: received the solvent of melatonin, M: received melatonin, S: the exercise protocol, MS: received melatonin and the exercise protocol. After 8 weeks, animals were scarified and antioxidant enzymes levels of testes, spermatogenic cells apoptosis and sperm quality were measured. Swimming decreased all parameters of spermatozoa. Nevertheless, melatonin could significantly improve the progressive motility of spermatozoa in MS rats. Swimming caused an increased apoptosis of S group and decreased all antioxidant enzymes. Melatonin could drastically reduce apoptosis and increased these enzymes. Therefore, melatonin seems to induce the production of antioxidant enzymes of testicular tissues and diminish the extent of apoptotic changes caused by forced exercise on the testis, which can, in turn, ameliorate the sperm parameters. © 2017 Blackwell Verlag GmbH.

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.

Repeated rat-forced swim test: reducing the number of animals to evaluate gradual effects of antidepressants.

PubMed

Mezadri, T J; Batista, G M; Portes, A C; Marino-Neto, J; Lino-de-Oliveira, C

2011-02-15

The forced swim test (FST) is a pre-clinical test to short and long term treatment with antidepressant drugs (ADT), which requires between-subject designs. Herein a modified protocol of the FST using within-subject design (repeated rat-FST) was evaluated. Male Wistar rats were submitted to 15 min of swimming (Day 1: pretest) followed by three subsequent 5 min-swimming tests one week apart (Day 2: test, Day 7: retest 1, Day 14: retest 2). To determine the temporal and factorial characteristics of the variables scored in the repeated rat-FST, the protocol was carried out in untreated animals (E1). To validate the method, daily injections of Fluoxetine (FLX, 2.5mg/kg, i.p.) or saline were given over a 2-week period (E2). Tests and retests have been videotaped for further register of the latency, frequency and duration of behaviors. Over retesting the latency to immobility decreased whereas duration of immobility tended to increase. Factorial analysis revealed that the test, the retest 1 as well as the retest 2 have variables suitable to detection of antidepressant-like effects of ADT. Compared to saline, FLX chronically administrated reduced duration of immobility whereas increased duration of swimming in retest 2. The data suggest that repeated rat-FST detected the gradual increase in the efficacy of low doses of FLX over time. Therefore, repeated rat-FST seemed suitable to detect short and long term effects of selective serotonin reuptake inhibitors, or other ADT, thus reducing the number of animals used in the screenings of this type of compounds. © 2010 Elsevier B.V. All rights reserved.

Ontogeny and adolescent alcohol exposure in Wistar rats: open field conflict, light/dark box and forced swim test

PubMed Central

Desikan, Anita; Wills, Derek N.; Ehlers, Cindy L.

2014-01-01

Epidemiological studies have demonstrated that heavy drinking and alcohol abuse and dependence peak during the transition between late adolescence and early adulthood. Studies in animal models have demonstrated that alcohol exposure during adolescence can cause a modification in some aspects of behavioral development, causing the “adolescent phenotype” to be retained into adulthood. However, the “adolescent phenotype” has not been studied for a number of behavioral tests. The objective of the present study was to investigate the ontogeny of behaviors over adolescence/young adulthood in the light/dark box, open field conflict and forced swim test in male Wistar rats. These data were compared to previously published data from rats that received intermittent alcohol vapor exposure during adolescence (AIE) to test whether they retained the “adolescent phenotype” in these behavioral tests. Three age groups of rats were tested (post-natal day (PD) 34–42; PD55-63; PD69-77). In the light/dark box test, younger rats escaped the light box faster than older adults, whereas AIE rats returned to the light box faster and exhibited more rears in the light than controls. In the open field conflict test, both younger and AIE rats had shorter times to first enter the center, spent more time in the center of the field, were closer to the food, and consumed more food than controls. In the forced swim test no clear developmental pattern emerged. The results of the light/dark box and the forced swim test do not support the hypothesis that adolescent ethanol vapor exposure can “lock-in” all adolescent phenotypes. However, data from the open field conflict test suggest that the adolescent and the AIE rats both engaged in more “disinhibited” and food motivated behaviors. These data suggest that, in some behavioral tests, AIE may result in a similar form of behavioral disinhibition to what is seen in adolescence. PMID:24785000

Ontogeny and adolescent alcohol exposure in Wistar rats: open field conflict, light/dark box and forced swim test.

PubMed

Desikan, Anita; Wills, Derek N; Ehlers, Cindy L

2014-07-01

Epidemiological studies have demonstrated that heavy drinking and alcohol abuse and dependence peak during the transition between late adolescence and early adulthood. Studies in animal models have demonstrated that alcohol exposure during adolescence can cause a modification in some aspects of behavioral development, causing the "adolescent phenotype" to be retained into adulthood. However, the "adolescent phenotype" has not been studied for a number of behavioral tests. The objective of the present study was to investigate the ontogeny of behaviors over adolescence/young adulthood in the light/dark box, open field conflict and forced swim test in male Wistar rats. These data were compared to previously published data from rats that received intermittent alcohol vapor exposure during adolescence (AIE) to test whether they retained the "adolescent phenotype" in these behavioral tests. Three age groups of rats were tested (post-natal day (PD) 34-42; PD55-63; PD69-77). In the light/dark box test, younger rats escaped the light box faster than older adults, whereas AIE rats returned to the light box faster and exhibited more rears in the light than controls. In the open field conflict test, both younger and AIE rats had shorter times to first enter the center, spent more time in the center of the field, were closer to the food, and consumed more food than controls. In the forced swim test no clear developmental pattern emerged. The results of the light/dark box and the forced swim test do not support the hypothesis that adolescent ethanol vapor exposure can "lock-in" all adolescent phenotypes. However, data from the open field conflict test suggest that the adolescent and the AIE rats both engaged in more "disinhibited" and food motivated behaviors. These data suggest that, in some behavioral tests, AIE may result in a similar form of behavioral disinhibition to what is seen in adolescence. Copyright © 2014. Published by Elsevier Inc.

Estrogen alters behavior and forebrain c-fos expression in ovariectomized rats subjected to the forced swim test

PubMed Central

Rachman, Ilya M.; Unnerstall, James R.; Pfaff, Donald W.; Cohen, Rochelle S.

1998-01-01

Estrogen has been implicated in brain functions related to affective state, including hormone-related affective disorders in women. Although some reports suggest that estrogen appears to decrease vulnerability to affective disorders in certain cases, the mechanisms involved are unknown. We used the forced swim test (FST), a paradigm used to test the efficacy of antidepressants, and addressed the hypotheses that estrogen alters behavior of ovariectomized rats in the FST and the FST-induced expression of c-fos, a marker for neuronal activity, in the rat forebrain. The behaviors displayed included struggling, swimming, and immobility. One hour after the beginning of the test on day 2, the animals were perfused, and the brains were processed for c-fos immunocytochemistry. On day 1, the estradiol benzoate-treated animals spent significantly less time struggling and virtually no time in immobility and spent most of the time swimming. Control rats spent significantly more time struggling or being immobile during a comparable period. On day 2, similar behavioral patterns with still more pronounced differences were observed between estradiol benzoate and ovariectomized control groups in struggling, immobility, and swimming. Analysis of the mean number of c-fos immunoreactive cell nuclei showed a significant reduction in the estradiol benzoate versus control groups in areas of the forebrain relating to sensory, contextual, and integrative processing. Our results suggest that estrogen-induced neurochemical changes in forebrain neurons may translate into an altered behavioral output in the affective domain. PMID:9811905

[Influence of estradiol on tryptophan hydroxylase and 5-hydroxytryptamine content in raphe nuclei of rats under forced swimming stress].

PubMed

Yang, Fu-zhong; Wu, Yan; Zhang, Wei-guo; Cai, Yi-yun; Shi, Shen-xun

2010-07-20

To investigate the effect of estradiol (E2) on tryptophan hydroxylase (TPH) and 5-hydroxytryptamine (5-HT) content in raphe nuclei of rats under forced swimming stress and explore the role of estrogen and stress in disease mechanism of depression in women. At Week 3 post-ovariectomy, 35 ovariectomized (OVX) female SD rats were randomly divided into 5 groups (n = 7): non-stress group, control group, estradiol (E2) group and fluoxetine (FLX) group and E2 plus FLX group. Animals were administered with different drugs for 2 weeks. At Day 14, animals except those in the non-stress group were subjected to the 15 min forced swimming test (FST). At 2 hours post-FST, all animals including those in the non-stress group were perfused with 4% paraformaldehyde and brains removed for TPH and 5-HT immunofluorescence staining. We compared the content of TPH and 5-HT by observing and calculating the integrated optical density (IOD) of immunofluorescent-positive signals in raphe nuclei. (1) The IOD value of TPH- and 5-HT-positive region in raphe nuclei of rats in the control group was significantly lower than that of the non-stress group (P < 0.01); (2) the IOD value of TPH- and 5-HT-positive region in raphe nuclei of rats in the E2, FLX and E2 plus FLX groups was significantly higher than that in the control group (P < 0.05). Forced swimming stress can decrease the TPH and 5-HT content in raphe nuclei. Such changes can be prevented by a pre-administration of estradiol. Similar results are observed with antidepressant fluoxetine. These effects may underlie the role of estradiol and stress in the disease mechanism of depression in women.

Differential Rearing Alters Forced Swim Test Behavior, Fluoxetine Efficacy, and Post-Test Weight Gain in Male Rats.

PubMed

Arndt, David L; Peterson, Christy J; Cain, Mary E

2015-01-01

Environmental factors play a key role in the etiology of depression. The rodent forced swim test (FST) is commonly used as a preclinical model of depression, with increases in escape-directed behavior reflecting antidepressant effects, and increases in immobility reflecting behavioral despair. Environmental enrichment leads to serotonergic alterations in rats, but it is unknown whether these alterations may influence the efficacy of common antidepressants. Male Sprague-Dawley rats were reared in enriched (EC), standard (SC), or isolated (IC) conditions. Following the rearing period, fluoxetine (10 or 20 mg/kg, i.p.) was administered 23.5 hrs, 5 hrs, and 1 hr before locomotor and FST measures. Following locomotor testing and FST exposure, rats were weighed to assess fluoxetine-, FST-, and environmental condition-induced moderations in weight gain. Results revealed an antidepressant effect of environmental enrichment and a depressant effect of isolation. Regardless of significant fluoxetine effects on locomotor activity, fluoxetine generally decreased swimming and increased immobility in all three environmental conditions, with IC-fluoxetine (10 mg/kg) rats and EC-fluoxetine (20 mg/kg) rats swimming less than vehicle counterparts. Subchronic 20 mg/kg fluoxetine also induced significant weight loss, and differential rearing appeared to moderate weight gain following FST stress. These results suggest that differential rearing has the ability to alter FST behaviors, fluoxetine efficacy, and post-stressor well-being. Moreover, 20 mg/kg fluoxetine, administered subchronically, may lead to atypical effects of those commonly observed in the FST, highlighting the importance and impact of both environmental condition and dosing regimen in common animal models of depression.

Differential Rearing Alters Forced Swim Test Behavior, Fluoxetine Efficacy, and Post-Test Weight Gain in Male Rats

PubMed Central

Arndt, David L.; Peterson, Christy J.; Cain, Mary E.

2015-01-01

Environmental factors play a key role in the etiology of depression. The rodent forced swim test (FST) is commonly used as a preclinical model of depression, with increases in escape-directed behavior reflecting antidepressant effects, and increases in immobility reflecting behavioral despair. Environmental enrichment leads to serotonergic alterations in rats, but it is unknown whether these alterations may influence the efficacy of common antidepressants. Male Sprague-Dawley rats were reared in enriched (EC), standard (SC), or isolated (IC) conditions. Following the rearing period, fluoxetine (10 or 20 mg/kg, i.p.) was administered 23.5 hrs, 5 hrs, and 1 hr before locomotor and FST measures. Following locomotor testing and FST exposure, rats were weighed to assess fluoxetine-, FST-, and environmental condition-induced moderations in weight gain. Results revealed an antidepressant effect of environmental enrichment and a depressant effect of isolation. Regardless of significant fluoxetine effects on locomotor activity, fluoxetine generally decreased swimming and increased immobility in all three environmental conditions, with IC-fluoxetine (10 mg/kg) rats and EC-fluoxetine (20 mg/kg) rats swimming less than vehicle counterparts. Subchronic 20 mg/kg fluoxetine also induced significant weight loss, and differential rearing appeared to moderate weight gain following FST stress. These results suggest that differential rearing has the ability to alter FST behaviors, fluoxetine efficacy, and post-stressor well-being. Moreover, 20 mg/kg fluoxetine, administered subchronically, may lead to atypical effects of those commonly observed in the FST, highlighting the importance and impact of both environmental condition and dosing regimen in common animal models of depression. PMID:26154768

Mechanism of synergistic action following co-treatment with pramipexole and fluoxetine or sertraline in the forced swimming test in rats.

PubMed

Rogóz, Zofia; Skuza, Grazyna

2006-01-01

The aim of the present study was to examine the effect of combined treatment of male Wistar rats with pramipexole and fluoxetine or sertraline in the forced swimming test. The obtained results showed that co-treatment with pramipexole (0.1 mg/kg) and fluoxetine (10 mg/kg) or sertraline (5 mg/kg) (in doses inactive per se) exhibited antidepressant-like activity in the forced swimming test. Sulpiride (a dopamine D(2/3) receptor antagonist) and WAY 100635 (a 5-HT(1A) receptor antagonist), either being ineffective in the forced swimming test, inhibited the antidepressant-like effect induced by co-administration of pramipexole and fluoxetine or sertraline. However, SCH 23390 (a dopamine D(1) receptor antagonist) only partly did not alter the effect of pramipexole given jointly with antidepressant drugs; on the other hand, S 33084 (a dopamine D(3) receptor antagonist) only partly decreased (in a statistically insignificant manner) that effect. Moreover, progesterone and BD 1047 (a sigma(1) receptor antagonist) counteracted the antidepressant-like effect induced by co-administration of pramipexole and sertraline (but not pramipexole and fluoxetine). In that test, active behavior did not reflect the increases in general activity, since combined administration of pramipexole and fluoxetine or sertraline failed to enhance the locomotor activity of rats. None of the tested drugs (SCH 23390, sulpiride, S 33084, WAY 100635, BD 1047 and progesterone) - alone or in combination with pramipexole and fluoxetine or sertraline - changed locomotor activity. The results described in the present paper indicate that co-administration of pramipexole and fluoxetine or sertraline may induce a more pronounced antidepressive activity than does treatment with pramipexole alone, and that in addition to other mechanisms, dopamine D(2/3) and 5-HT(1A) receptors may contribute to the antidepressant-like activity of pramipexole and fluoxetine or sertraline in the forced swimming test in rats

Acute reversible inactivation of the bed nucleus of stria terminalis induces antidepressant-like effect in the rat forced swimming test

PubMed Central

2010-01-01

Background The bed nucleus of stria terminalis (BNST) is a limbic forebrain structure involved in hypothalamo-pituitary-adrenal axis regulation and stress adaptation. Inappropriate adaptation to stress is thought to compromise the organism's coping mechanisms, which have been implicated in the neurobiology of depression. However, the studies aimed at investigating BNST involvement in depression pathophysiology have yielded contradictory results. Therefore, the objective of the present study was to investigate the effects of temporary acute inactivation of synaptic transmission in the BNST by local microinjection of cobalt chloride (CoCl2) in rats subjected to the forced swimming test (FST). Methods Rats implanted with cannulae aimed at the BNST were submitted to 15 min of forced swimming (pretest). Twenty-four hours later immobility time was registered in a new 5 min forced swimming session (test). Independent groups of rats received bilateral microinjections of CoCl2 (1 mM/100 nL) before or immediately after pretest or before the test session. Additional groups received the same treatment and were submitted to the open field test to control for unspecific effects on locomotor behavior. Results CoCl2 injection into the BNST before either the pretest or test sessions reduced immobility in the FST, suggesting an antidepressant-like effect. No significant effect of CoCl2 was observed when it was injected into the BNST immediately after pretest. In addition, no effect of BNST inactivation was observed in the open field test. Conclusion These results suggest that acute reversible inactivation of synaptic transmission in the BNST facilitates adaptation to stress and induces antidepressant-like effects. PMID:20515458

Swimming-Induced Taste Aversion and Its Prevention by a Prior History of Swimming

ERIC Educational Resources Information Center

Masaki, Takahisa; Nakajima, Sadahiko

2004-01-01

In two experiments, the evidence showed that 20 min of forced swimming by rats caused aversion to a taste solution consumed before swimming. When one of two taste solutions (sodium saccharin or sodium chloride, counterbalanced across rats) was paired with swimming and the other was not, the rats' intakes of these two solutions showed less…

Further evidence for conditioned taste aversion induced by forced swimming.

PubMed

Masaki, Takahisa; Nakajima, Sadahiko

2005-01-31

A series of experiments with rats reported that aversion to a taste solution can be established by forced swimming in a water pool. Experiment 1 demonstrated that correlation of taste and swimming is a critical factor for this phenomenon, indicating associative (i.e., Pavlovian) nature of this learning. Experiment 2 showed that this learning obeys the Pavlovian law of strength, by displaying a positive relationship between the duration of water immersion in training and the taste aversion observed in subsequent testing. Experiment 3 revealed that swimming rather than being wet is the critical agent, because a water shower did not endow rats with taste aversion. Experiment 4 found that taste aversion was a positive function of water level of the pools in training (0, 12 or 32 cm). These results, taken together, suggest that energy expenditure caused by physical exercise might be involved in the development of taste aversion.

The antidepressant-like effects of topiramate alone or combined with 17β-estradiol in ovariectomized Wistar rats submitted to the forced swimming test.

PubMed

Molina-Hernández, Miguel; Téllez-Alcántara, N Patricia; Olivera-López, Jorge I; Jaramillo, M Teresa

2014-09-01

There is a significant delay in the clinical response of antidepressant drugs, and antidepressant treatments produce side effects. We examined the relationship between 17β-estradiol and topiramate in ovariectomized Wistar rats submitted to the forced swimming test (FST). Topiramate was administered alone or combined with 17β-estradiol to ovariectomized rats submitted to the FST. Topiramate (20 mg/kg, P < 0.05; 30 mg/kg, P < 0.05) reduced immobility by increasing swimming; these effects were antagonized by finasteride (50 mg/kg). In interaction experiments, topiramate (10 mg/kg) plus 17β-estradiol (5 micrograms per rat; P < 0.05) reduced immobility by increasing swimming behavior. Besides, 17β-estradiol (2.5 micrograms per rat) shortened the onset of the antidepressant-like effects of topiramate (P < 0.05). In the open field test, topiramate alone or combined with 17β-estradiol (P < 0.05) reduced locomotion. Topiramate alone or combined with 17β-estradiol produced antidepressant-like actions; and 17β-estradiol shortened the onset of the antidepressant-like effects of topiramate.

The effects of central pro-and anti-inflammatory immune challenges on depressive-like behavior induced by chronic forced swim stress in rats.

PubMed

Pan, Yuqin; Lin, Wenjuan; Wang, Weiwen; Qi, Xiaoli; Wang, Donglin; Tang, Mingming

2013-06-15

Although increasing evidence demonstrates that both chronic stressors and inflammatory immune activation contribute to pathophysiology and behavioral alterations associated with major depression, little is known about the interaction effect of central inflammatory immune activation and stress on depressive-like behavior. Our previous work has shown that 14-day chronic forced swim stress induces significant depressive-like behavior. The present investigation assessed whether pro-inflammatory cytokine and anti-inflammatory cytokine challenges have differential interaction effect on depressive-like behavior induced by chronic forced swim stress in rats. The pro-inflammatory and anti-inflammatory immune challenges were achieved respectively by central administration of lipopolysaccharide (LPS), a pro-inflammatory cytokine inducer, and interleukin-10 (IL-10), an anti-inflammatory cytokine. It was found that either central LPS treatment alone or chronic forced swim stress alone significantly induced depressive-like behavior, including reduced body weight gain, reduced saccharin preference and reduced locomotor activity. However, there was no significant synergistic or additive effect of central LPS treatment and stress on depressive-like behavior. LPS treatment did not exacerbate the depressive-like behavior induced by forced swim stress. Nevertheless, IL-10 reversed depressive-like behavior induced by forced swim stress, a finding indicating that IL-10 has antidepressant effect on behavioral depression induced by stress. The present findings provide new insight into the complexity of the immunity-inflammation hypothesis of depression. Copyright © 2013 Elsevier B.V. All rights reserved.

Effect of prenatal forced-swim stress and morphine co-administration on pentylentetrazol-induced epileptic behaviors in infant and prepubertal rats.

PubMed

Ebrahimi, Loghman; Saboory, Ehsan; Roshan-Milani, Shiva; Hashemi, Paria

2014-09-01

Prenatal exposure to stress and morphine has complicated effects on epileptic seizure. Many reports have shown an interaction between morphine- and stress-induced behavioral changes in adult rats. In the present study, effect of prenatal forced-swim stress and morphine co-administration on pentylentetrazole (PTZ)-induced epileptic behaviors was investigated in rat offspring to address effect of the interaction between morphine and stress. Pregnant rats were divided to four groups of control-saline, control-morphine, stressed-saline and stressed-morphine. In the stressed group, the rats were placed in 25 °C water on 17-19 days of pregnancy. In the morphine/saline group, the rats received morphine/saline on the same days. In the morphine/saline-stressed group, they were exposed to stress and received morphine/saline simultaneously. On postnatal day 15 (P15), blood samples were collected to determine corticosterone (COS) level. On P15 and P25, PTZ was injected to the rest of pups to induce seizure. Then, epileptic behaviors of each rat were individually observed. Latency of tonic-colonic seizures decreased in control-morphine and stressed-saline groups while increasing in stressed-morphine rats compared to control-saline group on P15. Duration of tonic-colonic seizures significantly increased in control-morphine and stressed-saline rats compared to stressed-morphine and control-saline rats on P15, but not P25. COS levels increased in stressed-saline group but decreased in control-morphine group compared to control-saline rats. Body weight was significantly higher in morphine groups than saline treated rats. Prenatal exposure to forced-swim stress potentiated PTZ-induced seizure in the offspring rats. Co-administration of morphine attenuated effect of stress on body weight, COS levels, and epileptic behaviors. © 2014 Wiley Periodicals, Inc.

Effects of co-administration of fluoxetine or tianeptine with metyrapone on immobility time and plasma corticosterone concentration in rats subjected to the forced swim test.

PubMed

Rogóz, Zofia; Skuza, Grazyna; Leśkiewicz, Monika; Budziszewska, Bogusława

2008-01-01

Major depression is frequently associated with hyperactivity of the hypothalamic-pituitary-adrenocortical axis, and glucocorticoid synthesis inhibitors have been shown to exert antidepressant action. The aim of the present study was to examine the effect of co-administration of fluoxetine or tianeptine with metyrapone on immobility time and plasma corticosterone concentration in male Wistar rats subjected to the forced swim test. Metyrapone alone (50 mg/kg, but not 25 mg/kg) reduced the immobility time of rats in the forced swim test; moreover, both doses tested (25 and 50 mg/kg), dose-dependently decreased the stress-induced plasma corticosterone concentration. Joint administration of fluoxetine or tianeptine (10 mg/kg) and metyrapone (25 mg/kg - a dose inactive per se) exhibited antidepressant-like activity in the forced swim test in rats. WAY 100636 (a 5-HT(1A) antagonist), but not prazosin (an alpha(1)-adrenergic antagonist), used in doses ineffective in the forced swim test, inhibited the antidepressant-like effect induced by co-administration of fluoxetine or tianeptine with metyrapone (25 mg/kg). Combined treatment of fluoxetine or tianeptine and metyrapone inhibited stress-induced corticosterone secretion to a similar extent as metyrapone alone. The obtained results indicate that metyrapone potentiates the antidepressant-like activity of fluoxetine or tianeptine and that, among other mechanisms, 5-HT(1A) receptors may play some role in this effect. Moreover, metyrapone exerts a beneficial effect on the stress-induced increase in plasma corticosterone concentration. These findings suggest that the co-administration of metyrapone and an antidepressant drug may be useful for the treatment of drug-resistant depression and/or depression associated with a high cortisol level.

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.

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.

Influence of enrichment on behavioral and neurogenic effects of antidepressants in Wistar rats submitted to repeated forced swim test.

PubMed

Possamai, Fernanda; dos Santos, Juliano; Walber, Thais; Marcon, Juliana C; dos Santos, Tiago Souza; Lino de Oliveira, Cilene

2015-04-03

Repeated forced swimming test (rFST) may detect gradual effects of antidepressants in adult rats. Antidepressants, as enrichment, affected behavior and neurogenesis in rats. However, the influence of enrichment on behavioral and neurogenic effects of antidepressants is unknown. Here, effects of antidepressants on rFST and hippocampal neurogenesis were investigated in rats under enriched conditions. Behaviors of male Wistar rats, housed from weaning in standard (SE) or enriched environment (EE), were registered during rFST. The rFST consisted of 15min of swimming (pretest) followed by 5min of swimming in the first (test), seventh (retest 1) and fourteenth (retest 2) days after pretest. One hour before the test, rats received an intraperitoneal injection of saline (1ml/kg), fluoxetine (2.5mg/kg) or imipramine (2.5 or 5mg/kg). These treatments were performed daily until the day of the retest 2. After retest 2, rats were euthanized for the identification of markers for neurogenesis in the hippocampus. Fluoxetine or imipramine decreased immobility in retests 1 and 2, as compared to saline. EE abolished these differences. In EE, fluoxetine or imipramine (5mg/kg) reduced immobility time in retest 2, as compared to the test. Independent of the housing conditions, fluoxetine and imipramine (5mg/kg) increased the ratio of immature neurons per progenitor cell in the hippocampus. In summary, antidepressants or enrichment counteracted the high immobility in rFST. Enrichment changed the effects of antidepressants in rFST depending on the type, and the dose of a substance but failed to change neurogenesis in control or antidepressant treated-rats. Effects of antidepressants and enrichment on rFST seemed neurogenesis-independent. Copyright © 2014 Elsevier Inc. All rights reserved.

Gastrodia elata Bl. Attenuated learning deficits induced by forced-swimming stress in the inhibitory avoidance task and Morris water maze.

PubMed

Chen, Pei-Ju; Liang, Keng-Chen; Lin, Hui-Chen; Hsieh, Ching-Liang; Su, Kuan-Pin; Hung, Mei-Chu; Sheen, Lee-Yan

2011-06-01

This study adopted the forced-swimming paradigm to induce depressive symptoms in rats and evaluated the effects on learning and memory processing. Furthermore, the effects of the water extract of Gastrodia elata Bl., a well-known Chinese traditional medicine, on amnesia in rats subjected to the forced-swimming procedure were studied. Rats were subjected to the forced-swimming procedure, and the inhibitory avoidance task and Morris water maze were used to assess learning and memory performance. The acquisition of the two tasks was mostly impaired after the 15-minute forced-swimming procedure. Administration of the water extract of G. elata Bl. for 21 consecutive days at a dosage of 0.5 or 1.0 g/kg of body weight significantly improved retention in the inhibitory avoidance test, and the lower dose showed a better effect than the higher one and the antidepressant fluoxetine (18 mg/kg of body weight). In the Morris water maze, the lower dose of the water extract of G. elata Bl. significantly improved retention by shortening escape latency in the first test session and increasing the time in searching the target zone during the probe test. These findings suggest that water extracts of G. elata Bl. ameliorate the learning and memory deficits induced by forced swimming.

Repeated exposure to corticosterone increases depression-like behavior in two different versions of the forced swim test without altering nonspecific locomotor activity or muscle strength.

PubMed

Marks, Wendie; Fournier, Neil M; Kalynchuk, Lisa E

2009-08-04

We have recently shown that repeated high dose injections of corticosterone (CORT) reliably increase depression-like behavior on a modified one-day version of the forced swim test. The main purpose of this experiment was to compare the effect of these CORT injections on our one-day version of the forced swim test and the more traditional two-day version of the test. A second purpose was to determine whether altered behavior in the forced swim test could be due to nonspecific changes in locomotor activity or muscle strength. Separate groups of rats received a high dose CORT injection (40 mg/kg) or a vehicle injection once per day for 21 consecutive days. Then, half the rats from each group were exposed to the traditional two-day forced swim test and the other half were exposed to our one-day forced swim test. After the forced swim testing, all the rats were tested in an open field and in a wire suspension grip strength test. The CORT injections significantly increased the time spent immobile and decreased the time spent swimming in both versions of the forced swim test. However, they had no significant effect on activity in the open field or grip strength in the wire suspension test. These results show that repeated CORT injections increase depression-like behavior regardless of the specific parameters of forced swim testing, and that these effects are independent of changes in locomotor activity or muscle strength.

The folic acid combined with 17-β estradiol produces antidepressant-like actions in ovariectomized rats forced to swim.

PubMed

Molina-Hernández, Miguel; Téllez-Alcántara, N Patricia; Olivera-López, Jorge I; Jaramillo, M Teresa

2011-01-15

Folic acid or 17-β estradiol produces antidepressant effects, either alone or combined with several antidepressants. However, the antidepressant-like actions of folic acid combined with 17-β estradiol in the forced swimming test (FST) have not been tested before. Thus, in the present study, ovariectomized female rats received folic acid (5.0 nmol/i.c.v., P<0.05; 10.0 nmol/ i.c.v., P<0.05; or 50mg/kg, P<0.05, p.o.; 75.0; mg/kg, P<0.05, p.o.), or fluoxetine (20.0mg/kg, P<0.05; 25.0mg/kg, P<0.05) or 17-β estradiol (10.0 μg/rat, P<0.05; 20.0 μg/rat, P<0.05) and they displayed reduced immobility by increasing swimming behavior when they were tested in the FST. Combination of subthreshold doses of folic acid (2.5 nmol/i.c.v.; or 25.0mg/kg, p.o.) with subthreshold doses of 17-β estradiol (5.0 μg/rat, P<0.05) or with subthreshold doses of fluoxetine (15.0mg/kg, P<0.05) produced antidepressant-like actions. Ketanserin was used to evaluate the participation of the drugs used in the serotonergic pathway; ketanserin cancelled the antidepressant-like actions of the several combinations used. In conclusion, folic acid alone or combined with estradiol or fluoxetine in the FST reduced immobility in the FST. These antidepressant-like actions probably were due to modifications of the serotonergic system since swimming behavior was increased and these effects were cancelled by ketanserin. Copyright © 2010 Elsevier Inc. All rights reserved.

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.

Effect of co-administration of fluoxetine and amantadine on immunoendocrine parameters in rats subjected to a forced swimming test.

PubMed

Rogóz, Zofia; Kubera, Marta; Rogóz, Katarzyna; Basta-Kaim, Agnieszka; Budziszewska, Bogusława

2009-01-01

Considerable attention has been paid to a possible role of immunological dysregulation in the pathogenesis of depression. It has been reported that combined administration of antidepressant drugs and the non-competitive NMDA receptor antagonist amantadine reduces immobility time in the forced swimming test (FST). Moreover, preliminary clinical data show that such a combination of drugs has a beneficial effect on treatment-resistant depressed patients. Since immune activation and a pro-inflammatory response are clearly evident in treatment-resistant depression, the aim of the present study was to examine the effect of a combination of the antidepressant fluoxetine and amantadine on immunoendocrine parameters in rats subjected to the forced swimming test. The obtained results revealed synergistic antidepressant effects of the combined administration of fluoxetine (10 mg/kg) and amantadine (10 mg/kg) - drugs otherwise ineffective when given separately in the above doses. Antidepressant activity was accompanied with a significant decrease in the capacity of splenocytes to proliferate in response to concanavalin A. Moerover, fluoxetine and the combination of amantadine and fluoxetine reduced relative spleen weight in rats subjected to the FST, compared to rats treated with the vehicle. The combination of amantadine and fluoxetine enhanced the production of the negative immunoregulator interleukin-10 (but not interferon-gamma) in rats subjected to the FST. The exposure to the FST produced an increase in plasma corticosterone levels, which was significantly attenuated by pretreatment with fluoxetine and amantadine. In summary, the antidepressive efficacy of a combination of fluoxetine and amantadine given in suboptimal doses may be related to the negative immunoendocrine effects of these drugs.

Prophylactic effects of swimming exercise on autophagy-induced muscle atrophy in diabetic rats

PubMed Central

Lee, Youngjeon; Kim, Joo-Heon; Hong, Yunkyung; Lee, Sang-Rae; Chang, Kyu-Tae

2012-01-01

Diabetes decreases skeletal muscle mass and induces atrophy. However, the mechanisms by which hyperglycemia and insulin deficiency modify muscle mass are not well defined. In this study, we evaluated the effects of swimming exercise on muscle mass and intracellular protein degradation in diabetic rats, and proposed that autophagy inhibition induced by swimming exercise serves as a hypercatabolic mechanism in the skeletal muscles of diabetic rats, supporting a notion that swimming exercise could efficiently reverse the reduced skeletal muscle mass caused by diabetes. Adult male Sprague-Dawley rats were injected intraperitoneally with streptozotocin (60 mg/kg body weight) to induce diabetes and then submitted to 1 hr per day of forced swimming exercise, 5 days per week for 4 weeks. We conducted an intraperitoneal glucose tolerance test on the animals and measured body weight, skeletal muscle mass, and protein degradation and examined the level of autophagy in the isolated extensor digitorum longus, plantaris, and soleus muscles. Body weight and muscle tissue mass were higher in the exercising diabetic rats than in control diabetic rats that remained sedentary. Compared to control rats, exercising diabetic rats had lower blood glucose levels, increased intracellular contractile protein expression, and decreased autophagic protein expression. We conclude that swimming exercise improves muscle mass in diabetes-induced skeletal muscle atrophy, suggesting the activation of autophagy in diabetes contributes to muscle atrophy through hypercatabolic metabolism and that aerobic exercise, by suppressing autophagy, may modify or reverse skeletal muscle wasting in diabetic patients. PMID:23091517

Noradrenergic neurotransmission within the bed nucleus of the stria terminalis modulates the retention of immobility in the rat forced swimming test.

PubMed

Nagai, Michelly M; Gomes, Felipe V; Crestani, Carlos C; Resstel, Leonardo B M; Joca, Sâmia R L

2013-06-01

The bed nucleus of the stria terminalis (BNST) is a limbic structure that has a direct influence on the autonomic, neuroendocrine, and behavioral responses to stress. It was recently reported that reversible inactivation of synaptic transmission within this structure causes antidepressant-like effects, indicating that activation of the BNST during stressful situations would facilitate the development of behavioral changes related to the neurobiology of depression. Moreover, noradrenergic neurotransmission is abundant in the BNST and has an important role in the regulation of emotional processes related to the stress response. Thus, this study aimed to test the hypothesis that activation of adrenoceptors within the BNST facilitates the development of behavioral consequences of stress. To investigate this hypothesis, male Wistar rats were stressed (forced swimming, 15 min) and 24 h later received intra-BNST injections of vehicle, WB4101, RX821002, CGP20712, or ICI118,551, which are selective α(1), α(2), β(1), and β(2) adrenoceptor antagonists, respectively, 10 min before a 5-min forced swimming test. It was observed that administration of WB4101 (10 and 15 nmol), CGP20712 (5 and 10 nmol), or ICI118,551 (5 nmol) into the BNST reduced the immobility time of rats subjected to forced swimming test, indicating an antidepressant-like effect. These findings suggest that activation of α(1), β(1), and β(2) adrenoceptors in the BNST could be involved in the development of the behavioral consequences of stress. © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins.

Individual differences in the elevated plus-maze and the forced swim test.

PubMed

Estanislau, Celio; Ramos, Anna Carolina; Ferraresi, Paula Daniele; Costa, Naiara Fernanda; de Carvalho, Heloisa Maria Cotta Pires; Batistela, Silmara

2011-01-01

The elevated plus-maze is an apparatus composed of enclosed and open (elevated) arms and time spent in the open arms by a rat can be increased/decreased by anxiolytic/anxiogenic agents. In the forced swim test, floating behavior is used as an index of behavioral despair and can be decreased by antidepressant agents. As the comorbidity between anxiety and depression is a remarkable issue in human behavioral disorders, a possible relationship between the behaviors seen in the cited tests is of great relevance. In the present study, fifty-four male rats (Rattus norvegicus) were submitted to a plus-maze session and to a 2-day forced swim protocol. According to their time in the open arms, they were divided into three groups: Low Open, Medium Open and High Open. Some plus-maze measures were found to be coherent with time in the open arms and are suggested to also be reliable anxiety indexes. In the forced swim test, the Low Open group showed decreases in floating duration from forced swim Session 1 to Session 2, an alteration opposite to that observed in the other groups (particularly, the Medium Open group). The Low Open group also showed increases in floating latency, again in sharp contrast with the alteration found in the other groups. Accordingly, positive and negative correlation were found between time in the open arms and floating duration and latency, respectively. Results are compared to previous studies and mediation of the effect by reactivity to aversive stimulation or alterations induced by open arm exposure is discussed. Copyright © 2010 Elsevier B.V. All rights reserved.

Effects of forced swimming stress on thyroid function, pituitary thyroid-stimulating hormone and hypothalamus thyrotropin releasing hormone expression in adrenalectomy Wistar rats.

PubMed

Sun, Qiuyan; Liu, Aihua; Ma, Yanan; Wang, Anyi; Guo, Xinhong; Teng, Weiping; Jiang, Yaqiu

2016-11-01

In order to study the impact that is imposed on the hypothalamic-pituitary-thyroid (HPT) axis of adrenalectomy male Wistar rats by stress caused by swimming, the blood level of triiodothyronine (T3), thyroxine (T4) and thyroid-stimulating hormone (TSH), the expression of TSHβ mRNA at the pituitary and thyrotropin releasing hormone (TRH) expression at the paraventricular nucleus (PVN) were measured. A total of 50 male Wistar rats of 6-8 weeks of age and with an average weight of 190-210 grams were randomly divided into the following two groups: The surgical (without adrenal glands) and non-surgical (adrenalectomy) group. These two groups were then divided into the following five groups, according to the time delay of sacrifice following forced swim (10 min, 2 h, 12 h and 24 h) and control (not subjected to swimming) groups. A bilateral adrenalectomy animal model was established. Serum TSH in the blood was measurement by chemiluminescent immunoassay, and cerebrum tissue were excised for the measurement of TRH expression using an immunohistochemistry assay. In addition, pituitaries were excised for the extraction of total RNA. Finally, reverse transcription-quantitative polymerase chain reaction was performed for quantitation of TSHβ. Following swimming, the serum T3, T4 and TSH, the TSHβ mRNA expression levels in the pituitary and the TRH expression in the PVN of the surgical group were gradually increased. In the non-surgical group, no significant differences were observed in the serum T3, T4 and TSH levels compared with the control group. The TSHβ mRNA expression at the pituitary showed a similar result. Furthermore, the TRH expression at PVN was gradually increased and stress from swimming could increase the blood T4, T3 and TSH levels, TSHβ mRNA expression at the pituitary and TRH expression at the PVN in adrenalectomy Wistar rats. Moreover, the index in the surgical group changed significantly compared with the non-surgical group. In conclusion, the results

A medicinal herb, Melissa officinalis L. ameliorates depressive-like behavior of rats in the forced swimming test via regulating the serotonergic neurotransmitter.

PubMed

Lin, Shih-Hang; Chou, Mei-Ling; Chen, Wei-Cheng; Lai, Yi-Syuan; Lu, Kuan-Hung; Hao, Cherng-Wei; Sheen, Lee-Yan

2015-12-04

Depression is a serious psychological disorder that causes extreme economic loss and social problems. However, the conventional medications typically cause side effects that result in patients opting to out of therapy. Lemon balm (Melissa officinalis L., MO) is an old and particularly reliable medicinal herb for relieving feelings of melancholy, depression and anxiety. The present study aims to investigate the antidepressant-like activity of water extract of MO (WMO) by evaluating its influence on the behaviors and the relevant neurotransmitters of rats performed to forced swimming test. Two phases of the experiment were conducted. In the acute model, rats were administered ultrapure water (control), fluoxetine, WMO, or the indicated active compound (rosmarinic acid, RA) three times in one day. In the sub-acute model, rats were respectively administered ultrapure water (control), fluoxetine, or three dosages of WMO once a day for 10 days. Locomotor activity and depression-like behavior were examined using the open field test and the forced swimming test, respectively. The levels of relevant neurotransmitters and their metabolites in the frontal cortex, amygdala, hippocampus, and striatum were analyzed by high performance liquid chromatography. In the acute model, WMO and RA significantly reduced depressive-like behavior but the type of related neurotransmitter could not be determined. The results indicated that the effect of WMO administration on the reduction of immobility time was associated with an increase in swimming time of the rats, indicative of serotonergic neurotransmission modulation. Chromatography data validated that the activity of WMO was associated with a reduction in the serotonin turnover rate. The present study shows the serotonergic antidepressant-like activity of WMO. Hence, WMO may offer a serotonergic antidepressant activity to prevent depression and to assist in conventional therapies. Copyright © 2015. Published by Elsevier Ireland Ltd.

The Mouse Forced Swim Test

PubMed Central

Can, Adem; Dao, David T.; Arad, Michal; Terrillion, Chantelle E.; Piantadosi, Sean C.; Gould, Todd D.

2012-01-01

The forced swim test is a rodent behavioral test used for evaluation of antidepressant drugs, antidepressant efficacy of new compounds, and experimental manipulations that are aimed at rendering or preventing depressive-like states. Mice are placed in an inescapable transparent tank that is filled with water and their escape related mobility behavior is measured. The forced swim test is straightforward to conduct reliably and it requires minimal specialized equipment. Successful implementation of the forced swim test requires adherence to certain procedural details and minimization of unwarranted stress to the mice. In the protocol description and the accompanying video, we explain how to conduct the mouse version of this test with emphasis on potential pitfalls that may be detrimental to interpretation of results and how to avoid them. Additionally, we explain how the behaviors manifested in the test are assessed. PMID:22314943

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

Effects of combined administration of 5-HT1A and/or 5-HT1B receptor antagonists and paroxetine or fluoxetine in the forced swimming test in rats.

PubMed

Tatarczyńska, Ewa; Kłodzińska, Aleksandra; Chojnacka-Wójcik, Ewa

2002-01-01

Clinical data suggest that coadministration of pindolol, a 5-HT1A/5-HT1B/beta-adrenoceptor antagonist, and selective serotonin reuptake inhibitors (SSRIs) may shorten the time of onset of a clinical action and may increase beneficial effects of the therapy of drug-resistant depression. Effects of combined administration of SSRIs and 5-HT receptor ligands are currently evaluated in animal models for the detection of an antidepressant-like activity; however, the obtained results turned out to be inconsistent. The aim of the present study was to investigate effects of a 5-HT1A antagonist (WAY 100635), 5-HT1B antagonists (SB 216641 and GR 127935) or pindolol, given in combination with paroxetine or fluoxetine (SSRIs), in the forced swimming test in rats (Porsolt test). When given alone, paroxetine (10 and 20 mg/kg), fluoxetine (10 and 20 mg/kg), WAY 100635 (0.1 and 1 mg/kg), SB 216641 (2 mg/kg), GR 127935 (10 and 20 mg/kg) and pindolol (4 and 8 mg/kg) did not shorten the immobility time of rats in that test. Interestingly, SB 216641 administered alone at a dose of 4 mg/kg produced a significant reduction of the immobility time in that test. A combination of paroxetine (20 mg/kg) and WAY 100635 or pindolol failed to reveal a significant interaction; on the other hand, when paroxetine was given jointly with SB 216641 (2 mg/kg) or GR 127935 (10 and 20 mg/kg), that combination showed a significant antiimmobility action in the forced swimming test in rats. The active behaviors in that test did not reflect increased general activity because combined administration of both the 5-HT1B antagonists and paroxetine failed to alter the locomotor activity of rats, measured in the open field test. Coadministration of fluoxetine and all the antagonists used did not affect the behavior of rats in the forced swimming test. The obtained results seem to indicate that blockade of 5-HT1B receptors, but not 5-HT1A ones, can facilitate the antidepressant-like effect of paroxetine in the

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

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.

Effect of dielectrophoretic force on swimming bacteria.

PubMed

Tran, Ngoc Phu; Marcos

2015-07-01

Dielectrophoresis (DEP) has been applied widely in bacterial manipulation such as separating, concentrating, and focusing. Previous studies primarily focused on the collective effects of DEP force on the bacterial population. However, the influence of DEP force on the swimming of a single bacterium had not been investigated. In this study, we present a model to analyze the effect of DEP force on a swimming helically flagellated bacterium, particularly on its swimming direction and velocity. We consider a simple DEP force that acts along the X-direction, and its strength as well as direction varies with the X- and Y-positions. Resistive force theory is employed to compute the hydrodynamic force on the bacterium's flagellar bundle, and the effects of both DEP force and rotational diffusion on the swimming of the bacterium are simultaneously taken into consideration using the Fokker-Planck equation. We show the mechanism of how DEP force alters the orientation and velocity of the bacterium. In most cases, the DEP force dominantly influences the orientation of the swimming bacterium; however, when the DEP force strongly varies along the Y-direction, the rotational diffusion is also responsible for determining the bacterium's reorientation. More interestingly, the variance of DEP force along the Y-direction causes the bacterium to experience a translational velocity perpendicular to its primary axis, and this phenomenon could be utilized to focus the bacteria. Finally, we show the feasibility of applying our findings to achieve bacterial focusing. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Anti-anxiety activity of successive extracts of Angelica archangelica Linn. on the elevated T-maze and forced swimming tests in rats.

PubMed

Kumar, Dinesh; Bhat, Zulfiqar Ali; Shah, M Y

2012-09-01

Angelica archangelica Linn. is widely used in food and liquor preparations and also in Kashmiri folk medicine to reduce anxiety. We evaluated the anxiolytic effect of successive extracts of A. archangelica linn. (SAE) on rats tested in the elevated T-maze test (an animal model of generalized anxiety) at doses that exhibit antidepressant-like activity in humans. A. archangelica (1 kg) was subjected to successive extraction in a soxhlet apparatus with solvents [petroleum ether (40-60 degrees C), chloroform, ethyl acetate, methanol and decoction with water] in order of increasing polarity (yield: 6.9%, 7.3%, 5.1%, 11.88% and 8.2% w/w, respectively). SAE were evaluated for anxiolytic effects using the elevated T-maze and forced swimming tests in rats. Oral dosing of diazepam (1 mg/kg) and extracts (50, 100 and 200 mg/kg) clearly showed an anxiolytic-like profile in the elevated T-maze test: it increased one-way escape and decreased inhibitory avoidance on the first, third and seventh day. In the forced swimming test, imipramine and SAE showed antidepressant- and anxiolytic-like effects as reflected by increased climbing time, swimming time and decreased immobility time on the first, third and seventh day. Aqueous and methanol extracts showed the most, petroleum ether (40-60 degrees C) and chloroform intermediate, and ethyl acetate the least anxiolytic activity (*P<0.05, **P<0.01, ***P< 0.001) in both models. These results suggest the anti-anxiety activity of various extracts of A. archangelica and strongly justify its use in traditional Indian medicine for the treatment of anxiety.

Individual differences in the forced swimming test and neurochemical kinetics in the rat brain.

PubMed

Sequeira-Cordero, Andrey; Mora-Gallegos, Andrea; Cuenca-Berger, Patricia; Fornaguera-Trías, Jaime

2014-04-10

Individual differences in the forced swimming test (FST) could be associated with differential temporal dynamics of gene expression and neurotransmitter activity. We tested juvenile male rats in the FST and classified the animals into those with low and high immobility according to the amount of immobility time recorded in FST. These groups and a control group which did not undergo the FST were sacrificed either 1, 6 or 24 h after the test. We analyzed the expression of the CRF, CRFR1, BDNF and TrkB in the prefrontal cortex, hippocampus and nucleus accumbens as well as norepinephrine, dopamine, serotonin, glutamate, GABA and glutamine in the hippocampus and nucleus accumbens. Animals with low immobility showed significant reductions of BDNF expression across time points in both the prefrontal cortex and the nucleus accumbens when compared with non-swim control. Moreover, rats with high immobility only showed a significant decrease of BDNF expression in the prefrontal cortex 6h after the FST. Regarding neurotransmitters, only accumbal dopamine turnover and hippocampal glutamate content showed an effect of individual differences (i.e. animals with low and high immobility), whereas nearly all parameters showed significant differences across time points. Correlational analyses suggest that immobility in the FST, probably reflecting despair, is related to prefrontal cortical BDNF and to the kinetics observed in several other neurochemical parameters. Taken together, our results suggest that individual differences observed in depression-like behavior can be associated not only with changes in the concentrations of key neurochemical factors but also with differential time courses of such factors. Copyright © 2014 Elsevier Inc. All rights reserved.

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.

Pharmacological enhancement of cannabinoid CB1 receptor activity elicits an antidepressant-like response in the rat forced swim test.

PubMed

Hill, Matthew N; Gorzalka, Boris B

2005-12-01

These experiments aimed to assess whether enhanced activity at the cannabinoid CB1 receptor elicits antidepressant-like effects. To examine this we administered 1 and 5 mg/kg doses of the endocannabinoid uptake inhibitor AM404; 5 and 25 microg/kg doses of HU-210, a potent CB1 receptor agonist; 1, 2.5 and 5 mg/kg of oleamide, which elicits cannabinoidergic actions; 1 and 5 mg/kg doses of AM 251, a selective CB1 receptor antagonist, as well as 10 mg/kg desipramine (a positive antidepressant control) and measured the duration of immobility, during a 5-min test session of the rat Porsolt forced swim test. Results demonstrated that administration of desipramine reduced immobility duration by about 50% and that all of AM404, oleamide and HU-210 administration induced comparable decreases in immobility that were blocked by pretreatment with AM 251. Administration of the antagonist AM 251 alone had no effect on immobility at either dose. These data suggest that enhancement of CB1 receptor signaling results in antidepressant effects in the forced swim test similar to that seen following conventional antidepressant administration.

Oxidative stress parameters in diabetic rats submitted to forced swimming test: the clonazepam effect.

PubMed

da Silva Haeser, Alexsandro; Sitta, Angela; Barschak, Alethéa Gatto; Deon, Marion; Barden, Amanda Thomas; Schmitt, Graziela Oliveira; Landgraff, Sharon; Gomez, Rosane; Barros, Helena M T; Vargas, Carmen Regla

2007-06-18

Diabetes-associated depression may occur due to changes in the quality of life imposed by treatment, or may be a consequence of the biochemical changes accompanying the disease. We evaluated the oxidative stress from diabetic animals submitted to an experimental model of depression and the effects of clonazepam. Male Wistar rats were induced to diabetes with streptozotocin and submitted to forced swimming test. Clonazepam was administered 24, 5 and 1 h before test. The animals were sacrificed by decapitation, and plasma and erythrocytes were separated, as well as hippocampus, cortex and striatum. Reactive species of thiobarbituric acid (TBARS) and total antioxidant reactivity (TAR) as well as antioxidant enzyme activities catalase (CAT) and superoxide dismutase (SOD) were evaluated. Results showed a significant increase of TBARS and a significant decrease of TAR in plasma from diabetic animals, which was altered by clonazepam. There were no effects of CAT and SOD activities in erythrocytes from tested animals. The results observed in hippocampus showed a significant increase of TBARS from diabetic rats, altered by clonazepam, and no one alteration was verified in TAR. The significant increase of TBARS and the significant decrease of TAR in cortex from diabetic rats were not altered by clonazepam administration. There were no alterations of TBARS and TAR in striatum from tested animals. Besides, clonazepam reverses the immobility in diabetic rats. Considering the action of clonazepam, it is suggested that it could be an alternative therapeutic for depression to diabetic patients, once it could give a protection against free radicals.

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…

Stimulation of the metabotropic glutamate (mGlu) 2 receptor attenuates the MK-801-induced increase in the immobility time in the forced swimming test in rats.

PubMed

Kawaura, Kazuaki; Karasawa, Jun-Ichi; Hikichi, Hirohiko

2016-02-01

Negative symptoms of schizophrenia are poorly managed using the currently available antipsychotics. Previous studies indicate that agonists of the metabotropic glutamate (mGlu) 2/3 receptors may provide a novel approach for the treatment of schizophrenia. However, the effects of mGlu2/3 receptor agonists or mGlu2 receptor positive allosteric modulators have not yet been clearly elucidated in animal models of the negative symptoms of schizophrenia. Recently, we reported that the forced swimming test in rats treated with subchronic MK-801, an NMDA receptor antagonist, may be regarded as a useful test to evaluate the activities of drugs against the negative symptoms of schizophrenia. We evaluated the effects of LY379268, an mGlu2/3 receptor agonist, and BINA, an mGlu2 receptor positive allosteric modulator, on the hyperlocomotion induced by acute administration of MK-801 (0.15mg/kg, sc) and on the increase in the immobility time in the forced swimming test induced by subchronic treatment with MK-801 (0.5mg/kg, sc, twice a day for 7 days) in rats. Both LY379268 (3mg/kg, sc) and BINA (100mg/kg, ip) attenuated the increase in the immobility time induced by subchronic treatment with MK-801 at the same doses at which they attenuated the MK-801-induced increase in locomotor activity, but had no effect on the immobility time in saline-treated rats. The present results suggest that stimulation of the mGlu2 receptor attenuates the increase in the immobility time in the forced swimming test elicited by subchronic administration of MK-801, and may be potentially useful for treatment of the negative symptoms of schizophrenia. Copyright © 2015 Institute of Pharmacology, Polish Academy of Sciences. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

Brain cholinergic alterations in rats subjected to repeated immobilization or forced swim stress on lambda-cyhalothrin exposure.

PubMed

Shukla, Rajendra K; Gupta, Richa; Srivastava, Pranay; Dhuriya, Yogesh K; Singh, Anshuman; Chandravanshi, Lalit P; Kumar, Ajay; Siddiqui, M Haris; Parmar, Devendra; Pant, Aditya B; Khanna, Vinay K

2016-02-01

Role of immobilization stress (IMS), a psychological stressor and forced swim stress (FSS), a physical stressor was investigated on the neurobehavioral toxicity of lambda-cyhalothrin (LCT), a new generation type-II synthetic pyrethroid. Pre-exposure of rats to IMS (15 min/day) or FSS (3 min/day) for 28 days on LCT (3.0 mg/kg body weight, p.o.) treatment for 3 days resulted to decrease spatial learning and memory and muscle strength associated with cholinergic-muscarinic receptors in frontal cortex and hippocampus as compared to those exposed to IMS or FSS or LCT alone. Decrease in acetylcholinesterase activity, protein expression of ChAT and PKC-β1 associated with decreased mRNA expression of CHRM2, AChE and ChAT in frontal cortex and hippocampus was also evident in rats pre-exposed to IMS or FSS on LCT treatment, compared to rats exposed to IMS or FSS or LCT alone. Interestingly, changes both in behavioral and neurochemical endpoints were marginal in rats subjected to IMS or FSS for 28 days or those exposed to LCT for 3 days alone, compared to controls. The results suggest that stress is an important contributor in LCT induced cholinergic deficits. Copyright © 2016 Elsevier Ltd. All rights reserved.

Reduced effectiveness of escitalopram in the forced swimming test is associated with increased serotonin clearance rate in food restricted rats

PubMed Central

France, CP; Li, J-X; Owens, WA; Koek, W; Toney, GM; Daws, LC

2012-01-01

Efficacy of antidepressant drugs is often limited. One of the limiting factors may be diet. This study shows that the effect of escitalopram in the forced swimming test is diminished in rats by food restriction that decreased body weight by 8%. The primary target for escitalopram is the serotonin (5-HT) transporter. Using high-speed chronoamperometry to measure 5-HT clearance in vivo in rats fed the same food restricted diet, the rate of 5-HT clearance from extracellular fluid in brain was dramatically increased. Increased 5-HT transporter function under conditions of dietary restriction might contribute to the decreased effect of escitalopram. These results suggest that diet plays an integral role in determining efficacy of antidepressant drugs, and might well generalize to other psychoactive drugs that impinge upon the 5-HT transporter. PMID:19419596

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.

Effect of long-term intraperitoneal zinc administration on liver glycogen levels in diabetic rats subjected to acute forced swimming.

PubMed

Bicer, Mursel; Gunay, Mehmet; Akil, Mustafa; Avunduk, Mustafa Cihat; Mogulkoc, Rasim; Baltaci, Abdulkerim Kasim

2011-03-01

This study aims to examine the effect of zinc administration on liver glycogen levels of rats in which diabetes was induced with streptozotocin and which were subjected to acute swimming exercise. The study was conducted on 80 adult Sprague-Dawley male rats, which were equally allocated to eight groups: group 1, general control; group 2, zinc-administrated control; group 3, zinc-administrated diabetic control; group 4, swimming control; group 5, zinc-administrated swimming; group 6, zinc-administrated diabetic swimming; group 7, diabetic swimming; group 8, diabetic control group. In order to induce diabetes, animals were injected with 40 mg/kg intraperitoneal (ip) streptozotocin. The injections were repeated in the same dose after 24 h. Animals which had blood glucose at or above 300 mg/dl 6 days after the last injections were accepted as diabetic. Zinc was administrated ip for 4 weeks as 6 mg/kg/day per rat. Hepatic tissue samples taken from the animals at the end of the study were fixed in 95% ethyl alcohol. Cross sections of 5 µm thickness, taken by the help of a microtome from the tissue samples buried in paraffin, were placed on a microscope slide and stained with periodic acid-Schiff and evaluated by light microscope. All microscopic images were transferred to a PC and assessed with the help of Clemex PE3.5 image analysis software. The lowest liver glycogen levels in the study were obtained in groups 3, 4, 6, 7, and 8. Liver glycogen levels in group 5 were higher than groups 3, 4, 6, 7, and 8, but lower than groups 1 and 2 (p < 0.05). Groups 1 and 2 had the highest liver glycogen levels. The results obtained from the study indicate that liver glycogen levels which dropped in acute swimming exercise were restored by zinc administration and that diabetes induced in rats prevented the protective effect of zinc.

Melatonin improve the sperm quality in forced swimming test induced oxidative stress in nandrolone treated Wistar rats.

PubMed

Minaii, Bagher; Moayeri, Ardeshir; Shokri, Saeed; Habibi Roudkenar, Mehryar; Golmohammadi, Taghi; Malek, Fatemeh; Barbarestani, Mohammad

2014-01-01

This study investigates the effects of melatonin on the sperm quality and testis weight after the combination of swimming exercise and nandrolone decanoate (DECA). Two groups of male Wistar rats were treated for eight weeks as follows; group A consist of CO (control), Sham, N (DECA), S (swimming) and NS (DECA plus swimming); and group B: Sham M (sham melatonin), M (melatonin), MN (melatonin plus DECA), MS (melatonin plus swimming), MNS (melatonin, DECA plus swimming). The motility of sperm was significantly improved in melatonin groups in comparison to N, S and NS groups (P≤0.05).  The left testes weight was decreased in N, NS and MNS groups, and the right testes weight was decreased in N,S,NS, MS and MNS groups in compare with the control group. This study concluded that melatonin probably could improve the sperm motility and sex organs weight after the combination of DECA and exercise.

Conditioned taste avoidance induced by forced and voluntary wheel running in rats.

PubMed

Forristall, J R; Hookey, B L; Grant, V L

2007-03-01

Voluntary exercise by rats running in a freely rotating wheel (free wheel) produces conditioned taste avoidance (CTA) of a flavored solution consumed before running [e.g., Lett, B.T., Grant, V.L., 1996. Wheel running induces conditioned taste aversion in rats trained while hungry and thirsty. Physiol. Behav. 59, 699-702]. Forced exercise, swimming or running, also produces CTA in rats [e.g., Masaki, T., Nakajima, S., 2006. Taste aversion induced by forced swimming, voluntary running, forced running, and lithium chloride injection treatments. Physiol. Behav. 88, 411-416]. Energy expenditure may be the critical factor in producing such CTA. If so, forced running in a motorized running wheel should produce CTA equivalent to that produced by a similar amount of voluntary running. In two experiments, we compared forced running in a motorized wheel with voluntary running in a free wheel. Mean distance run over 30 min was equated as closely as possible in the two apparatuses. Both types of exercise produced CTA relative to sedentary, locked-wheel controls. However, voluntary running produced greater CTA than forced running. We consider differences between running in the free and motorized wheels that may account for the differences in strength of CTA.

Orally administered whole egg demonstrates antidepressant-like effects in the forced swimming test on rats.

PubMed

Nagasawa, Mao; Otsuka, Tsuyoshi; Ogino, Yumi; Yoshida, Junki; Tomonaga, Shozo; Yasuo, Shinobu; Furuse, Mitsuhiro

2014-08-01

Several studies have reported that vegetarian diets are associated with a higher prevalence of major depression. Therefore, we hypothesised that the consumption of animal products, especially eggs, may have positive effects on mental health, especially on major depression, because a previous study reported that egg consumption produces numerous beneficial effects in humans. The purpose of the present study was to evaluate the effects of chronic whole-egg treatment on depression-like behaviours in Wistar rats, a control strain, and Wistar Kyoto rats, an animal model of depression. In both the rats, either whole-egg solution (5 ml/kg) or distilled water (5 ml/kg) was orally administrated for 35 days. During these periods, the open-field test (OFT) was conducted on the 21st day, and a forced swimming test (FST) was enforced on the 27th and 28th days. On the 36th day, the plasma and brain were collected. Chronic whole-egg treatment did not affect line crossing in the OFT, whereas it reduced the total duration of immobility in the FST on both strains. Furthermore, interestingly, the results indicated the possibility that whole-egg treatment elevated the incorporation of tryptophan into the brain, and the tryptophan concentration in the prefrontal cortex was actually increased by the treatment. This study demonstrated that whole-egg treatment exerts an antidepressant-like effect in the FST. It is suggested that whole egg may be an excellent food for preventing and alleviating the conditions of major depression.

Effect of intraperitoneal selenium administration on liver glycogen levels in rats subjected to acute forced swimming.

PubMed

Akil, Mustafa; Bicer, Mursel; Kilic, Mehmet; Avunduk, Mustafa Cihat; Mogulkoc, Rasim; Baltaci, Abdulkerim Kasim

2011-03-01

There are a few of studies examining how selenium, which is known to reduce oxidative damage in exercise, influences glucose metabolism and exhaustion in physical activity. The present study aims to examine how selenium administration affects liver glycogen levels in rats subjected to acute swimming exercise. The study included 32 Sprague-Dawley type male rats, which were equally allocated to four groups: Group 1, general control; Group 2; selenium-supplemented control (6 mg/kg/day sodium selenite); Group 3, swimming control; Group 4, selenium-supplemented swimming (6 mg/kg/day sodium selenite). Liver tissue samples collected from the animals at the end of the study were fixed in 95% ethyl alcohol. From the tissue samples buried into paraffin, 5-µm cross-sections were obtained using a microtome, put on a microscope slide, and stained with PAS. Stained preparations were assessed using a Nikon Eclipse E400 light microscope. All images obtained with the light microscope were transferred to a PC and evaluated using Clemex PE 3.5 image analysis software. The highest liver glycogen levels were found in groups 1 and 2 (p < 0.05). The levels in group 4 were lower than those in groups 1 and 2 but higher than the levels in group 3 (p < 0.05). The lowest liver glycogen levels were obtained in group 3 (p < 0.05). Results of the study indicate that liver glycogen levels that decrease in acute swimming exercise can be restored by selenium administration. It can be argued that physiological doses of selenium administration can contribute to performance.

A forced damped oscillation framework for undulatory swimming provides new insights into how propulsion arises in active and passive swimming.

PubMed

Bhalla, Amneet Pal Singh; Griffith, Boyce E; Patankar, Neelesh A

2013-01-01

A fundamental issue in locomotion is to understand how muscle forcing produces apparently complex deformation kinematics leading to movement of animals like undulatory swimmers. The question of whether complicated muscle forcing is required to create the observed deformation kinematics is central to the understanding of how animals control movement. In this work, a forced damped oscillation framework is applied to a chain-link model for undulatory swimming to understand how forcing leads to deformation and movement. A unified understanding of swimming, caused by muscle contractions ("active" swimming) or by forces imparted by the surrounding fluid ("passive" swimming), is obtained. We show that the forcing triggers the first few deformation modes of the body, which in turn cause the translational motion. We show that relatively simple forcing patterns can trigger seemingly complex deformation kinematics that lead to movement. For given muscle activation, the forcing frequency relative to the natural frequency of the damped oscillator is important for the emergent deformation characteristics of the body. The proposed approach also leads to a qualitative understanding of optimal deformation kinematics for fast swimming. These results, based on a chain-link model of swimming, are confirmed by fully resolved computational fluid dynamics (CFD) simulations. Prior results from the literature on the optimal value of stiffness for maximum speed are explained.

The Relationship Between Propulsive Force in Tethered Swimming and 200-m Front Crawl Performance.

PubMed

Santos, Karini B; Bento, Paulo C B; Pereira, Gleber; Rodacki, André L F

2016-09-01

Santos, KB, Bento, PCB, Pereira, G, and Rodacki, ALF. The relationship between propulsive force in tethered swimming and 200-m front crawl performance. J Strength Cond Res 30(9): 2500-2507, 2016-The aims of this study were to determine whether propulsive force (peak force, mean force, impulse, and rate of force development) and stroke rate change during 2 minutes of front crawl tethered swimming and to correlate them with the stroke rate and swimming velocity in 200-m front crawl swimming. Twenty-one swimmers (21.6 ± 4.8 years, 1.78 ± 0.06 m, 71.7 ± 8.1 kg), with 200-m front crawl swimming performance equivalent to 78% of the world record (140.4 ± 10.1 seconds), were assessed during 2 minutes of maximal front crawl tethered swimming (propulsive forces and stroke rate) and 200-m front crawl swimming (stroke rate and clean velocity). Propulsive forces decreased between the beginning and the middle instants (∼20%; p ≤ 0.05) but remained stable between the middle and the end instants (∼6%; p > 0.05). The peak force was positively correlated with the clean velocity in the 200-m front crawl swimming (mean r = 0.61; p < 0.02). The stroke rates of the tethered swimming and 200-m front crawl swimming were positively correlated (r = 45; p≤ 0.01) at the middle instant. Therefore, the propulsive force and stroke rate changed throughout the 2 minutes of tethered swimming, and the peak force is the best propulsive force variable tested that correlated with 200-m front crawl swimming performance.

Effects of a glycine transporter-1 inhibitor and D-serine on MK-801-induced immobility in the forced swimming test in rats.

PubMed

Kawaura, Kazuaki; Koike, Hiroyuki; Kinoshita, Kohnosuke; Kambe, Daiji; Kaku, Ayaka; Karasawa, Jun-ichi; Chaki, Shigeyuki; Hikichi, Hirohiko

2015-02-01

Glutamatergic dysfunction, particularly the hypofunction of N-methyl-D-aspartate (NMDA) receptors, is involved in the pathophysiology of schizophrenia. The positive modulation of the glycine site on the NMDA receptor has been proposed as a novel therapeutic approach for schizophrenia. However, its efficacy against negative symptoms, which are poorly managed by current medications, has not been fully addressed. In the present study, the effects of the positive modulation of the glycine site on the NMDA receptor were investigated in an animal model of negative symptoms of schizophrenia. The subchronic administration of MK-801 increased immobility in the forced swimming test in rats without affecting spontaneous locomotor activity. The increased immobility induced by MK-801 was attenuated by the atypical antipsychotic clozapine but not by either the typical antipsychotic haloperidol or the antidepressant imipramine, indicating that the increased immobility induced by subchronic treatment with MK-801 in the forced swimming test may represent a negative symptom of schizophrenia. Likewise, positive modulation of the glycine sites on the NMDA receptor using an agonist for the glycine site, D-serine, and a glycine transporter-1 inhibitor, N-[(3R)-3-([1,1'-biphenyl]-4-yloxy)-3-(4-fluorophenyl)propyl]-N-methylglycine hydrochloride (NFPS), significantly reversed the increase in immobility in MK-801-treated rats without reducing the immobility time in vehicle-treated rats. The present results show that the stimulation of the NMDA receptor through the glycine site on the receptor either directly with D-serine or by blocking glycine transporter-1 attenuates the immobility elicited by the subchronic administration of MK-801 and may be potentially useful for the treatment of negative symptoms of schizophrenia. Copyright © 2014 Elsevier B.V. All rights reserved.

Sex and age differences in the impact of the forced swimming test on the levels of steroid hormones.

PubMed

Martínez-Mota, Lucía; Ulloa, Rosa-Elena; Herrera-Pérez, Jaime; Chavira, Roberto; Fernández-Guasti, Alonso

2011-10-24

Compared with the adult disorder, depression in children exhibits differences in its neurobiology, particularly in the HPA axis regulation. The bases of such differences can be evaluated in animal models of depression. The objective of the present study was to determine age and sex differences of Wistar rats in the forced swimming test (FST). The influence of sex and age on corticosterone, estrogens and testosterone serum levels was also determined. Prepubertal rats showed immobility, swimming and climbing behaviors during the pre-test and test sessions. In addition, in the prepubertal animals, no sex differences were found during the pre-test and test sessions. Age comparisons indicated no differences in the female groups, however adult males exhibited more immobility and less swimming than young males, in both FST sessions. The young and female rats showed less immobility behavior and increased levels of estrogens after the FST. The present results indicate that the FST is an animal model suitable to evaluate depressive-like behaviors in prepubertal subjects and to explore behavioral changes related to neurodevelopment. Copyright © 2011 Elsevier Inc. All rights reserved.

Fluoxetine increases the activity of the ERK-CREB signal system and alleviates the depressive-like behavior in rats exposed to chronic forced swim stress.

PubMed

Qi, Xiaoli; Lin, Wenjuan; Li, Junfa; Li, Huanhuan; Wang, Weiwen; Wang, Donglin; Sun, Meng

2008-08-01

Our previous research indicates that the extracellular signal-regulated kinase (ERK)-cyclic AMP-responsive-element-binding protein (CREB) signal system may be involved in the molecular mechanism of depression. The present study further investigated the effect of antidepressant fluoxetine on the ERK-CREB signal system and the depressive-like behaviors in rats. Fluoxetine was administrated to either naive rats or stressed rats for 21 days. The results showed that chronic forced swim stress induced depressive-like behaviors and decreased the levels of P-ERK2, P-CREB, ERK1/2 and CREB in hippocampus and prefrontal cortex. Fluoxetine alleviated the depressive-like behaviors and reversed the disruptions of the P-ERK2 and P-CREB in stressed rats. Fluoxetine also exerted mood-elevating effect and increased the levels of the P-ERK2 and P-CREB in naive rats. These results suggest that the ERK-CREB signal system may be the targets of the antidepressant action of fluoxetine and participate in the neuronal mechanism of depression.

A Forced Damped Oscillation Framework for Undulatory Swimming Provides New Insights into How Propulsion Arises in Active and Passive Swimming

PubMed Central

Bhalla, Amneet Pal Singh; Griffith, Boyce E.; Patankar, Neelesh A.

2013-01-01

A fundamental issue in locomotion is to understand how muscle forcing produces apparently complex deformation kinematics leading to movement of animals like undulatory swimmers. The question of whether complicated muscle forcing is required to create the observed deformation kinematics is central to the understanding of how animals control movement. In this work, a forced damped oscillation framework is applied to a chain-link model for undulatory swimming to understand how forcing leads to deformation and movement. A unified understanding of swimming, caused by muscle contractions (“active” swimming) or by forces imparted by the surrounding fluid (“passive” swimming), is obtained. We show that the forcing triggers the first few deformation modes of the body, which in turn cause the translational motion. We show that relatively simple forcing patterns can trigger seemingly complex deformation kinematics that lead to movement. For given muscle activation, the forcing frequency relative to the natural frequency of the damped oscillator is important for the emergent deformation characteristics of the body. The proposed approach also leads to a qualitative understanding of optimal deformation kinematics for fast swimming. These results, based on a chain-link model of swimming, are confirmed by fully resolved computational fluid dynamics (CFD) simulations. Prior results from the literature on the optimal value of stiffness for maximum speed are explained. PMID:23785272

Chronic treatment with fluoxetine and sertraline prevents forced swimming test-induced hypercontractility of rat detrusor muscle.

PubMed

Bilge, Sirri; Bozkurt, Ayhan; Bas, Duygu B; Aksoz, Elif; Savli, Evren; Ilkaya, Fatih; Kesim, Yuksel

2008-01-01

Serotonin (5-hydroxytryptamine, 5-HT) reuptake inhibitors represent important targets for the development of new treatments for detrusor overactivity and urinary incontinence. The present study was undertaken to investigate the effects of the forced swimming test (FST) on the contractile response of isolated rat detrusor muscle and to examine the effects of in vivo treatments of fluoxetine and sertraline on altered detrusor muscle contractility. Fluoxetine (20 mg/kg ip) and sertraline (10 mg/kg ip) were administered once a day for 14 days. Rats were exposed to the FST on the 15th day. After the test, detrusor muscles were removed and placed in organ baths, and the contraction responses induced by carbachol, potassium chloride (KCl) and electrical field stimulation (EFS) were recorded. The contractile responses of detrusor muscle strips to carbachol and electrical field stimulation were found to be increased at all carbachol doses and frequencies, respectively. FST also increased the contractile responses to KCl, which is used to test the differences in postreceptor-mediated contractions. The hypercontractile responses of detrusor strips to carbachol, EFS and KCl were abolished by treatment with both fluoxetine and sertraline. These treatments also decreased the immobility duration in the FST consistent with an antidepressant-like effect in this test. The results of this study provide the first evidence that FST increases contractility of the rat detrusor muscle, and this hypercontractility was abolished by chronic treatments of fluoxetine and sertraline at antidepressant doses by decreasing the postreceptor-mediated events.

Antidepressant-like effects of Tagetes lucida Cav. in the forced swimming test.

PubMed

Guadarrama-Cruz, G; Alarcon-Aguilar, F J; Lezama-Velasco, R; Vazquez-Palacios, G; Bonilla-Jaime, H

2008-11-20

Tagetes lucida (Asteraceae), has been referred in Mexican traditional medicine for the treatment of different central nervous system (CNS) diseases, mainly depression. Nevertheless, the available scientific information about this species is scarce and there are no reports related to its possible effect on the CNS. In this work, the antidepressant-like effect of extract of Tagetes lucida was evaluated in rats, as well as its potential adverse effects on male sexual behavior (MSB). Antidepressant activity was studied using forced swimming test (FST), motor activity in the open-field test and on MSB in sexually experienced male. The aqueous extract of Tagetes lucida in doses of 5, 10, 50, 100 and 200mg/(kgday)(-1) were administered orally for 14 consecutive days and evaluated on day 14, 2h after the last dose treatment. Fluoxetine (10mg/(kgday)(-1), p.o.) was used as the control positive. The aqueous extract (10, 50, 100mg/(kgday)(-1)) significantly reduced immobility and increased swimming without affecting climbing behavior in the FST. These same doses were not able to modify neither the motor activity nor the MSB. These data indicate that the extract of Tagetes lucida possesses antidepressant-like properties in rats.

Antidepressant-like effects of the ethyl acetate soluble fraction of the root bark of Morus alba on the immobility behavior of rats in the forced swim test.

PubMed

Lim, Dong Wook; Kim, Yun Tai; Park, Ji-Hae; Baek, Nam-In; Han, Daeseok

2014-06-12

In this study, the antidepressant-like effects of Morus alba fractions in rats were investigated in the forced swim test (FST). Male Wistar rats (9-week-old) were administered orally the M. alba ethyl acetate (EtOAc 30 and 100 mg/kg) and M. alba n-butanol fractions (n-BuOH 30 and 100 mg/kg) every day for 7 consecutive days. On day 7, 1 h after the final administration of the fractions, the rats were exposed to the FST. M. alba EtOAc fraction at the dose of 100 mg/kg induced a decrease in immobility behavior (p < 0.01) with a concomitant increase in both climbing (p < 0.05) and swimming (p < 0.05) behaviors when compared with the control group, and M. alba EtOAc fraction at the dose of 100 mg/kg decreased the hypothalamic-pituitary-adrenal (HPA) axis response to the stress, as indicated by an attenuated corticosterone response and decreased c-fos immunoreactivity in the hippocampal and hypothalamic paraventricular nucleus (PVN) region. These findings demonstrated that M. alba EtOAc fraction have beneficial effects on depressive behaviors and restore both altered c-fos expression and HPA activity.

Effect of swimming exercise on three-dimensional trabecular bone microarchitecture in ovariectomized rats.

PubMed

Ju, Yong-In; Sone, Teruki; Ohnaru, Kazuhiro; Tanaka, Kensuke; Fukunaga, Masao

2015-11-01

Swimming is generally considered ineffective for increasing bone mass in humans, at least compared with weight-bearing sports. However, swimming exercise has sometimes been shown to have a strong positive effect on bone mass in small animals. This study investigated the effects of swimming on bone mass, strength, and microarchitecture in ovariectomized (OVX) rats. OVX or sham operations were performed on 18-wk-old female Fisher 344 rats. Rats were randomly divided into four groups: sham sedentary (Sham-CON), sham swimming exercised (Sham-SWI), OVX sedentary (OVX-CON), and OVX swimming exercised (OVX-SWI). Rats in exercise groups performed swimming in a water bath for 60 min/day, 5 days/wk, for 12 wk. Bone mineral density (BMD) in right femurs was analyzed using dual-energy X-ray absorptiometry. Three-dimensional trabecular architecture at the distal femoral metaphysis was analyzed using microcomputed tomography (μCT). Geometrical properties of diaphyseal cortical bone were evaluated in the midfemoral region using μCT. The biomechanical properties of femurs were analyzed using three-point bending. Femoral BMD was significantly decreased following ovariectomy. This change was suppressed by swimming. Trabecular bone thickness, number, and connectivity were decreased by ovariectomy, whereas structure model index (i.e., ratio of rod-like to plate-like trabeculae) increased. These changes were also suppressed by swimming exercise. Femurs displayed greater cortical width and maximum load in SWI groups than in CON groups. Together, these results demonstrate that swimming exercise drastically alleviated both OVX-induced decreases in bone mass and mechanical strength and the deterioration of trabecular microarchitecture in rat models of osteoporosis. Copyright © 2015 the American Physiological Society.

Effects of swim stress and fluoxetine on 5-HT1A receptor gene expression and monoamine metabolism in the rat brain regions.

PubMed

Shishkina, G T; Kalinina, T S; Dygalo, N N

2012-07-01

Changes in gene expression of the brain serotonin (5-HT) 1A receptors may be important for the development and ameliorating depression, however identification of specific stimuli that activate or reduce the receptor transcriptional activity is far from complete. In the present study, the forced swim test (FST) exposure, the first stress session of which is already sufficient to induce behavioral despair in rats, significantly increased 5-HT1A receptor mRNA levels in the brainstem, frontal cortex, and hippocampus at 24 h. In the brainstem and frontal cortex, the elevation in the receptor gene expression after the second forced swim session was not affected following chronic administration of fluoxetine, while in the cortex, both control and FST values were significantly reduced in fluoxetine-treated rats. In contrast to untreated rats, no increase in hippocampal 5-HT1A receptor mRNA was observed in response to FST in rats chronically treated with fluoxetine. Metabolism of 5-HT (5-HIAA/5-HT) in the brainstem was significantly decreased by fluoxetine and further reduced by swim stress, showing a certain degree of independence of these changes on 5-HT1A receptor gene expression that was increased in this brain region only after the FST, but not after fluoxetine. FST exposure also decreased the brainstem dopamine metabolism, which was unexpectedly positively correlated with 5-HT1A receptor mRNA levels in the frontal cortex. Together, these data suggest that the effects of the forced swim stress as well as fluoxetine involve brain region-dependent alterations in 5-HT1A receptor gene transcription, some of which may be interrelated with concomitant changes in catecholamine metabolism.

Effects of fluoxetine on the rat brain in the forced swimming test: a [F-18]FDG micro-PET imaging study.

PubMed

Jang, Dong-Pyo; Lee, So-Hee; Park, Chan-Woong; Lee, Sang-Yoon; Kim, Young-Bo; Cho, Zang-Hee

2009-02-13

We used the [F-18]FDG micro-PET neuroimaging to examine the effects of fluoxetine on brain activity in rats and on their behavioral response in the forced swimming test (FST). In the first experiment, the rats were administered doses of fluoxetine (10 or 20mg/kg) 24, 19 and 1h before the rat brains were scanned. Fluoxetine induced strong activation of the dorsal hippocampus and the deactivation of the inferior colliculus, medulla oblongata, and prelimbic cortex in a dose-dependent manner. These results seemed to be related with the changes in 5-HT (5-hydroxytryptamine, serotonin) levels after selective serotonin reuptake-inhibitor treatments. In the second experiment, the changes in glucose metabolism in the test session were measured after fluoxetine was given between pre-test and test sessions of the FST. Fluoxetine administration significantly decreased immobility behavior compared with saline administration. At the same time, the activity of the insular/piriform cortex decreased significantly. In contrast, the extent of cerebellar activation increased. The glucose metabolism of the dorsal hippocampus also increased, which suggests that post-stress changes in the facilitation of hippocampal serotonergic neurotransmission lead to decreased immobilization in the FST.

Forced swimming and imipramine modify plasma and brain amino acid concentrations in mice.

PubMed

Murakami, Tatsuro; Yamane, Haruka; Tomonaga, Shozo; Furuse, Mitsuhiro

2009-01-05

The relationships between monoamine metabolism and forced swimming or antidepressants have been well studied, however information is lacking regarding amino acid metabolism under these conditions. Therefore, the aim of the present study was to investigate the effects of forced swimming and imipramine on amino acid concentrations in plasma, the cerebral cortex and the hypothalamus in mice. Forced swimming caused cerebral cortex concentrations of L-glutamine, L-alanine, and taurine to be increased, while imipramine treatment caused decreased concentrations of L-glutamate, L-alanine, L-tyrosine, L-methionine, and L-ornithine. In the hypothalamus, forced swimming decreased the concentration of L-serine while imipramine treatment caused increased concentration of beta-alanine. Forced swimming caused increased plasma concentration of taurine, while concentrations of L-serine, L-asparagine, L-glutamine and beta-alanine were decreased. Imipramine treatment caused increased plasma concentration of all amino acid, except for L-aspartate and taurine. In conclusion, forced swimming and imipramine treatment modify central and peripheral amino acid metabolism. These results may aid in the identification of amino acids that have antidepressant-like effects, or may help to refine the dosages of antidepressant drugs.

Effect of co-treatment with fluoxetine or mirtazapine and risperidone on the active behaviors and plasma corticosterone concentration in rats subjected to the forced swim test.

PubMed

Rogóż, Zofia; Kabziński, Marcin; Sadaj, Witold; Rachwalska, Paulina; Gądek-Michalska, Anna

2012-01-01

Several clinical reports have postulated a beneficial effect of the addition of a low dose of risperidone to the ongoing treatment with antidepressants in treatment-resistant depression. The present study aimed to examine the effect of treatment with fluoxetine or mirtazapine, given separately or jointly with risperidone, on active behavior and plasma corticosterone level in male Wistar rats subjected to the forced swim test (FST). The obtained results showed that fluoxetine (5 mg/kg), mirtazapine (5 and 10 mg/kg) or risperidone (0.05 and 0.1 mg/kg) did not change the active behavior of rats in the FST. However, co-treatment with fluoxetine (10 mg/kg) and risperidone (0.1 mg/kg) induced an antidepressant-like effect in that test because it significantly increased the swimming time and decreased the immobility time, while combined treatment with mirtazapine at 5 and 10 mg/kg and risperidone at 0.05 and 0.1 mg/kg evoked a significant increase in the swimming time and also climbing, and decreased the immobility time. WAY 100635 (a 5-HT(1A) receptor antagonist) at a dose of 0.1 mg/kg inhibited the antidepressant-like effect induced by co-administration of fluoxetine or mirtazapine and risperidone. Active behavior in that test did not reflect an increase in general activity, since combined treatment with fluoxetine or mirtazapine and risperidone failed to enhance the exploratory activity of rats. Co-treatment with fluoxetine or mirtazapine and risperidone did not reduce the stress-induced increase in plasma corticosterone concentration in animals subjected to the FST. The obtained results indicate that risperidone applied in a low dose enhances the antidepressant-like activity of fluoxetine and mirtazapine in the FST (but does not normalize the stress-induced increase in corticosterone level in these rats), and that 5-HT(1A) receptors may play some role in these effects.

Immobility time during the forced swimming test predicts sensitivity to amitriptyline, whereas traveled distance in the circular corridor indicates resistance to treatment in female Wistar rats.

PubMed

Flores-Serrano, Ana G; Zaldívar-Rae, Jaime; Salgado, Humberto; Pineda, Juan C

2015-03-25

Among the main issues in the pharmacological treatment of depression are the wide variation in response to antidepressants among individual patients and the lack of indexes that allow prediction of which drug will be effective in a particular case. We evaluated whether differential sensitivity to amitriptyline is related to dichotomous categorization of individuals on the basis of their behavioral responses to two common paradigms used to evaluate the potential of tricyclic drugs as antidepressants. Hence, we categorized a cohort of 38 female rats on the basis of their immobility time in the conditioning phase of the forced swimming test [FST; high immobility (HI) vs. low immobility (LI) rats] and their locomotor behavior in the circular corridor test [high locomotor response (HR) vs. low locomotor response (LR) rats]. We subjected the rodents to the FST while under the influence of vehicle (n=20) or amitriptyline (15 mg/kg; n=18). We found no statistical evidence of dependence between categorizations of rats on the basis of their behavior in the FST and circular corridor test. Rats categorized as HI/LI and HR/LR significantly differed in their sensitivity/resistance to amitriptyline, as evidenced by changes (or lack thereof) in their immobility time, climbing time, and swimming time during the FST. These results confirm that different behavioral styles among rats are linked to differential sensitivity/resistance to antidepressants. However, we specifically found that categorizing rats as HI/LI better reflected sensitivity to amitriptyline, whereas categorizing them as HR/LR better revealed resistance to the drug. These differential responses should be considered in experimental approaches. Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.

Pregnancy swimming causes short- and long-term neuroprotection against hypoxia-ischemia in very immature rats.

PubMed

Sanches, Eduardo Farias; Durán-Carabali, Luz Elena; Tosta, Andrea; Nicola, Fabrício; Schmitz, Felipe; Rodrigues, André; Siebert, Cassiana; Wyse, Angela; Netto, Carlos

2017-09-01

BackgroundHypoxia-ischemia (HI) is a major cause of neurological damage in preterm newborn. Swimming during pregnancy alters the offspring's brain development. We tested the effects of swimming during pregnancy in the very immature rat brain.MethodsFemale Wistar rats (n=12) were assigned to the sedentary (SE, n=6) or the swimming (SW, n=6) group. From gestational day 0 (GD0) to GD21 the rats in the SW group were made to swim for 20 min/day. HI on postnatal day (PND) 3 rats caused sensorimotor and cognitive impairments. Animals were distributed into SE sham (SESH), sedentary HIP3 (SEHI), swimming sham (SWSH), and swimming HIP3 (SWHI) groups. At PND4 and PND5, Na + /K + -ATPase activity and brain-derived neurotrophic factor (BDNF) levels were assessed. During lactation and adulthood, neurological reflexes, sensorimotor, anxiety-related, and cognitive evaluations were made, followed by histological assessment at PND60.ResultsAt early stages, swimming caused an increase in hippocampal BDNF levels and in the maintenance of Na + /K + -ATPase function in the SWHI group. The SWHI group showed smaller lesions and the preservation of white matter tracts. SEHI animals showed a delay in reflex maturation, which was reverted in the SWHI group. HIP3 induced spatial memory deficits and hypomyelination in SEHI rats, which was reverted in the SWHI group.ConclusionSwimming during pregnancy neuroprotected the brains against HI in very immature neonatal rats.

Rodent models of depression: forced swim and tail suspension behavioral despair tests in rats and mice.

PubMed

Castagné, Vincent; Moser, Paul; Roux, Sylvain; Porsolt, Roger D

2011-04-01

The development of antidepressants requires simple rodent behavioral tests for initial screening before undertaking more complex preclinical tests and clinical evaluation. Presented in the unit are two widely used screening tests used for antidepressants, the forced swim (also termed behavioral despair) test in the rat and mouse, and the tail suspension test in the mouse. These tests have good predictive validity and allow rapid and economical detection of substances with potential antidepressant-like activity. The behavioral despair and the tail suspension tests are based on the same principle: measurement of the duration of immobility when rodents are exposed to an inescapable situation. The majority of clinically used antidepressants decrease the duration of immobility. Antidepressants also increase the latency to immobility, and this additional measure can increase the sensitivity of the behavioral despair test in the mouse for certain classes of antidepressant. Testing of new substances in the behavioral despair and tail suspension tests allows a simple assessment of their potential antidepressant activity by the measurement of their effect on immobility. © 2011 by John Wiley & Sons, Inc.

Desipramine restricts estral cycle oscillations in swimming.

PubMed

Contreras, C M; Martínez-Mota, L; Saavedra, M

1998-10-01

1. Desipramine (DMI) is a tricyclic antidepressant which reduces the immobility in rats forced to swim; however, it is unknown whether estral cycle phases impinge on DMI actions on immobility in daily swimming tests during several weeks. 2. In female wistar rats, vaginal smears taken before testing defined four estral phases. Afterwards, the authors assessed the latency for the first period of immobility in five-min forced swim tests practiced on 21-day DMI (DMI group), 21-day washout saline given after a 21-day DMI treatment (washout-saline group), or non-treated rats (control group). 3. We observed a longer latency for the first period of immobility in proestrus-estrus from the control and washout-saline groups. The 21-day treatment with DMI (2.1 mg/kg i.p., once a day) significantly (p < 0.001) increased the latency by about 160% from control regardless of the estral cycle phase. 4. It is concluded that proestrus-estrus relates to increased struggling behavior. DMI enhances struggling behavior independently of hormonal state.

Effect of bacoside extract from Bacopa monniera on physical fatigue induced by forced swimming.

PubMed

Anand, T; Phani Kumar, G; Pandareesh, M D; Swamy, M S L; Khanum, Farhath; Bawa, A S

2012-04-01

The antifatigue effect of bacoside extract (BME) from Bacopa monniera (L.) Wettst. was investigated. Rats were subjected to weight-loaded forced swim test (WFST) every alternate day for 3 weeks. The BME at a dosage of 10 mg/kg body weight was administered orally to rats for 2 weeks in order to evaluate the following biomarkers of physical fatigue: swimming time, change in body weight, lipid peroxidation, lactic acid (LA), glycogen, antioxidant enzyme activities such as superoxide dismutase (SOD) and catalase (CAT) and blood parameters, namely blood urea nitrogen (BUN) and creatine kinase (CK). The exhaustive swimming time was increased by 3-fold in the BME supplemented group compared with that of the control group on day 13. The BME treatment lowered malondialdehyde (MDA) levels in brain, liver and muscle tissues by 11.2%, 16.2% and 37.7%, respectively, compared with the control exercised group (p < 0.05). The BME also reduced the LA, serum BUN and CK activities significantly compared with that of the control. Administration of BME significantly protected the depletion of SOD and CAT activities. The HSP-70 expression studies by western blot also confirmed the antifatigue property of BME. The present study thus indicates that BME ameliorates the various impairments associated with physical fatigue. Copyright © 2011 John Wiley & Sons, Ltd.

Active coping of prenatally stressed rats in the forced swimming test: involvement of the Nurr1 gene.

PubMed

Montes, Pedro; Ruiz-Sánchez, Elizabeth; Calvillo, Minerva; Rojas, Patricia

2016-09-01

Depending on genetic predisposition, prenatal stress may result in vulnerability or resilience to develop psychiatric disorders in adulthood. Nurr1 is an immediate early gene, important in the brain for the stress response. We tested the hypothesis that prenatal stress and the decrease of hippocampal Nurr1 alter offspring behavioral responses in the forced swimming test (FST). Pregnant Wistar rats were exposed to restraint stress (45 min, thrice daily) from gestation day 14. Prenatally stressed (PS) and non-prenatally stressed (NPS) male offspring were treated bilaterally with a Nurr1 antisense oligodeoxynucleotide (ODN; or control) into the hippocampus at 97 d of age. After 1 h, the rats were exposed to the FST (acute stressor) to analyze their behavioral responses. Thirty minutes after the FST, we analyzed the gene expression of Nurr1, Bdnf and Nr3c1 (genes for Nurr1, brain-derived neurotrophic factor (BDNF) and glucocorticoid receptor (GR), respectively) in the hippocampus, prefrontal cortex (PFC) and hypothalamus. Results showed that the decrease of hippocampal Nurr1 after the antisense ODN in adult NPS rats induces immobility (indicating depressive-like behavior). The PS adult rats, including the group with decreased hippocampal Nurr1, presented low immobility in the FST. This low immobility was concordant with maintenance of Nurr1 and Bdnf expression levels in the three analyzed brain regions; Nr3c1 gene expression was also maintained in the PFC and hypothalamus. These findings suggest that Nurr1 and associated genes could participate in the brain modifications induced by prenatal stress, allowing active coping (resilience) with acute stress in adulthood.

Clinical doses of citalopram or reboxetine differentially modulate passive and active behaviors of female Wistar rats with high or low immobility time in the forced swimming test.

PubMed

Flores-Serrano, Ana Gisela; Vila-Luna, María Leonor; Álvarez-Cervera, Fernando José; Heredia-López, Francisco José; Góngora-Alfaro, José Luis; Pineda, Juan Carlos

2013-09-01

The sensitivity of immobility time (IT) to antidepressant-drugs differs in rats expressing high or low motor activity during the forced swimming test (FST). However, whether this heterogeneity is expressed after the administration of the most selective serotonin and norepinephrine reuptake inhibitors (SSRIs and SNRIs, respectively) is unknown. We compared the influence of either the SSRI citalopram or the SNRI reboxetine with the tricyclic antidepressant amitriptyline on two subgroups of female Wistar rats expressing high IT (HI; at or above the mean value) or low IT (LI; below the mean) during the initial 5 min of the first session of the FST. None of the tested drugs increased motor activity in the open field test. When vehicle was applied to either HI or LI rats, IT increased in the second session of the FST. This increment concurred with a simultaneous climbing time (CT) decrement. When amitriptyline (15 mg/kg) was tested the CT increased for both HI and LI rats. This increment was accompanied by an IT decrement in HI and LI rats. Reboxetine (0.16 or 1 mg/kg) precluded IT and CT changes in both HI and LI rats and produced a swimming time reduction. Citalopram (0.4, 1, and 3 mg/kg) essentially mimicked the influence of reboxetine on the IT and CT in LI rats, as well as in HI rats, but in the latter case only at 3 mg/kg. Yet, at the dose of 10 mg/kg citalopram lacked this effect in both subgroups. No differences were detected when the IT of LI rats was evaluated with citalopram (3 mg/kg) during estrus or diestrus stage. These results show that clinical doses of citalopram produced an antidepressant-like effect selectively in LI rats, while amitriptyline or reboxetine produced this effect in both LI and HI animals. Copyright © 2013 Elsevier Inc. All rights reserved.

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.

Ovarian and uterine alterations following forced swimming: An immunohistochemical study.

PubMed

Seyed Saadat, Seyedeh Nazanin; Mohammadghasemi, Fahimeh; Ebrahimi, Hannan; Rafati Sajedi, Hanieh; Chatrnour, Gelayol

2016-10-01

Physical exercise is known to be a stressor stimulus that leads to reproductive disruption. The aim of this study was to evaluate the effect of forced swimming on the uterus and ovaries in mice. Adult mice (N=24) were divided into the following three groups: A, control; B, swimming in water (10 o C); and C, swimming in water (23 o C). Swimmers swam for 5 min daily for 5 consecutive days/ wk during 2 wks. An enzyme linked immunosorbent assay was used to determine serum estradiol, follicle stimulating hormone (FSH) and testosterone levels. Immunohistochemistry was performed to study apoptotic cells or estrogen receptor (ER) expression in uterine epithelial cells and ovaries. ANOVA was used for statistical analysis. Swimming in both groups reduced the serum FSH and estradiol levels (p<0.01) without having a significant effect on the serum testosterone level or percentage of apoptosis in ovarian and uterine tissues (p<0.01) compared with controls. A significant reduction in the number of ERs in the uterus and ovaries, and secondary and graafian follicles were observed in groups B and C compared with controls (p<0.01); however the number of primordial and primary follicles were not significantly changed in the ovaries. Forced swimming of 2 wks duration reduces the serum levels of FSH and estradiol without having effects on apoptosis in the ovaries or uteri of mice. Over a long period of time, forced swimming may have an adverse effect on fertility.

Swimming intervention mitigates HFD-induced obesity of rats through PGC-1α-irisin pathway.

PubMed

Yang, X-Q; Yuan, H; Li, J; Fan, J-J; Jia, S-H; Kou, X-J; Chen, N

2016-05-01

Irisin, a newly discovered myokine, can drive the browning of white adipocytes to control body weight or mitigate obesity progression through regulating energy metabolism. However, the underlying mechanisms or specific signal pathways of exercise-induced irisin on the management of obesity are still unclear. Totally 30 rats were subjected to high fat diet (HFD) feeding for 8 weeks to establish the rat model with obesity successfully. HFD-induced obese model rats were provided with 8 weeks swimming intervention at moderate intensity for exploring the treatment of obesity through exercise intervention. In addition, another 15 rats were subjected to HFD feeding coupled with total 16 weeks swimming intervention at a moderate intensity from the beginning of the experiment, which was used for exploring the prevention of obesity through exercise intervention. Blood and gastrocnemius samples were harvested from obese rats after swimming intervention to explore its specific signal pathways through ELISA analysis and Western blotting. HFD feeding of rats for 8 weeks could lead to the obesity due to the disorders of lipid metabolism. Totally 8 weeks swimming intervention at moderate intensity for rats with obesity could obviously alleviate the progression of obesity and 16 weeks swimming intervention from the beginning of the experiment could significantly inhibit the development of obesity. Meanwhile, swimming intervention could result in an increased phosphorylation of AMPK and up-regulation of irisin and PGC-1α as the biomarkers of energy metabolism. Exercise intervention can activate PGC-1α-dependent irisin to induce the browning of white adipocytes, thus inhibiting or alleviating the occurrence and development of obesity.

Histomorphometric analysis of the response of rat skeletal muscle to swimming, immobilization and rehabilitation.

PubMed

Nascimento, C C F; Padula, N; Milani, J G P O; Shimano, A C; Martinez, E Z; Mattiello-Sverzut, A C

2008-09-01

The objective of the present study was to determine to what extent, if any, swimming training applied before immobilization in a cast interferes with the rehabilitation process in rat muscles. Female Wistar rats, mean weight 260.52 +/- 16.26 g, were divided into 4 groups of 6 rats each: control, 6 weeks under baseline conditions; trained, swimming training for 6 weeks; trained-immobilized, swimming training for 6 weeks and then immobilized for 1 week; trained-immobilized-rehabilitated, swimming training for 6 weeks, immobilized for 1 week and then remobilized with swimming for 2 weeks. The animals were then sacrificed and the soleus and tibialis anterior muscles were dissected, frozen in liquid nitrogen and processed histochemically (H&E and mATPase). Data were analyzed statistically by the mixed effects linear model (P < 0.05). Cytoarchitectural changes such as degenerative characteristics in the immobilized group and regenerative characteristics such as centralized nucleus, fiber size variation and cell fragmentation in the groups submitted to swimming were more significant in the soleus muscle. The diameters of the lesser soleus type 1 and type 2A fibers were significantly reduced in the trained-immobilized group compared to the trained group (P < 0.001). In the tibialis anterior, there was an increase in the number of type 2B fibers and a reduction in type 2A fibers when trained-immobilized rats were compared to trained rats (P < 0.001). In trained-immobilized-rehabilitated rats, there was a reduction in type 2B fibers and an increase in type 2A fibers compared to trained-immobilized rats (P < 0.009). We concluded that swimming training did not minimize the deleterious effects of immobilization on the muscles studied and that remobilization did not favor tissue re-adaptation.

Swimming Training Induces Liver Mitochondrial Adaptations to Oxidative Stress in Rats Submitted to Repeated Exhaustive Swimming Bouts

PubMed Central

Lima, Frederico D.; Stamm, Daniel N.; Della-Pace, Iuri D.; Dobrachinski, Fernando; de Carvalho, Nélson R.; Royes, Luiz Fernando F.; Soares, Félix A.; Rocha, João B.; González-Gallego, Javier; Bresciani, Guilherme

2013-01-01

Background and Aims Although acute exhaustive exercise is known to increase liver reactive oxygen species (ROS) production and aerobic training has shown to improve the antioxidant status in the liver, little is known about mitochondria adaptations to aerobic training. The main objective of this study was to investigate the effects of the aerobic training on oxidative stress markers and antioxidant defense in liver mitochondria both after training and in response to three repeated exhaustive swimming bouts. Methods Wistar rats were divided into training (n = 14) and control (n = 14) groups. Training group performed a 6-week swimming training protocol. Subsets of training (n = 7) and control (n = 7) rats performed 3 repeated exhaustive swimming bouts with 72 h rest in between. Oxidative stress biomarkers, antioxidant activity, and mitochondria functionality were assessed. Results Trained group showed increased reduced glutathione (GSH) content and reduced/oxidized (GSH/GSSG) ratio, higher superoxide dismutase (MnSOD) activity, and decreased lipid peroxidation in liver mitochondria. Aerobic training protected against exhaustive swimming ROS production herein characterized by decreased oxidative stress markers, higher antioxidant defenses, and increases in methyl-tetrazolium reduction and membrane potential. Trained group also presented higher time to exhaustion compared to control group. Conclusions Swimming training induced positive adaptations in liver mitochondria of rats. Increased antioxidant defense after training coped well with exercise-produced ROS and liver mitochondria were less affected by exhaustive exercise. Therefore, liver mitochondria also adapt to exercise-induced ROS and may play an important role in exercise performance. PMID:23405192

The cardiovascular and endocrine responses to voluntary and forced diving in trained and untrained rats

PubMed Central

DiNovo, Karyn. M.; Connolly, Tiffanny M.

2010-01-01

The mammalian diving response, consisting of apnea, bradycardia, and increased total peripheral resistance, can be modified by conscious awareness, fear, and anticipation. We wondered whether swim and dive training in rats would 1) affect the magnitude of the cardiovascular responses during voluntary and forced diving, and 2) whether this training would reduce or eliminate any stress due to diving. Results indicate Sprague-Dawley rats have a substantial diving response. Immediately upon submersion, heart rate (HR) decreased by 78%, from 453 ± 12 to 101 ± 8 beats per minute (bpm), and mean arterial pressure (MAP) decreased 25%, from 143 ± 1 to 107 ± 5 mmHg. Approximately 4.5 s after submergence, MAP had increased to a maximum 174 ± 3 mmHg. Blood corticosterone levels indicate trained rats find diving no more stressful than being held by a human, while untrained rats find swimming and diving very stressful. Forced diving is stressful to both trained and untrained rats. The magnitude of bradycardia was similar during both voluntary and forced diving, while the increase in MAP was greater during forced diving. The diving response of laboratory rats, therefore, appears to be dissimilar from that of other animals, as most birds and mammals show intensification of diving bradycardia during forced diving compared with voluntary diving. Rats may exhibit an accentuated antagonism between the parasympathetic and sympathetic branches of the autonomic nervous system, such that in the autonomic control of HR, parasympathetic activity overpowers sympathetic activity. Additionally, laboratory rats may lack the ability to modify the degree of parasympathetic outflow to the heart during an intense cardiorespiratory response (i.e., the diving response). PMID:19923359

Biomechanical and structural parameters of tendons in rats subjected to swimming exercise.

PubMed

Bezerra, M A; Santos de Lira, K D; Coutinho, M P G; de Mesquita, G N; Novaes, K A; da Silva, R T B; de Brito Nascimento, A K; Inácio Teixeira, M F H B; Moraes, S R A

2013-12-01

The aim of this study was to evaluate the effect of swimming exercise, without overloading, on the biomechanical parameters of the calcaneal tendon of rats. 27 male Wistar rats (70 days) were distributed randomly into 2 groups, Control Group (CG; n=15) with restricted movements inside the cage and Swimming Group (SG; n=12), subjected to exercise training in a tank with a water temperature of 30±1°C, for 1 h/day, 5 days/week for 8 weeks. All animals were kept in a reversed light/dark cycle of 12 h with access to food and water ad libitum. After that, they were anesthetized and had their calcaneus tendons collected from their left rear paws. The tendon was submitted to a mechanical test on a conventional test machine. From the stress vs. strain curve, the biomechanical data were analyzed. For the statistical analysis, the Student-T test was used (p<0.05). Of the variables examined, the maximum tension (p=0.009), maximum force (p=0.03), energy of deformation/tendon cross sectional area (p=0.017) and elastic modulus of the tendon (p=0.013) showed positive outcomes in SG. There was no difference in the other parameters. The results indicate that the swimming exercise training, without overloading, was an important stimulus for improving the biomechanical parameters and structural properties of the calcaneal tendon. © Georg Thieme Verlag KG Stuttgart · New York.

Protein and lipid oxidative damage in streptozotocin-induced diabetic rats submitted to forced swimming test: the insulin and clonazepam effect.

PubMed

Wayhs, Carlos Alberto Yasin; Manfredini, Vanusa; Sitta, Angela; Deon, Marion; Ribas, Graziela; Vanzin, Camila; Biancini, Giovana; Ferri, Marcelo; Nin, Maurício; Barros, Helena Maria Tannhauser; Vargas, Carmen Regla

2010-09-01

Diabetes may modify central nervous system functions and is associated with moderate cognitive deficits and changes in the brain, a condition that may be referred to as diabetic encephalopathy. The prevalence of depression in diabetic patients is higher than in the general population, and clonazepam is being used to treat this complication. Oxidative stress may play a role in the development of diabetes complications. We investigated oxidative stress parameters in streptozotocin-induced diabetic rats submitted to forced swimming test (STZ) and evaluated the effect of insulin (STZ-INS) and/or clonazepam (STZ-CNZ and STZ-INS-CNZ) acute treatment on these animal model. Oxidative damage to proteins measured as carbonyl content in plasma was significantly increased in STZ group compared to STZ treated groups. Malondialdehyde plasma levels were significantly reduced in STZ-INS and STZ-INS-CNZ groups when compared to STZ rats, being significantly reduced in STZ-INS-CNZ than STZ-INS rats. The activities of the antioxidant enzymes catalase, superoxide dismutase and glutathione peroxidase showed no significant differences among all groups of animals. These findings showed that protein and lipid damage occurs in this diabetes/depression animal model and that the associated treatment of insulin and clonazepam is capable to protect against oxidative damage in this experimental model.

Age-related changes in the antidepressant-like effect of desipramine and fluoxetine in the rat forced-swim test.

PubMed

Olivares-Nazario, Maribel; Fernández-Guasti, Alonso; Martínez-Mota, Lucía

2016-02-01

Some reports suggest that older patients are less responsive to antidepressants than young adults, but this idea has not been fully supported. Here, we investigated the role of aging in the behavioral effects of the antidepressants, desipramine (DMI) (5, 10, and 20 mg/kg) and fluoxetine (FLX) (5, 10, and 20 mg/kg) in young adults (3-5 months), middle-aged (MA, 12-15 months), and senescent (SE, 23-25 months) male rats in the forced-swim test. In addition, locomotor activity and motor coordination were assessed as side-effects. DMI and fluoxetine produced an antidepressant-like effect in YA and MA animals, although in the latter group, a shift to the right in the dose-response curve was found for DMI. Importantly, neither drug was effective in SE animals. Motor side-effects were produced mainly by DMI in MA and SE rats. Therefore, a decrease in the antidepressant-like effect is associated strongly with senescence as well as an increased vulnerability to motor side-effects, particularly of tricyclics. This study is significant because SE animals are scarcely studied in pharmacological screening tests, and our findings might be useful for improving antidepressant treatments for the increasing aged population.

Ovarian and uterine alterations following forced swimming: An immunohistochemical study

PubMed Central

Seyed Saadat, Seyedeh Nazanin; Mohammadghasemi, Fahimeh; Ebrahimi, Hannan; Rafati Sajedi, Hanieh; Chatrnour, Gelayol

2016-01-01

Background: Physical exercise is known to be a stressor stimulus that leads to reproductive disruption. Objective: The aim of this study was to evaluate the effect of forced swimming on the uterus and ovaries in mice. Materials and Methods: Adult mice (N=24) were divided into the following three groups: A, control; B, swimming in water (10oC); and C, swimming in water (23oC). Swimmers swam for 5 min daily for 5 consecutive days/ wk during 2 wks. An enzyme linked immunosorbent assay was used to determine serum estradiol, follicle stimulating hormone (FSH) and testosterone levels. Immunohistochemistry was performed to study apoptotic cells or estrogen receptor (ER) expression in uterine epithelial cells and ovaries. ANOVA was used for statistical analysis. Results: Swimming in both groups reduced the serum FSH and estradiol levels (p<0.01) without having a significant effect on the serum testosterone level or percentage of apoptosis in ovarian and uterine tissues (p<0.01) compared with controls. A significant reduction in the number of ERs in the uterus and ovaries, and secondary and graafian follicles were observed in groups B and C compared with controls (p<0.01); however the number of primordial and primary follicles were not significantly changed in the ovaries. Conclusion: Forced swimming of 2 wks duration reduces the serum levels of FSH and estradiol without having effects on apoptosis in the ovaries or uteri of mice. Over a long period of time, forced swimming may have an adverse effect on fertility. PMID:27921086

Arctigenin enhances swimming endurance of sedentary rats partially by regulation of antioxidant pathways.

PubMed

Wu, Ruo-ming; Sun, Yan-yan; Zhou, Ting-ting; Zhu, Zhi-yuan; Zhuang, Jing-jing; Tang, Xuan; Chen, Jing; Hu, Li-hong; Shen, Xu

2014-10-01

Arctigenin, a phenylpropanoid dibenzylbutyrolactone lignan found in traditional Chinese herbs, has been determined to exhibit a variety of pharmacological activities, including anti-tumor, anti-inflammation, neuroprotection, and endurance enhancement. In the present study, we investigated the antioxidation and anti-fatigue effects of arctigenin in rats. Rat L6 skeletal muscle cell line was exposed to H2O2 (700 μmol/L), and ROS level was assayed using DCFH-DA as a probe. Male SD rats were injected with arctigenin (15 mg·kg(-1)·d(-1), ip) for 6 weeks, and then the weight-loaded forced swimming test (WFST) was performed to evaluate their endurance. The levels of antioxidant-related genes in L6 cells and the skeletal muscles of rats were analyzed using real-time RT-PCR and Western blotting. Incubation of L6 cells with arctigenin (1, 5, 20 μmol/L) dose-dependently decreased the H2O2-induced ROS production. WFST results demonstrated that chronic administration of arctigenin significantly enhanced the endurance of rats. Furthermore, molecular biology studies on L6 cells and skeletal muscles of the rats showed that arctigenin effectively increased the expression of the antioxidant-related genes, including superoxide dismutase (SOD), glutathione reductase (Gsr), glutathione peroxidase (GPX1), thioredoxin (Txn) and uncoupling protein 2 (UCP2), through regulation of two potential antioxidant pathways: AMPK/PGC-1α/PPARα in mitochondria and AMPK/p53/Nrf2 in the cell nucleus. Arctigenin efficiently enhances rat swimming endurance by elevation of the antioxidant capacity of the skeletal muscles, which has thereby highlighted the potential of this natural product as an antioxidant in the treatment of fatigue and related diseases.

The effects of Creatine Long-Term Supplementation on Muscle Morphology and Swimming Performance in Rats

PubMed Central

Yildiz, Ahmet; Ozdemir, Ercan; Gulturk, Sefa; Erdal, Sena

2009-01-01

Creatine (Cr) has been shown to increase the total muscle mass. The purpose of this study was to investigate the effect of Cr supplementation on muscle morphology and swimming performance, using an animal model. Each rat was subjected to exercise 15-minute period daily for the 12 weeks. The rats were randomly divided into four groups: no Cr supplementation (CON), no Cr supplementation and incomplete food intake (lacking lysine and methionine in diet for rats) (INCO), Cr supplementation 1 g·kg-1·day-1 (CREAT-I) and Cr supplementation 2 g·kg-1·day-1 (CREAT-II). Three months later, all groups adult rats exercised in swimming pool chambers. Swimming time was recorded as minute for each rat. Following swimming performance period, the animals were killed by cervical dislocation and the gastrocnemius and diaphragm muscles were dissected. Serial slices of 5-7 μm were allocated paraffin wax and histochemical staining procedure of cross-sections was carried out with heamatoxylin-eosin technics. All groups gained body weight at the end of 12 weeks but there was no statistical difference among them. Swimming time values were statistical difference between CREAT-II and CON group as well as between CREAT-I and CON group (p < 0.05). In the INCO group was determined increased connective tissue cell of the muscle sample. In contrast, in the CREAT-I and CREAT-II group, the basic histological changes were large-scale muscle fibers and hypertrophic muscle cells. These results suggest that long-term creatine supplementation increased the number of muscle fibers and enhanced endurance swimming performance in rats. Key points There is no study about the effects of creatine long-term supplementation on muscle morphology and swimming performance in rats. Long-term creatine supplementation increase muscle hypertrophy (but not body weight) and enhance endurance swimming performance in rats. The quantitative analysis indicated that the number of muscle fibers per defined area increased

Investigating the metabolic alterations in a depressive-like rat model of chronic forced swim stress: An in vivo proton magnetic resonance spectroscopy study at 7T.

PubMed

Yoo, Chi-Hyeon; Lim, Song-I; Song, Kyu-Ho; Woo, Dong-Cheol; Choe, Bo-Young

2018-06-01

Although recent investigations of major depressive disorder (MDD) have focused on the monoaminergic system, accumulating evidences suggest that alternative pathophysiological models of MDD and treatment options for patients with MDD are needed. Animals subjected to chronic forced swim stress (CFSS) develop behavioral despair. The purpose of this study was to investigate the in vivo effects of CFSS on systems other than the monoamine system in the rat prefrontal cortex (PFC) with 7T and short-echo-time (16.3 ms) proton magnetic resonance spectroscopy ( 1 H MRS). Ten male Wistar rats underwent 14 days of CFSS, and in vivo 1 H MRS and forced swim tests were performed before and after CFSS. Point-resolved spectroscopy was used to quantify metabolite levels in the rat PFC. To investigate spectral overlap in glutamate and glutamine, spectral analyses in the spectra obtained in the in vivo 1 H MRS, parametrically matched spectral simulation, and in vitro experiments were performed. The results of the spectral analyses showed that the glutamate/glutamine spectral overlap was not critical, which suggested that in vivo 1 H MRS can be used to reliably assess the glutamate system. The rats showed significantly increased immobility times and decreased climbing times in the FST after CFSS, which suggested that the rats developed behavioral despair. The pre-CFSS and post-CFSS glutamate and glutamine levels did not significantly differ (p > 0.050). The levels of myo-inositol, total choline, and N-acetylaspartate, myo-inositol/creatine, and total choline/creatine increased significantly (p < 0.050). Similar findings have been reported in patients with MDD. Taken together, these results suggest that the CFSS-induced metabolic alterations were similar to those found in patients and that high-field and short-echo-time in vivo 1 H MRS can be used to investigate depression-induced metabolic alterations. Such investigations might provide alternative insights into the

Antidepressant-like effects induced by NMDA receptor blockade and NO synthesis inhibition in the ventral medial prefrontal cortex of rats exposed to the forced swim test.

PubMed

Pereira, Vitor Silva; Romano, Angélica; Wegener, Gregers; Joca, Sâmia R L

2015-07-01

Systemic treatment with NMDA receptor (NMDAR) antagonists, inhibitors of neuronal nitric oxide synthase (nNOS) or of soluble guanylyl cyclase (sGC), induce antidepressant-like effects in rats. Increased levels of glutamate and nitric oxide (NO) in the medial prefrontal cortex (MPFC) of stressed animals have been described in the literature. However, the role of the NMDAR-nNOS-sGC pathway of the MPFC in the mediation of forced swim-induced behaviors remains unclear. The aim of this work was to test the hypothesis that the inhibition of the NMDAR-nNOS-sGC pathway in the ventral MPFC (infralimbic (IL) or prelimbic (PL)) would elicit antidepressant-like effects in the forced swim test (FST). Rats implanted with cannulae aimed at the PL or the IL were exposed to the FST and injected with LY235959 (NMDAR antagonist), NPA (nNOS inhibitor), ODQ (sGC inhibitor), or carboxy-PTIO (NO scavenger). Additional groups received the AMPA antagonist, NBQX, before the effective doses of LY235959 or NPA. LY235959 administration into PL or IL before the FS pretest produced no effects. Administration of LY235959 (3 and 10 nmol/0.2 μL) after pretest was effective only when administered into the PL. However, the administration of NPA (0.01 nmol/0.2 μL), c-PTIO (1.0 nmol/0.2 μL), and ODQ (1.0 nmol/0.2 μL) into the PL or IL before the FST produced antidepressant-like effects. NBQX blocked the antidepressant-like effect of LY235959 but not of NPA. Blocking NMDAR or NO signaling in the vMPFC, either in the IL or the PL, induces antidepressant-like effects in the rat FST. These effects seemingly occur through independent mechanisms, since NBQX blocked the former effect but not the latter.

Effects of prolonged ethanol vapor exposure on forced swim behavior, and neuropeptide Y and corticotropin-releasing factor levels in rat brains.

PubMed

Walker, Brendan M; Drimmer, David A; Walker, Jennifer L; Liu, Tianmin; Mathé, Aleksander A; Ehlers, Cindy L

2010-09-01

Depressive symptoms in alcohol-dependent individuals are well-recognized and clinically relevant phenomena. The etiology has not been elucidated although it is clear that the depressive symptoms may be alcohol independent or alcohol induced. To contribute to the understanding of the neurobiology of chronic ethanol use, we investigated the effects of chronic intermittent ethanol vapor exposure on behaviors in the forced swim test (FST) and neuropeptide Y (NPY) and corticotropin-releasing factor (CRF) levels in specific brain regions. Adult male Wistar rats were subjected to intermittent ethanol vapor (14 h on/10 h off) or air exposure for 2 weeks and were then tested at three time points corresponding to acute withdrawal (8-12 h into withdrawal) and protracted withdrawal (30 and 60 days of withdrawal) in the FST. The behaviors that were measured in the five-min FST consisted of latency to immobility, swim time, immobility time, and climbing time. The FST results showed that the vapor-exposed animals displayed depressive-like behaviors; for instance, decreased latency to immobility in acute withdrawal and decreased latency to immobility, decreased swim time and increased immobility time in protracted withdrawal, with differences between air- and vapor-exposed animals becoming more pronounced over the 60-day withdrawal period. NPY levels in the frontal cortex of the vapor-exposed animals were decreased compared with the control animals, and CRF levels in the amygdala were correlated with increased immobility time. Thus, extended ethanol vapor exposure produced long-lasting changes in FST behavior and NPY levels in the brain. Copyright © 2010 Elsevier Inc. All rights reserved.

Male rats with same-sex preference show higher immobility in the forced swim test, but similar effects of fluoxetine and desipramine than males that prefer females.

PubMed

Hernández, Alejandra; Fernández-Guasti, Alonso

2018-05-25

Sex preference in male rats is partly determined by the organizational action of estradiol. Thus, several paradigms have used aromatase inhibitors to manipulate sex preference. We recently showed that a subpopulation of male rats prenatally treated with letrozole (0.56 μg/kg, G10-G22), a non-steroidal third generation aromatase inhibitor, had same sex preference, female sexual behavior (including lordosis and proceptivity) and penile erections when exposed to other males. These males, in addition, displayed high levels of experimental anxiety in the plus maze test and were insensitive to the anxiogenic-like acute effect of FLX (10 mg/kg). The two main purposes of the present work were: a) to study the behavioral profile of males displaying same sex preference in the forced swim test (FST), and b) to analyze if the antidepressant-like effect of the subchronic treatment with FLX (10 mg/kg, 3 times) or desipramine (DMI, 10 mg/kg, 3 times) vary according to sex preference. Males treated prenatally with letrozole with same-sex preference showed more immobility and less active behaviors (swimming and climbing) in the FST than males with female preference. Subchronic treatment with FLX and DMI reduced immobility when compared to saline controls, while FLX increased swimming and DMI increased climbing behavior. Treatments were equally effective in males with preference for other males and those that preferred females. These results indicate that an association exists between prenatal letrozole treatment, same sex preference and immobility in the FST. Copyright © 2017. Published by Elsevier Inc.

Impact of water temperature and stressor controllability on swim stress-induced changes in body temperature, serum corticosterone, and immobility in rats.

PubMed

Drugan, Robert C; Eren, Senem; Hazi, Agnes; Silva, Jennifer; Christianson, John P; Kent, Stephen

2005-10-01

The present study compared the effects of three different water temperatures (20, 25, and 30 degrees C) and stressor controllability on several physiological and behavioral endpoints in an intermittent swim stress paradigm. The escape latency of rats in the 20 and 25 degrees C water was less than that observed for the 30 degrees C group. Both escape and yoked groups at 20 and 25 degrees C exhibited moderate to severe hypothermia following the swim stress session that returned to prestress levels 30-40 min post-stress. At 30 degrees C core body temperature (Tb) only decreased by 1 degree C for either swim group. Following swim, serum corticosterone (CORT) levels were significantly elevated in both escape and yoked groups in comparison to confined and home cage controls. The confined control group showed a significant elevation that was approximately halfway between the home cage control and the swim stress groups. At 30 degrees C, there was still a significant elevation of serum CORT in both swim groups in comparison to confined and home cage controls. Therefore, 30 degrees C appears to be the optimal water temperature to evaluate stress controllability effects in the current paradigm. In a final experiment, swim stressor controllability effects were examined in a 5 min forced swim test (FST) 24 h following the initial stress exposure. Rats exposed to yoked-inescapable swim stress at 30 degrees C exhibited more immobility than their escapable swim stress and confined counterparts, while the escape and confined controls did not differ. These results demonstrate that the behavioral deficits observed in the FST are attributable to the stress of inescapable swim and not swim stress per se.

The effect of nandrolone treatment with and without enforced swimming on histological and biochemical changes in the heart and coronary artery of male rats

PubMed Central

Tofighi, Asghar; Shirpoor, Minoo; Ansari, Mohammad Hasan Khadem; Shirpoor, Alireza; Zerehpoosh, Mitra

2017-01-01

Objective: Chronic anabolic androgenic steroid (AAS) consumption increases incidence of cardiovascular abnormalities in athletes and mechanisms underlying those abnormalities continue to be investigated. This study examines whether nandrolone consumption induced cardiac and coronary artery wall abnormalities via oxidative stress. It was also designed to determine whether enforced swimming augmented possible cardiotoxic effects of nandrolone in rat heart. Methods: Twenty-four male Wistar rats were divided into 3 groups: control, nandrolone, and nandrolone with enforced swimming. Nandrolone group received 10 mg/kg body weight nandrolone 3 times a week for 6 weeks. Nandrolone group with enforced swimming received the same amount of nandrolone and was forced to swim with excess weight of 20% body weight. Results: After 6 weeks of treatment, results indicated proliferation of heart muscle and coronary smooth muscle cells and lipid peroxidation; significant rise in levels of 8-hydroxy-2’-deoxyguanosine (8-OHdG), nicotinamide adenine dinucleotide phosphate oxidase, homocysteine (Hcy), apolipoprotein B, low-density lipoprotein, and cholesterol, as well as severe fibrosis in heart tissue and around coronary arteries of nandrolone and nandrolone with enforced swimming groups compared with control group. Conclusion: These findings strongly support idea that nandrolone intake by sedentary rats and exercised rats induced heart abnormality mediated by oxidative stress, which was manifest in increased lipid peroxidation, Hcy, and 8-OHdG in heart tissue. PMID:27752030

Arctigenin enhances swimming endurance of sedentary rats partially by regulation of antioxidant pathways

PubMed Central

Wu, Ruo-ming; Sun, Yan-yan; Zhou, Ting-ting; Zhu, Zhi-yuan; Zhuang, Jing-jing; Tang, Xuan; Chen, Jing; Hu, Li-hong; Shen, Xu

2014-01-01

Aim: Arctigenin, a phenylpropanoid dibenzylbutyrolactone lignan found in traditional Chinese herbs, has been determined to exhibit a variety of pharmacological activities, including anti-tumor, anti-inflammation, neuroprotection, and endurance enhancement. In the present study, we investigated the antioxidation and anti-fatigue effects of arctigenin in rats. Methods: Rat L6 skeletal muscle cell line was exposed to H2O2 (700 μmol/L), and ROS level was assayed using DCFH-DA as a probe. Male SD rats were injected with arctigenin (15 mg·kg−1·d−1, ip) for 6 weeks, and then the weight-loaded forced swimming test (WFST) was performed to evaluate their endurance. The levels of antioxidant-related genes in L6 cells and the skeletal muscles of rats were analyzed using real-time RT-PCR and Western blotting. Results: Incubation of L6 cells with arctigenin (1, 5, 20 μmol/L) dose-dependently decreased the H2O2-induced ROS production. WFST results demonstrated that chronic administration of arctigenin significantly enhanced the endurance of rats. Furthermore, molecular biology studies on L6 cells and skeletal muscles of the rats showed that arctigenin effectively increased the expression of the antioxidant-related genes, including superoxide dismutase (SOD), glutathione reductase (Gsr), glutathione peroxidase (GPX1), thioredoxin (Txn) and uncoupling protein 2 (UCP2), through regulation of two potential antioxidant pathways: AMPK/PGC-1α/PPARα in mitochondria and AMPK/p53/Nrf2 in the cell nucleus. Conclusion: Arctigenin efficiently enhances rat swimming endurance by elevation of the antioxidant capacity of the skeletal muscles, which has thereby highlighted the potential of this natural product as an antioxidant in the treatment of fatigue and related diseases. PMID:25152028

Prevention of atherosclerosis by Yindan Xinnaotong capsule combined with swimming in rats.

PubMed

Wang, Jianlu; Wang, Lan; Yang, Hongjun; You, Yun; Xu, Haiyu; Gong, Leilei; Yin, Xiaojie; Wang, Wandan; Gao, Shuangrong; Cheng, Long; Liang, Rixin; Liao, Fulong

2015-04-08

Yindan Xinnaotong capsule has been used for treating cardio-cerebrovascular diseases for several decades in China. Exercise training can protect against the development of atherosclerosis. The aim of the present study is to evaluate the joint effect of YXC and exercise on atherosclerosis in rats. A combined method involving low shear stress and a high-fat diet was used to establish the atherosclerosis model in rats. Partial ligation of the left common carotid artery was performed, and then the rats were divided into 9 treatment groups according to a 3 × 3 factorial design with two factors and three levels for each factor, swimming of 0, 0.5, 1 h daily and YXC administration of 0, 1, 2 g/kg p.o. daily. Next the interventions of swimming and YXC were executed for 8 weeks. After that, blood samples were collected to determine blood viscosity, plasma viscosity, haematocrit (HCT), fibrinogen (FIB), blood lipid profile (including total cholesterol (TC), low-density lipoprotein-cholesterol (LDL-C), triglyceride (TG) and high-density lipoprotein-cholesterol (HDL-C)), nitric oxide (NO), 6-keto- prostaglandin (PG) F1α, endothelin (ET) and thromboxane (TX) B2. The common carotid arteries of the rats were harvested to examine pathological changes, wall thickness and circumference, and the expression of SM22αwas assayed via immune-histochemistry. The early pathological changes were observed. The joint effects of YXC and swimming showed significant changes in the examined parameters: (1) decreases in plasma viscosity, blood viscosity and FIB; (2) increases in NO and 6-keto-PGF1α; (3) decreases in ET and TXB2; and (4) decreases in LDL-C and TG. The combination of 2 g/kg YXC and 1 h of swimming led to synergistic decreases in LDL-C and TG. The interactive effect between YXC and swimming was obvious in decreasing wall thickness. Swimming alone was able to up-regulate the expression of SM22α. In conclusion, this study indicates that the combination of YXC and swimming may

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

Psychostimulants and forced swim stress interaction: how activation of the hypothalamic-pituitary-adrenal axis and stress-induced hyperglycemia are affected.

PubMed

Gagliano, Humberto; Ortega-Sanchez, Juan Antonio; Nadal, Roser; Armario, Antonio

2017-10-01

We recently reported that simultaneous exposure to amphetamine and various stressors resulted in reduced hypothalamic-pituitary-adrenal (HPA) and glycemic responses to the stressors. Since this is a new and relevant phenomenon, we wanted to further explore this interaction. This study aims (i) to characterize the effect of various doses of amphetamine on the physiological response to a predominantly emotional stressor (forced swim) when the drug was given immediately before stress; (ii) to study if an interaction appears when the drug was given 30 min or 7 days before swim; and (iii) to know whether cocaine causes similar effects when given just before stress. Adult male rats were used and plasma levels of ACTH, corticosterone, and glucose were the outcomes. Amphetamine caused a dose-dependent activation of the HPA axis, but all doses reduced HPA and glycemic responses to swim when given just before the stressor. Importantly, during the post-swim period, the stressor potently inhibited the ACTH response to amphetamine, demonstrating mutual inhibition between the two stimuli. The highest dose of amphetamine also reduced the response to swim when given 30 min before stress, whereas it caused HPA sensitization when given 7 days before. Cocaine also reduced stress-induced HPA activation when given just before swim. The present results demonstrate a negative synergy between psychostimulants (amphetamine and cocaine) and stress regarding HPA and glucose responses when rats were exposed simultaneously to both stimuli. The inhibitory effect of amphetamine is also observed when given shortly before stress, but not some days before.

Oxidative Stress Status and Placental Implications in Diabetic Rats Undergoing Swimming Exercise After Embryonic Implantation

PubMed Central

Damasceno, Débora Cristina; Sinzato, Yuri Karen; Ribeiro, Viviane Maria; Rudge, Marilza Vieira Cunha; Calderon, Iracema Mattos Paranhos

2015-01-01

The potential benefits and risks of physical exercise on fetal development during pregnancy remain unclear. The aim was to analyze maternal oxidative stress status and the placental morphometry to relate to intrauterine growth restriction (IUGR) from diabetic female rats submitted to swimming program after embryonic implantation. Pregnant Wistar rats were distributed into 4 groups (11 animals/group): control—nondiabetic sedentary rats, control exercised—nondiabetic exercised rats, diabetic—diabetic sedentary rats, and diabetic exercised—diabetic exercised rats. A swimming program was used as an exercise model. At the end of pregnancy, the maternal oxidative stress status, placental morphology, and fetal weight were analyzed. The swimming program was not efficient to reduce the hyperglycemia-induced oxidative stress. This fact impaired placental development, resulting in altered blood flow and energy reserves, which contributed to a deficient exchange of nutrients and oxygen for the fetal development, leading to IUGR. PMID:25361551

Participation of hippocampal nitric oxide synthase and soluble guanylate cyclase in the modulation of behavioral responses elicited by the rat forced swimming test.

PubMed

Sales, Amanda J; Hiroaki-Sato, Vinícius A; Joca, Sâmia R L

2017-02-01

Systemic or hippocampal administration of nitric oxide (NO) synthase inhibitors induces antidepressant-like effects in animals, implicating increased hippocampal levels of NO in the neurobiology of depression. However, the role played by different NO synthase in this process has not been clearly defined. As stress is able to induce neuroinflammatory mechanisms and trigger the expression of inducible nitric oxide synthase (iNOS) in the brain, as well as upregulate neuronal nitric oxide synthase (nNOS) activity, the aim of the present study was to investigate the possible differential contribution of hippocampal iNOS and nNOS in the modulation of the consequences of stress elicited by the forced swimming test. Male Wistar rats received intrahippocampal injections, immediately after the pretest or 1 h before the forced swimming test, of selective inhibitors of nNOS (N-propyl-L-arginine), iNOS (1400W), or sGC (ODQ), the main pharmacological target for NO. Stress exposure increased nNOS and phospho-nNOS levels at all time points, whereas iNOS expression was increased only 24 h after the pretest. All drugs induced an antidepressant-like effect. However, whereas the nNOS inhibitor was equally effective when injected at different times, the iNOS inhibitor was more effective 24 h after the pretest. These results suggest that hippocampal nNOS and iNOS contribute to increase in NO levels in response to stress, although with a differential time course after stress exposure.

Comparison of time-dependent effects of (+)-methamphetamine or forced swim on monoamines, corticosterone, glucose, creatine, and creatinine in rats.

PubMed

Herring, Nicole R; Schaefer, Tori L; Tang, Peter H; Skelton, Matthew R; Lucot, James P; Gudelsky, Gary A; Vorhees, Charles V; Williams, Michael T

2008-05-30

Methamphetamine (MA) use is a worldwide problem. Abusers can have cognitive deficits, monoamine reductions, and altered magnetic resonance spectroscopy findings. Animal models have been used to investigate some of these effects, however many of these experiments have not examined the impact of MA on the stress response. For example, numerous studies have demonstrated (+)-MA-induced neurotoxicity and monoamine reductions, however the effects of MA on other markers that may play a role in neurotoxicity or cell energetics such as glucose, corticosterone, and/or creatine have received less attention. In this experiment, the effects of a neurotoxic regimen of (+)-MA (4 doses at 2 h intervals) on brain monoamines, neostriatal GFAP, plasma corticosterone, creatinine, and glucose, and brain and muscle creatine were evaluated 1, 7, 24, and 72 h after the first dose. In order to compare MA's effects with stress, animals were subjected to a forced swim test in a temporal pattern similar to MA administration [i.e., (30 min/session) 4 times at 2 h intervals]. MA increased corticosterone from 1-72 h with a peak 1 h after the first treatment, whereas glucose was only increased 1 h post-treatment. Neostriatal and hippocampal monoamines were decreased at 7, 24, and 72 h, with a concurrent increase in GFAP at 72 h. There was no effect of MA on regional brain creatine, however plasma creatinine was increased during the first 24 h and decreased by 72 h. As with MA treatment, forced swim increased corticosterone more than MA initially. Unlike MA, forced swim reduced creatine in the cerebellum with no change in other brain regions while plasma creatinine was decreased at 1 and 7 h. Glucose in plasma was decreased at 7 h. Both MA and forced swim increase demand on energy substrates but in different ways, and MA has persistent effects on corticosterone that are not attributable to stress alone.

Comparison of time-dependent effects of (+)-methamphetamine or forced swim on monoamines, corticosterone, glucose, creatine, and creatinine in rats

PubMed Central

Herring, Nicole R; Schaefer, Tori L; Tang, Peter H; Skelton, Matthew R; Lucot, James P; Gudelsky, Gary A; Vorhees, Charles V; Williams, Michael T

2008-01-01

Background Methamphetamine (MA) use is a worldwide problem. Abusers can have cognitive deficits, monoamine reductions, and altered magnetic resonance spectroscopy findings. Animal models have been used to investigate some of these effects, however many of these experiments have not examined the impact of MA on the stress response. For example, numerous studies have demonstrated (+)-MA-induced neurotoxicity and monoamine reductions, however the effects of MA on other markers that may play a role in neurotoxicity or cell energetics such as glucose, corticosterone, and/or creatine have received less attention. In this experiment, the effects of a neurotoxic regimen of (+)-MA (4 doses at 2 h intervals) on brain monoamines, neostriatal GFAP, plasma corticosterone, creatinine, and glucose, and brain and muscle creatine were evaluated 1, 7, 24, and 72 h after the first dose. In order to compare MA's effects with stress, animals were subjected to a forced swim test in a temporal pattern similar to MA administration [i.e., (30 min/session) 4 times at 2 h intervals]. Results MA increased corticosterone from 1–72 h with a peak 1 h after the first treatment, whereas glucose was only increased 1 h post-treatment. Neostriatal and hippocampal monoamines were decreased at 7, 24, and 72 h, with a concurrent increase in GFAP at 72 h. There was no effect of MA on regional brain creatine, however plasma creatinine was increased during the first 24 h and decreased by 72 h. As with MA treatment, forced swim increased corticosterone more than MA initially. Unlike MA, forced swim reduced creatine in the cerebellum with no change in other brain regions while plasma creatinine was decreased at 1 and 7 h. Glucose in plasma was decreased at 7 h. Conclusion Both MA and forced swim increase demand on energy substrates but in different ways, and MA has persistent effects on corticosterone that are not attributable to stress alone. PMID:18513404

Estradiol or fluoxetine alters depressive behavior and tryptophan hydroxylase in rat raphe.

PubMed

Yang, Fu-Zhong; Wu, Yan; Zhang, Wei-Guo; Cai, Yi-Yun; Shi, Shen-Xun

2010-03-10

The effects of 17beta-estradiol and fluoxetine on behavior of ovariectomized rats subjected to the forced swimming test and the expression of tryptophan hydroxylase (TPH) in dorsal and median raphe were investigated, respectively through time sampling technique of behavior scoring and immunohistochemistry. Both estradiol and fluoxetine increased swimming and decreased immobility in the forced swimming test. The forced swimming stress decreased integrated optical density of TPH-positive regions in dorsal and median raphe. Both estradiol and fluoxetine administration prevented integrated optical density of TPH-positive regions from being decreased by forced swimming stress. These observations suggest that both estradiol and fluoxetine have protective bearing on ovariectomized rats enduring forced swimming stress.

Effects of a flavonoid extract from Cynomorium songaricum on the swimming endurance of rats.

PubMed

Yu, Fa-Rong; Liu, Ying; Cui, Yong-Zhi; Chan, Er-Qing; Xie, Ming-Ren; McGuire, Peter P; Yu, Fa-Hong

2010-01-01

The present study investigated the effects of a flavonoid extract from Cynomorium songaricum on the swimming endurance of rats by measuring changes of free radical scavenging enzymes, such as CuZn-SOD (copper, zinc-superoxide dismutase) and GSH-px (glutathione peroxidase), and body weights. Significant and dose-dependent antioxidant and anti-fatigue effects of flavonoids (rutin, catechin and isoquercitrin) on swimming rats were observed during 10 days of swimming exercise. After treatment with the flavonoid extract at doses of 0.5, 1.0, and 2.0 g/kg body weight, the CuZn-SOD and GSH-px activities in swimming rats were increased by 1.4%, 3.3%, 4.1% and 112.2%, 208.7%, 261.7%, respectively, while the levels of MDA (malondialdehyde) were decreased by 64.7%, 79.4%, and 86.4% respectively. Furthermore, the average body weight and the total swimming time were increased by 3.1%, 8.8%, 10.6%, and 7.7%, 34.5%, 61.5%, respectively. Our experimental results suggest that flavonoid supplementation could not only reduce free radical formation and scavenge free radicals, but also enhance endurance exercise performance by reducing muscle fatigue.

Effects of high-intensity swimming training on the bones of ovariectomized rats

PubMed Central

Oh, Taewoong; Tanaka, Sakura; Naka, Tatsuki; Igawa, Shoji

2016-01-01

[Purpose] This study was performed to assess the effects of high-intensity intermittent swimming training(HIT) on bone in ovariectomized rats. [Methods] Six-week-old female Sprague-Dawley rats were randomly assigned to either sham operation or bilateral ovariectomy. After surgery, they were divided into the following four groups: 1) sham-operated sedentary (S), 2) sham-operated exercise training (SE), 3) OVX sedentary (O), 4) OVX exercise training (OE) 5) OVX given 17β-estradiol (OE2) and 6) OVX exercise training and given 17β-estradiol (OEE). SE, OE and OEE rats were used extremely high-intensity swim exercise. The rats repeated fourteen 20-s swimming bouts with a weight equivalent to 14, 15, and 16% of body weight for the first 5, the next 9, and the last 5 days, respectively. Between exercise bouts, a 10-s pause was allowed. HIT was originally designed as an exercise method; a method that very quickly induces an increase in the maximum oxygen intake (Tabata I et al., 1996). OEE and OE2 rats were subcutaneously injected ethanol with 25μg/kg body weight 17β-estradiol 3 times per week. [Results] Bone strength, bone mineral density and trabecular bone parameters were measured after a 8-weeks experimental period. Bone strength was significantly higher in the SE, OE, OE2 and OEE group compared with the O group. BV/TV was significant increase in the SE, OE groups compared with the O group. BMD showed no difference in the OE group compared with the O group. [Conclusion] This study demonstrate some beneficial effects of postmenopausal osteoporosis of high-intensity intermittent swimming training on bone structure and strength. PMID:27757386

Effects of high-intensity swimming training on the bones of ovariectomized rats.

PubMed

Oh, Taewoong; Tanaka, Sakura; Naka, Tatsuki; Igawa, Shoji

2016-09-01

This study was performed to assess the effects of high-intensity intermittent swimming training(HIT) on bone in ovariectomized rats. Six-week-old female Sprague-Dawley rats were randomly assigned to either sham operation or bilateral ovariectomy. After surgery, they were divided into the following four groups: 1) sham-operated sedentary (S), 2) sham-operated exercise training (SE), 3) OVX sedentary (O), 4) OVX exercise training (OE) 5) OVX given 17β-estradiol (OE2) and 6) OVX exercise training and given 17β-estradiol (OEE). SE, OE and OEE rats were used extremely high-intensity swim exercise. The rats repeated fourteen 20-s swimming bouts with a weight equivalent to 14, 15, and 16% of body weight for the first 5, the next 9, and the last 5 days, respectively. Between exercise bouts, a 10-s pause was allowed. HIT was originally designed as an exercise method; a method that very quickly induces an increase in the maximum oxygen intake (Tabata I et al., 1996). OEE and OE2 rats were subcutaneously injected ethanol with 25μg/kg body weight 17β-estradiol 3 times per week. Bone strength, bone mineral density and trabecular bone parameters were measured after a 8-weeks experimental period. Bone strength was significantly higher in the SE, OE, OE2 and OEE group compared with the O group. BV/TV was significant increase in the SE, OE groups compared with the O group. BMD showed no difference in the OE group compared with the O group. This study demonstrate some beneficial effects of postmenopausal osteoporosis of high-intensity intermittent swimming training on bone structure and strength.

Swim training and the genetic expression of adipokines in monosodium glutamate-treated obese rats.

PubMed

Svidnicki, Paulo Vinicius; Leite, Nayara Carvalho; Vicari, Marcelo Ricardo; Almeida, Mara Cristina de; Artoni, Roberto Ferreira; Favero, Giovani Marino; Grassiolli, Sabrina; Nogaroto, Viviane

2015-06-01

The aim of this study was to evaluate the genetic expression of adipokines in the adipocytes of monosodium glutamate (MSG)-treated obese rats submitted to physical activity. Obesity was induced by neonatal MSG administration. Exercised rats (MSG and control) were subjected to swim training for 30 min for 10 weeks, whereas their respective controls remained sedentary. Total RNA was obtained from sections of the mesenteric adipose tissue of the rats. mRNA levels of adiponectin (Adipoq), tumor necrosis factor alpha (Tnf), peroxisome proliferator-activated receptor alpha (Ppara), and peroxisome proliferator-activated receptor gamma (Pparg) adipokines were quantified by quantitative Real-Time Polymerase Chain Reaction (qRT-PCR). In the exercise-trained control group, the expression of Adipoq increased compared to the sedentary control, which was not observed in the MSG-obese rats. Increased levels of Tnf in MSG-obese rats were not reversed by the swim training. The expression of Ppara was higher in sedentary MSG-obese rats compared to the sedentary control. Swimming increased this adipokine expression in the exercise-trained control rats compared to the sedentary ones. mRNA levels of Pparg were higher in the sedentary MSG-rats compared to the sedentary control; however, the exercise did not influenced its expression in the groups analyzed. In conclusion, regular physical activity was not capable to correct the expression of proinflammatory adipokines in MSG-obese rat adipocytes.

Aerobic and Anaerobic Swimming Force Evaluation in One Single Test Session for Young Swimmers.

PubMed

de Barros Sousa, Filipe Antônio; Rodrigues, Natalia Almeida; Messias, Leonardo Henrique Dalcheco; Queiroz, Jair Borges; Manchado-Gobatto, Fulvia Barros; Gobatto, Claudio Alexandre

2017-05-01

This study aims to propose and validate the tethered swimming lactate minimum test (TSLacmin) estimating aerobic and anaerobic capacity in one single test session, using force as measurement parameter. 6 male and 6 female young swimmers (age=15.7±1.1 years; height=173.3±9.5 cm; weight=66.1±9.5 kg) performed 4 sessions comprising i) an all-out 30 s test and incremental test (TSLacmin); ii) 30 min of tethered swimming at constant intensity (2 sessions); iii) free-swimming time trials used to calculate critical velocity. Tethered swimming sessions used an acquisition system enabling maximum (Fmax) and mean (Fmean) force measurement and intensity variation. The tethered all-out test lasting 30 s resulted in hyperlactatemia of 7.9±2.0 mmol·l -1 . TSLacmin presented a 100% success applicability rate, which is equivalent to aerobic capacity in 75% of cases. TSLacmin intensity was 37.7±7.3 N, while maximum force in the all-out test was 105±27 N. Aerobic and anaerobic TSLacmin parameters were significantly related to free-swimming performance (r=-0.67 for 100 m and r=-0.80 for 200 m) and critical velocity (r=0.80). TSLacmin estimates aerobic capacity in most cases, and both aerobic and anaerobic force parameters are well related to critical velocity and free swimming performance. © Georg Thieme Verlag KG Stuttgart · New York.

Effects of Forced Swimming Stress on ERK and Histone H3 Phosphorylation in Limbic Areas of Roman High- and Low-Avoidance Rats.

PubMed

Morello, Noemi; Plicato, Ornella; Piludu, Maria Antonietta; Poddighe, Laura; Serra, Maria Pina; Quartu, Marina; Corda, Maria Giuseppa; Giorgi, Osvaldo; Giustetto, Maurizio

2017-01-01

Stressful events evoke molecular adaptations of neural circuits through chromatin remodeling and regulation of gene expression. However, the identity of the molecular pathways activated by stress in experimental models of depression is not fully understood. We investigated the effect of acute forced swimming (FS) on the phosphorylation of the extracellular signal-regulated kinase (ERK)1/2 (pERK) and histone H3 (pH3) in limbic brain areas of genetic models of vulnerability (RLA, Roman low-avoidance rats) and resistance (RHA, Roman high-avoidance rats) to stress-induced depression-like behavior. We demonstrate that FS markedly increased the density of pERK-positive neurons in the infralimbic (ILCx) and the prelimbic area (PrLCx) of the prefrontal cortex (PFCx), the nucleus accumbens, and the dorsal blade of the hippocampal dentate gyrus to the same extent in RLA and RHA rats. In addition, FS induced a significant increase in the intensity of pERK immunoreactivity (IR) in neurons of the PFCx in both rat lines. However, RHA rats showed stronger pERK-IR than RLA rats in the ILCx both under basal and stressed conditions. Moreover, the density of pH3-positive neurons was equally increased by FS in the PFCx of both rat lines. Interestingly, pH3-IR was higher in RHA than RLA rats in PrLCx and ILCx, either under basal conditions or upon FS. Finally, colocalization analysis showed that in the PFCx of both rat lines, almost all pERK-positive cells express pH3, whereas only 50% of the pH3-positive neurons is also pERK-positive. Moreover, FS increased the percentage of neurons that express exclusively pH3, but reduced the percentage of cells expressing exclusively pERK. These results suggest that (i) the distinctive patterns of FS-induced ERK and H3 phosphorylation in the PFCx of RHA and RLA rats may represent molecular signatures of the behavioural traits that distinguish the two lines and (ii) FS-induced H3 phosphorylation is, at least in part, ERK-independent.

Effects of Forced Swimming Stress on ERK and Histone H3 Phosphorylation in Limbic Areas of Roman High- and Low-Avoidance Rats

PubMed Central

Piludu, Maria Antonietta; Poddighe, Laura; Serra, Maria Pina; Quartu, Marina; Corda, Maria Giuseppa; Giorgi, Osvaldo

2017-01-01

Stressful events evoke molecular adaptations of neural circuits through chromatin remodeling and regulation of gene expression. However, the identity of the molecular pathways activated by stress in experimental models of depression is not fully understood. We investigated the effect of acute forced swimming (FS) on the phosphorylation of the extracellular signal-regulated kinase (ERK)1/2 (pERK) and histone H3 (pH3) in limbic brain areas of genetic models of vulnerability (RLA, Roman low-avoidance rats) and resistance (RHA, Roman high-avoidance rats) to stress-induced depression-like behavior. We demonstrate that FS markedly increased the density of pERK-positive neurons in the infralimbic (ILCx) and the prelimbic area (PrLCx) of the prefrontal cortex (PFCx), the nucleus accumbens, and the dorsal blade of the hippocampal dentate gyrus to the same extent in RLA and RHA rats. In addition, FS induced a significant increase in the intensity of pERK immunoreactivity (IR) in neurons of the PFCx in both rat lines. However, RHA rats showed stronger pERK-IR than RLA rats in the ILCx both under basal and stressed conditions. Moreover, the density of pH3-positive neurons was equally increased by FS in the PFCx of both rat lines. Interestingly, pH3-IR was higher in RHA than RLA rats in PrLCx and ILCx, either under basal conditions or upon FS. Finally, colocalization analysis showed that in the PFCx of both rat lines, almost all pERK-positive cells express pH3, whereas only 50% of the pH3-positive neurons is also pERK-positive. Moreover, FS increased the percentage of neurons that express exclusively pH3, but reduced the percentage of cells expressing exclusively pERK. These results suggest that (i) the distinctive patterns of FS-induced ERK and H3 phosphorylation in the PFCx of RHA and RLA rats may represent molecular signatures of the behavioural traits that distinguish the two lines and (ii) FS-induced H3 phosphorylation is, at least in part, ERK-independent. PMID:28107383

Omega-3 Fatty Acid Deficient Male Rats Exhibit Abnormal Behavioral Activation in the Forced Swim Test Following Chronic Fluoxetine Treatment: Association with Altered 5-HT1A and Alpha2A Adrenergic Receptor Expression

PubMed Central

Able, Jessica A.; Liu, Yanhong; Jandacek, Ronald; Rider, Therese; Tso, Patrick; McNamara, Robert K.

2014-01-01

Omega-3 fatty acid deficiency during development leads to enduing alterations in central monoamine neurotransmission in rat brain. Here we investigated the effects of omega-3 fatty acid deficiency on behavioral and neurochemical responses to chronic fluoxetine (FLX) treatment. Male rats were fed diets with (CON, n=34) or without (DEF, n=30) the omega-3 fatty acid precursor alpha-linolenic acid (ALA) during peri-adolescent development (P21-P90). A subset of CON (n=14) and DEF (n=12) rats were administered FLX (10 mg/kg/d) through their drinking water for 30 d beginning on P60. The forced swimming test (FST) was initiated on P90, and regional brain mRNA markers of serotonin and noradrenaline neurotransmission were determined. Dietary ALA depletion led to significant reductions in frontal cortex docosahexaenoic acid (DHA, 22:6n-3) composition in DEF (−26%, p=0.0001) and DEF+FLX (−32%, p=0.0001) rats. Plasma FLX and norfluoxetine concentrations did not different between FLX-treated DEF and CON rats. During the 15-min FST pretest, DEF+FLX rats exhibited significantly greater climbing behavior compared with CON+FLX rats. During the 5-min test trial, FLX treatment reduced immobility and increased swimming in CON and DEF rats, and only DEF+FLX rats exhibited significant elevations in climbing behavior. DEF+FLX rats exhibited greater midbrain, and lower frontal cortex, 5-HT1A mRNA expression compared with all groups including CON+FLX rats. DEF+FLX rats also exhibited greater midbrain alpha2A adrenergic receptor mRNA expression which was positively correlated with climbing behavior in the FST. These preclinical data demonstrate that low omega-3 fatty acid status leads to abnormal behavioral and neurochemical responses to chronic FLX treatment in male rats. PMID:24360505

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.

Inhibition of the CRF1 receptor influences the activity of antidepressant drugs in the forced swim test in rats.

PubMed

Wróbel, Andrzej; Serefko, Anna; Szopa, Aleksandra; Rojek, Karol; Poleszak, Ewa; Skalicka-Woźniak, Krystyna; Dudka, Jarosław

2017-08-01

Hyperactivity of the hypothalamic-pituitary-adrenal axis (HPA) and impairment of the central corticotropin-releasing factor (CRF) system are factors in the pathogenesis of depression. Though several antagonists of the CRF 1 receptor were effective in the recognized behavioral tests for antidepressant activity, there is still little information on the potential interactions between CRF 1 receptor inhibitors and conventional antidepressant therapy. The aim of our study was to assess the influence of SN003, a CRF 1 receptor blocker, on the activity of imipramine and fluoxetine in the forced swim test (FST) in rats which presented some signs of depression. The experiments were carried out on female Wistar rats subjected to 14-day subcutaneous corticosterone (CORT) administration (20 mg/kg/day). The antidepressant-like effect was determined by the FST and the CRF levels in the hypothalamus, amygdala, and peripheral blood were measured by a high-sensitivity immunoenzymatic test. SN003 (0.5 mg/kg) potentiated the antidepressant-like effect of imipramine (15 mg/kg) and fluoxetine (7.5 mg/kg). Moreover, the co-administration of the tested agents abolished CORT-induced increase in CRF levels in the examined biological material more profoundly than monotherapy. Our present findings give further evidence that the blockage of CRF action may be useful in the treatment of mood disorders. The concurrent use of well-known antidepressants with CRF 1 receptor antagonists could be beneficial in terms of safety, since it requires lower doses of the applied agents.

Fluoxetine, 17-β estradiol or folic acid combined with intra-lateral septal infusions of neuropeptide Y produced antidepressant-like actions in ovariectomized rats forced to swim.

PubMed

Molina-Hernández, Miguel; Téllez-Alcántara, N Patricia

2011-12-01

Folic acid is antidepressant, either alone or combined with several antidepressant drugs. However, the antidepressant-like actions of folic acid combined with intra-lateral septal (LSN) infusions of neuropeptide Y (NPY) in the forced swimming test (FST) have not been tested before. Thus, systemic injections of fluoxetine (20.0mg/kg, P<0.05; s.c.) or 17-β estradiol (10.0 μg/rat, P<0.05; s.c.) or oral administrations of folic acid (50.0 mg/kg, P<0.05; 75.0 mg/kg, P<0.05) or NPY intra-LSN (3.0 μg, P<0.05; 3.5 μg, P<0.05) reduced immobility of ovariectomized Wistar rats. Subthreshold doses of: folic acid (25.0 mg/kg) or 17-β estradiol (5.0 μg/rat, P<0.05) or fluoxetine (15.0 mg/kg, P<0.05; s.c.) combined with subthreshold doses of NPY (2.5 μg/rat, P<0.05; intra-LSN) and these combinations produced antidepressant-like actions; which were canceled by BIBP 3226 (a NPY-Y1 receptor antagonist). It is concluded that folic acid produced antidepressant-like effects probably through the participation of the NPY Y1 receptors found in the lateral septal nuclei. Copyright © 2011 Elsevier Inc. All rights reserved.

The antidepressant-like effect of ethynyl estradiol is mediated by both serotonergic and noradrenergic systems in the forced swimming test.

PubMed

Vega-Rivera, N M; López-Rubalcava, C; Estrada-Camarena, E

2013-10-10

17α-Ethynyl-estradiol (EE2, a synthetic steroidal estrogen) induces antidepressant-like effects in the forced swimming test (FST) similar to those induced by 5-HT and noradrenaline reuptake inhibitors (dual antidepressants). However, the precise mechanism of action of EE2 has not been studied. In the present study, the participation of estrogen receptors (ERs) and the serotonergic and the noradrenergic presynaptic sites in the antidepressant-like action of EE2 was evaluated in the FST. The effects of the ER antagonist ICI 182,780 (10 μg/rat; i.c.v.), the serotonergic and noradrenergic terminal destruction with 5,7-dihydroxytryptamine (5,7-DHT; 200 μg/rat, i.c.v.), and N-(2-chloro-ethyl)-N-ethyl-2-bromobenzylamine (DSP4; 10mg/kg, i.p.) were studied in ovariectomized rats treated with EE2 and subjected to the FST. In addition, the participation of α2-adrenergic receptors in the antidepressant-like action of EE2 was explored using the selective α2-receptor antagonist idazoxan (0.25, 0.5 and 1.0mg/kg, i.p.). EE2 induced an antidepressant-like action characterized by a decrease in immobility behavior with a concomitant increase in swimming and climbing behaviors. The ER antagonist, 5,7-DHT, DSP4, and idazoxan blocked the effects of EE2 on the immobility behavior, whereas ICI 182,780 and 5,7-DHT affected swimming behavior. The noradrenergic compound DSP4 altered climbing behavior, while Idazoxan inhibited the increase of swimming and climbing behaviors induced by EE2. Our results suggest that the antidepressant-like action of EE2 implies a complex mechanism of action on monoaminergic systems and estrogen receptors. Copyright © 2013 IBRO. Published by Elsevier Ltd. All rights reserved.

Maternal Forced Swimming Reduces Cell Proliferation in the Postnatal Dentate Gyrus of Mouse Offspring

PubMed Central

Wasinski, Frederick; Estrela, Gabriel R.; Arakaki, Aline M.; Bader, Michael; Alenina, Natalia; Klempin, Friederike; Araújo, Ronaldo C.

2016-01-01

Physical exercise positively affects the metabolism and induces proliferation of precursor cells in the adult brain. Maternal exercise likewise provokes adaptations early in the offspring. Using a high-intensity swimming protocol that comprises forced swim training before and during pregnancy, we determined the effect of maternal swimming on the mouse offspring's neurogenesis. Our data demonstrate decreased proliferation in sublayers of the postnatal dentate gyrus in offspring of swimming mother at postnatal day (P) 8 accompanied with decreased survival of newly generated cells 4 weeks later. The reduction in cell numbers was predominantly seen in the hilus and molecular layer. At P35, the reduced amount of cells was also reflected by a decrease in the population of newly generated immature and mature neurons of the granule cell layer. Our data suggest that forced maternal swimming at high-intensity has a negative effect on the neurogenic niche development in postnatal offspring. PMID:27621701

Glycolytic and mitochondrial metabolism in pancreatic islets from MSG-treated obese rats subjected to swimming training.

PubMed

Leite, Nayara de Carvalho; Ferreira, Thiago Rentz; Rickli, Sarah; Borck, Patricia Cristine; Mathias, Paulo Cezar de Freitas; Emilio, Henriette Rosa de Oliveira; Grassiolli, Sabrina

2013-01-01

Obese rats obtained by neonatal monosodium glutamate (MSG) administration present insulin hypersecretion. The metabolic mechanism by which glucose catabolism is coupled to insulin secretion in the pancreatic β-cells from MSG-treated rats is understood. The purpose of this study was to evaluate glucose metabolism in pancreatic islets from MSG-treated rats subjected to swimming training. MSG-treated and control (CON) rats swam for 30 minutes (3 times/week) over a period of 10 weeks. Pancreatic islets were isolated and incubated with glucose in the presence of glycolytic or mitochondrial inhibitors. Swimming training attenuated fat pad accumulation, avoiding changes in the plasma levels of lipids, glucose and insulin in MSG-treated rats. Adipocyte and islet hypertrophy observed in MSG-treated rats were attenuated by exercise. Pancreatic islets from MSG-treated obese rats also showed insulin hypersecretion, greater glucose transporter 2 (GLUT2) expression, increased glycolytic flux and reduced mitochondrial complex III activity. Swimming training attenuated islet hypertrophy and normalised GLUT2 expression, contributing to a reduction in the glucose responsiveness of pancreatic islets from MSG-treated rats without altering glycolytic flux. However, physical training increased the activity of mitochondrial complex III in pancreatic islets from MSG-treated rats without a subsequent increase in glucose-induced insulin secretion. Copyright © 2013 S. Karger AG, Basel.

A pressure-based force and torque prediction technique for the study of fish-like swimming

PubMed Central

Dabiri, John O.; Lauder, George V.

2017-01-01

Many outstanding questions about the evolution and function of fish morphology are linked to swimming dynamics, and a detailed knowledge of time-varying forces and torques along the animal’s body is a key component in answering many of these questions. Yet, quantifying these forces and torques experimentally represents a major challenge that to date prevents a full understanding of fish-like swimming. Here, we develop a method for obtaining these force and torque data non-invasively using standard 2D digital particle image velocimetry in conjunction with a pressure field algorithm. We use a mechanical flapping foil apparatus to model fish-like swimming and measure forces and torques directly with a load cell, and compare these measured values to those estimated simultaneously using our pressure-based approach. We demonstrate that, when out-of-plane flows are relatively small compared to the planar flow, and when pressure effects sufficiently dominate shear effects, this technique is able to accurately reproduce the shape, magnitude, and timing of locomotor forces and torques experienced by a fish-like swimmer. We conclude by exploring of the limits of this approach and its feasibility in the study of freely-swimming fishes. PMID:29216264

Performance during a strenuous swimming session is associated with high blood lactate: pyruvate ratio and hypoglycemia in fasted rats

PubMed Central

Travassos, P.B.; Godoy, G.; De Souza, H.M.; Curi, R.; Bazotte, R.B.

2018-01-01

The aim of this study was to investigate the effect of lactatemia elevation and glycemia reduction on strenuous swimming performance in fasted rats. Three rats were placed in a swimming tank at the same time. The first rat was removed immediately (control group) and the remaining ones were submitted to a strenuous swimming session. After the second rat was exhausted (Exh group), the third one was immediately removed from the water (Exe group). According to the period of time required for exhaustion, the rats were divided into four groups: low performance (3–7 min), low-intermediary performance (8–12 min), high-intermediary performance (13–17 min), and high performance (18–22 min). All rats were removed from the swimming tanks and immediately killed by decapitation for blood collection or anesthetized for liver perfusion experiments. Blood glucose, lactate, and pyruvate concentrations, blood lactate/pyruvate ratio, and liver lactate uptake and its conversion to glucose were evaluated. Exhaustion in low and low-intermediary performance were better associated with higher lactate/pyruvate ratio. On the other hand, exhaustion in high-intermediary and high performance was better associated with hypoglycemia. Lactate uptake and glucose production from lactate in livers from the Exe and Exh groups were maintained. We concluded that there is a time sequence in the participation of lactate/pyruvate ratio and hypoglycemia in performance during an acute strenuous swimming section in fasted rats. The liver had an important participation in preventing hyperlactatemia and hypoglycemia during swimming through lactate uptake and its conversion to glucose. PMID:29590261

Performance during a strenuous swimming session is associated with high blood lactate: pyruvate ratio and hypoglycemia in fasted rats.

PubMed

Travassos, P B; Godoy, G; De Souza, H M; Curi, R; Bazotte, R B

2018-03-26

The aim of this study was to investigate the effect of lactatemia elevation and glycemia reduction on strenuous swimming performance in fasted rats. Three rats were placed in a swimming tank at the same time. The first rat was removed immediately (control group) and the remaining ones were submitted to a strenuous swimming session. After the second rat was exhausted (Exh group), the third one was immediately removed from the water (Exe group). According to the period of time required for exhaustion, the rats were divided into four groups: low performance (3-7 min), low-intermediary performance (8-12 min), high-intermediary performance (13-17 min), and high performance (18-22 min). All rats were removed from the swimming tanks and immediately killed by decapitation for blood collection or anesthetized for liver perfusion experiments. Blood glucose, lactate, and pyruvate concentrations, blood lactate/pyruvate ratio, and liver lactate uptake and its conversion to glucose were evaluated. Exhaustion in low and low-intermediary performance were better associated with higher lactate/pyruvate ratio. On the other hand, exhaustion in high-intermediary and high performance was better associated with hypoglycemia. Lactate uptake and glucose production from lactate in livers from the Exe and Exh groups were maintained. We concluded that there is a time sequence in the participation of lactate/pyruvate ratio and hypoglycemia in performance during an acute strenuous swimming section in fasted rats. The liver had an important participation in preventing hyperlactatemia and hypoglycemia during swimming through lactate uptake and its conversion to glucose.

Interactions between internal forces, body stiffness, and fluid environment in a neuromechanical model of lamprey swimming.

PubMed

Tytell, Eric D; Hsu, Chia-Yu; Williams, Thelma L; Cohen, Avis H; Fauci, Lisa J

2010-11-16

Animal movements result from a complex balance of many different forces. Muscles produce force to move the body; the body has inertial, elastic, and damping properties that may aid or oppose the muscle force; and the environment produces reaction forces back on the body. The actual motion is an emergent property of these interactions. To examine the roles of body stiffness, muscle activation, and fluid environment for swimming animals, a computational model of a lamprey was developed. The model uses an immersed boundary framework that fully couples the Navier-Stokes equations of fluid dynamics with an actuated, elastic body model. This is the first model at a Reynolds number appropriate for a swimming fish that captures the complete fluid-structure interaction, in which the body deforms according to both internal muscular forces and external fluid forces. Results indicate that identical muscle activation patterns can produce different kinematics depending on body stiffness, and the optimal value of stiffness for maximum acceleration is different from that for maximum steady swimming speed. Additionally, negative muscle work, observed in many fishes, emerges at higher tail beat frequencies without sensory input and may contribute to energy efficiency. Swimming fishes that can tune their body stiffness by appropriately timed muscle contractions may therefore be able to optimize the passive dynamics of their bodies to maximize peak acceleration or swimming speed.

Inhibition of the L-arginine-nitric oxide pathway mediates the antidepressant effects of ketamine in rats in the forced swimming test.

PubMed

Zhang, Guang-Fen; Wang, Nan; Shi, Jin-Yun; Xu, Shi-Xia; Li, Xiao-Min; Ji, Mu-Huo; Zuo, Zhi-Yi; Zhou, Zhi-Qiang; Yang, Jian-Jun

2013-09-01

Converging evidence shows that the acute administration of a sub-anaesthetic dose ketamine produces fast-acting and robust antidepressant properties in patients suffering from major depressive disorder. However, the underlying mechanisms have not been fully elucidated. The present study aimed to investigate the role of the L-arginine-nitric oxide pathway in the antidepressant effects of ketamine in rats performing the forced swimming test (FST). Ketamine (10 mg/kg) significantly decreased immobility times in the FST and the activities of total nitric oxide synthases (T-NOS), inducible NOS (iNOS), and endothelial NOS (eNOS) in the rat hippocampus. Interestingly, the plasma activities of T-NOS, iNOS, and eNOS increased after administration of ketamine. Furthermore, the activities of neuronal NOS (nNOS) did not change significantly in either the hippocampus or plasma after ketamine administration. The antidepressant effects of ketamine were prevented by pre-treatment with l-arginine (750 mg/kg). Pre-treatment with the NOS inhibitor L-NG-nitroarginine methyl ester at a sub-antidepressant dose of 50 mg/kg and ketamine at a sub-antidepressant dose of 3 mg/kg reduced immobility time in the FST compared to treatment with either drug alone. None of the drugs affected crossing and rearing scores in the open field test. These results suggest that the L-arginine-nitric oxide pathway is involved in the antidepressant effects of ketamine observed in rats in the FST and this involvement is characterised by the inhibition of brain T-NOS, iNOS, and eNOS activities. Copyright © 2013 Elsevier Inc. All rights reserved.

Using Magnetic Forces to Probe the Gravi-response of Swimming Paramecium

NASA Astrophysics Data System (ADS)

Guevorkian, Karine; Valles, James M., Jr.

2004-03-01

Paramecium Caudatum, a single celled ciliate, alters its swimming behavior when subjected to different gravity environments (e.g. centrifugation and micro-gravity). To dissect the mechanisms behind this gravi-response and that of other biological systems, we are developing the use of magnetic body forces as a means of creating a rapidly tunable, simulated variable gravity environment. Since biological materials are weakly diamagnetic, we must subject them to intense inhomogeneous magnetic fields with characteristic field-field gradient products on the order of 16 T^2/cm. We will describe experiments on Paramecium Caudatum in which we adjust their net buoyancy with magnetic forces and measure the resulting changes in their swimming behavior.

Swimming reduces the severity of physical and psychological dependence and voluntary morphine consumption in morphine dependent rats.

PubMed

Fadaei, Atefeh; Gorji, Hossein Miladi; Hosseini, Shahrokh Makvand

2015-01-15

Previous studies have indicated that voluntary exercise decreases the severity of the anxiogenic-like behaviors in both morphine-dependent and withdrawn rats. This study examined the effects of regular swimming exercise during the development of dependency and spontaneous morphine withdrawal on the anxiety-depression profile and voluntary morphine consumption in morphine dependent rats. The rats were chronically treated with bi-daily doses (10 mg/kg, at 12h intervals) of morphine over a period of 14 days. The exercising rats were allowed to swim (45 min/d, five days per a week, for 14 or 21 days) during the development of morphine dependence and withdrawal. Then, rats were tested for the severity of morphine dependence, the elevated plus-maze (EPM), sucrose preference test (SPT) and voluntary morphine consumption using a two-bottle choice paradigm in animal models of craving. The results showed that withdrawal signs were decreased in swimmer morphine dependent rats than sedentary rats (P<0.05). Also, the swimmer morphine-dependent and withdrawn rats exhibited an increase in EPM open arm time and entries (P<0.05), higher levels of sucrose preference (P<0.001) than sedentary rats. Voluntary consumption of oral morphine was less in the swimmer morphine-withdrawn rats than the sedentary groups during four periods of the intake of drug (P<0.01). We conclude that regular swimming exercise reduces the severity of morphine dependence and voluntary morphine consumption with reducing anxiety and depression in morphine-dependent and withdrawn rats. Thus, swimming exercise may be a potential method to ameliorate some of the deleterious behavioral consequences of morphine dependence. Copyright © 2014 Elsevier B.V. All rights reserved.

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.

The effect of intracerebroventricular allopregnanolone on depressive-like behaviors of rats selectively bred for high and low immobility in the forced swim test.

PubMed

Almeida, Felipe Borges; Fonseca, Alan Rios; Heidrich, Núbia; Nin, Maurício Schüler; Barros, Helena Maria Tannhauser

2018-06-12

Depression is a highly incapacitating disorder known to have a multifactorial etiology, including a hereditary genetic background. The neurosteroid allopregnanolone (ALLO) is a positive allosteric modulator of the GABA A receptor and has been shown to have an antidepressant-like effect in animals. This study aimed to assess the behavioral effect of ALLO in animals with different backgrounds of depressive-like activity. An initial population (F0) of male and female Wistar rats was screened for immobility behavior utilizing the Forced Swim Test (FST). Rats with extreme immobility scores were selected for either the High Immobility (HI) group or the Low Immobility (LI) group for breeding, giving origin to the subsequent generations F1 and F2. Guide cannulas were implanted in the lateral ventricle of F2 males for intracerebroventricular infusions of 5 μg/rat of ALLO, 5 μg/rat of imipramine (IMI) or vehicle (CTR), which occurred 24, 5 and 1 h prior to the test session of the drug FST. In the pre-drug FST, a statistically significant difference was observed between the immobility scores from the HI and LI groups of F2 rats. HI rats from F2 also showed significantly higher immobility time when compared to F0. In these HI animals, both IMI and ALLO significantly reduced immobility when compared to the CTR group. IMI-treated rats also showed lower immobility than the ALLO group. In the LI rats, no difference in immobility was found between treatments. In conclusion, two strains of rats with significantly different immobility profiles in the FST were obtained in a relatively short time, after only two generations. Infusions of both ALLO and IMI showed a strain-dependent antidepressant-like effect, being detected in the HI animals but not in the LI animals, which is in line with the clinical understanding that antidepressants have higher efficacy in more severe forms of depression. Copyright © 2018 Elsevier Inc. All rights reserved.

Swimming training alleviated insulin resistance through Wnt3a/β-catenin signaling in type 2 diabetic rats

PubMed Central

Yang, Qiang; Wang, Wen-wen; Ma, Pu; Ma, Zhong-xuan; Hao, Meng; Adelusi, Temitope I; Lei-Du; Yin, Xiao-Xing; Lu, Qian

2017-01-01

Objective(s): Increasing evidence suggests that regular physical exercise improves type 2 diabetes mellitus (T2DM). However, the potential beneficial effects of swimming on insulin resistance and lipid disorder in T2DM, and its underlying mechanisms remain unclear. Materials and Methods: Rats were fed with high fat diet and given a low dosage of Streptozotocin (STZ) to induce T2DM model, and subsequently treated with or without swimming exercise. An 8-week swimming program (30, 60 or 120 min per day, 5 days per week) decreased body weight, fasting blood glucose and fasting insulin. Results: Swimming ameliorated lipid disorder, improved muscular atrophy and revealed a reduced glycogen deposit in skeletal muscles of diabetic rats. Furthermore, swimming also inhibited the activation of Wnt3a/β-catenin signaling pathway, decreased Wnt3a mRNA and protein level, upregulated GSK3β phosphorylation activity and reduced the expression of β-catenin phosphorylation in diabetic rats. Conclusion: The trend of the result suggests that swimming exercise proved to be a potent ameliorator of insulin resistancein T2DM through the modulation of Wnt3a/β-catenin pathway and therefore, could present a promising therapeutic measure towards the treatment of diabetes and its relatives. PMID:29299199

Methods for measurement of energy expenditure and substrate concentrations in swimming rats.

PubMed

Benthem, L; Bolhuis, J W; van der Leest, J; Steffens, A B; Zock, J P; Zijlstra, W G

1994-07-01

A measuring system is described for the determination of oxygen consumption (Vo2) and carbon dioxide production (Vco2) in swimming rats. Vo2 and Vco2 were measured by means of an O2-analyzer (Ametek S3A) and a mass spectrometer (Balzers QMG 511), respectively, combined with a gas flow meter. The measurements were made in a 5-1 metabolic chamber on top of a swimming pool in which a water flow of 0.22 m/s was maintained. The rats were fitted with an indwelling catheter with its tip at the entrance of the right atrium for the repeated determination of energy substrate and hormone concentrations, before, during, and after swimming. The inaccuracy of the Vo2 and Vco2 measurements was 0.18% and 0.31% of the reading, respectively; the imprecision was 2.15% and 2.59%. This high accuracy and precision of the system was attained by measuring room air for 20 s after each 100 s of measuring air from the metabolic chamber, and by using demineralized water in the swimming pool. Vo2 during steady-state swimming was 1.89 +/- 0.06 mmol/kg.min (ca. 60% Vo2max), indicating moderate exercise. Respiratory quotient (RQ), during steady-state exercise, was 0.80 +/- 0.01. Vo2 and RQ resulted in rates for carbohydrate and fat utilization of 15.6 +/- 0.8 and 15.1 +/- 0.7 mg/kg.min, respectively.

Influence of immobilization and forced swim stress on the neurotoxicity of lambda-cyhalothrin in rats: Effect on brain biogenic amines and BBB permeability.

PubMed

Shukla, Rajendra K; Dhuriya, Yogesh K; Chandravanshi, Lalit P; Gupta, Richa; Srivastava, Pranay; Pant, Aditya B; Kumar, Ajay; Pandey, Chandra M; Siddiqui, M Haris; Khanna, Vinay K

2017-05-01

Experimental studies have been carried out on rats to understand the influence of immobilization stress (IMS), a psychological stressor and forced swim stress (FSS), a physical stressor in the neurotoxicity of lambda-cyhalothrin (LCT), a new generation type II synthetic pyrethroid with extensive applications. No significant change in plasma corticosterone levels and blood brain barrier (BBB) permeability was observed in rats subjected to IMS (one session of 15min/day), FSS (one session of 3min/day) for 28days or LCT treatment (3.0mg/kg body weight, p.o. suspended in groundnut oil) for 3days (26th, 27th and 28th day) as compared to controls. Marginal changes in the levels of biogenic amines and their metabolites (NE, EPN, DA, HVA, DOPAC, 5-HT) in hypothalamus, frontal cortex, hippocampus, and corpus striatum were observed in rats subjected to IMS or FSS or LCT alone as compared to controls. It was interesting to note that pre-exposure to IMS or FSS followed by LCT treatment for 3days caused a marked increase in plasma corticosterone levels associated with disruption in the BBB permeability as compared to rats exposed to IMS or FSS or LCT alone. Pre-exposure to IMS or FSS followed by LCT treatment for 3days resulted to alter the levels of biogenic amines and their metabolites in hypothalamus, frontal cortex, hippocampus, and corpus striatum as compared to rats exposed to IMS or FSS or LCT alone. Although neurochemical changes were more intense in rats pre-exposed to IMS as compared to those subjected to FSS on LCT treatment, the results indicate that both psychological and physical stress could be important influencing factors in the neurotoxicity of LCT. Copyright © 2016. Published by Elsevier B.V.

Comparative analysis of two different models of swimming applied to pregnant rats born small for pregnant age.

PubMed

Corvino, Silvana B; Damasceno, Débora C; Sinzato, Yuri K; Netto, Aline O; Macedo, Nathália C D; Zambrano, Elena; Volpato, Gustavo T

2017-01-01

The aim of this study was to compare two models of swimming applied to pregnant rats born small for pregnancy age (SPA). Diabetes was chemically induced in adult female rats to develop an inadequate intrauterine environment, leading to birth of a SPA offspring. In adulthood, the female SPA rats were mated and submitted to different swimming programs. The exercise program 1 (Ex1) consisted of swimming for 15 minutes, followed by 15 minutes of rest and another 15 minutes of swimming, 3 days a week before and during pregnancy. Another program (Ex2) was applied during 60 minutes uninterrupted a day, 6 days/week during pregnancy. The pregnant rats presented no interference on body weight and glycemia. The rats submitted to Ex2 model showed decreased insulin and blood glucose levels by oral glucose tolerance test, and reduction in area under curve values. The offspring from dams submitted to both exercise protocols presented an increased rate of newborns SPA. However, the offspring from Ex2 dams showed percentage twice higher of newborns SPA than Ex1 offspring. Our data suggests that continuous exercise of 60 min/day ameliorated the enhanced peripheral insulin sensitivity in growth-restricted females. However, this protocol employed at pregnancy leads to intrauterine growth restriction.

Omega-3 fatty acid deficient male rats exhibit abnormal behavioral activation in the forced swim test following chronic fluoxetine treatment: association with altered 5-HT1A and alpha2A adrenergic receptor expression.

PubMed

Able, Jessica A; Liu, Yanhong; Jandacek, Ronald; Rider, Therese; Tso, Patrick; McNamara, Robert K

2014-03-01

Omega-3 fatty acid deficiency during development leads to enduing alterations in central monoamine neurotransmission in rat brain. Here we investigated the effects of omega-3 fatty acid deficiency on behavioral and neurochemical responses to chronic fluoxetine (FLX) treatment. Male rats were fed diets with (CON, n = 34) or without (DEF, n = 30) the omega-3 fatty acid precursor alpha-linolenic acid (ALA) during peri-adolescent development (P21-P90). A subset of CON (n = 14) and DEF (n = 12) rats were administered FLX (10 mg/kg/d) through their drinking water for 30 d beginning on P60. The forced swimming test (FST) was initiated on P90, and regional brain mRNA markers of serotonin and noradrenaline neurotransmission were determined. Dietary ALA depletion led to significant reductions in frontal cortex docosahexaenoic acid (DHA, 22:6n-3) composition in DEF (-26%, p = 0.0001) and DEF + FLX (-32%, p = 0.0001) rats. Plasma FLX and norfluoxetine concentrations did not different between FLX-treated DEF and CON rats. During the 15-min FST pretest, DEF + FLX rats exhibited significantly greater climbing behavior compared with CON + FLX rats. During the 5-min test trial, FLX treatment reduced immobility and increased swimming in CON and DEF rats, and only DEF + FLX rats exhibited significant elevations in climbing behavior. DEF + FLX rats exhibited greater midbrain, and lower frontal cortex, 5-HT1A mRNA expression compared with all groups including CON + FLX rats. DEF + FLX rats also exhibited greater midbrain alpha2A adrenergic receptor mRNA expression which was positively correlated with climbing behavior in the FST. These preclinical data demonstrate that low omega-3 fatty acid status leads to abnormal behavioral and neurochemical responses to chronic FLX treatment in male rats. Copyright © 2013 Elsevier Ltd. All rights reserved.

Effect of high-intensity intermittent swimming training on fatty acid oxidation enzyme activity in rat skeletal muscle.

PubMed

Terada, Shin; Tabata, Izumi; Higuchi, Mitsuru

2004-02-01

We previously reported that high-intensity exercise training significantly increased citrate synthase (CS) activity, a marker of oxidative enzyme, in rat skeletal muscle to a level equaling that attained after low-intensity prolonged exercise training (Terada et al., J Appl Physiol 90: 2019-2024, 2001). Since mitochondrial oxidative enzymes and fatty acid oxidation (FAO) enzymes are often increased simultaneously, we assessed the effect of high-intensity intermittent swimming training on FAO enzyme activity in rat skeletal muscle. Male Sprague-Dawley rats (3 to 4 weeks old) were assigned to a 10-day period of high-intensity intermittent exercise training (HIT), low-intensity prolonged exercise training (LIT), or sedentary control conditions. In the HIT group, the rats repeated fourteen 20 s swimming sessions with a weight equivalent to 14-16% of their body weight. Between the exercise sessions, a 10 s pause was allowed. Rats in the LIT group swam 6 h/day in two 3 h sessions separated by 45 min of rest. CS activity in the triceps muscle of rats in the HIT and LIT groups was significantly higher than that in the control rats by 36 and 39%, respectively. Furthermore, 3-beta hydroxyacyl-CoA dehydrogenase (HAD) activity, an important enzyme in the FAO pathway in skeletal muscle, was higher in the two training groups than in the control rats (HIT: 100%, LIT: 88%). No significant difference in HAD activity was observed between the two training groups. In conclusion, the present investigation demonstrated that high-intensity intermittent swimming training elevated FAO enzyme activity in rat skeletal muscle to a level similar to that attained after 6 h of low-intensity prolonged swimming exercise training.

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.

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.

Effect of Resveratrol Administration on the Element Metabolism in the Blood and Brain Tissues of Rats Subjected to Acute Swimming Exercise.

PubMed

Baltaci, Abdulkerim Kasim; Arslangil, Dilek; Mogulkoc, Rasim; Patlar, Suleyman

2017-02-01

The aim of the present study is to examine how resveratrol administration affects the element metabolism in the blood and brain cortex tissues of rats subjected to an acute swimming exercise. The study was carried out on Wistar-Albino-type adult male rats supplied by the Center. Group 1 is the control group. Group 2 is the swimming control group. Group 3 is the resveratrol (10 mg/kg/day) + swimming group. Group 4 is the resveratrol (10 mg/kg/day) group. Blood and brain cortex tissues were analyzed for some elements. The acute swimming exercise led to increases in the rats' serum iron, selenium, lead, cobalt, and boron levels, while the resveratrol-swimming group has increases in copper, phosphorus, and calcium values. The brain cortex tissue of the resveratrol-swimming group had significantly higher molybdenum levels than others. The results obtained in the study indicate that acute swimming exercise altered the distribution of elements in the serum to a considerable extent; however, resveratrol's affect is limited. Especially, resveratrol supplementation may have a regulatory affect on serum iron and magnesium levels.

Swim training restores glucagon-like peptide-1 insulinotropic action in pancreatic islets from monosodium glutamate-obese rats.

PubMed

Svidnicki, P V; de Carvalho Leite, N; Venturelli, A C; Camargo, R L; Vicari, M R; de Almeida, M C; Artoni, R F; Nogaroto, V; Grassiolli, S

2013-09-01

Glucagon-like peptide-1 (GLP-1) is an important modulator of insulin secretion by endocrine pancreas. In the present study, we investigated the effect of swim training on GLP-1 insulinotropic action in pancreatic islets from monosodium glutamate (MSG)-obese rats. Obesity was induced by neonatal MSG administration. MSG-obese and control (CON) exercised rats swam for 30 min (3 times week(-1) ) for 10 weeks. Pancreatic islets were isolated by colagenase technique and incubated with low (5.6 mM) or high (16.7 mM) glucose concentrations in the presence or absence of GLP-1 (10 nM). In addition, GLP-1 gene expression in ileum was quantified in fasting and glucose conditions. Exercise reduced obesity and hyperinsulinemia in MSG-obese rats. Swim training also inhibited glucose-induced insulin secretion in islets from both groups. Islets from MSG-obese rats maintained GLP-1 insulinotropic response in low glucose concentration. In contrast, in the presence of high glucose concentration, GLP-1 insulinotropic action was absent in islets from MSG-obese rats. Islets from MSG-exercised rats showed reduced GLP-1 insulinotropic action in the presence of low glucose. However, in high glucose concentration swim training restored GLP-1 insulinotropic response in islets from MSG-obese rats. In all groups, glucose intake increased GLP-1 immunoreactivity and gene expression in ileum cells in relation to fasting conditions. Swim training reduced these parameters only in ileum cells from CON-exercised rats. Neither MSG treatment nor exercise affected GLP-1 expression in the ileum. Exercise avoids insulin hypersecretion restoring GLP-1's insulinotropic action in pancreatic islets from MSG-obese rats. © 2013 Scandinavian Physiological Society. Published by John Wiley & Sons Ltd.

Determination of a quantitative parameter to evaluate swimming technique based on the maximal tethered swimming test.

PubMed

Soncin, Rafael; Mezêncio, Bruno; Ferreira, Jacielle Carolina; Rodrigues, Sara Andrade; Huebner, Rudolf; Serrão, Julio Cerca; Szmuchrowski, Leszek

2017-06-01

The aim of this study was to propose a new force parameter, associated with swimmers' technique and performance. Twelve swimmers performed five repetitions of 25 m sprint crawl and a tethered swimming test with maximal effort. The parameters calculated were: the mean swimming velocity for crawl sprint, the mean propulsive force of the tethered swimming test as well as an oscillation parameter calculated from force fluctuation. The oscillation parameter evaluates the force variation around the mean force during the tethered test as a measure of swimming technique. Two parameters showed significant correlations with swimming velocity: the mean force during the tethered swimming (r = 0.85) and the product of the mean force square root and the oscillation (r = 0.86). However, the intercept coefficient was significantly different from zero only for the mean force, suggesting that although the correlation coefficient of the parameters was similar, part of the mean velocity magnitude that was not associated with the mean force was associated with the product of the mean force square root and the oscillation. Thus, force fluctuation during tethered swimming can be used as a quantitative index of swimmers' technique.

Effects of crude oil and swimming behavior and survival in the rice rat

USGS Publications Warehouse

Wolfe, J.L.; Esher, R.J.

1981-01-01

Oil slicks in laboratory test chambers inhibited swimming behavior of rice rats, and reduced survival at low temperature. Predisposition to enter the water and swim was greatly reduced at both high (200 ml/m2 water surface) and low (20 ml/m2) concentrations of oil. Survival was significantly affected only at high concentrations. The results may be of value in predicting the impact of oil spills on the mammal community of coastal marshes.

[Electromagnetic Shielding Alters Behaviour of Rats].

PubMed

Temuryants, N A; Kostyuk, A S; Tumanyants, K N

2015-01-01

It has been found that long-term electromagnetic shielding (19 hours per day for 10 days) leads to an increase in the duration of passive swimming time in male rats, decrease the duration of active swimming in the "forced swim" test as well as decrease of libido. On the other hand animals kept under the "open field" conditions do not show significant deviations from their normal behavior. Therefore, one could conclude that moderate electromagnetic shielding causes a depression-like state in rats.

Antidepressant-like effects of the acute and chronic administration of nicotine in the rat forced swimming test and its interaction with fluoxetine [correction of flouxetine].

PubMed

Vázquez-Palacios, G; Bonilla-Jaime, H; Velázquez-Moctezuma, J

2004-05-01

An antidepressant action of nicotine (NIC) has recently been suggested. Flouxetine, a selective serotonin reuptake inhibitor, is currently the most widely used antidepressant. In the present study, we analyzed the effects of the administration of NIC, fluoxetine (FLX), and the combination of both drugs given acutely, subchronically, and chronically as well as 7 days after chronic administration of these drugs on the forced swim test. Results showed that NIC induced a significant reduction of the time in immobility during the forced swim test (antidepressant effect), with a concomitant increase in swimming activity (serotonergic activation), after acute administration. These effects remain the same after subchronic and chronic administration. FLX failed to induce any effect after acute administration but did induce a significant decrease of immobility and an increase of swimming after subchronic administration. The effect of the chronic administration was significantly larger compared to subchronic administration. The combination of both drugs induced a larger effect than that observed after a single administration but only after subchronic treatment. No effect was observed after the end of the 7-day treatments. Data suggest that NIC has an antidepressant action that is expressed faster than FLX but remains the same later. Thus, cholinergic-serotonergic interactions could play an important role in the treatment of depression.

Post-activation Potentiation in Propulsive Force after Specific Swimming Strength Training.

PubMed

Barbosa, A C; Barroso, R; Andries, O

2016-04-01

We investigated whether a conditioning activity (8×12.5 m with 2.5 min-interval using both hand paddles and parachute) induced post-activation potentiation in swimming propulsive force and whether a swimmer's force level affected a post-activation potentiation response. 8 competitive swimmers (5 males and 3 females, age: 18.4±1.3 years; IPS=796±56) performed a 10 s maximum tethered swimming test 8 and 4 min before (the highest value was considered as PRE), and 2.5 and 6.5 min after (POST1 and POST2, respectively) the conditioning activity. Rate of force development was not affected, but peak force in POST1 (p=0.02) and impulse in both POST1 (p=0.007) and POST2 (p=0.004) were reduced. Possibly the conditioning activity induced greater fatigue than post-activation potentiation benefits. For instance, the number of repetitions might have been excessive, and rest intervals between the conditioning activity and POST1 and POST2 were possibly too short. There were positive correlations between PRE peak force and changes in peak force and rate of force development. Although conditioning activity was detrimental, positive correlations suggest that weaker swimmers experience a deterioration of performance more than the stronger ones. This conditioning activity is not recommended for swimmers with the current competitive level before a competitive event. © Georg Thieme Verlag KG Stuttgart · New York.

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.

Enhanced anti-immobility effects of Sanggenon G isolated from the root bark of Morus alba combined with the α2-antagonist yohimbine in the rat forced swim test.

PubMed

Lim, Dong Wook; Baek, Nam-In; Kim, Yun Tai; Lee, Changho; Kim, In-Ho; Han, Daeseok

2016-07-01

In this study, we aimed to determine whether Sanggenon G, an active compound isolated from the root bark of Morus alba, exhibited enhanced anti-immobility activity with the addition of the α2-antagonist yohimbine in rats subjected to forced swim test (FST)-induced depression. Fluoxetine (a selective serotonin reuptake inhibitor) treatment in rats reduced the immobility time, and pretreatment with yohimbine significantly enhanced the antidepressant-like behavior of fluoxetine at 5, 10 and 20 mg/kg. Similarly, Sanggenon G significantly decreased the immobility time, reducing immobility by a maximum of 43.9 % when treated at a dose of 20 mg/kg. Furthermore, pretreatment with yohimbine significantly enhanced the antidepressant-like behavior of Sanggenon G at 5 and 10 mg/kg. Our findings suggest that the antidepressant-like effect of Sanggenon G could be facilitated by concomitant use of the α2-antagonist. Further studies are needed to evaluate the potential of Sanggenon G as an alternative therapeutic approach for the treatment of depression.

Concomitant administration of fluoxetine and amantadine modulates the activity of peritoneal macrophages of rats subjected to a forced swimming test.

PubMed

Roman, Adam; Rogóz, Zofia; Kubera, Marta; Nawrat, Dominika; Nalepa, Irena

2009-01-01

Recent studies show that administration of a non-competitive NMDA receptor antagonist, amantadine (AMA), potentiates the action of antidepressant drugs. Since antidepressants may modulate functioning of the immune system and activation of a pro-inflammatory response in depressive disorders is frequently reported, the aim of the present study was to examine whether a combined administration of AMA and the antidepressant, fluoxetine (FLU), to rats subsequently subjected to a forced swimming test (FST) modifies the parameters of macrophage activity, directly related to their immunomodulatory functions, i.e., arginase (ARG) activity and synthesis of nitric oxide (NO). We found that 10 mg/kg AMA and 10 mg/kg FLU, ineffective in FST for antidepressant-like activity when administered alone, increased the ARG/NO ratio in macrophages when administered concomitantly. This effect was accompanied by a decrease of cellular adherence. Concurrently, the basal metabolic activity of the cells measured with reduction of resazurin, and intracellular host defense as assessed by a synthesis of superoxide anion, were not affected by such antidepressive treatment. Our data indicate that co-administration of AMA and FLU decreases the pro-inflammatory properties of macrophages and causes a redirection of immune response toward anti-inflammatory activity, as one can anticipate in the case of an effective antidepressive treatment.

Kappa-opioid receptors mediate the antidepressant-like activity of hesperidin in the mouse forced swimming test.

PubMed

Filho, Carlos B; Del Fabbro, Lucian; de Gomes, Marcelo G; Goes, André T R; Souza, Leandro C; Boeira, Silvana P; Jesse, Cristiano R

2013-01-05

The opioid system has been implicated as a contributing factor for major depression and is thought to play a role in the mechanism of action of antidepressants. This study investigated the involvement of the opioid system in the antidepressant-like effect of hesperidin in the mouse forced swimming test. Our results demonstrate that hesperidin (0.1, 0.3 and 1 mg/kg; intraperitoneal) decreased the immobility time in the forced swimming test without affecting locomotor activity in the open field test. The antidepressant-like effect of hesperidin (0.3 mg/kg) in the forced swimming test was prevented by pretreating mice with naloxone (1 mg/kg, a nonselective opioid receptor antagonist) and 2-(3,4-dichlorophenyl)-Nmethyl-N-[(1S)-1-(3-isothiocyanatophenyl)-2-(1-pyrrolidinyl)ethyl] acetamide (DIPPA (1 mg/kg), a selective κ-opioid receptor antagonist), but not with naloxone methiodide (1 mg/kg, a peripherally acting opioid receptor antagonist), naltrindole (3 mg/kg, a selective δ-opioid receptor antagonist), clocinnamox (1 mg/kg, a selective μ-opioid receptor antagonist) or caffeine (3 mg/kg, a nonselective adenosine receptor antagonist). In addition, a sub-effective dose of hesperidin (0.01 mg/kg) produced a synergistic antidepressant-like effect in the forced swimming test when combined with a sub-effective dose of morphine (1 mg/kg). The antidepressant-like effect of hesperidin in the forced swimming test on mice was dependent on its interaction with the κ-opioid receptor, but not with the δ-opioid, μ-opioid or adenosinergic receptors. Taken together, these results suggest that hesperidin possesses antidepressant-like properties and may be of interest as a therapeutic agent for the treatment of depressive disorders. Published by Elsevier B.V.

Antidepressant-like effects of young green barley leaf (Hordeum vulgare L.) in the mouse forced swimming test.

PubMed

Yamaura, Katsunori; Nakayama, Noriyuki; Shimada, Maki; Bi, Yuanyuan; Fukata, Hideki; Ueno, Koichi

2012-01-01

Young green barley leaf is one of the richest sources of antioxidants and has been widely consumed for health management in Japan. In this study, we examined whether oral administration of young green barley leaf has an antidepressant effect on the forced swimming test in mice. Mice were individually forced to swim in an open cylindrical container, one hour after oral administration of young green barley leaf (400 or 1000 mg / kg) or imipramine (100 mg / kg). Expression of mRNA for nerve growth factor (NGF), brain-derived neurotrophic factor, and glucocorticoid receptor in the brain was analyzed using real-time quantitative polymerase chain reaction (PCR). There was a significant antidepressant-like effect in the forced swimming test; both 400 and 1000 mg / kg young green barley leaves, as well as the positive control imipramine (100 mg / kg), reduced the immobility duration compared to the vehicle group. The expression of mRNA for NGF detected in the hippocampus immediately after the last swimming test was higher than that in the non-swimming group (Nil). Oral administration of imipramine suppressed this increase to the level of the Nil group. Young green barley leaf (400 and 1000 mg / kg) also showed a moderate decrease in the expression of mRNA for NGF, in a dose-dependent manner. Oral administration of young green barley leaf is able to produce an antidepressant-like effect in the forced swimming test. Consequently it is possible that the antidepressant-like effects of the young green barley leaf are, at least in part, mediated by an inhibition of the increase in the hippocampus levels of NGF.

A Correlational Analysis of Tethered Swimming, Swim Sprint Performance and Dry-land Power Assessments.

PubMed

Loturco, I; Barbosa, A C; Nocentini, R K; Pereira, L A; Kobal, R; Kitamura, K; Abad, C C C; Figueiredo, P; Nakamura, F Y

2016-03-01

Swimmers are often tested on both dry-land and in swimming exercises. The aim of this study was to test the relationships between dry-land, tethered force-time curve parameters and swimming performances in distances up to 200 m. 10 young male high-level swimmers were assessed using the maximal isometric bench-press and quarter-squat, mean propulsive power in jump-squat, squat and countermovement jumps (dry-land assessments), peak force, average force, rate of force development (RFD) and impulse (tethered swimming) and swimming times. Pearson product-moment correlations were calculated among the variables. Peak force and average force were very largely correlated with the 50- and 100-m swimming performances (r=- 0.82 and -0.74, respectively). Average force was very-largely/largely correlated with the 50- and 100-m performances (r=- 0.85 and -0.67, respectively). RFD and impulse were very-largely correlated with the 50-m time (r=- 0.72 and -0.76, respectively). Tethered swimming parameters were largely correlated (r=0.65 to 0.72) with mean propulsive power in jump-squat, squat-jump and countermovement jumps. Finally, mean propulsive power in jump-squat was largely correlated (r=- 0.70) with 50-m performance. Due to the significant correlations between dry-land assessments and tethered/actual swimming, coaches are encouraged to implement strategies able to increase leg power in sprint swimmers. © Georg Thieme Verlag KG Stuttgart · New York.

Swimming training attenuates oxidative damage and increases enzymatic but not non-enzymatic antioxidant defenses in the rat brain.

PubMed

Nonato, L F; Rocha-Vieira, E; Tossige-Gomes, R; Soares, A A; Soares, B A; Freitas, D A; Oliveira, M X; Mendonça, V A; Lacerda, A C; Massensini, A R; Leite, H R

2016-09-29

Although it is well known that physical training ameliorates brain oxidative function after injuries by enhancing the levels of neurotrophic factors and oxidative status, there is little evidence addressing the influence of exercise training itself on brain oxidative damage and data is conflicting. This study investigated the effect of well-established swimming training protocol on lipid peroxidation and components of antioxidant system in the rat brain. Male Wistar rats were randomized into trained (5 days/week, 8 weeks, 30 min; n=8) and non-trained (n=7) groups. Forty-eight hours after the last session of exercise, animals were euthanized and the brain was collected for oxidative stress analysis. Swimming training decreased thiobarbituric acid reactive substances (TBARS) levels (P<0.05) and increased the activity of the antioxidant enzyme superoxide dismutase (SOD) (P<0.05) with no effect on brain non-enzymatic total antioxidant capacity, estimated by FRAP (ferric-reducing antioxidant power) assay (P>0.05). Moreover, the swimming training promoted metabolic adaptations, such as increased maximal workload capacity (P<0.05) and maintenance of body weight. In this context, the reduced TBARS content and increased SOD antioxidant activity induced by 8 weeks of swimming training are key factors in promoting brain resistance. In conclusion, swimming training attenuated oxidative damage and increased enzymatic antioxidant but not non-enzymatic status in the rat brain.

Swim Training Improves HOMA-IR in Type 2 Diabetes Induced by High Fat Diet and Low Dose of Streptozotocin in Male Rats.

PubMed

Ghiasi, Rafigheh; Ghadiri Soufi, Farhad; Somi, Mohammad Hossein; Mohaddes, Gisou; Mirzaie Bavil, Fariba; Naderi, Roya; Alipour, Mohammad Reza

2015-09-01

Insulin resistance plays a key role in the onset and development of type 2 diabetes mellitus (T2DM) and its complications. In this study, we evaluated the effect of swim training on insulin resistance in diabetic rats. Forty male Wistar rats were randomly divided into four groups (n=10): sedentary control (Con), sedentary diabetic (Dia), swim trained control (Exe) and swim trained diabetic (Dia+Exe) rats. Diabetes was induced by high fat diet (HFD) and a low dose of streptozotocin (35 mg/kg, i.p). In trained groups, one week after the induction of diabetes, animals were subjected to swimming (60 min/5 days a week) for 10 weeks. At the end of training, fasting blood sugar (FBS), oral glucose tolerance test (OGTT), fasting/basal insulin, glycosylated hemoglobin (HbA1c) levels, insulin resistance index, homeostasis model assessment method (HOMA-IR), triglycerides (TG,) total cholesterol (TCh), and high density lipoprotein (HDL) levels in blood were measured. Swimming significantly improved OGTT (P<0.01) and HOMA-IR (P<0.01). Swim training also significantly decreased FBS (p<0.01), fasting/basal insulin (P<0.01), HbA1C (p<0.01), TG (P<0.05), and TCh (P<0.05) levels. It also significantly increased HDL (p<0.05) level. Our findings indicate that swim training improved glycemic control and insulin sensitivity in type 2 diabetes caused by high fat diet in male rats.

Antidepressant-like effects of Gan-Mai-Dazao-Tang via monoamine regulatory pathways on forced swimming test in rats.

PubMed

Huang, Hsiang-Ling; Lim, Swee-Ling; Lu, Kuan-Hung; Sheen, Lee-Yan

2018-01-01

Depression is a highly prevalent and recurrent mental disorder that impacts all aspects of human life. Undesirable effects of the antidepressant drugs led to the development of complementary and alternative therapies. Gan-Mai-Da-Zao-Tang (, gān mài dà zǎo tang) is a traditional herbal formula commonly used for the treatment of depression, but lack of scientific proof on its mechanism. It consisted of Glycyrrhiza uralensis Fisch. (licorice), Triticum aestivum L. (wheat) and Zizphus jujuba Mill. (jujube). The objective of this study is to investigate the antidepressant effects of Gan-Mai-Dazao-Tang and its ingredients in rats exposed to forced swimming test (FST). The 72 of male Nerl: Wistar rats (8 weeks old) were randomized into control (10 mL/kg bw H 2 O), licorice (0.4 g/kg bw), wheat (1.6 g/kg bw), jujube (0.5 g/kg bw), Gan-Mai-Da-Zao-Tang (2.5 g/kg bw of licorice: wheat: jujube in ratio of 5:20:6) and Prozac (18 mg/kg bw) groups. Samples were administered by oral gavage for 21 days. FST was performed on 21st day, with 15 min for pretest followed by 5 min for real test. Then, the animals were sacrificed and brain tissues were collected for monoamines analyses. The Gan-Mai-Da-Zao-Tang (LWJ) showed significantly down-regulation of immobility time, 3,4-dihydroxyphenylacetic acid (DOPAC) and DOPAC/dopamine (DA) turnover rates, and also enhanced the concentration of serotonin (5-HT) and DA in brain tissues, as compared with the control. The LWJ stated the potent antidepressant-like effect by modulating these monoamines concentration, while the licorice, wheat and jujube did not reported significant results as compared with control group. The positive control (Prozac) was noted with significantly reduction in body weight and appetite. In conclusion, the antidepressant-like effects of LWJ might be mediated by the regulation of monoamine neurotransmitters. Thus, it could beneficial in depression treatment as a complementary approach.

Swimming activity in marine fish.

PubMed

Wardle, C S

1985-01-01

Marine fish are capable of swimming long distances in annual migrations; they are also capable of high-speed dashes of short duration, and they can occupy small home territories for long periods with little activity. There is a large effect of fish size on the distance fish migrate at slow swimming speeds. When chased by a fishing trawl the effect of fish size on swimming performance can decide their fate. The identity and thickness of muscle used at each speed and evidence for the timing of myotomes used during the body movement cycle can be detected using electromyogram (EMG) electrodes. The cross-sectional area of muscle needed to maintain different swimming speeds can be predicted by relating the swimming drag force to the muscle force. At maximum swimming speed one completed cycle of swimming force is derived in sequence from the whole cross-sectional area of the muscles along the two sides of the fish. This and other aspects of the swimming cycle suggest that each myotome might be responsible for generating forces involved in particular stages of the tail sweep. The thick myotomes at the head end shorten during the peak thrust of the tail blade whereas the thinner myotomes nearer the tail generate stiffness appropriate for transmission of these forces and reposition the tail for the next cycle.

Muscle protein metabolism in neonatal alloxan-administered rats: effects of continuous and intermittent swimming training

PubMed Central

2012-01-01

Background This study aimed to examine the effects of intermittent and continuous swimming training on muscle protein metabolism in neonatal alloxan-administered rats. Methods Wistar rats were used and divided into six groups: sedentary alloxan (SA), sedentary control (SC), continuous trained alloxan (CA), intermittent trained alloxan (IA), continuous trained control (CC) and intermittent trained control (IC). Alloxan (250 mg/kg body weight) was injected into newborn rats at 6 days of age. The continuous training protocol consisted of 12 weeks of swimming training in individual cylinder tanks while supporting a load that was 5% of body weight; uninterrupted swimming for 1 h/day, five days a week. The intermittent training protocol consisted of 12 weeks of swimming training in individual cylinder tanks while supporting a load that was 15% of body weight; 30 s of activity interrupted by 30 s of rest for a total of 20 min/day, five days a week. Results At 28 days, the alloxan animals displayed higher glycemia after glucose overload than the control animals. No differences in insulinemia among the groups were detected. At 120 days, no differences in serum albumin and total protein among the groups were observed. Compared to the other groups, DNA concentrations were higher in the alloxan animals that were subjected to continuous training, whereas the DNA/protein ratio was higher in the alloxan animals that were subjected to intermittent training. Conclusion It was concluded that continuous and intermittent training sessions were effective in altering muscle growth by hyperplasia and hypertrophy, respectively, in alloxan-administered animals. PMID:22309804

Antidepressant-Like Effect of 1α-Hydroxyvitamin D3 on Mice in the Forced Swimming Test.

PubMed

Kawaura, Akihiko; Kitamura, Yoshihisa; Tanida, Noritoshi; Akiyama, Junichi; Mizutani, Masatoshi; Harada, Kazuhiro; Morishita, Motoyoshi; Inoue, Shigeki; Kano, Yoshio; Okano, Toshio; Takeda, Eiji

2017-01-01

We examined the effect of 1α-hydroxyvitamin D 3 [1α(OH)D 3 ] on mice in the forced swimming test. Intragastric administration of 1.0 μg/kg of 1α(OH)D 3 reduced immobility time in the forced swimming test. At all concentrations tested (0.5, 1.0, 2.0 μg/kg), 1α(OH)D 3 had no effect on locomotor activity, compared with controls. These results suggest that 1α(OH)D 3 may have antidepressant-like activity.

Ethopharmacology of the antidepressant effect of clonazepam in diabetic rats.

PubMed

Gomez, R; Barros, H M

2000-06-01

Diabetes-associated depression may occur due to changes in the quality of life imposed by treatment, or may be a consequence of the biochemical changes accompanying the disease. It was our objective to evaluate the behaviors of diabetic rats through an animal model of depression, and determine if a positive GABA modulator agent, clonazepam, is an effective antidepressant. Wistar male rats were submitted to the forced-swimming test after 26 days of the induction of diabetes with streptozotocin (60 mg/kg). Test and retest days analyzed with an ethological approach. Clonazepam (control, 0.25, 0. 5, and 1.0 mg/kg) was administered IP 24, 5, and 1 h before the retest. Diabetic rats presented longer immobility duration during test and retest of forced swimming. Diabetic rats dived significantly less during the test. Clonazepam 0.25 and 0.5 mg/kg decreased immobility of diabetic rats with no consequences on the behaviors of nondiabetic rats. These results demonstrate that diabetic rats present more intense depressive-like behavior, such as immobility and lack of interest in exploring the environment, when exposed to the forced-swimming test. It is possible that decreased GABA function is involved in depression associated with diabetes, because a benzodiazepine partially counteracts these changes without modifying blood glucose and glycogen parameters.

Effect of Polysaccharide from Cordyceps militaris (Ascomycetes) on Physical Fatigue Induced by Forced Swimming.

PubMed

Xu, Yan-Feng

2016-01-01

Cordyceps militaris is the one of the most important medicinal mushrooms, widely used in East Asian countries. Polysaccharide is considered to be the principal active component in C. militaris and has a wide range of biological and pharmacological properties. This study was undertaken to investigate the effect of polysaccharide from C. militaris (PCM) on physical fatigue induced in animals through a forced swimming test. The mice were divided into 4 groups receiving 28 days' treatment with drinking water (exercise control) or low-, medium-, and high-dose PCM (40, 80, and 160 mg/kg/day, respectively). After 28 days, the mice were subjected to the forced swimming test; the exhaustive swimming time was measured and fatigue-related biochemical parameters, including serum lactic acid, urea nitrogen, creatine kinase, alanine aminotransferase, aspartate aminotransferase, superoxide dismutase, glutathi- one peroxidase, catalase, malondialdehyde, liver glycogen, and muscle glycogen, were analyzed. The results showed that PCM could significantly prolong the exhaustive swimming time of mice; decrease concentrations of serum lactic acid, urea nitrogen, creatine kinase, aspartate aminotransferase, alanine aminotransferase, and malondialdehyde; and increase liver and muscle glycogen contents and the concentrations of serum superoxide dismutase, glutathione per- oxidase, and catalase. The data suggest that PCM has an antifatigue effect, and it might become a new functional food or medicine for fatigue resistance.

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.

[Unpredictable chronic mild stress effects on antidepressants activities in forced swim test].

PubMed

Kudryashov, N V; Kalinina, T S; Voronina, T A

2015-02-01

The experiments has been designed to study unpredictable chronic mild stress effect on anti-depressive activities of amitriptyline (10 mg/kg) and fluoxetine (20 mg/kg) in forced swim test in male outbred mice. It is shown that acute treatment with fluoxetine does not produce any antidepressant effects in mice following stress of 14 days while the sub-chronic injections of fluoxetine result in more deep depressive-like behavior. In 28 daily stressed mice, antidepressant effect of fluoxetine is observed independently of the injection rates. Amitriptyline demonstrates the antidepressant activity regardless of the duration of stress or administration scheduling, but at the same time the severity of anti-immobilization effect of amitriptyline in stressed mice is weaker in compare to non-stressed trails. Thus, the injection rates and duration of unpredictable mild chronic stress are the parameters that determine the efficiency of antidepressants in the mouse forced swimming test.

Enhancement of the anti-immobility action of antidepressants by risperidone in the forced swimming test in mice.

PubMed

Rogóż, Zofia; Kabziński, Marcin

2011-01-01

The aim of the present study was to examine the effect of antidepressants (ADs) belonging to different pharmacological groups and risperidone (an atypical antipsychotic drug), given separately or jointly, on immobility time in the forced swimming test in male C57BL/6J mice. The antidepressants: citalopram, fluvoxamine, sertraline, reboxetine, milnacipran (5 and 10 mg/kg), or risperidone in low doses (0.05 and 0.1 mg/kg) given alone did not change the immobility time of mice in the forced swimming test. Co-treatment with reboxetine or milnacipran (10 mg/kg) and risperidone in a lower dose of 0.05 mg/kg or with sertraline, reboxetine (5 and 10 mg/kg), citalopram, fluvoxamine, milnacipran (10 mg/kg) and risperidone in a higher dose of 0.1 mg/kg produced antidepressant-like effect in the forced swimming test. WAY100635 (a 5-HT(1A) receptor antagonist) inhibited the effects induced by co-administration of ADs and risperidone. Active behavior in the forced swimming test was not a consequence of an increased general activity, since the combined treatment with ADs and risperidone failed to enhance the locomotor activity of mice. The obtained results indicate that a low dose of risperidone enhances the activity of ADs in an animal model of depression, and that, among other mechanisms, 5-HT(1A) receptors may play a role in these effects.

[Reverse learning in WAG/Rij rats with depression-like behavior].

PubMed

Malyshev, A V; Zakharov, A M; Sarkisova, K Iu; Dubynin, V A

2012-01-01

Learning and reverse learning in a complex maze, behavior in the open field test, novelty-suppressed feeding test, and forced swimming test were studies in WAG/Rij and Wistar rats. As compared with Wistar rats, WAG/Rij rats more slowly learned the spatial task, more slowly performed in the learning and reverse learning tasks, and made more errors in the complex maze (18% of WAG/Rij rats didn't reach learning criterion). Moreover, WAG/Rij rats exhibited reduced grooming reactions in the open field test, longer latency of approaching to food in the novel open field, reduced amount of food consumed in the home cage in the novelty-suppressed feeding test, and increased immobility time in the forced swimming test. The results suggest cognitive impaiment in WAG/Rij rats with depression-like behavior.

Effect of Swimming on the Production of Aldosterone in Rats

PubMed Central

Wang, Paulus S.; Jian, Cai-Yun; Yeh, Yung-Hsing; Chen, Yi-An; Wang, Kai-Lee; Lin, Yi-Chun; Chang, Ling-Ling; Wang, Guei-Jane; Wang, Shyi-Wu

2014-01-01

It has been demonstrated that exercise is one of the stresses known to increase the aldosterone secretion. Both potassium and angiotensin II (Ang II) levels are shown to be correlated with aldosterone production during exercise, but the mechanism is still unclear. In an in vivo study, male rats were catheterized via right jugular vein (RJV), and divided into four groups namely water immersion, swimming, lactate infusion (13 mg/kg/min) and pyruvate infusion (13 mg/kg/min) groups. Each group was treated for 10 min. Blood samples were collected at 0, 10, 15, 30, 60 and 120 min from RJV after administration. In an in vitro study, rat zona glomerulosa (ZG) cells were challenged by lactate (1–10 mM) in the presence or absence of Ang II (10−8 M) for 60 min. The levels of aldosterone in plasma and medium were measured by radioimmunoassay. Cell lysates were analyzed by immunoblotting assay. After exercise and lactate infusion, plasma levels of aldosterone and lactate were significantly higher than those in the control group. Swimming for 10 min significantly increased the plasma Ang II levels in male rats. Administration of lactate plus Ang II significantly increased aldosterone production and enhanced protein expression of steroidogenic acute regulatory protein (StAR) in ZG cells. These results demonstrated that acute exercise led to the increase of both aldosterone and Ang II secretion, which is associated with lactate action on ZG cells and might be dependent on the activity of renin-angiotensin system. PMID:25289701

Level of Interleukins IL-6 and IL-15 in Blood Plasma of Mice after Forced Swimming Test.

PubMed

Kapilevich, L V; Kironenko, T A; Zakharova, A N; Kabachkova, A V; Orlov, S N

2017-05-01

We measured the concentrations of IL-6 and IL-15 in blood plasma of mice at different terms after forced swimming, taking into account exercise intensity and preliminary training. It was shown that training was an important factor affecting blood plasma level of IL both at rest and after single forced swimming: in trained animals, the concentration of both myokines increased immediately after swimming, while in untrained animals, this increase was observed only after 5 h. Changes in cytokine production against the background of training can be associated with various factors, including neuroendocrine mechanisms, stress, modification of intracellular signaling, as well as reorganization of transcriptional mechanisms in muscle fibers. The most important factor is shift in the ratio of monovalent cations (sodium and potassium) in the cytoplasm.

Omega-3 Fatty Acid Deficiency Does Not Alter the Effects of Chronic Fluoxetine Treatment on Central Serotonin Turnover or Behavior in the Forced Swim Test in Female Rats

PubMed Central

McNamara, Robert K.; Able, Jessica A.; Liu, Yanhong; Jandacek, Ronald; Rider, Therese; Tso, Patrick; Lipton, Jack W.

2013-01-01

While translational evidence suggests that long-chain omega-3 fatty acid status is positively associated with the efficacy of selective serotonin reuptake inhibitor drugs, the neurochemical mechanisms mediating this interaction are not known. Here we investigated the effects of dietary omega-3 (n-3) fatty acid insufficiency on the neurochemical and behavioral effects of chronic fluoxetine (FLX) treatment. Female rats were fed diets with (CON, n=56) or without (DEF, n=40) the n-3 fatty acids during peri-adolescent development (P21-P90), and one half of each group were administered FLX (10 mg/kg/d) for 30 d (P60-P90) prior to testing. In adulthood (P90), regional brain serotonin (5-HT) and 5-hydroxyindoleacetic (5-HIAA) concentrations, presynaptic markers of 5-HT neurotransmission, behavioral responses in the forced swim test (FST), and plasma FLX and norfluoxetine (NFLX) concentrations were investigated. Peri-adolescent n-3 insufficiency led to significant reductions in cortical docosahexaenoic acid (DHA, 22:6n-3) composition in DEF (−25%, p≤0.0001) and DEF+FLX (−28%, p≤0.0001) rats. Untreated DEF rats exhibited significantly lower regional 5-HIAA/5-HT ratios compared with untreated CON rats, but exhibited similar behavioral responses in the FST. In both CON and DEF rats, chronic FLX treatment similarly and significantly decreased 5-HIAA concentrations and the 5-HIAA/5-HT ratio in the hypothalamus, hippocampus, and nucleus accumbens, brainstem tryptophan hydroxylase-2 mRNA expression, and immobility in the FST. While the FLX-induced reduction in 5-HIAA concentrations in the prefrontal cortex was significantly blunted in DEF rats, the reduction in the 5-HIAA/5-HT ratio was similar to CON rats. Although plasma FLX and NFLX levels were not significantly different in DEF and CON rats, the NFLX/FLX ratio was significantly lower in DEF+FLX rats. These preclinical data demonstrate that n-3 fatty acid deficiency does not significantly reduce the effects of chronic

Physical Forces Shape Group Identity of Swimming Pseudomonas putida Cells.

PubMed

Espeso, David R; Martínez-García, Esteban; de Lorenzo, Víctor; Goñi-Moreno, Ángel

2016-01-01

The often striking macroscopic patterns developed by motile bacterial populations on agar plates are a consequence of the environmental conditions where the cells grow and spread. Parameters such as medium stiffness and nutrient concentration have been reported to alter cell swimming behavior, while mutual interactions among populations shape collective patterns. One commonly observed occurrence is the mutual inhibition of clonal bacteria when moving toward each other, which results in a distinct halt at a finite distance on the agar matrix before having direct contact. The dynamics behind this phenomenon (i.e., intolerance to mix in time and space with otherwise identical others) has been traditionally explained in terms of cell-to-cell competition/cooperation regarding nutrient availability. In this work, the same scenario has been revisited from an alternative perspective: the effect of the physical mechanics that frame the process, in particular the consequences of collisions between moving bacteria and the semi-solid matrix of the swimming medium. To this end, we set up a simple experimental system in which the swimming patterns of Pseudomonas putida were tested with different geometries and agar concentrations. A computational analysis framework that highlights cell-to-medium interactions was developed to fit experimental observations. Simulated outputs suggested that the medium is compressed in the direction of the bacterial front motion. This phenomenon generates what was termed a compression wave that goes through the medium preceding the swimming population and that determines the visible high-level pattern. Taken together, the data suggested that the mechanical effects of the bacteria moving through the medium created a factual barrier that impedes to merge with neighboring cells swimming from a different site. The resulting divide between otherwise clonal bacteria is thus brought about by physical forces-not genetic or metabolic programs.

Granular resistive force theory explains the neuromechanical phase lag during sand-swimming

NASA Astrophysics Data System (ADS)

Ding, Yang; Sharpe, Sarah; Goldman, Daniel

2012-11-01

Undulatory locomotion is a common gait used by a diversity of animals in a range of environments. This mode of locomotion is characterized by the propagation of a traveling wave of body bending, which propels the animal in the opposite direction of the wave. Previous studies of undulatory locomotion in fluids, on land, and even within sand revealed that the wave of muscle activation progresses faster than the traveling wave of curvature. This leads to an increasing phase lag between activation and curvature at more posterior segments, known as the neuromechanical phase lag. In this study, we compare biological measurements of phase lag during the sand-swimming of the sandfish lizard to predictions of a simple model of undulatory swimming that consists of prescribed kinematics and granular resistive forces. The neuromechanical phase lag measured using electromyography (EMG) quantitatively matches the predicted phase lag between the local body curvature and torque exerted by granular resistive forces. Two effects are responsible for the phase lag in this system: the yaw motion of the body and different integration length over a traveling force pattern for different positions along the body.

Hippocampal 3alpha,5alpha-THP may alter depressive behavior of pregnant and lactating rats.

PubMed

Frye, Cheryl A; Walf, Alicia A

2004-07-01

The 5alpha-reduced metabolite of progesterone (P), 5alpha-pregnan-3alpha-ol-20-one (3alpha,5alpha-THP), may mediate progestins' effects to reduce depressive behavior of female rats in part through actions in the hippocampus. To investigate, forced swim test behavior and plasma and hippocampal progestin levels were assessed in groups of rats expected to differ in their 3alpha,5alpha-THP levels due to endogenous differences (pregnant and postpartum), administration of a 5alpha-reductase inhibitor (finasteride; 50 mg/kg sc), and/or gestational stress [prenatal stress (PNS)], an animal model of depression. Pregnant rats had higher plasma and hippocampal 3alpha,5alpha-THP levels and less depressive behavior (decreased immobility, increased struggling and swimming) in the forced swim test than did postpartum rats. Finasteride, compared to vehicle-administration, reduced plasma and hippocampal 3alpha,5alpha-THP levels and increased depressive behavior (increased immobility, decreased struggling and swimming). PNS was associated with lower hippocampal, but not plasma, 3alpha,5alpha-THP levels and increased swimming compared to that observed in control rats. Together, these data suggest that 3alpha,5alpha-THP in the hippocampus may mediate antidepressive behavior of female rats.

Measurement of hydrodynamic force generation by swimming dolphins using bubble DPIV.

PubMed

Fish, Frank E; Legac, Paul; Williams, Terrie M; Wei, Timothy

2014-01-15

Attempts to measure the propulsive forces produced by swimming dolphins have been limited. Previous uses of computational hydrodynamic models and gliding experiments have provided estimates of thrust production by dolphins, but these were indirect tests that relied on various assumptions. The thrust produced by two actively swimming bottlenose dolphins (Tursiops truncatus) was directly measured using digital particle image velocimetry (DPIV). For dolphins swimming in a large outdoor pool, the DPIV method used illuminated microbubbles that were generated in a narrow sheet from a finely porous hose and a compressed air source. The movement of the bubbles was tracked with a high-speed video camera. Dolphins swam at speeds of 0.7 to 3.4 m s(-1) within the bubble sheet oriented along the midsagittal plane of the animal. The wake of the dolphin was visualized as the microbubbles were displaced because of the action of the propulsive flukes and jet flow. The oscillations of the dolphin flukes were shown to generate strong vortices in the wake. Thrust production was measured from the vortex strength through the Kutta-Joukowski theorem of aerodynamics. The dolphins generated up to 700 N during small amplitude swimming and up to 1468 N during large amplitude starts. The results of this study demonstrated that bubble DPIV can be used effectively to measure the thrust produced by large-bodied dolphins.

Protocols for hyperlactatemia induction in the lactate minimum test adapted to swimming rats.

PubMed

de Araujo, Gustavo Gomes; Papoti, Marcelo; Manchado, Fúlvia de Barros; de Mello, Maria Alice Rostom; Gobatto, Claudio Alexandre

2007-12-01

The lactate minimum test (LACmin) has been considered an important indicator of endurance exercise capacity and a single session protocol can predict the maximal steady state lactate (MLSS). The objective of this study was to determine the best swimming protocol to induce hyperlactatemia in order to assure the LACmin in rats (Rattus norvegicus), standardized to four different protocols (P) of lactate elevation. The protocols were P1: 6 min of intermittent jumping exercise in water (load of 50% of the body weight - bw); P2: two 13% bw load swimming bouts until exhaustion (tlim); P3: one tlim 13% bw load swimming bout; and P4: two 13% bw load swimming bouts (1st 30 s, 2nd to tlim), separated by a 30 s interval. The incremental phase of LACmin beginning with initial loads of 4% bw, increased in 0.5% at each 5 min. Peak lactate concentration was collected after 5, 7 and 9 min (mmol L(-1)) and differed among the protocols P1 (15.2+/-0.4, 14.9+/-0.7, 14.8+/-0.6) and P2 (14.0+/-0.4, 14.9+/-0.4, 15.5+/-0.5) compared to P3 (5.1+/-0.1, 5.6+/-0.3, 5.6+/-0.3) and P4 (4.7+/-0.2, 6.8+/-0.2, 7.1+/-0.2). The LACmin determination success rates were 58%, 55%, 80% and 91% in P1, P2, P3 and P4 protocols, respectively. The MLSS did not differ from LACmin in any protocol. The LACmin obtained from P4 protocol showed better assurance for the MLSS identification in most of the tested rats.

[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.

Effects of single and combined gabapentin use in elevated plus maze and forced swimming tests.

PubMed

Kilic, Fatma Sultan; Ismailoglu, Sule; Kaygisiz, Bilgin; Oner, Setenay

2014-10-01

Gabapentin, a third-generation antiepileptic drug, is a structural analogue of γ-aminobutyric acid, which is an important mediator of central nervous system. There is clinical data indicating its effectiveness in the treatment of psychiatric illnesses such as bipolar disorder and anxiety disorders. We aimed to investigate the antidepressant and anxiolytic-like effects and mechanisms of gabapentin in rats. Female Spraque-Dawley rats weighing 250±20 g were used. A total of 13 groups were formed, each containing 8 rats: gabapentin (5, 10, 20, 40 mg/kg), amitriptyline (10 mg/kg), sertraline (5 mg/kg), diazepam (5 mg/kg), ketamine (10 mg/kg), gabapentin 20 mg/kg was also combined with amitriptyline (10 mg/kg), sertraline (5 mg/kg), diazepam (5 mg/kg) and ketamine (10 mg/kg). All the drugs were used intraperitoneally as single dose. Saline was administered to the control group. Elevated plus maze and forced swimming tests were used as experimental models of anxiety and depression, respectively. It was observed that gabapentin showed an anxiolytic-like and antidepressant-like effect in all doses in rats. Its antidepressant effect was found to be the same as the antidepressant effects of amitriptyline and sertraline. There was no change in the antidepressant effect when gabapentin was combined with amitriptyline and ketamine, but there was an increase when combined with sertraline and diazepam. Gabapentin and amitriptyline showed similar anxiolytic effect, whereas ketamine and diazepam had more potent anxiolytic effect compared with them. These data suggest that gabapentin may possess antidepressant- and anxiolytic-like effects.

A maternal methyl-containing diet alters learning ability in the Morris swimming test in adult rats.

PubMed

Plyusnina, I Z; Os'kina, I N; Shchepina, O A; Prasolova, L A; Trut, L N

2007-06-01

Maternal choline diet is known to affect the processes of spatial learning. We report here our studies of learning ability in the Morris swimming test in the adult offspring of maternal rats given a methyl-containing supplement enriched with choline and betaine during pregnancy and lactation. Increases in the time taken to find the invisible platform and the duration of swimming close to the vessel walls were seen, these demonstrating worsening of learning ability in response to the maternal diet. Changes in the platform search strategy were not associated with increases in anxiety in male rats. The possible role of a maternal methyl-containing diet in altering the expression of genes controlling the development of the nervous system is discussed.

Forced sustained swimming exercise at optimal speed enhances growth of juvenile yellowtail kingfish (Seriola lalandi).

PubMed

Palstra, Arjan P; Mes, Daan; Kusters, Kasper; Roques, Jonathan A C; Flik, Gert; Kloet, Kees; Blonk, Robbert J W

2014-01-01

Swimming exercise at optimal speed may optimize growth performance of yellowtail kingfish in a recirculating aquaculture system. Therefore, optimal swimming speeds (U opt in m s(-1) or body lengths s(-1), BL s(-1)) were assessed and then applied to determine the effects of long-term forced and sustained swimming at U opt on growth performance of juvenile yellowtail kingfish. U opt was quantified in Blazka-type swim-tunnels for 145, 206, and 311 mm juveniles resulting in values of: (1) 0.70 m s(-1) or 4.83 BL s(-1), (2) 0.82 m s(-1) or 3.25 BL s(-1), and (3) 0.85 m s(-1) or 2.73 BL s(-1). Combined with literature data from larger fish, a relation of U opt (BL s(-1)) = 234.07(BL)(-0.779) (R (2) = 0.9909) was established for this species. Yellowtail kingfish, either forced to perform sustained swimming exercise at an optimal speed of 2.46 BL s(-1) ("swimmers") or allowed to perform spontaneous activity at low water flow ("resters") in a newly designed 3600 L oval flume (with flow created by an impeller driven by an electric motor), were then compared. At the start of the experiment, ten fish were sampled representing the initial condition. After 18 days, swimmers (n = 23) showed a 92% greater increase in BL and 46% greater increase in BW as compared to resters (n = 23). As both groups were fed equal rations, feed conversion ratio (FCR) for swimmers was 1.21 vs. 1.74 for resters. Doppler ultrasound imaging showed a statistically significant higher blood flow (31%) in the ventral aorta of swimmers vs. resters (44 ± 3 vs. 34 ± 3 mL min(-1), respectively, under anesthesia). Thus, growth performance can be rapidly improved by optimal swimming, without larger feed investments.

Forced sustained swimming exercise at optimal speed enhances growth of juvenile yellowtail kingfish (Seriola lalandi)

PubMed Central

Palstra, Arjan P.; Mes, Daan; Kusters, Kasper; Roques, Jonathan A. C.; Flik, Gert; Kloet, Kees; Blonk, Robbert J. W.

2015-01-01

Swimming exercise at optimal speed may optimize growth performance of yellowtail kingfish in a recirculating aquaculture system. Therefore, optimal swimming speeds (Uopt in m s−1 or body lengths s−1, BL s−1) were assessed and then applied to determine the effects of long-term forced and sustained swimming at Uopt on growth performance of juvenile yellowtail kingfish. Uopt was quantified in Blazka-type swim-tunnels for 145, 206, and 311 mm juveniles resulting in values of: (1) 0.70 m s−1 or 4.83 BL s−1, (2) 0.82 m s−1 or 3.25 BL s−1, and (3) 0.85 m s−1 or 2.73 BL s−1. Combined with literature data from larger fish, a relation of Uopt (BL s−1) = 234.07(BL)−0.779 (R2 = 0.9909) was established for this species. Yellowtail kingfish, either forced to perform sustained swimming exercise at an optimal speed of 2.46 BL s−1 (“swimmers”) or allowed to perform spontaneous activity at low water flow (“resters”) in a newly designed 3600 L oval flume (with flow created by an impeller driven by an electric motor), were then compared. At the start of the experiment, ten fish were sampled representing the initial condition. After 18 days, swimmers (n = 23) showed a 92% greater increase in BL and 46% greater increase in BW as compared to resters (n = 23). As both groups were fed equal rations, feed conversion ratio (FCR) for swimmers was 1.21 vs. 1.74 for resters. Doppler ultrasound imaging showed a statistically significant higher blood flow (31%) in the ventral aorta of swimmers vs. resters (44 ± 3 vs. 34 ± 3 mL min−1, respectively, under anesthesia). Thus, growth performance can be rapidly improved by optimal swimming, without larger feed investments. PMID:25620933

Role of different types of potassium channels in the antidepressant-like effect of agmatine in the mouse forced swimming test.

PubMed

Budni, Josiane; Gadotti, Vinícius M; Kaster, Manuella P; Santos, Adair R S; Rodrigues, Ana Lúcia S

2007-12-01

The administration of agmatine elicits an antidepressant-like effect in the mouse forced swimming test by a mechanism dependent on the inhibition of the NMDA receptors and the L-arginine-nitric oxide (NO) pathway. Since it has been reported that the NO can activate different types of potassium (K(+)) channels in several tissues, the present study investigates the possibility of synergistic interactions between different types of K(+) channel inhibitors and agmatine in the forced swimming test. Treatment of mice by i.c.v. route with subeffective doses of tetraethylammonium (a non specific inhibitor of K(+) channels, 25 pg/site), glibenclamide (an ATP-sensitive K(+) channels inhibitor, 0.5 pg/site), charybdotoxin (a large- and intermediate-conductance calcium-activated K(+) channel inhibitor, 25 pg/site) or apamin (a small-conductance calcium-activated K(+) channel inhibitor, 10 pg/site), augmented the effect of agmatine (0.001 mg/kg, i.p.) in the forced swimming test. Furthermore, the administration of agmatine and the K(+) channel inhibitors, alone or in combination, did not affect locomotion in the open-field test. Moreover, the reduction in the immobility time elicited by an active dose of agmatine (10 mg/kg, i.p.) in the forced swimming test was prevented by the pre-treatment of mice with the K(+) channel openers cromakalim (10 microg/site, i.c.v.) and minoxidil (10 microg/site, i.c.v.), without affecting locomotion. Together these data raise the possibility that the antidepressant-like effect of agmatine in the forced swimming test is related to its modulatory effects on neuronal excitability, via inhibition of K(+) channels.

Nigella sativa seed extract attenuates the fatigue induced by exhaustive swimming in rats

PubMed Central

Rahman, Mahbubur; Yang, Dong Kwon; Kim, Gi-Beum; Lee, Sei-Jin; Kim, Shang-Jin

2017-01-01

In previous studies, Nigella sativa (NS) has been studied due to its various physiological and pharmacological activities. However, evidence on the effects of NS on physical fatigue following exhaustive swimming remains limited. In the present study, the authors evaluated the potential beneficial effects of NS against the fatigue activity following exhaustive swimming. Rats were orally administered with NS extract (2 g/kg/day) for 21 days, and the anti-fatigue effect was assessed by exhaustive swimming exercise. The presented results indicated that pre-treatment of NS extract significantly increased the time to exhaustion. In hemodynamic parameters, NS extract increased blood pO2 and O2sat, but decreased pCO2. For underlying mechanisms, NS extract protected depletion of energy, indicated by increased levels of blood pH, glucose and tissue glycogen contents, and decreased levels of blood lactate, tissue lactic dehydrogenase and creatine kinase, when the NS extract was pre-treated. In addition, the NS extract inhibited oxidative stress following exhaustive swimming, as reflected by the results of increased levels of superoxide dismutase and redox ratio, and decreased the level of malondialdehyde when the NS extract was pre-treated. Collectively, the present study demonstrated that NS extract has an anti-fatigue activity against exhaustive swimming by energy restoration and oxidative-stress defense. PMID:28413647

Omega-3 fatty acid deficiency does not alter the effects of chronic fluoxetine treatment on central serotonin turnover or behavior in the forced swim test in female rats.

PubMed

McNamara, Robert K; Able, Jessica A; Liu, Yanhong; Jandacek, Ronald; Rider, Therese; Tso, Patrick; Lipton, Jack W

2013-12-01

While translational evidence suggests that long-chain omega-3 fatty acid status is positively associated with the efficacy of selective serotonin reuptake inhibitor drugs, the neurochemical mechanisms mediating this interaction are not known. Here, we investigated the effects of dietary omega-3 (n-3) fatty acid insufficiency on the neurochemical and behavioral effects of chronic fluoxetine (FLX) treatment. Female rats were fed diets with (CON, n=56) or without (DEF, n=40) the n-3 fatty acids during peri-adolescent development (P21-P90), and one half of each group was administered FLX (10mg/kg/day) for 30days (P60-P90) prior to testing. In adulthood (P90), regional brain serotonin (5-HT) and 5-hydroxyindoleacetic (5-HIAA) concentrations, presynaptic markers of 5-HT neurotransmission, behavioral responses in the forced swim test (FST), and plasma FLX and norfluoxetine (NFLX) concentrations were investigated. Peri-adolescent n-3 insufficiency led to significant reductions in cortical docosahexaenoic acid (DHA, 22:6n-3) composition in DEF (-25%, p≤0.0001) and DEF+FLX (-28%, p≤0.0001) rats. Untreated DEF rats exhibited significantly lower regional 5-HIAA/5-HT ratios compared with untreated CON rats, but exhibited similar behavioral responses in the FST. In both CON and DEF rats, chronic FLX treatment similarly and significantly decreased 5-HIAA concentrations and the 5-HIAA/5-HT ratio in the hypothalamus, hippocampus, and nucleus accumbens, brainstem tryptophan hydroxylase-2 mRNA expression, and immobility in the FST. While the FLX-induced reduction in 5-HIAA concentrations in the prefrontal cortex was significantly blunted in DEF rats, the reduction in the 5-HIAA/5-HT ratio was similar to CON rats. Although plasma FLX and NFLX levels were not significantly different in DEF and CON rats, the NFLX/FLX ratio was significantly lower in DEF+FLX rats. These preclinical data demonstrate that n-3 fatty acid deficiency does not significantly reduce the effects of chronic

Effects of co-administration of fluoxetine and risperidone on properties of peritoneal and pleural macrophages in rats subjected to the forced swimming test.

PubMed

Roman, Adam; Kuśmierczyk, Justyna; Klimek, Ewa; Rogóż, Zofia; Nalepa, Irena

2012-01-01

Literature data show that administration of atypical antipsychotic drug, risperidone (RIS), enhances antidepressive action of fluoxetine (FLU). As antidepressive treatments also regulate immune functions, we examined whether combined administration of FLU and RIS to rats subsequently subjected to a forced swimming test (FST) modifies parameters of macrophage activity that are directly related to their immunomodulatory functions, i.e., arginase (ARG) activity and nitric oxide (NO) synthesis. Antidepressive action of the drugs was assessed with FST. Peritoneal and pleural cells were eluted and selected parameters of immunoreactivity were assessed colorimetrically. We found that the concomitant administration of FLU (10 mg/kg) and RIS (0.1 mg/kg) produced antidepressive-like effects in the FST,whereas the drugs were ineffective if administered separately. Stress related to the FST affected immune cell redistribution and changed some of the metabolic and immunomodulatory properties of macrophages. FLU administered to rats at a suboptimal dose for antidepressive action potently influenced macrophage immunomodulatory properties and redirected their activity toward anti-inflammatory M2 functional phenotype, as manifested by changes in the ARG/NO ratio. These effects resulted from a direct cellular influence of the drug, as well as its action via neuroendocrine pathways, as evidenced in peritoneal and pleural cells. Addition of RIS did not augment immunomodulatory action of FLU, though the combination showed antidepressant-like activity in the FST. Our results suggest that when the drugs were administered together, FLU was potent enough to redirect macrophages toward M2 activity. It is also postulated that drug-induced changes in the immune system are not so closely related to antidepressant-like effects or might be secondary to those produced in the neuroendocrine system.

Embryo developmental capacity of oocytes fertilised by sperm of mouse exposed to forced swimming stress.

PubMed

Ghasem, Saki; Majid, Jasemi; Shiva, Razi

2013-07-01

To assess developmental capacity of fertilised oocytes by sperm of mouse exposed to forced swimming stress. The experimental study was conducted at the Physiology Research Center of Ahvaz Jundishapur University of Medical Sciences, from August 2011 to January 2012. It comprised 20 adult male and 10 female mice. The male mice were randomly divided into two equal groups (n=10): control and experimental. Animals of the experimental group were submitted to forced swimming stress. All male mice were euthanised and the cauda epididymis removed before contents were squeezed out. A pre-incubated capacitated sperm was gently added to the freshly collected ova of the two groups of study. The combined sperm-oocyte suspension was incubated for 4-6 hours under a condition of 5% Carbon dioxide and 37 degreeC temperature. The ova were then washed through several changes of medium and finally incubated. Fertilisation was assessed by recording the number of 1-cell embryos 4-6 hours after insemination. The 1-cell embryos were allowed to further develop in vitro for about 120 hours. Development of embryos everyday and during 5 days of culture was observed by using inverted microscope. SPSS 13.0.1 was used for statistical analysis. The percentage of oocytes fertilised was 75:96 (78.12+/-4.8%) and 50:10 (49.5+/-3.9%) in the control and experimental groups, respectively. The difference was significant (p <0.001). At 24 hours after insemination, 70:75 (93.33+/-2.7%) and 39:50 (78+/-3.5%)of fertilized oocytes developed to two=cell embryos in control and experimental groups respectively.The difference was significant (p <0.02).There were not significant differences (p>0.05) between the two groups in terms of speed and developmental capacity of blastocysts. Fertilisation capacity of male mice affected by forced swimming stress and also the developmental capacity of oocyte fertilised by sperm of mouse exposed to forced swimming stress decreased.

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

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.

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

Effects of Laminaria japonica polysaccharides on exercise endurance and oxidative stress in forced swimming mouse model.

PubMed

Yan, Feiwei; Hao, Haitao

2016-12-01

Polysaccharides are the major active ingredients responsible for the bioactivities of Laminaria japonica. However, the effects of L. japonica polysaccharides (LJP) on exercise endurance and oxidative stress have never been investigated. Therefore, this study was conducted to investigate the effects of LJP on exercise endurance and oxidative stress in a forced swimming mouse model. The animals were divided into four groups, namely the control (C), LJP-75, LJP-150, and LJP-300 groups, which received physiological saline and 75, 150, and 300 mg kg(-1) LJP, respectively, by gavage once a day for 28 days. This was followed by a forced swimming test and measurements of various biochemical parameters. LJP increased swimming time to exhaustion, the liver and muscle glycogen content, and levels of superoxide dismutase, glutathione peroxidase, and catalase in the serum, liver, and muscle, which were accompanied by corresponding decreases in the malondialdehyde (MDA) content of the same tissues. Furthermore, decreases in blood lactic acid and serum myeloperoxidase (MPO) levels were observed. LJP enhanced exercise endurance and protected mice against exhaustive exercise-induced oxidative stress.

Effects of periadolescent fluoxetine and paroxetine on elevated plus-maze, acoustic startle, and swimming immobility in rats while on and off-drug.

PubMed

Vorhees, Charles V; Morford, LaRonda R; Graham, Devon L; Skelton, Matthew R; Williams, Michael T

2011-10-05

Whether selective serotonin reuptake inhibitors (SSRIs) exposure during adolescent brain development causes lasting effects remains unresolved. Assess the effects of fluoxetine and paroxetine 60 days after adolescent exposure compared with when on-drug. Male Sprague-Dawley littermates (41 litters) were gavaged on postnatal days 33-53 with fluoxetine (3 or 10 mg/kg/day), paroxetine (3, 10 or, 17 mg/kg/day), or water; half were tested while on-drug (21 litters) and half after 60 days off-drug (20 litters). The highest dose of the drugs reduced body weight gain during treatment that rebounded 1 week post-treatment. On-drug, no significant group differences were found on elevated plus maze time-in-open, zone entries, or latency to first open entry; however, the high dose of paroxetine significantly reduced head-dips (N=20/group). No significant effects were found on-drug for acoustic startle response/prepulse inhibition (ASR/PPI) although a trend (p<0.10) was seen, which after combining dose levels, showed a significant increase in ASR amplitude for both fluoxetine and paroxetine (N=20-21/group). No differences on immobility time were seen in the Porsolt forced swim test or in plasma corticosterone at the end of forced swim (N-19-21/group). Off-drug, no effects were seen in the elevated plus maze (N=16/group), ASR/PPI (N=20/group), forced swim (N=19-20/group), or plasma corticosterone (N=19/group). At the doses tested, fluoxetine and paroxetine induced minor effects with drug on-board but no residual, long-term adverse effects in rats 60 days after drug discontinuation. The data provide no evidence that fluoxetine or paroxetine have long-term adverse effects on the behaviors measured here after adolescent to young adult exposure.

Effect of fish oil and coconut fat supplementation on depressive-type behavior and corticosterone levels of prenatally stressed male rats.

PubMed

Borsonelo, Elizabethe Cristina; Suchecki, Deborah; Galduróz, José Carlos Fernandes

2011-04-18

Prenatal stress (PNS) during critical periods of brain development has been associated with numerous behavioral and/or mood disorders in later life. These outcomes may result from changes in the hypothalamic-pituitary-adrenal (HPA) axis activity, which, in turn, can be modulated by environmental factors, such as nutritional status. In this study, the adult male offspring of dams exposed to restraint stress during the last semester of pregnancy and fed different diets were evaluated for depressive-like behavior in the forced swimming test and for the corticosterone response to the test. Female Wistar rats were allocated to one of three groups: regular diet, diet supplemented with coconut fat or with fish oil, offered during pregnancy and lactation. When pregnancy was confirmed, they were distributed into control or stress groups. Stress consisted of restraint and bright light for 45 min, three times per day, in the last week of pregnancy. The body weight of the adult offspring submitted to PNS was lower than that of controls. In the forced swimming test, time of immobility was reduced and swimming was increased in PNS rats fed fish oil and plasma corticosterone levels immediately after the forced swimming test were lower in PNS rats fed regular diet than their control counterparts; this response was reduced in control rats whose mothers were fed fish oil and coconut fat. The present results indicate that coconut fat and fish oil influenced behavioral and hormonal responses to the forced swimming test in both control and PNS adult male rats. Copyright © 2011 Elsevier B.V. All rights reserved.

Just Keep Swimming: Neuroendocrine, Metabolic, and Behavioral Changes After a Forced Swimming Test in Zebrafish.

PubMed

da Rosa, João Gabriel Santos; Barcellos, Heloísa Helena de Alcântara; Idalencio, Renan; Marqueze, Alessandra; Fagundes, Michele; Rossini, Mainara; Variani, Cristiane; Balbinoti, Francine; Tietböhl, Tássia Michele Huff; Rosemberg, Denis Broock; Barcellos, Leonardo José Gil

2017-02-01

In this study, we show that an adaptation of the spinning test can be used as a model to study the exercise-exhaustion-recovery paradigm in fish. This forced swimming test promotes a wide range of changes in the hypothalamus-pituitary-interrenal axis functioning, intermediary metabolism, as well in fish behavior at both exercise and recovery periods. Our results pointed that this adapted spinning test can be considered a valuable tool for evaluating drugs and contaminant effects on exercised fish. This can be a suitable protocol both to environmental-to evaluate contaminants that act in fish energy mobilization and recovery after stressors-and translational perspectives-effects of drugs on exercised or stressed humans.

Antidepressant-like effects of Perilla frutescens seed oil during a forced swimming test.

PubMed

Lee, Hsiu-Chuan; Ko, Hsiang-Kai; Huang, Brian E T-G; Chu, Yan-Hwa; Huang, Shih-Yi

2014-05-01

Unipolar depressive disorder may become one of the major leading causes of disease burden by 2030 according to the World Health Organization (WHO). Thus, the discovery of antidepressive foods is attractive and could have considerable impacts worldwide. We investigated the antidepressant-like effects of Perilla frutescens seed oil on adult male rats subjected to a forced swimming test (FST). Forty Sprague-Dawley rats were housed and fed various diets, including soybean oil-rich, eicosapentaenoic acid (EPA)-rich, and P. frutescens seed oil-rich diets for 6 weeks. After the dietary intervention, animals were tested using an FST and were sacrificed after the test. We analyzed the fatty acid profiles of red blood cells (RBCs) and the brain prefrontal cortex (PFC). Levels of brain-derived neurotrophic factor (BDNF), serotonin, and dopamine in the PFC were also determined. After the FST, the imipramine, EPA-rich, and P. frutescens seed oil-rich groups showed significant shorter immobility time and longer struggling time than the control group (p < 0.05). Levels of BDNF in the P. frutescens seed oil-rich group and levels of serotonin in the EPA-rich group were significantly (p < 0.05) higher than those of the control group. Moreover, the BDNF concentration in the PFC was significantly positively correlated with the struggling time. However, there were no significant differences in dopamine levels between the intervention groups and the control group. In conclusion, a P. frutescens seed oil-rich diet exhibited antidepressant-like properties through modulation of fatty acid profiles and BDNF expression in the brain during an FST.

Age differences in the impact of forced swimming test on serotonin transporter levels in lateral septum and dorsal raphe

PubMed Central

2014-01-01

Background Forced swimming test (FST) is an animal model which evaluates behavioral despair and the effect of antidepressants such as the selective serotonin reuptake inhibitors; the FST modifies the expression of some receptors related to antidepressant response, but it is not known whether serotonin transporter (SERT), their main target, is affected by this test in animals of different ages. Antidepressant response has shown age-dependent variations which could be associated with SERT expression. The aim of the present study was to analyze changes in the SERT immunoreactivity (SERT-IR) in dorsal raphe and lateral septum of male rats from different age groups with or without behavioral despair induced by their exposure to the FST, since these two structures are related to the expression of this behavior. Methods Prepubertal (24 PN), pubertal (40 PN), young adult (3–5 months) and middle-aged (12 months) male rats were assigned to a control group (non-FST) or depressed group (FST, two sessions separated by 24 h). Changes in SERT-IR in dorsal raphe and lateral septum were determined with immunofluorescence. Results Pubertal and middle-aged rats showed higher levels of immobility behavior compared to prepubertal rats on the FST. SERT-IR showed an age-dependent increase followed by a moderate decrease in middle-aged rats in both structures; a decreased in SERT-IR in lateral septum and dorsal raphe of pubertal rats was observed after the FST. Conclusions Age differences were observed in the SERT-IR of structures related to behavioral despair; SERT expression was modified by the FST in lateral septum and dorsal raphe of pubertal rats. PMID:24490994

Mice receiving infrared irradiation have a higher survival rate under forced swimming in cold.

PubMed

Tsai, Jui-Feng

2009-10-01

To explore the effect of infrared (IR) irradiation on the survival rates of mice under forced swimming in cold conditions. IR irradiation has been found to be beneficial for wound healing, tumor reduction, pain relief, and even against depression. However, whether the antidepressant effect of IR irradiation came from heat has remained unanswered. The goals of the study were originally aimed at using an animal model for depression to understand the relationship between the antidepressant effect of IR irradiation and hyperthermia as well as seasonality. Forty-four mice were housed in cages in a room subject to the outdoor temperature, and randomly assigned to the IR-treated group (n = 15), the heat-treated group (n = 14), and the control group (n = 15) during winter. The mice of the IR-treated group received whole-body IR irradiation for 60 min daily, while the heat-treated group received heat diffusion to reach the same temperature level. The control group received neither IR nor heat. All groups of mice underwent a forced swimming test weekly. Incidentally, two episodes of cold current occurred during the study period, and some mice died. The survival rates were compared pairwise against the control. The IR-treated group had a significantly reduced relative risk (p = 0.013) when compared with the control group, while the heat-treated group did not show any significant reduction (p = 0.087). There was no significant difference in body temperatures of the three groups before and after the irradiation. IR irradiation resulted in a significantly higher survival rate for mice that were concurrently subjected to cold and a forced swimming test. This result may be beyond the thermal effect.

Acute Aerobic Swimming Exercise Induces Distinct Effects in the Contractile Reactivity of Rat Ileum to KCl and Carbachol

PubMed Central

Araujo, Layanne C. da Cunha; de Souza, Iara L. L.; Vasconcelos, Luiz H. C.; Brito, Aline de Freitas; Queiroga, Fernando R.; Silva, Alexandre S.; da Silva, Patrícia M.; Cavalcante, Fabiana de Andrade; da Silva, Bagnólia A.

2016-01-01

Aerobic exercise promotes short-term physiological changes in the intestinal smooth muscle associated to the ischemia-reperfusion process; however, few studies have demonstrated its effect on the intestinal contractile function. Thus, this work describes our observations regarding the influence of acute aerobic swimming exercise in the contractile reactivity, oxidative stress, and morphology of rat ileum. Wistar rats were divided into sedentary (SED) and acutely exercised (EX-AC) groups. Animals were acclimated by 10, 10, and 30 min of swimming exercise in intercalated days 1 week before exercise. Then they were submitted to forced swimming for 1 h with a metal of 3% of their body weight attached to their body. Animals were euthanized immediately after the exercise section and the ileum was suspended in organ baths for monitoring isotonic contractions. The analysis of lipid peroxidation was performed in order to determinate the malondialdehyde (MDA) levels as a marker of oxidative stress, and intestinal smooth muscle morphology by histological staining. Cumulative concentration-response curves to KCl were altered in the EX-AC with an increase in both its efficacy and potency (Emax = 153.2 ± 2.8%, EC50 = 1.3 ± 0.1 × 10−2 M) compared to the SED group (Emax = 100%, EC50 = 1.8 ± 0.1 × 10−2 M). Interestingly, carbachol had its efficacy and potency reduced in the EX-AC (Emax = 67.1 ± 1.4%, EC50 = 9.8 ± 1.4 × 10−7 M) compared to the SED group (Emax = 100%, EC50 = 2.0 ± 0.2 × 10−7 M). The exercise did not alter the MDA levels in the ileum (5.4 ± 0.6 μ mol/mL) in the EX-AC compared to the SED group (8.4 ± 1.7 μ mol/mL). Moreover, neither the circular nor the longitudinal smooth muscle layers thickness were modified by the exercise (66.2 ± 6.0 and 40.2 ± 2.6 μm, respectively), compared to the SED group (61.6 ± 6.4 and 34.8 ± 3.7 μm, respectively). Therefore, the ileum sensitivity to contractile agents is differentially altered by the acute aerobic

Water spray-induced grooming is negatively correlated with depressive behavior in the forced swimming test in rats.

PubMed

Shiota, Noboru; Narikiyo, Kimiya; Masuda, Akira; Aou, Shuji

2016-05-01

Rodents show grooming, a typical self-care behavior, under stress and non-stress conditions. Previous studies revealed that grooming under stress conditions such as the open-field test (OFT) or the elevated plus-maze test (EPM) is associated with anxiety, but the roles of grooming under non-stress conditions are not well understood. Here, we examined spray-induced grooming as a model of grooming under a non-stress condition to investigate the relationship between this grooming and depression-like behavior in the forced swim test (FST) and tail suspension test, and we compared spray-induced grooming with OFT- and EPM-induced grooming. The main finding was that the duration of spray-induced grooming, but not that of OFT/EPM-induced grooming, was negatively correlated with the duration of immobility in the FST, an index of depression-like behavior. The results suggest that spray-induced grooming is functionally different from the grooming in the OFT and EPM and is related to reduction of depressive behavior.

Swimming exercise demonstrates advantages over running exercise in reducing proteinuria and glomerulosclerosis in spontaneously hypertensive rats.

PubMed

Totou, N L; Moura, S S; Coelho, D B; Oliveira, E C; Becker, L K; Lima, W G

2018-03-01

Experimental studies in animal models have described the benefits of physical exercise (PE) to kidney diseases associated with hypertension. Land- and water-based exercises induce different responses in renal function. Our aim was to evaluate the renal alterations induced by different environments of PE in spontaneously hypertensive rats (SHRs). The SHRs were divided into sedentary (S), swimming exercise (SE), and running exercise (RE) groups, and were trained for 8 weeks under similar intensities (60 min/day). Arterial pressure (AP) and heart rate (HR) were recorded. The renal function was evaluated through urinary volume at each week of training; sodium and potassium excretions, plasma and urinary osmolarities, glomerular filtration rate (GFR), levels of proteinuria, and renal damage were determined. SE and RE rats presented reduced mean AP, systolic blood pressure, and HR in comparison with S group. SE and RE rats showed higher urine osmolarity compared with S. SE rats showed higher free water clearance (P < 0.01), lower urinary density (P < 0.0001), and increased weekly urine volume (P < 0.05) in comparison with RE and S groups. GFR was increased in both SE and RE rats. The proteinuria of SE (7.0 ± 0.8 mg/24 h) rats was decreased at the 8th week of the PE in comparison with RE (9.6 ± 0.8 mg/24 h) and S (9.8 ± 0.5 mg/24 h) groups. The glomerulosclerosis was reduced in SE rats (P < 0.02). SE produced different response in renal function in comparison with RE, in which only swimming-trained rats had better profile for proteinuria and glomerulosclerosis.

Swimming attenuates inflammation, oxidative stress, and apoptosis in a rat model of dextran sulfate sodium-induced chronic colitis

PubMed Central

Zhu, Xiao-shan; Liu, Qin-qin; Wang, Li-feng; Yang, An-gang; Gao, Chun-fang; Li, Jun-tang

2017-01-01

Increasing evidence suggests that regular physical exercise suppresses chronic inflammation. However, the potential inhibitory effects of swimming on dextran sulfate sodium (DSS)-induced chronic colitis, and its underlying mechanisms, remain unclear. In this study, rats were orally administered DSS to induce chronic colitis, and subsequently treated with or without swimming exercise. A 7-week swimming program (1 or 1.5 hours per day, 5 days per week) ameliorated DSS-caused colon shortening, colon barrier disruption, spleen enlargement, serum LDH release, and reduction of body weight gain. Swimming for 1.5 hours per day afforded greater protection than 1 hour per day. Swimming ameliorated DSS-induced decrease in crypt depth, and increases in myeloperoxidase activity, infiltration of Ly6G+ neutrophils and TNF-a- and IFN-?-expressing CD3+ T cells, as well as fecal calprotectin and lactoferrin. Swimming inhibited pro-inflammatory cytokine and chemokine production and decreased the protein expression of phosphorylated nuclear factor-?B p65 and cyclooxygenase 2, whereas it elevated interleukin-10 levels. Swimming impeded the generation of reactive oxygen species, malondialdehyde, and nitric oxide; however, it boosted glutathione levels, total antioxidant capacity, and superoxide dismutase and glutathione peroxidase activities. Additionally, swimming decreased caspase-3 activity and expression of apoptosis-inducing factor, cytochrome c, Bax, and cleaved-caspase-3, but increased Bcl-2 levels. Overall, these results suggest that swimming exerts beneficial effects on DSS-induced chronic colitis by modulating inflammation, oxidative stress, and apoptosis. PMID:28030847

Swimming attenuates inflammation, oxidative stress, and apoptosis in a rat model of dextran sulfate sodium-induced chronic colitis.

PubMed

Qin, Ling; Yao, Zhi-Qiang; Chang, Qi; Zhao, Ya-Li; Liu, Ning-Ning; Zhu, Xiao-Shan; Liu, Qin-Qin; Wang, Li-Feng; Yang, An-Gang; Gao, Chun-Fang; Li, Jun-Tang

2017-01-31

Increasing evidence suggests that regular physical exercise suppresses chronic inflammation. However, the potential inhibitory effects of swimming on dextran sulfate sodium (DSS)-induced chronic colitis, and its underlying mechanisms, remain unclear. In this study, rats were orally administered DSS to induce chronic colitis, and subsequently treated with or without swimming exercise. A 7-week swimming program (1 or 1.5 hours per day, 5 days per week) ameliorated DSS-caused colon shortening, colon barrier disruption, spleen enlargement, serum LDH release, and reduction of body weight gain. Swimming for 1.5 hours per day afforded greater protection than 1 hour per day. Swimming ameliorated DSS-induced decrease in crypt depth, and increases in myeloperoxidase activity, infiltration of Ly6G+ neutrophils and TNF-α- and IFN-γ-expressing CD3+ T cells, as well as fecal calprotectin and lactoferrin. Swimming inhibited pro-inflammatory cytokine and chemokine production and decreased the protein expression of phosphorylated nuclear factor-κB p65 and cyclooxygenase 2, whereas it elevated interleukin-10 levels. Swimming impeded the generation of reactive oxygen species, malondialdehyde, and nitric oxide; however, it boosted glutathione levels, total antioxidant capacity, and superoxide dismutase and glutathione peroxidase activities. Additionally, swimming decreased caspase-3 activity and expression of apoptosis-inducing factor, cytochrome c, Bax, and cleaved-caspase-3, but increased Bcl-2 levels. Overall, these results suggest that swimming exerts beneficial effects on DSS-induced chronic colitis by modulating inflammation, oxidative stress, and apoptosis.

Forced swim stress but not exogenous corticosterone could induce the reinstatement of extinguished morphine conditioned place preference in rats: involvement of glucocorticoid receptors in the basolateral amygdala.

PubMed

Karimi, Sara; Attarzadeh-Yazdi, Ghassem; Yazdi-Ravandi, Saeid; Hesam, Soghra; Azizi, Pegah; Razavi, Yasaman; Haghparast, Abbas

2014-05-01

Addiction is a common psychiatric disease and stress has an important role in the drug seeking and relapse behaviors. The involvement of basolateral amygdala (BLA) in the effects of stress on reward pathway is discussed in several studies. In this study, we tried to find out the involvement of glucocorticoid receptors (GRs) in the BLA in stress-induced reinstatement of extinguished morphine-induced conditioned place preference (CPP) in rats. The CPP paradigm was done in adult male Wistar rats weighing 220-320 g, and conditioning score and locomotor activity were recorded by Ethovision software. Animals received effective dose of morphine (5mg/kg) daily, during the 3-day conditioning phase. In extinction phase, rats were put in the CPP box for 30 min a day for 8 days. After extinction, animals were injected by corticosterone (10 m/kg) or exposed to forced swim stress (FSS) 10 min before subcutaneous administration of ineffective dose of morphine (0.5mg/kg) in order to reinstate the extinguished morphine-CPP. To block the glucocorticoid receptors in the BLA, after stereotaxic surgery and placing two cannulae in this area bilaterally, animals received GR antagonist mifepristone (RU38486; 0.3, 3 and 30 ng/0.3 μl DMSO per side) prior to exposure to FSS then each animal received ineffective dose of morphine (0.5mg/kg) as drug-induced reinstatement. The results revealed that physical stress (FSS) but not exogenous corticosterone can significantly induce reinstatement of extinguished morphine-CPP, and intra-BLA mifepristone prevents the stress-induced reinstatement. It can be proposed that stress partially exerts its effect on the reward pathway via glucocorticoid receptors in the BLA. Copyright © 2014 Elsevier B.V. All rights reserved.

Propulsive efficiency of frog swimming with different feet and swimming patterns

PubMed Central

Jizhuang, Fan; Wei, Zhang; Bowen, Yuan; Gangfeng, Liu

2017-01-01

ABSTRACT Aquatic and terrestrial animals have different swimming performances and mechanical efficiencies based on their different swimming methods. To explore propulsion in swimming frogs, this study calculated mechanical efficiencies based on data describing aquatic and terrestrial webbed-foot shapes and swimming patterns. First, a simplified frog model and dynamic equation were established, and hydrodynamic forces on the foot were computed according to computational fluid dynamic calculations. Then, a two-link mechanism was used to stand in for the diverse and complicated hind legs found in different frog species, in order to simplify the input work calculation. Joint torques were derived based on the virtual work principle to compute the efficiency of foot propulsion. Finally, two feet and swimming patterns were combined to compute propulsive efficiency. The aquatic frog demonstrated a propulsive efficiency (43.11%) between those of drag-based and lift-based propulsions, while the terrestrial frog efficiency (29.58%) fell within the range of drag-based propulsion. The results illustrate the main factor of swimming patterns for swimming performance and efficiency. PMID:28302669

Chronic Fluoxetine Treatment Upregulates the Activity of the ERK1/2-NF-κB Signaling Pathway in the Hippocampus and Prefrontal Cortex of Rats Exposed to Forced-Swimming Stress.

PubMed

Cui, Jingqiu; Yang, Kun; Yu, Xue; Wang, Jing-Lan; Li, Jie; Zhang, Yong; Li, Hengfen

2016-01-01

The aim of this study was to explore whether or not the antidepressant actions of fluoxetine (FLX) are correlated with extracellular signal-regulated kinase 1 and 2 (ERK1/2) and nuclear factor κ-light chain enhancer of activated B cells (NF-κB) in the hippocampus (HC) and prefrontal cortex (PFC) of rats. A total of 108 male Sprague-Dawley rats were randomly divided into 6 groups of 18 rats each. Group 1 was the control group, while group 2 comprised the depressed model in which rats were subjected to 28 days of forced-swimming stress (FST); groups 3-6 were also subjected to 28 days of FST and treated with FLX once a day for 1 day (group 3; F1d), 1 week (group 4; F1w), 2 weeks (group 5; F2w), or 4 weeks (group 6; F4w). The control group was not subjected to FST or treated with FLX. Behavior tests that included the Morris water maze (MWM) and saccharin preference were performed, and ERK1/2 and NF-κB proteins were assayed using Western blot. The rats in the control group and in groups 5 and 6 (F2w and F4w, respectively) had a significantly shorter average escape latency, needed more attempts in order to successfully cross the platform, and had a greater saccharin preference than those in the depressed group (p < 0.05). In the depressed group, the phosphorylated ERK1/2 (p-ERK1/2) and phosphorylated NF-κB (p-NF-κB) expression in the HC and PFC were lower than in the control group (p < 0.05). Treatment with FLX reversed the changes in the expression of p-ERK1/2 and p-NF-κB in rats in the F2w and F4w groups. In this study, FLX treatment for 2 weeks or longer reversed the impaired spatial learning, memory, and anhedonia observed in the depressed model rats and upregulated the activities of the ERK1/2-NF-κB signaling pathway. © 2016 S. Karger AG, Basel.

Quantification of upper limb kinetic asymmetries in front crawl swimming.

PubMed

Morouço, Pedro G; Marinho, Daniel A; Fernandes, Ricardo J; Marques, Mário C

2015-04-01

This study aimed at quantifying upper limb kinetic asymmetries in maximal front crawl swimming and to examine if these asymmetries would affect the contribution of force exertion to swimming performance. Eighteen high level male swimmers with unilateral breathing patterns and sprint or middle distance specialists, volunteered as participants. A load-cell was used to quantify the forces exerted in water by completing a 30s maximal front crawl tethered swimming test and a maximal 50 m free swimming was considered as a performance criterion. Individual force-time curves were obtained to calculate the mean and maximum forces per cycle, for each upper limb. Following, symmetry index was estimated and breathing laterality identified by questionnaire. Lastly, the pattern of asymmetries along the test was estimated for each upper limb using linear regression of peak forces per cycle. Asymmetrical force exertion was observed in the majority of the swimmers (66.7%), with a total correspondence of breathing laterality opposite to the side of the force asymmetry. Forces exerted by the dominant upper limb presented a higher decrease than from the non-dominant. Very strong associations were found between exerted forces and swimming performance, when controlling the isolated effect of symmetry index. Results point that force asymmetries occur in the majority of the swimmers, and that these asymmetries are most evident in the first cycles of a maximum bout. Symmetry index stood up as an influencing factor on the contribution of tethered forces over swimming performance. Thus, to some extent, a certain degree of asymmetry is not critical for short swimming performance. Copyright © 2015 Elsevier B.V. All rights reserved.

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.

Swimming exercise enhances the hippocampal antioxidant status of female Wistar rats.

PubMed

Stone, Vinícius; Kudo, Karen Yurika; Marcelino, Thiago Beltram; August, Pauline Maciel; Matté, Cristiane

2015-05-01

Moderate exercise is known to have health benefits, while both sedentarism and strenuous exercise have pro-oxidant effects. In this study, we assessed the effect of moderate exercise on the antioxidant homeostasis of rats' hippocampi. Female Wistar rats were submitted to a 30-minute swimming protocol on 5 days a week, for 4 weeks. Control rats were immersed in water and carefully dried. Production of hippocampal reactive species, activity of antioxidant enzymes, and glutathione levels in these animals were determined up to 30 days after completion of the 4-week protocol. Production of reactive species and hippocampal glutathione levels were increased 1 day after completion of the 4-week protocol, and returned to control levels after 7 days. Antioxidant enzyme activities were increased both 1 day (catalase) and 7 days (superoxide dismutase and glutathione peroxidase) after completion of the protocol. Thirty days after completion of the protocol, none of the antioxidant parameters evaluated differed from those of controls. Our results reinforce the benefits of aerobic exercise, which include positive modulation of antioxidant homeostasis in the hippocampi. The effects of exercise are not permanent; rather, an exercise regimen must be continued in order to maintain the neurometabolic adaptations.

Protective effects of forced exercise against methylphenidate-induced anxiety, depression and cognition impairment in rat.

PubMed

Motaghinejad, Majid; Motevalian, Manijeh; Larijani, Setare Farokhi; Khajehamedi, Zohreh

2015-01-01

Methylphenidate (MPH), a neural stimulant, can cause damages to brain; the chronic neurochemical and behavioral effects of MPH remain unclear. Exercise lowers stress and anxiety and can act as non-pharmacologic neuroprotective agent. In this study protective effects of exercise in MPH-induced anxiety, depression and cognition impairment were investigated. Seventy adult male rats were divided randomly into five groups. Group 1 served as negative control, received normal saline (0.2 ml/rat) for 21 days, group 2 and 3 (as positive controls) received MPH (10 and 20 mg/kg) for 21 days. Groups 4 and 5 concurrently were treated with MPH (10 and 20 mg/kg) and forced exercise for 21 days. On day 21, Elevated Plus Maze (EPM), Open Field Test (OFT), Forced Swim Test (FST) and Tail Suspension Test (TST) were used to investigate the level of anxiety and depression in animals. In addition between 17(th) and 21(th) days, Morris Water Maze (MWM) was applied to evaluate the effect of MPH on spatial learning and memory. MPH-treated animals indicated a reflective depression and anxiety in a dose-dependent manner in FST, EPM and TST which were significantly different from the control group and also can significantly attenuate the motor activity and anxiety in OFT. Forced exercise by treadmill can attenuate MPH-induced anxiety, depression and motor activity alteration in OFT. MPH also can disturb learning and memory in MWM and forced exercise can neutralize this effect of MPH. We conclude that forced exercise can be protective in brain against MPH-induced anxiety, depression and cognition alteration.

Stress-induced anhedonia in mice is associated with deficits in forced swimming and exploration.

PubMed

Strekalova, Tatyana; Spanagel, Rainer; Bartsch, Dusan; Henn, Fritz A; Gass, Peter

2004-11-01

In order to develop a model for a depression-like syndrome in mice, we subjected male C57BL/6 mice to a 4-week-long chronic stress procedure, consisting of rat exposure, restraint stress, and tail suspension. This protocol resulted in a strong decrease in sucrose preference, a putative indicator of anhedonia in rodents. Interestingly, predisposition for stress-induced anhedonia was indicated by submissive behavior in a resident-intruder test. In contrast, most mice with nonsubmissive behavior did not develop a decrease in sucrose preference and were regarded as nonanhedonic. These animals were used as an internal control for stress-induced behavioral features not associated with the anhedonic state, since they were exposed to the same stressors as the anhedonic mice. Using a battery of behavioral tests after termination of the stress procedure, we found that anhedonia, but not chronic stress per se, is associated with key analogues of depressive symptoms, such as increased floating during forced swimming and decreased exploration of novelty. On the other hand, increased anxiety, altered locomotor activity, and loss of body weight were consequences of chronic stress, which occurred independently from anhedonia. Thus, behavioral correlates of stress-induced anhedonia and of chronic stress alone can be separated in the present model.

Factors influencing behavior in the forced swim test

PubMed Central

Bogdanova, Olena V.; Kanekar, Shami; D’Anci, Kristen E.; Renshaw, Perry F.

2017-01-01

The forced swim test (FST) is a behavioral test in rodents which was developed in 1978 by Porsolt and colleagues as a model for predicting the clinical efficacy of antidepressant drugs. A modified version of the FST added the classification of active behaviors into swimming and climbing, in order to facilitate the differentiation between serotonergic and noradrenergic classes of antidepressant drugs. The FST is now widely used in basic research and the pharmaceutical screening of potential antidepressant treatments. It is also one of the most commonly used tests to assess depressive-like behavior in animal models. Despite the simplicity and sensitivity of the FST procedure, important differences even in baseline immobility rates have been reported between different groups, which complicate the comparison of results across studies. In spite of several methodological papers and reviews published on the FST, the need still exists for clarification of factors which can influence the procedure. While most recent reviews have focused on antidepressant effects observed with the FST, this one considers the methodological aspects of the procedure, aiming to summarize issues beyond antidepressant action in the FST. The previously published literature is analyzed for factors which are known to influence animal behavior in the FST. These include biological factors, such as strain, age, body weight, gender and individual differences between animals; influence of preconditioning before the FST: handling, social isolation or enriched environment, food manipulations, various kinds of stress, endocrine manipulations and surgery; schedule and routes of treatment, dosage and type of the drugs as well as experimental design and laboratory environmental effects. Consideration of these factors in planning experiments may result in more consistent FST results. PMID:23685235

Antidepressant-like responses in the forced swimming test elicited by glutathione and redox modulation.

PubMed

Rosa, Juliana M; Dafre, Alcir Luiz; Rodrigues, Ana Lúcia S

2013-09-15

Glutathione (GSH) displays a broad range of functions, among them a role as a neuromodulator with some neuroprotective properties. Taking into account that oxidative stress has been associated with depressive disorders, this study investigated the possibility that GSH, a major cell antioxidant, elicits an antidepressant-like effect in mice. Thus, GSH was administered by i.c.v. route to mice that were tested in the forced swimming test and in the tail suspension test, two predictive tests for antidepressant drug activity. In addition, GSH metabolism and the redox environment were modulated in order to study the possible mechanisms underlying the effects of GSH in the forced swimming test. The administration of GSH decreased the immobility time in the forced swimming test (300-3000nmol/site) and tail suspension test (100-1000nmol/site), consistent with an antidepressant-like effect. GSH depletion elicited by l-buthionine sulfoximine (3.2μmol/site, i.c.v.) did not alter the antidepressant-like effect of GSH, whereas the inhibition of extracellular GSH catabolism by acivicin (100nmol/site, i.c.v.) prevented the antidepressant-like effect of GSH. Moreover, a sub-effective dose (0.01nmol/site, i.c.v.) of the oxidizing agent DTNB (5,5'-dithiobis(2-nitrobenzoic acid)) potentiated the effect of GSH (100nmol/site, i.c.v.), while the pretreatment (25-100mg/kg, i.p.) with the reducing agent DTT (dl-dithiothreitol) prevented the antidepressant-like effect of GSH (300nmol/site, i.c.v.). DTNB (0.1nmol/site, i.c.v.), produced an antidepressant-like effect, per se, which was abolished by DTT (25mg/kg, i.p.). The results show, for the first time, that centrally administered GSH produces an antidepressant-like effect in mice, which can be modulated by the GSH metabolism and the thiol/disulfide reagents. The redox environment may constitute a new venue for future antidepressant-drug development. Copyright © 2013 Elsevier B.V. All rights reserved.

Neurochemical changes underlying schizophrenia-related behavior in a modified forced swim test in mice.

PubMed

Wożniak, Monika; Cieślik, Paulina; Marciniak, Marcin; Lenda, Tomasz; Pilc, Andrzej; Wieronska, Joanna M

2018-06-15

The modified forced swim test (MFST) has excellent predictive validity for investigating the antipsychotic activity of drugs, with particular emphasis on their activity toward negative symptoms of schizophrenia. However, its face and construct validity are less understood. Therefore, in the present study, some biochemical changes within GABAergic and serotonergic neurotransmission that could be related to observed MK-801-induced disturbances and the activity of compounds active at those neurotransmitters were investigated. In biochemical experiments, mice were treated acutely or chronically with MK-801 (13 days, 0.4 mg/kg). Their brains were dissected and frontal cortices and hippocampi were taken for further analysis. The levels of neurotransmitters were investigated with HPLC, and the expression of surrogate markers of schizophrenia (5-HT 1A receptors, GAD 65 , and GAD 67 , at both protein and mRNA levels) was measured via western blotting and q RT-PCR. The modified forced swim test and locomotor activity were used to assess the activity of GABA B and 5-HT 1A -related compounds. Repeated MK-801 treatment (13 days, 0.4 mg/kg dose) led to decreases in the DOPAC/DA, 3MT/DA and HVA/DA metabolic ratios. Increased 5-HT 1A protein expression and decreased GAD 65 and GAD 67 protein expression was observed in both the cortex and hippocampus. mRNA levels for all proteins were decreased. The increased immobility in the forced swim test was reversed both by a GABA B agonist (SKF97541, 0.025 or 0.05 mg/kg), a positive allosteric modulator of GABA B receptor (racBHFF, 5 or 10 mg/kg) and by a 5-HT 1A agonist ((R)-(+)-8-OH-DPAT 0.01 or 0.025 mg/kg). Our research supports the hypothesis that changes in the levels of GABA and/or 5-HT 1A receptors may contribute to the schizophrenia-like phenotype, and GABAergic and serotonergic agents may be good candidates for treating negative symptoms of schizophrenia. Copyright © 2018. Published by Elsevier Inc.

Swim stress exaggerates the hyperactive mesocortical dopamine system in a rodent model of autism.

PubMed

Nakasato, Akane; Nakatani, Yasushi; Seki, Yoshinari; Tsujino, Naohisa; Umino, Masahiro; Arita, Hideho

2008-02-08

Several clinical reports have suggested that there is a hyperactivation of the dopaminergic system in people with autism. Using rats exposed prenatally to valproic acid (VPA) as an animal model of autism, we measured dopamine (DA) levels in samples collected from the frontal cortex (FC) using in vivo microdialysis and HPLC. The basal DA level in FC was significantly higher in VPA-exposed rats relative to controls. Since the mesocortical DA system is known to be sensitive to physical and psychological stressors, we measured DA levels in FC before, during, and after a 60-min forced swim test (FST). There were further gradual increases in FC DA levels during the FST in the VPA-exposed rats, but not in the control rats. Behavioral analysis during the last 10 min of the FST revealed a significant decrease in active, escape-oriented behavior and an increase in immobility, which is thought to reflect the development of depressive behavior that disengages the animal from active forms of coping with stressful stimuli. These results suggest that this rodent model of autism exhibits a hyperactive mesocortical DA system, which is exaggerated by swim stress. This abnormality may be responsible for depressive and withdrawal behavior observed in autism.

Individual differences in the forced swimming test and the effect of environmental enrichment: searching for an interaction.

PubMed

Sequeira-Cordero, A; Mora-Gallegos, A; Cuenca-Berger, P; Fornaguera-Trías, J

2014-04-18

Animals with low and high immobility in the forced swimming test (FST) differ in a number of neurobehavioral factors. A growing body of evidence suggests that the exposure to enriched environments mediates a number of changes in the brain. Therefore, we studied if animals' individuality can somehow modulate the response to environmental stimuli. Male rats were classified according to their immobility time scores in the FST test session as animals with low, medium or high immobility. Then, rats from groups with low and high immobility were randomly distributed in two groups to be reared in different housing conditions (i.e., enriched and standard conditions) during 8weeks. Animals were subjected to the open field test (OFT) before and 6weeks after the start of housing protocol. Rats with high immobility in the FST also showed high ambulation and high rearing time in the first OFT. Such findings were not observed in the second OFT. Conversely, an effect of environmental enrichment was found in the second OFT where enriched animals showed lower ambulation and higher grooming time than the standard control group. Rats were sacrificed after the housing protocol and neurochemical content and/or gene expression were studied in three different brain regions: the prefrontal cortex, the hippocampus and the nucleus accumbens. Rats with low immobility showed significantly higher accumbal 5-HT levels than animals with high immobility, whereas no neurochemical differences were observed between enriched and standard animals. Regarding expression data, however, an effect of enrichment on accumbal corticotropin-releasing factor (CRF) and its receptor 1 (CRFR1) levels was observed, and such effect depended on immobility levels. Thus, our results not only allowed us to identify a number of differences between animals with low and high immobility or animals housed in standard and enriched conditions, but also suggested that animals' individuality modulated in some way the response to

The effect of acute swim stress and training in the water maze on hippocampal synaptic activity as well as plasticity in the dentate gyrus of freely moving rats: revisiting swim-induced LTP reinforcement.

PubMed

Tabassum, Heena; Frey, Julietta U

2013-12-01

Hippocampal long-term potentiation (LTP) is a cellular model of learning and memory. An early form of LTP (E-LTP) can be reinforced into its late form (L-LTP) by various behavioral interactions within a specific time window ("behavioral LTP-reinforcement"). Depending on the type and procedure used, various studies have shown that stress differentially affects synaptic plasticity. Under low stress, such as novelty detection or mild foot shocks, E-LTP can be transformed into L-LTP in the rat dentate gyrus (DG). A reinforcing effect of a 2-min swim, however, has only been shown in (Korz and Frey (2003) J Neurosci 23:7281-7287; Korz and Frey (2005) J Neurosci 25:7393-7400; Ahmed et al. (2006) J Neurosci 26:3951-3958; Sajikumar et al., (2007) J Physiol 584.2:389-400) so far. We have reinvestigated these studies using the same as well as an improved recording technique which allowed the recording of field excitatory postsynaptic potentials (fEPSP) and the population spike amplitude (PSA) at their places of generation in freely moving rats. We show that acute swim stress led to a long-term depression (LTD) in baseline values of PSA and partially fEPSP. In contrast to earlier studies a LTP-reinforcement by swimming could never be reproduced. Our results indicate that 2-min swim stress influenced synaptic potentials as well as E-LTP negatively. Copyright © 2013 Wiley Periodicals, Inc.

Influence of the brain sexual differentiation process on despair and antidepressant-like effect of fluoxetine in the rat forced swim test.

PubMed

Gómez, M L; Martínez-Mota, L; Estrada-Camarena, E; Fernández-Guasti, A

2014-03-07

Sex differences exist in the depressive disorder prevalence and response to treatment. Several studies suggest that females respond better than males to the action of selective serotonin reuptake inhibitors (SSRIs), suggesting that gonadal hormones modulate mood and the response to these drugs. Sexual steroid hormones exert organizational actions (perennial and on early development) and activational effects (transient and on differentiated tissues). The aim of this study was to analyze sex differences in the forced swim test (FST) in animals without treatment and after fluoxetine (FLX, 0, 2.5, 5.0 and 10.0mg/kg). Initially, we compared male and female adult rats under control conditions or after altering their sexual differentiation process (at day 5 postnatally, PN, 60μg of testosterone propionate to females and male castration to induce or preclude masculinization, respectively). To further analyze if the sex differences depend on organizational or activational steroid hormone action we tested the same animals before and after adult gonadectomy. To prevent variations depending upon the estrous cycle, control and masculinized females were tested in estrus. Control females showed lower immobility and required lower doses of FLX (5mg/kg), to show an antidepressant-like effect, than males (10mg/kg), even after adult gonadectomy. In control males adult orchidectomy prevented FLX's action. Neonatally masculinized females exhibited analogous levels of immobility than control ones; before ovariectomy they responded to FLX similar to controls, but after the surgery they did not respond to fluoxetine. Neonatally orchidectomized males exhibited similar immobility values and response to FLX than control females. The findings suggest that the sex difference in despair depends on the hormones organizational effects and, in males, the response to FLX relies on organizational and activational actions. Copyright © 2013 IBRO. Published by Elsevier Ltd. All rights reserved.

Analysis of swimming motions.

NASA Technical Reports Server (NTRS)

Gallenstein, J.; Huston, R. L.

1973-01-01

This paper presents an analysis of swimming motion with specific attention given to the flutter kick, the breast-stroke kick, and the breast stroke. The analysis is completely theoretical. It employs a mathematical model of the human body consisting of frustrums of elliptical cones. Dynamical equations are written for this model including both viscous and inertia forces. These equations are then applied with approximated swimming strokes and solved numerically using a digital computer. The procedure is to specify the input of the swimming motion. The computer solution then provides the output displacement, velocity, and rotation or body roll of the swimmer.

Antidepressant-like effect of harmane and other beta-carbolines in the mouse forced swim test.

PubMed

Farzin, Davood; Mansouri, Nazanin

2006-07-01

The purpose of the present study was to determine the effects of harmane, norharmane and harmine on the immobility time in the mouse forced swim test (FST) - an animal model of depression. After 30 min of the beta-carbolines injections, mice were placed individually in a vertical glass cylinder (height, 25 cm; diameter, 12 cm) containing water about 15 cm deep at 22+/-1 degrees C and forced to swim. Treatment of animals with harmane (5-15 mg/kg, i.p.), norharmane (2.5-10 mg/kg, i.p.) and harmine (5-15 mg/kg, i.p.) reduced dose-dependently the time of immobility. Their antidepressant-like effects were not affected by pretreatment with reserpine at the dose of 5 mg/kg, i.p., 18 h before the test, which did not modify the immobility time. Conversely, when flumazenil (5 mg/kg, i.p.) was administered 30 min before the test, it was able to antagonize completely the antidepressant-like effects of harmane, norharmane and harmine. It was concluded that harmane, norharmane and harmine reduce the immobility time in this test, suggesting an antidepressant-like effect, via an inverse-agonistic mechanism located in the benzodiazepine receptors.

Maternal swimming exercise during pregnancy attenuates anxiety/depressive-like behaviors and voluntary morphine consumption in the pubertal male and female rat offspring born from morphine dependent mothers.

PubMed

Torabi, Masoumeh; Pooriamehr, Alireza; Bigdeli, Imanollah; Miladi-Gorji, Hossein

2017-10-17

This study was designed to examine whether maternal swimming exercise during pregnancy would attenuate prenatally morphine-induced anxiety, depression and voluntary consumption of morphine in the pubertal male and female rat offspring. Pregnant rats during the development of morphine dependence were allowed to swim (30-45min/d, 3days per a week) on gestational days 11-18. Then, the pubertal male and female rat offspring were tested for the elevated plus-maze (EPM), sucrose preference test (SPT) and voluntary morphine consumption using a two-bottle choice (TBC) paradigm. The results showed that male and female rat offspring born of the swimmer morphine-dependent mothers exhibited an increase in EPM open arm time and entries, higher levels of sucrose preference than their sedentary control mothers. Voluntary consumption of morphine was less in the male and female rat offspring born of the swimmer morphine-dependent mothers as compared with their sedentary control mothers during three periods of the intake of drug. Thus, swimming exercise in pregnant morphine dependent mothers decreased anxiety, depressive-like behavior and also the voluntary morphine consumption in the pubertal male and female offspring, which may prevent prenatally morphine-induced behavioral sensitization in offspring. Copyright © 2017 Elsevier B.V. All rights reserved.

Swimming in a granular frictional fluid

NASA Astrophysics Data System (ADS)

Goldman, Daniel

2012-02-01

X-ray imaging reveals that the sandfish lizard swims within granular media (sand) using axial body undulations to propel itself without the use of limbs. To model the locomotion of the sandfish, we previously developed an empirical resistive force theory (RFT), a numerical sandfish model coupled to an experimentally validated Discrete Element Method (DEM) model of the granular medium, and a physical robot model. The models reveal that only grains close to the swimmer are fluidized, and that the thrust and drag forces are dominated by frictional interactions among grains and the intruder. In this talk I will use these models to discuss principles of swimming within these granular ``frictional fluids". The empirical drag force laws are measured as the steady-state forces on a small cylinder oriented at different angles relative to the displacement direction. Unlike in Newtonian fluids, resistive forces are independent of speed. Drag forces resemble those in viscous fluids while the ratio of thrust to drag forces is always larger in the granular media than in viscous fluids. Using the force laws as inputs, the RFT overestimates swimming speed by approximately 20%. The simulation reveals that this is related to the non-instantaneous increase in force during reversals of body segments. Despite the inaccuracy of the steady-state assumption, we use the force laws and a recently developed geometric mechanics theory to predict optimal gaits for a model system that has been well-studied in Newtonian fluids, the three-link swimmer. The combination of the geometric theory and the force laws allows us to generate a kinematic relationship between the swimmer's shape and position velocities and to construct connection vector field and constraint curvature function visualizations of the system dynamics. From these we predict optimal gaits for forward, lateral and rotational motion. Experiment and simulation are in accord with the theoretical prediction, and demonstrate that

Mechanics of undulatory swimming in a frictional fluid.

PubMed

Ding, Yang; Sharpe, Sarah S; Masse, Andrew; Goldman, Daniel I

2012-01-01

The sandfish lizard (Scincus scincus) swims within granular media (sand) using axial body undulations to propel itself without the use of limbs. In previous work we predicted average swimming speed by developing a numerical simulation that incorporated experimentally measured biological kinematics into a multibody sandfish model. The model was coupled to an experimentally validated soft sphere discrete element method simulation of the granular medium. In this paper, we use the simulation to study the detailed mechanics of undulatory swimming in a "granular frictional fluid" and compare the predictions to our previously developed resistive force theory (RFT) which models sand-swimming using empirically determined granular drag laws. The simulation reveals that the forward speed of the center of mass (CoM) oscillates about its average speed in antiphase with head drag. The coupling between overall body motion and body deformation results in a non-trivial pattern in the magnitude of lateral displacement of the segments along the body. The actuator torque and segment power are maximal near the center of the body and decrease to zero toward the head and the tail. Approximately 30% of the net swimming power is dissipated in head drag. The power consumption is proportional to the frequency in the biologically relevant range, which confirms that frictional forces dominate during sand-swimming by the sandfish. Comparison of the segmental forces measured in simulation with the force on a laterally oscillating rod reveals that a granular hysteresis effect causes the overestimation of the body thrust forces in the RFT. Our models provide detailed testable predictions for biological locomotion in a granular environment.

Mechanics of Undulatory Swimming in a Frictional Fluid

PubMed Central

Ding, Yang; Sharpe, Sarah S.; Masse, Andrew; Goldman, Daniel I.

2012-01-01

The sandfish lizard (Scincus scincus) swims within granular media (sand) using axial body undulations to propel itself without the use of limbs. In previous work we predicted average swimming speed by developing a numerical simulation that incorporated experimentally measured biological kinematics into a multibody sandfish model. The model was coupled to an experimentally validated soft sphere discrete element method simulation of the granular medium. In this paper, we use the simulation to study the detailed mechanics of undulatory swimming in a “granular frictional fluid” and compare the predictions to our previously developed resistive force theory (RFT) which models sand-swimming using empirically determined granular drag laws. The simulation reveals that the forward speed of the center of mass (CoM) oscillates about its average speed in antiphase with head drag. The coupling between overall body motion and body deformation results in a non-trivial pattern in the magnitude of lateral displacement of the segments along the body. The actuator torque and segment power are maximal near the center of the body and decrease to zero toward the head and the tail. Approximately 30% of the net swimming power is dissipated in head drag. The power consumption is proportional to the frequency in the biologically relevant range, which confirms that frictional forces dominate during sand-swimming by the sandfish. Comparison of the segmental forces measured in simulation with the force on a laterally oscillating rod reveals that a granular hysteresis effect causes the overestimation of the body thrust forces in the RFT. Our models provide detailed testable predictions for biological locomotion in a granular environment. PMID:23300407

Unsteady swimming of small organisms

NASA Astrophysics Data System (ADS)

Wang, Shiyan; Ardekani, Arezoo

2012-11-01

Small planktonic organisms ubiquitously display unsteady or impulsive motion to attack a prey or escape a predator in natural environments. Despite this, the role of unsteady hydrodynamic forces such as history and added mass forces on the low Reynolds number propulsion of small organisms is poorly understood. In this paper, we derive the fundamental equation of motion for an organism swimming by the means of surface distortion in a nonuniform flow at a low Reynolds number regime. We show that the history and added mass forces, that where traditionally neglected in the literature for small swimming organisms, cannot be neglected as the Stokes number increases above unity. For example, these unsteady inertial forces are of the same order as quasi-steady Stokes forces for Paramecium. Finally, we quantify the effects of convective inertial forces in the limit of small, but nonzero, Reynolds number regime. This work is supported by NSF grant CBET-1066545.

Effects of high-intensity swimming training on GLUT-4 and glucose transport activity in rat skeletal muscle.

PubMed

Terada, S; Yokozeki, T; Kawanaka, K; Ogawa, K; Higuchi, M; Ezaki, O; Tabata, I

2001-06-01

This study was performed to assess the effects of short-term, extremely high-intensity intermittent exercise training on the GLUT-4 content of rat skeletal muscle. Three- to four-week-old male Sprague-Dawley rats with an initial body weight ranging from 45 to 55 g were used for this study. These rats were randomly assigned to an 8-day period of high-intensity intermittent exercise training (HIT), relatively high-intensity intermittent prolonged exercise training (RHT), or low-intensity prolonged exercise training (LIT). Age-matched sedentary rats were used as a control. In the HIT group, the rats repeated fourteen 20-s swimming bouts with a weight equivalent to 14, 15, and 16% of body weight for the first 2, the next 4, and the last 2 days, respectively. Between exercise bouts, a 10-s pause was allowed. RHT consisted of five 17-min swimming bouts with a 3-min rest between bouts. During the first bout, the rat swam without weight, whereas during the following four bouts, the rat was attached to a weight equivalent to 4 and 5% of its body weight for the first 5 days and the following 3 days, respectively. Rats in the LIT group swam 6 h/day for 8 days in two 3-h bouts separated by 45 min of rest. In the first experiment, the HIT, LIT, and control rats were compared. GLUT-4 content in the epitrochlearis muscle in the HIT and LIT groups after training was significantly higher than that in the control rats by 83 and 91%, respectively. Furthermore, glucose transport activity, stimulated maximally by both insulin (2 mU/ml) (HIT: 48%, LIT: 75%) and contractions (25 10-s tetani) (HIT: 55%, LIT: 69%), was higher in the training groups than in the control rats. However, no significant differences in GLUT-4 content or in maximal glucose transport activity in response to both insulin and contractions were observed between the two training groups. The second experiment demonstrated that GLUT-4 content after HIT did not differ from that after RHT (66% higher in trained rats than

Antidepressant-like effects of aniracetam in aged rats and its mode of action.

PubMed

Nakamura, K; Tanaka, Y

2001-11-01

Aniracetam has been reported to be efficacious for treating poststroke depression, but no studies that basically examined the antidepressive effects have been made. We aimed to test the antidepressant-like property of aniracetam in rats and to clarify the mechanisms of action through the interaction studies with some receptor antagonists. Antidepressant-like effects of aniracetam and various classes of compounds including different antidepressants were examined in a forced swim test with young (9 weeks old) and aged (25-30 months old) rats. Rats were exposed to a 5-min swim in a test session on day 2 following a 15-min swim in a training session on day 1, and immobility time during the period on day 2 was measured. The test compounds were administered subacutely (three doses over 2 days) or acutely (0.5 h before the testing). Standard antidepressants except for tandospirone significantly reduced immobility time in both young and aged rats. Aniracetam (10-100 mg/kg PO) failed to decrease immobility time in young rats, but it (100 mg/kg PO) significantly shortened immobility in aged rats, the effects of which were mainly mimicked by combined treatment of the metabolites, 2-pyrrolidinone and N-anisoyl-GABA. The effects of aniracetam was reversed completely by mecamylamine (10 mg/kg IP) or haloperidol (0.1 mg/kg IP) and slightly by ketanserin (1 m/kg IP) but was potentiated by scopolamine (0.03 mg/kg IP). These results indicate that aniracetam acts more effective when the forced swim stress-induced immobility is accompanied with brain dysfunction that occurs with aging. The antidepressant-like activity of aniracetam, which is probably due to the combined effects of 2-pyrrolidinone and N-anisoyl-GABA, may be mediated by mainly facilitating dopaminergic transmission (dopamine release and dopamine D2 receptor activation) through nicotinic acetylcholine receptor stimulation.

Effects of MK-886, a 5-lipoxygenase activating protein (FLAP) inhibitor, and 5-lipoxygenase deficiency on the forced swimming behavior of mice

PubMed Central

Uz, Tolga; Dimitrijevic, Nikola; Imbesi, Marta; Manev, Hari; Manev, Radmila

2008-01-01

A common biological pathway may contribute to the comorbidity of atherosclerosis and depression. Increased activity of the enzymatic 5-lipoxygenase (5-LOX; 5LO) pathway is a contributing factor in atherosclerosis and a 5-LOX inhibitor, MK-886, is beneficial in animal models of atherosclerosis. In the brain, MK-886 increases phosphorylation of the glutamate receptor subunit GluR1, and the increased phosphorylation of this receptor has been associated with antidepressant treatment. In this work, we evaluated the behavioral effects of MK-886 in an automated assay of mouse forced swimming, which identifies antidepressant activity as increased climbing behavior and/or decreased rest time. Whereas a single injection of MK-886 (3 and 10 mg/kg) did not affect forced swimming behaviors assayed 30 min later, 6 daily injections of 3 mg/kg MK-886 slightly increased climbing and significantly reduced rest time in wild-type mice but not in 5-LOX-deficient mice. A diet delivery of MK-886, 4 μg per 100 mg body-weight per day, required three weeks to affect forced swimming; it increased climbing behavior. Climbing behavior was also increased in naive 5-LOX-deficient mice compared to naive wild-type controls. These results suggest that 5-LOX inhibition and deficiency may be associated with antidepressant activity. Increased climbing in a forced swimming assay is a typical outcome of antidepressants that increase noradrenergic and dopaminergic activity. Interestingly, 5-LOX deficiency and MK-886 treatment have been shown to be capable of increasing the behavioral effects of a noradrenaline/dopamine-potentiating drug, cocaine. Future research is needed to evaluate the clinical relevance of our findings. PMID:18403121

Forced swimming sabotages the morphological and synaptic maturation of newborn granule neurons and triggers a unique pro-inflammatory milieu in the hippocampus.

PubMed

Llorens-Martín, María; Jurado-Arjona, Jerónimo; Bolós, Marta; Pallas-Bazarra, Noemí; Ávila, Jesús

2016-03-01

Recent experimental data suggest that mood disorders are related to inflammatory phenomena and have led to the "inflammatory hypothesis of depression". Given that the hippocampus is one of the most affected areas in these disorders, we used a model of acute stress (the Porsolt test) to evaluate the consequences of forced swimming on two crucial events related to the pathophysiology of major depression: the functional maturation of newborn granule neurons; and the hippocampal inflammatory milieu. Using PSD95:GFP-expressing retroviruses, we found that forced swimming selectively alters the dendritic morphology of newborn neurons and impairs their connectivity by reducing the number and volume of their postsynaptic densities. In addition, acute stress triggered a series of morphological changes in microglial cells, together with an increase in microglial CD68 expression, thus suggesting the functional and morphological activation of this cell population. Furthermore, we observed an intriguing change in the hippocampal inflammatory milieu in response to forced swimming. Importantly, the levels of several molecules affected by acute stress (such as Interleukin-6 and eotaxin) have been described to also be altered in patients with depression and other mood disorders. Copyright © 2015 Elsevier Inc. All rights reserved.

Tethered Swimming Test: Reliability and the Association to Swimming Performance and Land-based Anaerobic Performance.

PubMed

Nagle Zera, Jacquelyn; Nagle, Elizabeth F; Nagai, Takashi; Lovalekar, Mita; Abt, John P; Lephart, Scott M

2018-02-14

The purpose of this study was three-fold: (a) to examine the test-retest reliability of a 30 second maximal tethered freestyle swimming test (TST), (b) to assess the validity of the TST by examining the association to sprint swimming performance and, (c) to examine the associations between a swim-specific and land-based measure of anaerobic performance. A total of twenty-nine male and female swimmers were recruited to participate in the study. Each participant completed a Wingate Anaerobic cycling test (WAnT), two or four TST, and a 22.9 meter (25 yard), 45.7 meter (50 yard), and 91.4 meter (100 yard) maximal freestyle performance swims (PS). Mean and peak force (Fmean, Fpeak) were recorded for both the WAnT and TST, and average swimming velocity and time were recorded for the PS. Additionally, physiological and perceptual measures were recorded immediate post exercise for all tests. The results of the present investigation showed strong intersession and intrasession reliability (R= 0.821-0.975; p<0.001) for force parameters of the TST. Moderate correlations were found between Fmean and PS time and velocity of all distances, with slightly weaker correlations between Fpeak and the 22.9 meter (time and velocity) and 45.7 meter (velocity) PS. Finally, moderate correlations were found for Fmean and Fpeak of the TST and WAnT. This study demonstrated that the TST is a reliable measure, with moderate association to swimming performance, producing similar physiological responses compared to free swimming. Therefore, future research shoulSd focus on investigating the potential benefits of utilizing the TST as a regular assessment tool as a part of a competitive swimming training program to track adaptations and inform training decisions.

Effect of potassium channel modulators in mouse forced swimming test

PubMed Central

Galeotti, Nicoletta; Ghelardini, Carla; Caldari, Bernardetta; Bartolini, Alessandro

1999-01-01

The effect of intracerebroventricular (i.c.v.) administration of different potassium channel blockers (tetraethylammonium, apamin, charybdotoxin, gliquidone), potassium channel openers (pinacidil, minoxidil, cromakalim) and aODN to mKv1.1 on immobility time was evaluated in the mouse forced swimming test, an animal model of depression. Tetraethylammonium (TEA; 5 μg per mouse i.c.v.), apamin (3 ng per mouse i.c.v.), charybdotoxin (1 μg per mouse i.c.v.) and gliquidone (6 μg per mouse i.c.v.) administered 20 min before the test produced anti-immobility comparable to that induced by the tricyclic antidepressants amitriptyline (15 mg kg−1 s.c.) and imipramine (30 mg kg−1 s.c.). By contrast pinacidil (10–20 μg per mouse i.c.v.), minoxidil (10–20 μg per mouse i.c.v.) and cromakalim (20–30 μg per mouse i.c.v.) increased immobility time when administered in the same experimental conditions. Repeated administration of an antisense oligonucleotide (aODN) to the mKv1.1 gene (1 and 3 nmol per single i.c.v. injection) produced a dose-dependent increase in immobility time of mice 72 h after the last injection. At day 7, the increasing effect produced by aODN disappeared. A degenerate mKv1.1 oligonucleotide (dODN), used as control, did not produce any effect in comparison with saline- and vector-treated mice. At the highest effective dose, potassium channels modulators and the mKv1.1 aODN did not impair motor coordination, as revealed by the rota rod test, nor did they modify spontaneous motility as revealed by the Animex apparatus. These results suggest that modulation of potassium channels plays an important role in the regulation of immobility time in the mouse forced swimming test. PMID:10323599

Swimming and feeding of mixotrophic biflagellates

NASA Astrophysics Data System (ADS)

Dölger, Julia; Nielsen, Lasse Tor; Kiørboe, Thomas; Andersen, Anders

2017-01-01

Many unicellular flagellates are mixotrophic and access resources through both photosynthesis and prey capture. Their fitness depends on those processes as well as on swimming and predator avoidance. How does the flagellar arrangement and beat pattern of the flagellate affect swimming speed, predation risk due to flow-sensing predators, and prey capture? Here, we describe measured flows around two species of mixotrophic, biflagellated haptophytes with qualitatively different flagellar arrangements and beat patterns. We model the near cell flows using two symmetrically arranged point forces with variable position next to a no-slip sphere. Utilizing the observations and the model we find that puller force arrangements favour feeding, whereas equatorial force arrangements favour fast and quiet swimming. We determine the capture rates of both passive and motile prey, and we show that the flow facilitates transport of captured prey along the haptonema structure. We argue that prey capture alone cannot fulfil the energy needs of the observed species, and that the mixotrophic life strategy is essential for survival.

Chronic fluoxetine treatment partly attenuates the long-term anxiety and depressive symptoms induced by MDMA ('Ecstasy') in rats.

PubMed

Thompson, Murray R; Li, Kong M; Clemens, Kelly J; Gurtman, Clint G; Hunt, Glenn E; Cornish, Jennifer L; McGregor, Iain S

2004-04-01

Use of the drug 3,4-methylenedioxymethamphetamine (MDMA, 'Ecstasy') can have long-term adverse effects on emotion in both humans and laboratory animals. The present study examined whether chronic treatment with the antidepressant drug fluoxetine could reverse such effects. Male Wistar rats were briefly exposed to MDMA (4 x 5 mg/kg over 4 h) or vehicle on 2 consecutive days. Approximately 9-12 weeks later, half of the rats received a dose of approximately 6 mg/kg/day fluoxetine in their drinking water for a 5-week period. Fluoxetine administration reduced fluid intake and body weight in MDMA and vehicle pretreated rats. After several weeks of fluoxetine treatment, rats were assessed on the social interaction test, the emergence test of anxiety and the forced swim model of depression. MDMA pretreated rats showed reduced social interaction, increased anxiety on the emergence test, and increased immobility and decreased active responses in the forced swim test. Fluoxetine treatment reversed MDMA-induced anxiety in the emergence test and depressive-like effects in the forced swim test, yet exhibited no effects on the social interaction test. MDMA pretreated rats had decreased 5-HT and 5-HIAA levels in limbic and cortical regions, and decreased density of serotonin transporter sites in the cortex. Fluoxetine treatment did not greatly affect 5-HT levels in MDMA pretreated rats, but significantly decreased 5-HIAA levels in all brain sites examined. Postmortem blood serum levels of fluoxetine and norfluoxetine did not differ in MDMA and vehicle pretreated rats. These results indicate that fluoxetine may provide a treatment option for some of the deleterious long-term effects resulting from MDMA exposure.

A diphenyl diselenide-supplemented diet and swimming exercise promote neuroprotection, reduced cell apoptosis and glial cell activation in the hypothalamus of old rats.

PubMed

Leite, Marlon R; Cechella, José L; Pinton, Simone; Nogueira, Cristina W; Zeni, Gilson

2016-09-01

Aging is a process characterized by deterioration of the homeostasis of various physiological systems; although being a process under influence of multiple factors, the mechanisms involved in aging are not well understood. Here we investigated the effect of a (PhSe)2-supplemented diet (1ppm, 4weeks) and swimming exercise (1% of body weight, 20min per day, 4weeks) on proteins related to glial cells activation, apoptosis and neuroprotection in the hypothalamus of old male Wistar rats (27month-old). Old rats had activation of astrocytes and microglia which was demonstrated by the increase in the levels of glial fibrillary acidic protein (GFAP) and ionized calcium-binding adaptor molecule 1 (Iba-1) in hypothalamus. A decrease of B-cell lymphoma 2 (Bcl-2) and procaspase-3 levels as well as an increase of the cleaved PARP/full length PARP ratio (poly (ADP-ribose) polymerase, PARP) and the pJNK/JNK ratio (c-Jun N-terminal kinase, JNK) were observed. The levels of mature brain-derived neurotrophic factor (mBDNF), the pAkt/Akt ratio (also known as protein kinase B) and NeuN (neuronal nuclei), a neuron marker, were decreased in the hypothalamus of old rats. Old rats that received a (PhSe)2-supplemented diet and performed swimming exercise had the hypothalamic levels of Iba-1 and GFAP decreased. The combined treatment also increased the levels of Bcl-2 and procaspase-3 and decreased the ratios of cleaved PARP/full length PARP and pJNK/JNK in old rats. The levels of mBDNF and NeuN, but not the pAkt/Akt ratio, were increased by combined treatment. In conclusion, a (PhSe)2-supplemented diet and swimming exercise promoted neuroprotection in the hypothalamus of old rats, reducing apoptosis and glial cell activation. Copyright © 2016 Elsevier Inc. All rights reserved.

Antidepressant-like effect of m-trifluoromethyl-diphenyl diselenide in the mouse forced swimming test involves opioid and serotonergic systems.

PubMed

Brüning, César Augusto; Souza, Ana Cristina Guerra; Gai, Bibiana Mozzaquatro; Zeni, Gilson; Nogueira, Cristina Wayne

2011-05-11

Serotonergic and opioid systems have been implicated in major depression and in the action mechanism of antidepressants. The organoselenium compound m-trifluoromethyl-diphenyl diselenide (m-CF(3)-PhSe)(2) shows antioxidant and anxiolytic activities and is a selective inhibitor of monoamine oxidase A activity. The present study was designed to investigate the antidepressant-like effect of (m-CF(3)-PhSe)(2) in female mice, employing the forced swimming test. The involvement of the serotonergic and opioid systems in the antidepressant-like effect of (m-CF(3)-PhSe)(2) was appraised. (m-CF(3)-PhSe)(2) at doses of 50 and 100mg/kg (p.o.) exhibited antidepressant-like action in the forced swimming test. The effect of (m-CF(3)-PhSe)(2) (50mg/kg p.o.) was prevented by pretreatment of mice with WAY100635 (0.1mg/kg, s.c. a selective 5-HT(1A) receptor antagonist), ritanserin (4 mg/kg, i.p., a non-selective 5HT(2A/2C) receptor antagonist), ondansetron (1mg/kg, i.p., a selective 5-HT(3) receptor antagonist) and naloxone (1mg/kg, i.p., a non-selective antagonist of opioid receptors). These results suggest that (m-CF(3)-PhSe)(2) produced an antidepressant-like effect in the mouse forced swimming test and this effect seems most likely to be mediated through an interaction with serotonergic and opioid systems. Copyright © 2011 Elsevier B.V. All rights reserved.

Is Forced Swimming Immobility a Good Endpoint for Modeling Negative Symptoms of Schizophrenia? - Study of Sub-Anesthetic Ketamine Repeated Administration Effects.

PubMed

Neves, Gilda; Borsoi, Milene; Antonio, Camila B; Pranke, Mariana A; Betti, Andresa H; Rates, Stela M K

2017-01-01

Immobility time in the forced swimming has been described as analogous to emotional blunting or apathy and has been used for characterizing schizophrenia animal models. Several clinical studies support the use of NMDA receptor antagonists to model schizophrenia in rodents. Some works describe the effects of ketamine on immobility behavior but there is variability in the experimental design used leading to controversial results. In this study, we evaluated the effects of repeated administration of ketamine sub-anesthetic doses in forced swimming, locomotion in response to novelty and novel object recognition, aiming a broader evaluation of the usefulness of this experimental approach for modeling schizophrenia in mice. Ketamine (30 mg/kg/day i.p. for 14 days) induced a not persistent decrease in immobility time, detected 24h but not 72h after treatment. This same administration protocol induced a deficit in novel object recognition. No change was observed in mice locomotion. Our results confirm that repeated administration of sub-anesthetic doses of ketamine is useful in modeling schizophrenia-related behavioral changes in mice. However, the immobility time during forced swimming does not seem to be a good endpoint to evaluate the modeling of negative symptoms in NMDAR antagonist animal models of schizophrenia.

No evidence for a bioenergetic advantage from forced swimming in rainbow trout under a restrictive feeding regime

PubMed Central

Skov, Peter V.; Lund, Ivar; Pargana, Alexandre M.

2015-01-01

Sustained swimming at moderate speeds is considered beneficial in terms of the productive performance of salmonids, but the causative mechanisms have yet to be unequivocally established. In the present study, the effects of moderate exercise on the bioenergetics of rainbow trout were assessed during a 15 week growth experiment, in which fish were reared at three different current speeds: 1 BL s−1, 0.5 BL s−1 and still water (≈ 0 BL s−1). Randomly selected groups of 100 fish were distributed among twelve 600 L tanks and maintained on a restricted diet regime. Specific growth rate (SGR) and feed conversion ratio (FCR) were calculated from weight and length measurements every 3 weeks. Routine metabolic rate (RMR) was measured every hour as rate of oxygen consumption in the tanks, and was positively correlated with swimming speed. Total ammonia nitrogen (TAN) excretion rates showed a tendency to decrease with increasing swimming speeds, yet neither they nor the resulting nitrogen quotients (NQ) indicated that swimming significantly reduced the fraction of dietary protein used to fuel metabolism. Energetic budgets revealed a positive correlation between energy expenditure and the current speed at which fish were reared, fish that were forced to swim and were fed restrictively consequentially had poorer growth and feed utilization. The results show that for rainbow trout, water current can negatively affect growth despite promoting minor positive changes in substrate utilization. We hypothesize that this may be the result of either a limited dietary energy supply from diet restriction being insufficient for both covering the extra costs of swimming and supporting enhanced growth. PMID:25705195

Unsteady computational fluid dynamics in front crawl swimming.

PubMed

Samson, Mathias; Bernard, Anthony; Monnet, Tony; Lacouture, Patrick; David, Laurent

2017-05-01

The development of codes and power calculations currently allows the simulation of increasingly complex flows, especially in the turbulent regime. Swimming research should benefit from these technological advances to try to better understand the dynamic mechanisms involved in swimming. An unsteady Computational Fluid Dynamics (CFD) study is conducted in crawl, in order to analyse the propulsive forces generated by the hand and forearm. The k-ω SST turbulence model and an overset grid method have been used. The main objectives are to analyse the evolution of the hand-forearm propulsive forces and to explain this relative to the arm kinematics parameters. In order to validate our simulation model, the calculated forces and pressures were compared with several other experimental and numerical studies. A good agreement is found between our results and those of other studies. The hand is the segment that generates the most propulsive forces during the aquatic stroke. As the pressure component is the main source of force, the orientation of the hand-forearm in the absolute coordinate system is an important kinematic parameter in the swimming performance. The propulsive forces are biggest when the angles of attack are high. CFD appears as a very valuable tool to better analyze the mechanisms of swimming performance and offers some promising developments, especially for optimizing the performance from a parametric study.

Controlled-frequency breath swimming improves swimming performance and running economy.

PubMed

Lavin, K M; Guenette, J A; Smoliga, J M; Zavorsky, G S

2015-02-01

Respiratory muscle fatigue can negatively impact athletic performance, but swimming has beneficial effects on the respiratory system and may reduce susceptibility to fatigue. Limiting breath frequency during swimming further stresses the respiratory system through hypercapnia and mechanical loading and may lead to appreciable improvements in respiratory muscle strength. This study assessed the effects of controlled-frequency breath (CFB) swimming on pulmonary function. Eighteen subjects (10 men), average (standard deviation) age 25 (6) years, body mass index 24.4 (3.7) kg/m(2), underwent baseline testing to assess pulmonary function, running economy, aerobic capacity, and swimming performance. Subjects were then randomized to either CFB or stroke-matched (SM) condition. Subjects completed 12 training sessions, in which CFB subjects took two breaths per length and SM subjects took seven. Post-training, maximum expiratory pressure improved by 11% (15) for all 18 subjects (P < 0.05) while maximum inspiratory pressure was unchanged. Running economy improved by 6 (9)% in CFB following training (P < 0.05). Forced vital capacity increased by 4% (4) in SM (P < 0.05) and was unchanged in CFB. These findings suggest that limiting breath frequency during swimming may improve muscular oxygen utilization during terrestrial exercise in novice swimmers. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Simulation of swimming strings immersed in a viscous fluid flow

NASA Astrophysics Data System (ADS)

Huang, Wei-Xi; Sung, Hyung Jin

2006-11-01

In nature, many phenomena involve interactions between flexible bodies and their surrounding viscous fluid, such as a swimming fish or a flapping flag. The intrinsic dynamics is complicate and not well understood. A flexible string can be regarded as a one-dimensional flag model. Many similarities can be found between the flapping string and swimming fish, although different wake speed results in a drag force for the flapping string and a propulsion force for the swimming fish. In the present study, we propose a mathematical formulation for swimming strings immersed in a viscous fluid flow. Fluid motion is governed by the Navier-Stokes equations and a momentum forcing is added in order to bring the fluid to move at the same velocity with the immersed surface. A flexible inextensible string model is described by another set of equations with an additional momentum forcing which is a result of the fluid viscosity and the pressure difference across the string. The momentum forcing is calculated by a feedback loop. Simulations of several numerical examples are carried out, including a hanging string which starts moving under gravity without ambient fluid, a swinging string immersed in a quiescent viscous fluid, a string swimming within a uniform surrounding flow, and flow over two side-by-side strings. The numerical results agree well with the theoretical analysis and previous experimental observations. Further simulation of a swimming fish is under consideration.

Hydrodynamic Attraction of Swimming Microorganisms by Surfaces

NASA Astrophysics Data System (ADS)

Berke, Allison P.; Turner, Linda; Berg, Howard C.; Lauga, Eric

2008-07-01

Cells swimming in confined environments are attracted by surfaces. We measure the steady-state distribution of smooth-swimming bacteria (Escherichia coli) between two glass plates. In agreement with earlier studies, we find a strong increase of the cell concentration at the boundaries. We demonstrate theoretically that hydrodynamic interactions of the swimming cells with solid surfaces lead to their reorientation in the direction parallel to the surfaces, as well as their attraction by the closest wall. A model is derived for the steady-state distribution of swimming cells, which compares favorably with our measurements. We exploit our data to estimate the flagellar propulsive force in swimming E. coli.

Swim pressure on walls with curves and corners.

PubMed

Smallenburg, Frank; Löwen, Hartmut

2015-09-01

The concept of swim pressure quantifies the average force exerted by microswimmers on confining walls in nonequilibrium. Here we explore how the swim pressure depends on the wall curvature and on the presence of sharp corners in the wall. For active Brownian particles at high dilution, we present a coherent framework which describes the force and torque on passive particles of arbitrary shape, in the limit of large particles compared to the persistence length of the swimmer trajectories. The resulting forces can be used to derive, for example, the activity-induced depletion interaction between two disks, as well as to optimize the shape of a tracer particle for high swimming velocity. Our predictions are verifiable in experiments on passive obstacles exposed to a bath of bacteria or artificial microswimmers.

Swim pressure on walls with curves and corners

NASA Astrophysics Data System (ADS)

Smallenburg, Frank; Löwen, Hartmut

2015-09-01

The concept of swim pressure quantifies the average force exerted by microswimmers on confining walls in nonequilibrium. Here we explore how the swim pressure depends on the wall curvature and on the presence of sharp corners in the wall. For active Brownian particles at high dilution, we present a coherent framework which describes the force and torque on passive particles of arbitrary shape, in the limit of large particles compared to the persistence length of the swimmer trajectories. The resulting forces can be used to derive, for example, the activity-induced depletion interaction between two disks, as well as to optimize the shape of a tracer particle for high swimming velocity. Our predictions are verifiable in experiments on passive obstacles exposed to a bath of bacteria or artificial microswimmers.

Amoeboid swimming in a channel

NASA Astrophysics Data System (ADS)

Wu, Hao; Farutin, Alexander; Hu, Wei-Fan; Thiébaud, Marine; Rafaï, Salima; Peyla, Philippe; Lai, Ming-Chih; Misbah, Chaouqi

Several micro-organisms, such as bacteria, algae, or spermatozoa, use flagella or cilia to swim in a fluid, while many other micro-organisms instead use ample shape deformation, described as amoeboid, to propel themselves by either crawling on a substrate or swimming. Many eukaryotic cells were believed to require an underlying substratum to migrate (crawl) by using membrane deformation (like blebbing or generation of lamellipodia) but there is now increasing evidence that a large variety of cells (including those of the immune system) can migrate without the assistance of focal adhesion, allowing them to swim as efficiently as they can crawl. This paper details the analysis of amoeboid swimming in a confined fluid by modeling the swimmer as an inextensible membrane deploying local active forces. The swimmer displays a rich behavior: it may settle into a straight trajectory in the channel or navigate from one wall to the other depending on its confinement. The nature of the swimmer is also found to be affected by confinement: the swimmer can behave, on the average over one swimming cycle, as a pusher at low confinement, and becomes a puller at higher confinement. The swimmer's nature is thus not an intrinsic property. The scaling of the swimmer velocity V with the force amplitude A is analyzed in detail showing that at small enough A, $V\\sim A^2/\\eta^2$, whereas at large enough A, V is independent of the force and is determined solely by the stroke frequency and swimmer size. This finding starkly contrasts with currently known results found from swimming models where motion is based on flagellar or ciliary activity, where $V\\sim A/\\eta$. To conclude, two definitions of efficiency as put forward in the literature are analyzed with distinct outcomes. We find that one type of efficiency has an optimum as a function of confinement while the other does not. Future perspectives are outlined.

Protective effects of forced exercise against nicotine-induced anxiety, depression and cognition impairment in rat.

PubMed

Motaghinejad, Majid; Fatima, Sulail; Karimian, Morteza; Ganji, Saeid

2016-01-01

Nicotine is one of the psychostimulant agents displaying parasympathomimetic activity; the chronic neurochemical and behavioral effects of nicotine remain unclear. Exercise lowers stress and anxiety and can act as a non-pharmacologic neuroprotective agent. In this study, the protective effects of exercise in nicotine withdrawal syndrome-induced anxiety, depression, and cognition impairment were investigated. Seventy adult male rats were divided randomly into five groups. Group 1 served as negative control and received normal saline (0.2 mL/rat, i.p.) for 30 days, whereas group 2 (as positive control) received nicotine (6 mg/kg/day, s.c.) for the first 15 days. Groups 4, 5, and 6 were treated with nicotine (6 mg/kg/day, s.c.) for the first 15 days and then were treated with forced exercise, bupropion (20 mg/kg/day, i.p.), or a combination of the two for the following 15 days. Between day 25 and day 30, Morris water maze was used to evaluate spatial learning and memory. From days 31 to 35, the elevated plus maze (EPM), open field test (OFT), forced swim test (FST), and tail suspension test (TST) were used to investigate the level of anxiety and depression in the subjects. Nicotine-dependent animals indicated a reflective depression and anxiety in a dose-dependent manner in FST, EPM, and TST, which were significantly different from the control group and also can significantly attenuate the motor activity and anxiety in OFT. Forced exercise, bupropion, or their combination can attenuate nicotine cessation-induced anxiety, depression, and motor activity in the mentioned behavioral assay. We conclude that forced exercise can protect the brain against nicotine withdrawal-induced anxiety, depression, and cognitive alteration.

Swimming Exercise in the Acute or Late Phase after Sciatic Nerve Crush Accelerates Nerve Regeneration

PubMed Central

Teodori, Rosana Macher; Betini, Joice; de Oliveira, Larissa Salgado; Sobral, Luciane Lobato; Takeda, Sibele Yoko Mattozo; Montebelo, Maria Imaculada de Lima

2011-01-01

There is no consensus about the best time to start exercise after peripheral nerve injury. We evaluated the morphological and functional characteristics of the sciatic nerves of rats that began to swim immediately after crush nerve injury (CS1), those that began to swim 14 days after injury (CS14), injured rats not submitted to swimming (C), and uninjured rats submitted to swimming (S). After 30 days the number of axons in CS1 and CS14 was lower than in C (P < 0.01). The diameter of axons and nerve fibers was larger in CS1 (P < 0.01) and CS14 (P < 0.05) than in C, and myelin sheath thickness was lower in all crushed groups (P < 0.05). There was no functional difference between CS1 and CS14 (P > 0.05). Swimming exercise applied during the acute or late phase of nerve injury accelerated nerve regeneration and synaptic elimination after axonotmesis, suggesting that exercise may be initiated immediately after injury. PMID:21876821

Chronic aerobic swimming exercise promotes functional and morphological changes in rat ileum

PubMed Central

da Cunha Araujo, Layanne Cabral; de Souza, Iara Leão Luna; Vasconcelos, Luiz Henrique César; de Freitas Brito, Aline; Queiroga, Fernando Ramos; Silva, Alexandre Sérgio; da Silva, Patrícia Mirella; de Andrade Cavalcante, Fabiana; da Silva, Bagnólia Araújo

2015-01-01

Several studies have reported the gastrointestinal (GI) effects promoted by the physical exercise. Thus, we aimed to evaluate the influence of swimming exercise on the contractile reactivity, lipid peroxidation and morphology of rat ileum. Wistar rats were divided into sedentary (SED) and groups exercised for two (EX2), four (EX4), six (EX6) or eight (EX8) weeks, 5 days/week. Animals were killed; the ileum was removed and suspended in organ baths where the isotonic contractions were recorded. Lipid peroxidation was evaluated by MDA (malondialdehyde) measurement with TBARS (thiobarbituric acid reactive substances) assay and morphology by histological staining. Cumulative concentration-response curves to KCl were attenuated, as the Emax values were changed from 100% (SED) to 63.1±3.9 (EX2), 48.8±3.8 (EX4), 19.4±1.8 (EX6) and 59.4±2.8% (EX8). Similarly, cumulative concentration-response curves to carbamylcholine hydrochloride (CCh) were attenuated, as the Emax values were changed from 100% (SED) to 74.1±5.4 (EX2), 75.9±5.2 (EX4) and 62.9±4.6 (EX6), but not in the EX8 (89.7±3.4%). However, CCh potency was increased in this latter, as the EC50 was altered from 1.0±0.1×10−6 (SED) to 2.1±0.4×10−7 (EX8). MDA concentration was altered only in EX4 (44.3±4.4) compared with SED (20.6±3.6 μmol/l). Circular layer was reduced in SED when compared with the exercised groups. Conversely, longitudinal layer was increased. In conclusion, chronic swimming exercise reduces the ileum contraction, equilibrates the oxidative damage and promotes changes in tissue size to establish an adaptation to the exercise. PMID:26424698

Computer assisted video analysis of swimming performance in a forced swim test: simultaneous assessment of duration of immobility and swimming style in mice selected for high and low swim-stress induced analgesia.

PubMed

Juszczak, Grzegorz R; Lisowski, Paweł; Sliwa, Adam T; Swiergiel, Artur H

2008-10-20

In behavioral pharmacology, two problems are encountered when quantifying animal behavior: 1) reproducibility of the results across laboratories, especially in the case of manual scoring of animal behavior; 2) presence of different behavioral idiosyncrasies, common in genetically different animals, that mask or mimic the effects of the experimental treatments. This study aimed to develop an automated method enabling simultaneous assessment of the duration of immobility in mice and the depth of body submersion during swimming by means of computer assisted video analysis system (EthoVision from Noldus). We tested and compared parameters of immobility based either on the speed of an object (animal) movement or based on the percentage change in the object's area between the consecutive video frames. We also examined the effects of an erosion-dilation filtering procedure on the results obtained with both parameters of immobility. Finally, we proposed an automated method enabling assessment of depth of body submersion that reflects swimming performance. It was found that both parameters of immobility were sensitive to the effect of an antidepressant, desipramine, and that they yielded similar results when applied to mice that are good swimmers. The speed parameter was, however, more sensitive and more reliable because it depended less on random noise of the video image. Also, it was established that applying the erosion-dilation filtering procedure increased the reliability of both parameters of immobility. In case of mice that were poor swimmers, the assessed duration of immobility differed depending on a chosen parameter, thus resulting in the presence or lack of differences between two lines of mice that differed in swimming performance. These results substantiate the need for assessing swimming performance when the duration of immobility in the FST is compared in lines that differ in their swimming "styles". Testing swimming performance can also be important in the

Reduction in the latency of action of antidepressants by 17 beta-estradiol in the forced swimming test.

PubMed

Estrada-Camarena, E; Rivera, N M Vega; Berlanga, C; Fernández-Guasti, A

2008-12-01

Antidepressants (ADs) are slow to produce their therapeutic effect. This long latency promotes the development of new strategies to short their onset of action. Previous reports indicated that 17beta-estradiol (E(2)) promotes the antidepressant-like activity of fluoxetine (FLX) and desipramine (DMI) in the forced swimming test (FST). The aim of the present work was to analyze if E(2) reduces the antidepressant-like onset of action of venlafaxine (VLX), FLX, and DMI. Independent groups of ovariectomized female Wistar rats were tested in the FST and in the open field after chronic (1 to 14 days) treatment with VLX (20 mg/kg/day), FLX (1.25 mg/kg/day), or DMI (1.25 mg/kg/day) alone or in combination with a single injection of E(2) (2.5 microg/rat sc, 8 h before FST). VLX, FLX, or DMI by themselves at these doses did not induce changes in the FST at short intervals after their injection (from 1 to 7 days). The addition of E(2) promoted the antidepressant-like effect of VLX and DMI as early as day 1. Such action was also evident after 3, for FLX, and 14 days for both FLX and DMI, but not for VLX. The behavioral actions of these ADs combined with E(2) were not accompanied by increases in general activity in the open-field test. E(2) clearly reduced the latency to the onset of action for these ADs in the FST. These results represent an interesting therapeutic strategy for the treatment of depression in perimenopausal women.

Effects of co-treatment with mirtazapine and low doses of risperidone on immobility time in the forced swimming test in mice.

PubMed

Rogóż, Zofia

2010-01-01

The aim of the present study was to examine the effect of mirtazapine (MIR) and risperidone (an atypical antipsychotic drug), given separately or jointly, on immobility time in the forced swimming test in male C57BL/6J mice. Fluoxetine (FLU) was used as a reference drug. MIR (2.5, 5 and 10 mg/kg) and FLU (5 and 10 mg/kg), or risperidone in low doses (0.05 and 0.1 mg/kg) given alone did not change the immobility time of mice in the forced swimming test. Joint administration of MIR (5 and 10 mg/kg) or FLU (10 mg/kg) and risperidone (0.1 mg/kg) produced antidepressant-like activity in the forced swimming test. WAY100636 (a 5-HT(1A) receptor antagonist) inhibited, while yohimbine (an α(2)-adrenergic receptor antagonist) potentiated the antidepressant-like effect induced by co-administration of MIR and risperidone. Active behavior in that test did not reflect an increase in general activity, since combined administration of antidepressants and risperidone failed to enhance the locomotor activity of mice. The obtained results indicate that risperidone applied in a low dose enhances the antidepressant-like activity of MIR and that, among other mechanisms, 5-HT(1A)-, and α(2)-adrenergic receptors may play a role in this effect.

Time to exhaustion at anaerobic threshold in swimming rats: metabolic investigation.

PubMed

Beck, W F; De Araujo, G G; Menezes Scariot, P P; Masselli dos Reis, I G; Gobatto, C A

2014-01-01

The purpose of this study was to determine the time to exhaustion (tlim) for swimming exercise at anaerobic threshold (AT) intensity in rats and to analyze metabolic consequences on serum and tissues levels. Eighteen rats were divided in control (CG) and exercised (EG) groups, being the former submitted to tlim. We analyzed the glycogen content of liver and ten skeletal muscles, as well as serum parameters. Parametric statistic was used with significance level at p < 0.05. The tlim, which was correspondent to 114.37 ± 36.23 min, promoted significant decrease in blood glucose (42.99 %; p < 0.01) and an increase in free fatty acids (167.12 %; p < 0.01) when EG was compared to CG. We did not find differences in albumin, total protein uric acid and creatinine between groups. The proposed exercise at individualized AT intensity promoted severe glycogen depletion for all tissues (mean of 78.05 % for all muscles and 89 % for liver). With substantial control of exercise intensity, our study establishes a useful rodent model that can be further explored, contributing to the advancement on knowledge and better understanding of exhaustion mechanisms.

Antidepressant effects of ginseng total saponins in the forced swimming test and chronic mild stress models of depression.

PubMed

Dang, Haixia; Chen, Ying; Liu, Xinmin; Wang, Qiong; Wang, Liwei; Jia, William; Wang, Yuqing

2009-11-13

Ginseng total saponins (GTS) are the major active components of Panax ginseng C.A. Meyer, which has been used as a popular tonic herb for 2000 years in Far East countries. In the present study, two classic animal models: the forced swimming test (FST) and the chronic mild stress (CMS) model were used to evaluate the antidepressant-like activities of GTS. It was observed that GTS at doses of 50 and 100 mg/kg significantly reduced the immobility time in the FST in mice after 7-day treatment. GTS also reversed the reduction in the sucrose preference index, decrease in locomotor activity as well as prolongation of latency of feeding in the novelty environment displayed by CMS rats. In addition, HPLC-ECD and immunohistochemical staining analysis indicated that the CMS-induced decrease in monoamine neurotransmitter concentration and brain-derived neurotrophic factor (BDNF) expression in the hippocampus were almost completely reversed by GTS. In conclusion, GTS exerts antidepressant-like effects in two highly specific and predictive animal models of depression. The activity of GTS in antidepression may be mediated partly through enhancing the monoamine neurotransmitter concentration and BDNF expression in the hippocampus.

Cholinergic mechanisms of analgesia produced by physostigmine, morphine and cold water swimming.

PubMed

Romano, J A; Shih, T M

1983-07-01

This study concerns the cholinergic involvement in three experimental procedures which produce analgesia. Rats were given one of seven treatments: saline (1.0 ml/kg, i.p.); morphine sulfate (3.5, 6.0 or 9.0 mg/kg, i.p.); physostigmine salicylate (0.65 mg/kg, i.p.); warm water swim (3.5 min at 28 degrees C); and cold water swim (3.5 min at 2 degrees C). Each rat was tested on a hot plate (59.1 degrees C) once prior to and 30 min after treatment. Immediately after the last test the rats were killed with focussed microwave radiation. Levels of acetylcholine (ACh) and choline (Ch) in six brain areas (brain stem, cerebral cortex, hippocampus, midbrain, cerebellum and striatum) were analyzed by gas chromatograph-mass spectrometer. Morphine (9.0 mg/kg), physostigmine and cold water swimming caused significant analgesia. Morphine elevated the levels of ACh in the cerebellum and striatum, cold water swimming--in the cerebellum, striatum and cortex, and physostigmine--in the striatum and hippocampus. Levels of choline were elevated by morphine in the cerebellum, cortex and hippocampus, while cold water swimming elevated levels of choline in the cerebellum, cortex, striatum and hippocampus. Physostigmine did not change levels of choline in any of the brain areas studied. These data suggest that the analgetic effects of morphine or cold water swimming may be mediated by components of the cholinergic system that differ from those involved in the analgetic effects of physostigmine.

Effect of zinc supplementation on lipid peroxidation and lactate levels in rats with diabetes induced by streptozotocin and subjected to acute swimming exercise.

PubMed

Bicer, M; Gunay, M; Baltaci, A K; Uney, K; Mogulkoc, R; Akil, M

2012-01-01

The present study aims to explore the effect of zinc supplementation on lipid peroxidation and lactate levels in rats having diabetes induced by streptozotocin and subjected to acute swimming exercise. A total of 80 adult male rats of Sprague-Dawley type were equally allocated to 8 groups: Group 1, general control. Group 2, zinc-supplemented group. Group 3, zinc-supplemented, diabetic group. Group 4, swimming control group. Group 5, zinc-supplemented swimming group. Group 6, zinc-supplemented diabetic swimming group. Group 7, diabetic swimming group. Group 8, diabetic group. At the end of the 4-week study, blood samples were collected to determine MDA, GSH, GPx, SOD, lactate and zinc levels. The highest MDA values were found in group 7 and 8 (p<0.001). GSH values in groups 5 and 6 were higher (p<0.001). The highest GPx values were established in groups 2, 5 and 6 (p<0.001). SOD values were the highest in groups 5 and 6 (p<0.001) and lowest in groups 2, 3 and 8 (p<0.001). The highest plasma lactate levels were found in group 7 (p<0.001). The highest zinc levels were obtained in groups 1, 2 and 5 (p<0.001), and the lowest zinc levels were found in groups 7 and 8 (p<0.001). Results of the study reveal that zinc supplementation prevents the increase of free radical formation, suppression of antioxidant activity and muscle exhaustion, all of which result from diabetes and acute exercise. Zinc supplementation may contribute to health performance in diabetes and acute exercise (Tab. 2, Fig. 1 Ref. 47). Full Text in PDF www.elis.sk.

Coordination strategies for limb forces during weight-bearing locomotion in normal rats, and in rats spinalized as neonates

PubMed Central

Giszter, Simon F; Davies, Michelle R; Graziani, Virginia

2010-01-01

Some rats spinally transected as neonates (ST rats) achieve weight-supporting independent locomotion. The mechanisms of coordinated hindlimb weight support in such rats are not well understood. To examine these in such ST rats and normal rats, rats with better than 60% of weight supported steps on a treadmill as adults were trained to cross an instrumented runway. Ground reaction forces, coordination of hindlimb and forelimb forces and the motions of the center of pressure were assessed. Normal rats crossed the runway with a diagonal trot. On average hindlimbs bore about 80% of the vertical load carried by forelimbs, although this varied. Forelimbs and hindlimb acted synergistically to generate decelerative and propulsive rostrocaudal forces, which averaged 15% of body weight with maximums of 50% . Lateral forces were very small (<8% of body weight). Center of pressure progressed in jumps along a straight line with mean lateral deviations <1 cm. ST rats hindlimbs bore about 60% of the vertical load of forelimbs, significantly less compared to intact (p<0.05). ST rats showed similar mean rostrocaudal forces, but with significantly larger maximum fluctuations of up to 80% of body weight (p<0.05). Joint force-plate recordings showed forelimbs and hindlimb rostrocaudal forces in ST rats were opposing and significantly different from intact rats (p<0.05). Lateral forces were ~20% of body weight and significantly larger than in normal rats (p<0.05). Center of pressure zig-zagged, with mean lateral deviations of ~ 2cm and a significantly larger range (p<0.05). The haunches were also observed to roll more than normal rats. The locomotor strategy of injured rats using limbs in opposition was presumably less efficient but their complex gait was statically stable. Because forelimbs and hindlimbs acted in opposition, the trunk was held compressed. Force coordination was likely managed largely by the voluntary control in forelimbs and trunk. PMID:18612631

Creatine Supplementation Induces Alteration in Cross-Sectional Area in Skeletal Muscle Fibers of Wistar Rats Under Swimming Training

PubMed Central

Santos, Fernando Farias Dos; Moura, José A. A.; Curi, Rui; Fernandes, Luiz C.

2002-01-01

Creatine has been shown to increase the total muscle mass. In this study, we investigated the effect of oral creatine monohydrate supplementation on cross-sectional area of type I, IIA and IIB fibers of gastrocnemius, extensor digitorum longus - EDL and soleus muscles from male Wistar rats subjected to swimming training for 33 days. Four groups were set up: sedentary with no supplementation (CON), sedentary with creatine supplementation (3.3 mg creatine per g chow) (CR), exercised with no supplementation (EX) and exercised with supplementation (CREX). The rats performed in a special swimming pool and swam five times a week for 1 hour each day, with a extra lead weight corresponding to 15% of their body weight. At the end of 33 days, skeletal muscles of the animals were dissected and the samples got immediately frozen using liquid nitrogen. Muscle samples were allocated to slices of 10 μm by a cryostat at -20°C, which was followed by histochemical analysis in order to identify fiber types of the muscles, and morphometrical analysis to calculate the muscle fiber areas. All groups gained body weight at the end of 33 days but there was no statistical difference among them. The EX and CREX rats had a larger food intake than the sedentary groups (CON and CR), and the CREX group had a larger food intake than CR rats. The cross-sectional area of type I and IIA fibers of the soleus muscle, type IIA and IIB fibers of EDL muscle and type IIA and IIB fibers of the white portion of gastrocnemius muscle were greater in the EX and CREX groups in comparison to sedentary rats. In addition, these fibers were greater in the CREX rats than in the EX group. There was no change in the cross sectional area of type I fibers in EDL muscle among all groups studied. Our results suggest that creatine supplementation enhances the exercise related muscle fiber hypertrophy in rodents. PMID:24701129

Nerve growth factor (NGF) immunoreactive neurons in the juvenile rat hippocampus: response to acute and long-term high-light open-field (HL-OF) or forced swim (FS) stress stimulation.

PubMed

Badowska-Szalewska, E; Spodnik, E; Ludkiewicz, B; Klejbor, I; Moryś, J

2011-12-29

This study aimed at examining and comparing the influence of two different stress stimuli on the density (number of cells/mm²) of nerve growth factor (NGF) containing neurons in the hippocampal CA1 and CA3 pyramidal cell layers and the dentate gyrus (DG) granule cell layer in juvenile rats (P28; P-postnatal day). The high-light open-field (HL-OF) test and forced swim (FS) test were employed to investigate the effects of a single, 15-min acute exposure and repeated (15 min daily for 21 days) long-term exposure to stress. In order to detect NGF-ir neurons, immunohistochemical (-ir) techniques were used. In comparison with nonstressed animals, acute and long-term HL-OF or FS stimulation resulted in a marked increase (P<0.001) in the density of NGF-ir containing cells in all the hippocampal structures. The frequency of stress application (acute vs. long-term), however, did not have a substantial impact on the studied parameter, with the exception of the CA3 sector, where a decreased density (P<0.001) of NGF-ir neurons was observed after long-term exposure to FS. It may be concluded that a rise in the density of NGF-ir neurons in the juvenile rat hippocampus after exposure to HL-OF or FS stressors could have affected the activity of the hypothalamic-pituitary-adrenocortical (HPA) stress axis. Prolonged HL-OF or FS stress was probably aggravating enough not to trigger the habituation process. The type of stressor applied (HL-OF vs. FS) was not essentially a factor determining the density of NGF-ir cells in the hippocampus. Copyright © 2011 IBRO. Published by Elsevier Ltd. All rights reserved.

[Maternal methyl-containing dietary supplementation alters the ability to learn in adult rats in swimming Morris test].

PubMed

Pliusnina, I Z; Os'kina, I N; Shchepina, O A; Prasolova, L A; Trut, L N

2006-01-01

Maternal choline diet influences the spatial learning processes. In this work, the learning ability of adult progeny of mothers who had received methyl diet enriched with choline and betain during pregnancy and lactation was studied in Morris test. The introduction of the diet to pregnant rats resulted in an increase in the time of search for invisible platform and time of swimming near the pool walls in offsprings, which meant a worsening of their learning ability. It was also found that change in platform searching strategy was not associated with an increase in anxiety of male rats. Possible involvement of maternal methyl diet in the change of expression of genes which control development of the nervous system is discussed.

The Aqueous Crude Extracts of Montanoa frutescens and Montanoa grandiflora Reduce Immobility Faster Than Fluoxetine Through GABAA Receptors in Rats Forced to Swim.

PubMed

Rodríguez-Landa, Juan Francisco; Cueto-Escobedo, Jonathan; Flores-Aguilar, Luis Ángel; Rosas-Sánchez, Gilberto Uriel; Rovirosa-Hernández, María de Jesús; García-Orduña, Francisco; Carro-Juárez, Miguel

2018-01-01

Montanoa frutescens and Montanoa grandiflora have been indistinctly used for centuries in traditional Mexican medicine for reproductive impairments, anxiety, and mood disorders. Preclinical studies support their aphrodisiac and anxiolytic properties, but their effects on mood are still unexplored. The effects of 25 and 50 mg/kg of M frutescens and M grandiflora extracts were evaluated on days 1, 7, 14, 21, and 28 of treatment, and compared with fluoxetine (1 mg/kg) and Remotiv (7.14 mg/kg) in Wistar rats. The participation of GABA A receptor in the effects produced by the treatments was explored. Montanoa extracts reduced immobility since day 1 of treatment, while fluoxetine and Remotiv required 14 days. The GABA A antagonism blocked the effects of Montanoa extracts, but not of fluoxetine or Remotiv. Montanoa extracts prevented quickly the stress-induced behaviors in the swimming test through action at the GABA A receptor, exerting a protective effect different to the typical antidepressants drugs.

Experimental hydrodynamics of swimming in fishes

NASA Astrophysics Data System (ADS)

Tytell, Eric Daniel

2005-11-01

The great diversity of fish body shapes suggests that they have adapted to different selective pressures. For many fishes, the pressures include hydrodynamic demands: swimming efficiently or accelerating rapidly, for instance. However, the hydrodynamic advantages or disadvantages to specific morphologies are poorly understood. In particular, eels have been considered inefficient swimmers, but they migrate long distances without feeding, a task that requires efficient swimming. This dissertation, therefore, begins with an examination of the swimming hydrodynamics of American eels, Anguilla rostrata, at steady swimming speeds from 0.5 to 2 body lengths (L) per second and during accelerations from -1.4 to 1.3 L s -2. The final chapter examines the hydrodynamic effects of body shape directly by describing three-dimensional flow around swimming bluegill sunfish, Lepomis macrochirus. In all chapters, flow is quantified using digital particle image velocimetry, and simultaneous kinematics are measured from high-resolution digital video. The wake behind a swimming eel in the horizontal midline plane is described first. Rather than producing a wake with fluid jets angled backwards, like in fishes such as sunfish, eels have a wake with exclusively lateral jets. The lack of downstream momentum indicates that eels balance the axial forces of thrust and drag evenly over time and over their bodies, and therefore do not change axial fluid momentum. This even balance, present at all steady swimming speeds, is probably due to the relatively uniform body shape of eels. As eels accelerate, thrust exceeds drag, axial momentum increases, and the wake approaches that of other fishes. During steady swimming, though, the lack of axial momentum prevents direct efficiency estimation. The effect of body shape was examined directly by measuring flow in multiple transverse planes along the body of bluegill sunfish swimming at 1.2 L s-1. The dorsal and anal fin, neglected in many previous

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.

The antidepressant effects of curcumin in the forced swimming test involve 5-HT1 and 5-HT2 receptors.

PubMed

Wang, Rui; Xu, Ying; Wu, Hong-Li; Li, Ying-Bo; Li, Yu-Hua; Guo, Jia-Bin; Li, Xue-Jun

2008-01-06

Curcuma longa is a main constituent of many traditional Chinese medicines, such as Xiaoyao-san, used to manage mental disorders effectively. Curcumin is a major active component of C. longa and its antidepressant-like effect has been previously demonstrated in the forced swimming test. The purpose of this study was to explore the possible contribution of serotonin (5-HT) receptors in the behavioral effects induced by curcumin in this animal model of depression. 5-HT was depleted by the tryptophan hydroxylase inhibitor p-chlorophenylalanine (PCPA, 100 mg/kg, i.p.) prior to the administration of curcumin, and the consequent results showed that PCPA blocked the anti-immobility effect of curcumin in forced swimming test, suggesting the involvement of the serotonergic system. Moreover, pre-treatment of pindolol (10 mg/kg, i.p., a beta-adrenoceptors blocker/5-HT(1A/1B) receptor antagonist), 4-(2'-methoxy-phenyl)-1-[2'-(n-2''-pyridinyl)-p-iodobenzamino-]ethyl-piperazine (p-MPPI, 1 mg/kg, s.c., a selective 5-HT(1A) receptor antagonist), or 1-(2-(1-pyrrolyl)-phenoxy)-3-isopropylamino-2-propanol (isamoltane, 2.5 mg/kg, i.p., a 5-HT(1B) receptor antagonist) was found to prevent the effect of curcumin (10 mg/kg) in forced swimming test. On the other hand, a sub-effective dose of curcumin (2.5 mg/kg, p.o.) produced a synergistic effect when given jointly with (+)-8-hydroxy-2-(di-n-propylamino)tetralin, (8-OH-DPAT, 1 mg/kg, i.p., a 5-HT(1A) receptor agonist), anpirtoline (0.25 mg/kg, i.p., a 5-HT(1B) receptor agonist) or ritanserin (4 mg/kg, i.p., a 5-HT(2A/2C) receptor antagonist), but not with ketanserin (5 mg/kg, i.p., a 5-HT(2A/2C) receptor antagonist with higher affinity to 5-HT(2A) receptor) or R(-)-1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane (DOI, 1 mg/kg, i.p., a 5-HT(2A) receptor agonist). Taken together, these results indicate that the antidepressant-like effect of curcumin in the forced swimming test is related to serotonergic system and may be mediated by, at least

Expression of the Mir-133 and Bcl-2 could be affected by swimming training in the heart of ovariectomized rats.

PubMed

Habibi, Parisa; Alihemmati, Alireza; NourAzar, Alireza; Yousefi, Hadi; Mortazavi, Safieh; Ahmadiasl, Nasser

2016-04-01

The beneficial and more potent role of exercise to prevent heart apoptosis in ovariectomized rats has been known. The aim of this study was to examine the effects of swimming training on cardiac expression of Bcl-2, and Mir-133 levels and glycogen changes in the myocyte. Forty animals were separated into four groups as control, sham, ovariectomy (OVX) and ovariectomized group with 8 weeks swimming training (OVX.E). Training effects were evaluated by measuring lipid profiles, Bcl-2 and Mir-133 expression levels in the cardiac tissue. Grafts were analyzed by reverse transcription-polymerase chain reaction for Bcl-2 mRNA and Mir-133 and by Western blot for Bcl-2 protein. Ovariectomy down-regulated Bcl-2 and Mir-133 expression levels in the cardiac tissue, and swimming training up-regulated their expression significantly (P<0.05). Our results showed that regular exercise as a physical replacement therapy could prevent and improve the effects of estrogen deficiency in the cardia.

The Impact of Resistance Training on Swimming Performance: A Systematic Review.

PubMed

Crowley, Emmet; Harrison, Andrew J; Lyons, Mark

2017-11-01

The majority of propulsive forces in swimming are produced from the upper body, with strong correlations between upper body strength and sprint performance. There are significant gaps in the literature relating to the impact of resistance training on swimming performance, specifically the transfer to swimming performance. The aims of this systematic literature review are to (1) explore the transfer of resistance-training modalities to swimming performance, and (2) examine the effects of resistance training on technical aspects of swimming. Four online databases were searched with the following inclusion criteria: (1) journal articles with outcome measures related to swimming performance, and (2) competitive swimmers participating in a structured resistance-training programme. Exclusion criteria were (1) participants with a mean age <16 years; (2) untrained, novice, masters and paraplegic swimmers; (3) triathletes and waterpolo players; (4) swimmers with injuries or illness; and (5) studies of starts and turns specifically. Data were extracted using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, and the Physiotherapy Evidence Database (PEDro) scale was applied. For optimal transfer, specific, low-volume, high-velocity/force resistance-training programmes are optimal. Stroke length is best achieved through resistance training with low repetitions at a high velocity/force. Resisted swims are the most appropriate training modality for improving stroke rate. Future research is needed with respect to the effects of long-term resistance-training interventions on both technical parameters of swimming and overall swimming performance. The results of such work will be highly informative for the scientific community, coaches and athletes.

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.

Prey capture by freely swimming flagellates

NASA Astrophysics Data System (ADS)

Andersen, Anders; Dolger, Julia; Nielsen, Lasse Tor; Kiorboe, Thomas

2017-11-01

Flagellates are unicellular microswimmers that propel themselves using one or several beating flagella. Here, we explore the dependence of swimming kinematics and prey clearance rate on flagellar arrangement and determine optimal flagellar arrangements and essential trade-offs. To describe near-cell flows around freely swimming flagellates we consider a model in which the cell is represented by a no-slip sphere and each flagellum by a point force. For uniflagellates pulled by a single flagellum the model suggests that a long flagellum favors fast swimming, whereas high clearance rate is favored by a very short flagellum. For biflagellates with both a longitudinal and a transversal flagellum we explore the helical swimming kinematics and the prey capture sites. We compare our predictions with observations of swimming kinematics, prey capture, and flows around common marine flagellates. The Centre for Ocean Life is a VKR Centre of Excellence supported by the Villum Foundation.

Floppy swimming: Viscous locomotion of actuated elastica

NASA Astrophysics Data System (ADS)

Lauga, Eric

2007-04-01

Actuating periodically an elastic filament in a viscous liquid generally breaks the constraints of Purcell’s scallop theorem, resulting in the generation of a net propulsive force. This observation suggests a method to design simple swimming devices—which we call “elastic swimmers”—where the actuation mechanism is embedded in a solid body and the resulting swimmer is free to move. In this paper, we study theoretically the kinematics of elastic swimming. After discussing the basic physical picture of the phenomenon and the expected scaling relationships, we derive analytically the elastic swimming velocities in the limit of small actuation amplitude. The emphasis is on the coupling between the two unknowns of the problems—namely the shape of the elastic filament and the swimming kinematics—which have to be solved simultaneously. We then compute the performance of the resulting swimming device and its dependence on geometry. The optimal actuation frequency and body shapes are derived and a discussion of filament shapes and internal torques is presented. Swimming using multiple elastic filaments is discussed, and simple strategies are presented which result in straight swimming trajectories. Finally, we compare the performance of elastic swimming with that of swimming micro-organisms.

Neurotrophic peptide ACTH-(4-10) permits glucocorticoid-facilitated retention of acquired immobility response of hypophysectomized rats.

PubMed

De Kock, S; De Kloet, E R

1987-09-23

The Porsolt swimming test, which was originally designed as an experimental model to screen potential antidepressants demands that rats be forced to swim for 15 min in a narrow cylinder. Twenty four hours later they are retested for 5 min during which they stay immobile for approximately 70% of the time. The present study showed that hypophysectomized animals, 14 days after operation, were unable to retain the acquired immobility. Subcutaneous glucocorticoid administration did not restore the retention of acquired immobility in contrast to our earlier finding with adrenalectomized animals. The deficit in responsiveness to glucocorticoids was eliminated when the hypophysectomized rats received ACTH-(4-10)s.c. (20 micrograms/rat) every other day. Chronic treatment with only the peptide did not improve the impaired retention of hypophysectomized rats and a single ACTH-(4-10) injection 1 day or 1 h prior to initial testing was also ineffective. We conclude that the neurotrophic peptide ACTH-(4-10) permits the expression of the glucocorticoid effect on retention of acquired immobility in the swimming test.

Swimming exercise reverses aging-related contractile abnormalities of female heart by improving structural alterations.

PubMed

Ozturk, Nihal; Olgar, Yusuf; Er, Hakan; Kucuk, Murathan; Ozdemir, Semir

2017-01-01

The objective of this study was to examine the effect of swimming exercise on aging-related Ca2+ handling alterations and structural abnormalities of female rat heart. For this purpose, 4-month and 24-month old female rats were used and divided into three following groups: sedentary young (SY), sedentary old (SO), and exercised old (Ex-O). Swimming exercise was performed for 8 weeks (60 min/day, 5 days/week). Myocyte shortening, L-type Ca2+ currents and associated Ca2+ transients were measured from ventricular myocytes at 36 ± 1°C. NOX-4 levels, aconitase activity, glutathione measurements and ultrastructural examination by electron microscopy were conducted in heart tissue. Swimming exercise reversed the reduced shortening and slowed kinetics of aged cardiomyocytes. Although the current density was similar for all groups, Ca2+ transients were higher in SO and Ex-O myocytes with respect to the SY group. Caffeine-induced Ca2+ transients and the integrated NCX current were lower in cardiomyocytes of SY rats compared with other groups, suggesting an increased sarcoplasmic reticulum Ca2+ content in an aged heart. Aging led to upregulated cardiac NOX-4 along with declined aconitase activity. Although it did not reverse these oxidative parameters, swimming exercise achieved a significant increase in glutathione levels and improved structural alterations of old rats' hearts. We conclude that swimming exercise upregulates antioxidant defense capacity and improves structural abnormalities of senescent female rat heart, although it does not change Ca2+ handling alterations further. Thereby, it improves contractile function of aged myocardium by mitigating detrimental effects of oxidative stress.

Spiral swimming of an artificial micro-swimmer

NASA Astrophysics Data System (ADS)

Keaveny, Eric E.; Maxey, Martin R.

A device constructed from a filament of paramagnetic beads connected to a human red blood cell will swim when subject to an oscillating magnetic field. Bending waves propagate from the tip of the tail toward the red blood cell in a fashion analogous to flagellum beating, making the artificial swimmer a candidate for studying what has been referred to as micro-swimming. In this study, we demonstrate that under the influence of a rotating field the artificial swimmer will perform -type swimming. We conduct numerical simulations of the swimmer where the paramagnetic tail is represented as a series of rigid spheres connected by flexible but inextensible links. An optimal range of parameters governing the relative strength of viscous, elastic and magnetic forces is identified for swimming speed. A parameterization of the motion is extracted and examined as a function of the driving frequency. With a continuous elastica/resistive force model, we obtain an expression for the swimming speed in the low-frequency limit. Using this expression we explore further the effects of the applied field, the ratio of the transverse field to the constant field, and the ratio of the radius of the sphere to the length of the filament tail on the resulting dynamics.

Effect of Aging on Tongue Protrusion Forces in Rats

PubMed Central

Nagai, Hiromi; Russell, John A.; Jackson, Michelle A.

2010-01-01

The purpose of this study was to ascertain the effect of aging on muscle contractile properties associated with tongue protrusion in a rat model. Fischer 344/Brown Norway hybrid rats, ten young (9 months old) and ten old (32 months old), were used to measure protrusive contractile properties. Results showed a significant reduction in tetanic forces in the old animals. The following measures of muscle contraction were not different between age groups: mean twitch contraction force, twitch contraction time, twitch contraction half-decay time, and a calculated measure of fatigability. In conclusion, aging influenced protrusive tongue muscle contractions in a rat model such that tetanic forces were reduced. The reduction of tetanus force may parallel findings in human subjects relative to isometric tongue force generation and may be associated with age-related disorders of swallowing. PMID:17694408

Effect of desipramine and citalopram treatment on forced swimming test-induced changes in cocaine- and amphetamine-regulated transcript (CART) immunoreactivity in mice.

PubMed

Chung, Sung; Kim, Hee Jeong; Kim, Hyun Ju; Choi, Sun Hye; Kim, Jin Wook; Kim, Jeong Min; Shin, Kyung Ho

2014-05-01

Recent study demonstrates antidepressant-like effect of cocaine- and amphetamine-regulated transcript (CART) in the forced swimming test (FST), but less is known about whether antidepressant treatments alter levels of CART immunoreactivity (CART-IR) in the FST. To explore this possibility, we assessed the treatment effects of desipramine and citalopram, which inhibit the reuptake of norepinephrine and serotonin into the presynaptic terminals, respectively, on changes in levels of CART-IR before and after the test swim in mouse brain. Levels of CART-IR in the nucleus accumbens shell (AcbSh), dorsal bed nucleus of the stria terminalis (dBNST), and hypothalamic paraventricular nucleus (PVN) were significantly increased before the test swim by desipramine and citalopram treatments. This increase in CART-IR in the AcbSh, dBNST, and PVN before the test swim remained elevated by desipramine treatment after the test swim, but this increase in these brain areas returned to near control levels after test swim by citalopram treatment. Citalopram, but not desipramine, treatment increased levels of CART-IR in the central nucleus of the amygdala (CeA) and the locus ceruleus (LC) before the test swim, and this increase was returned to control levels after the test swim in the CeA, but not in the LC. These results suggest common and distinct regulation of CART by desipramine and citalopram treatments in the FST and raise the possibility that CART in the AcbSh, dBNST, and CeA may be involved in antidepressant-like effect in the FST.

Free Swimming in Ground Effect

NASA Astrophysics Data System (ADS)

Cochran-Carney, Jackson; Wagenhoffer, Nathan; Zeyghami, Samane; Moored, Keith

2017-11-01

A free-swimming potential flow analysis of unsteady ground effect is conducted for two-dimensional airfoils via a method of images. The foils undergo a pure pitching motion about their leading edge, and the positions of the body in the streamwise and cross-stream directions are determined by the equations of motion of the body. It is shown that the unconstrained swimmer is attracted to a time-averaged position that is mediated by the flow interaction with the ground. The robustness of this fluid-mediated equilibrium position is probed by varying the non-dimensional mass, initial conditions and kinematic parameters of motion. Comparisons to the foil's fixed-motion counterpart are also made to pinpoint the effect that free swimming near the ground has on wake structures and the fluid-mediated forces over time. Optimal swimming regimes for near-boundary swimming are determined by examining asymmetric motions.

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.

Alterations in Plasma Glucose and Cardiac Antioxidant Enzymes Activity in Streptozotocin-Induced Diabetic Rats: Effects of Trigonella foenum-graecum Extract and Swimming Training.

PubMed

Haghani, Karimeh; Bakhtiyari, Salar; Doost Mohammadpour, Jafar

2016-04-01

Diabetes mellitus is a group of metabolic diseases characterized by chronic hyperglycemia. Trigonella foenum-graecum (fenugreek) and swimming training have previously been reported to have hypoglycemic and antioxidant effects. We aimed to evaluate the effects of swimming training and fenugreek aqueous extract, alone and in combination, on plasma glucose and cardiac antioxidant enzymes activity of streptozotocin-induced diabetes in rats. We divided 70 male Wistar rats equally into 7 groups: diabetic control (DC), healthy control (HC), swimming (S), fenugreek seed extract (1.74 g/kg) (F1), fenugreek seed extract (0.87 g/kg) (F2), swimming + fenugreek seed extract (1.74 g/kg) (SF1), and swimming + fenugreek seed extract (0.87 g/kg) (SF2). We used streptozotocin for the induction of diabetes. Statistical analyses were performed using the statistical program SPSS. We did not detect any significant differences in body weight in the F1, F2, S, SF1 and SF2 groups compared with the DC group (p>0.05). The results also revealed that the hypoglycemic effect of combined swimming and fenugreek was significantly stronger (p<0.05) than either of those alone. The F1, S, SF1 and SF2 groups showed improved superoxide dismutase activity with respect to the DC group (p<0.05). Catalase activity in the F1, S, SF1 and SF2 groups were significantly higher than those of the DC group (p<0.05). Glutathione peroxidase activity in the S, SF1 and SF2 groups were significantly increased compared with the DC group (p<0.05). Our findings suggest that the combination of fenugreek seed extract and swimming could be useful for the treatment of hyperglycemia and cardiac oxidative stress induced by type 1 diabetes mellitus. Copyright © 2016 Canadian Diabetes Association. Published by Elsevier Inc. All rights reserved.

Adenosine signaling in reserpine-induced depression in rats.

PubMed

Minor, Thomas R; Hanff, Thomas C

2015-06-01

A single, 6 mg/kg intraperitoneal injection of reserpine increased floating time during forced swim testing 24h after administration in rats in five experiments. Although such behavioral depression traditionally is attributed to drug-induced depletion of brain monoamines, we examined the potential contribution of adenosine signaling, which is plausibly activated by reserpine treatment and contributes to behavioral depression in other paradigms. Whereas peripheral administration of the highly selective A1 receptor antagonist 8-cyclopentyl-1,3-dipropylxanthine (0.5, 1.0, or 5.0mg/kg i.p.) 15 min before swim testing failed to improve performance in reserpine-treated rats, swim deficits were completely reversed by 7 mg/kg of the nonselective receptor antagonist caffeine. Performance deficits were also reversed by the nonselective A2 antagonist 3,7-dimethylxanthine (0, 0.5, 1.0mg/kg i.p.), and the highly selective A2A receptor antagonist (CSC: 8-(3 chlorostyral)caffeine) (0.01, 0.1, or 1.0mg/kg i.p.) in a dose-dependent manner. The highly selective A2B antagonist alloxazine had no beneficial effect on swim performance at any dose under study (0.1, 1.0, and 5.0mg/kg i.p.). Copyright © 2015 Elsevier B.V. All rights reserved.

Anthriscus nemorosa essential oil inhalation prevents memory impairment, anxiety and depression in scopolamine-treated rats.

PubMed

Bagci, Eyup; Aydin, Emel; Ungureanu, Eugen; Hritcu, Lucian

2016-12-01

Anthriscus nemorosa (Bieb.) Sprengel is used for medicinal purposes in traditional medicine around the world, including Turkey. Ethnobotanical studies suggest that Anthriscus essential oil could improve memory in Alzheimer's disease. The current study was hypothesized to investigate the beneficial effects of inhaled Anthriscus nemorosa essential oil on memory, anxiety and depression in scopolamine-treated rats. Anthriscus nemorosa essential oil was administered by inhalation in the doses of 1% and 3% for 21 continuous days and scopolamine (0.7mg/kg) was injected intraperitoneally 30min before the behavioral testing. Y-maze and radial arm-maze tests were used for assessing memory processes. Also, the anxiety and depressive responses were studied by elevated plus-maze and forced swimming tests. As expected, the scopolamine alone-treated rats exhibited the following: decrease the percentage of the spontaneous alternation in Y-maze test, increase the number of working and reference memory errors in radial arm-maze test, decrease of the exploratory activity, the percentage of the time spent and the number of entries in the open arm within elevated plus-maze test and decrease of swimming time and increase of immobility time within forced swimming test. However, dual scopolamine and Anthriscus nemorosa essential oil-treated rats showed significant improvement of memory formation and exhibited anxiolytic- and antidepressant-like effects in scopolamine-treated rats. These results suggest that Anthriscus nemorosa essential oil inhalation can prevent scopolamine-induced memory impairment, anxiety and depression. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

The swimming test is effective for evaluating spasticity after contusive spinal cord injury

PubMed Central

Ryu, Youngjae; Ogata, Toru; Nagao, Motoshi; Kitamura, Taku; Morioka, Kazuhito; Ichihara, Yoshinori; Doi, Toru; Sawada, Yasuhiro; Akai, Masami; Nishimura, Ryohei; Fujita, Naoki

2017-01-01

Spasticity is a frequent chronic complication in individuals with spinal cord injury (SCI). However, the severity of spasticity varies in patients with SCI. Therefore, an evaluation method is needed to determine the severity of spasticity. We used a contusive SCI model that is suitable for clinical translation. In this study, we examined the feasibility of the swimming test and an EMG for evaluating spasticity in a contusive SCI rat model. Sprague-Dawley rats received an injury at the 8th thoracic vertebra. Swimming tests were performed 3 to 6 weeks after SCI induction. We placed the SCI rats into spasticity-strong or spasticity-weak groups based on the frequency of spastic behavior during the swimming test. Subsequently, we recorded the Hoffman reflex (H-reflex) and examined the immunoreactivity of serotonin (5-HT) and its receptor (5-HT2A) in the spinal tissues of the SCI rats. The spasticity-strong group had significantly decreased rate-dependent depression of the H-reflex compared to the spasticity-weak group. The area of 5-HT2A receptor immunoreactivity was significantly increased in the spasticity-strong group. Thus, both electrophysiological and histological evaluations indicate that the spasticity-strong group presented with a more severe upper motor neuron syndrome. We also observed the groups in their cages for 20 hours. Our results suggest that the swimming test provides an accurate evaluation of spasticity in this contusive SCI model. We believe that the swimming test is an effective method for evaluating spastic behaviors and developing treatments targeting spasticity after SCI. PMID:28182676

The swimming test is effective for evaluating spasticity after contusive spinal cord injury.

PubMed

Ryu, Youngjae; Ogata, Toru; Nagao, Motoshi; Kitamura, Taku; Morioka, Kazuhito; Ichihara, Yoshinori; Doi, Toru; Sawada, Yasuhiro; Akai, Masami; Nishimura, Ryohei; Fujita, Naoki

2017-01-01

Spasticity is a frequent chronic complication in individuals with spinal cord injury (SCI). However, the severity of spasticity varies in patients with SCI. Therefore, an evaluation method is needed to determine the severity of spasticity. We used a contusive SCI model that is suitable for clinical translation. In this study, we examined the feasibility of the swimming test and an EMG for evaluating spasticity in a contusive SCI rat model. Sprague-Dawley rats received an injury at the 8th thoracic vertebra. Swimming tests were performed 3 to 6 weeks after SCI induction. We placed the SCI rats into spasticity-strong or spasticity-weak groups based on the frequency of spastic behavior during the swimming test. Subsequently, we recorded the Hoffman reflex (H-reflex) and examined the immunoreactivity of serotonin (5-HT) and its receptor (5-HT2A) in the spinal tissues of the SCI rats. The spasticity-strong group had significantly decreased rate-dependent depression of the H-reflex compared to the spasticity-weak group. The area of 5-HT2A receptor immunoreactivity was significantly increased in the spasticity-strong group. Thus, both electrophysiological and histological evaluations indicate that the spasticity-strong group presented with a more severe upper motor neuron syndrome. We also observed the groups in their cages for 20 hours. Our results suggest that the swimming test provides an accurate evaluation of spasticity in this contusive SCI model. We believe that the swimming test is an effective method for evaluating spastic behaviors and developing treatments targeting spasticity after SCI.

Antidepressant-like effect of a Ginkgo biloba extract (EGb761) in the mouse forced swimming test: role of oxidative stress.

PubMed

Rojas, Patricia; Serrano-García, Norma; Medina-Campos, Omar N; Pedraza-Chaverri, José; Ogren, Sven O; Rojas, Carolina

2011-10-01

EGb761 is a well-defined mixture of active compounds extracted from Ginkgo biloba leaves. This extract is used clinically due to its neuroprotective effects, exerted probably via its potent antioxidant or free radical scavenger action. Previous studies suggest that oxidative stress, via free radical production, may play an important role in depression and animal models for depression-like behavior. Preclinical studies have suggested that antioxidants may have antidepressants properties. The aim of this study was to investigate the antidepressant-like of EGb761 due to its antioxidant role against oxidative stress induced in the forced swimming test, the most widely used preclinical model for assessing antidepressant-like behavior. Male BALB/c mice were pretreated with EGb761 (10mg/kg, ip) daily for 17 days followed by the forced swimming test and spontaneous locomotor activity. Animals were sacrificed to evaluate lipid peroxidation, different antioxidant enzyme activities, serotonin and dopamine content in midbrain, hippocampus and prefrontal cortex. EGb761 significantly decreased the immobility time (39%) in the forced swimming test. This antidepressant-like effect of EGb761 was associated with a reduction in lipid peroxidation and superoxide radical production (indicated by a downregulation of Mn-superoxide dismutase activity), both of which are indicators of oxidative stress. The protective effect of EGb761 is not related to excitatory or inhibitory effects in locomotor activity, and was also associated with the modulation of serotonergic and dopaminergic neurotransmission. It is suggested that EGb761 produces an antidepressant-like effect, and that an antioxidant effect against oxidative stress may be partly responsible for its observed neuroprotective effects. Copyright © 2011 Elsevier B.V. All rights reserved.

Chelidonic acid evokes antidepressant-like effect through the up-regulation of BDNF in forced swimming test.

PubMed

Jeong, Hyun-Ja; Yang, Shi-Young; Kim, Hee-Yun; Kim, Na-Rae; Jang, Jae-Bum; Kim, Hyung-Min

2016-08-01

Depression is usually accompanied by neuro-inflammatory reactions. Chelidonic acid, in particular, has shown anti-inflammatory effects. The objective of this study was to evaluate the anti-depressant effects of chelidonic acid and to discuss the potential mechanisms of a forced swimming test. Chelidonic acid was administered orally once a day for 14 days. On the 14th day, chelidonic acid resulted in a significant decrease in immobility time during the forced swimming test without alteration of locomotor activity, in an open field test. Chelidonic acid also increased the number of nissl bodies in the hippocampus. Brain-derived neurotrophic factor expression and extracellular signal-regulated protein kinase phosphorylation in the hippocampus were up-regulated by the administration of chelidonic acid. Chelidonic acid administration significantly increased the mRNA expression of hippocampal estrogen receptor-β. The levels of hippocampal interleukin (IL)-1β, IL-6, and tumor necrosis factor-α were effectively attenuated by the administration of chelidonic acid. In addition, chelidonic acid significantly increased the levels of 5-hydroxytryptamine (serotonin), dopamine, and norepinephrine compared with those levels for the mice that were administered distilled water in the hippocampus. These results suggest that chelidonic acid might serve as a new therapeutic strategy for the regulation of depression associated with inflammation. © 2016 by the Society for Experimental Biology and Medicine.

Swimming Training Reduces Neuroma Pain by Regulating Neurotrophins.

PubMed

Tian, Jinge; Yu, Tingting; Xu, Yongming; Pu, Shaofeng; Lv, Yingying; Zhang, Xin; DU, Dongping

2018-01-01

Neuroma formation after peripheral nerve transection leads to severe neuropathic pain in amputees. Previous studies suggested that physical exercise could bring beneficial effect on alleviating neuropathic pain. However, the effect of exercise on neuroma pain still remained unclear. In addition, long-term exercise can affect the expression of neurotrophins (NT), such as nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF), which play key roles in nociceptor sensitization and nerve sprouting after nerve injury. Here, we investigated whether long-term swimming exercise could relieve neuroma pain by modulating NT expression. We used a tibial neuroma transposition (TNT) rat model to mimic neuroma pain. After TNT surgery, rats performed swimming exercise for 5 wk. Neuroma pain and tactile sensitivities were detected using von Frey filaments. Immunofluorescence was applied to analyze neuroma formation. NGF and BDNF expressions in peripheral neuroma, dorsal root ganglion, and the spinal cord were measured using enzyme-linked immunosorbent assay and Western blotting. TNT led to neuroma formation, induced neuroma pain, and mechanical allodynia in hind paw. Five-week swimming exercise inhibited neuroma formation and relieved mechanical allodynia in the hind paw and neuroma pain in the lateral ankle. The analgesic effect lasted for at least 1 wk, even when the exercise ceased. TNT elevated the expressions of BDNF and NGF in peripheral neuroma, dorsal root ganglion, and the spinal cord to different extents. Swimming also decreased the elevation of NT expression. Swimming exercise not only inhibits neuroma formation induced by nerve transection but also relieves pain behavior. These effects might be associated with the modulation of NT.

Effects of hydrodynamic interactions in bacterial swimming.

NASA Astrophysics Data System (ADS)

Chattopadhyay, Suddhashil; Lun Wu, Xiao

2008-03-01

The lack of precise experimental data has prevented the investigation of the effects of long range hydrodynamic interactions in bacterial swimming. We perform measurements on various strains of bacteria with the aid of optical tweezers to shed light on this aspect of bacterial motility. Geometrical parameters recorded by fluorescence microscopy are used with theories which model flagella propulsion (Resistive force theory & Lighthill's formulation which includes long range interactions). Comparison of the predictions of these theories with experimental data, observed directly from swimming bacterium, led to the conclusion that while long range inetractions were important for single polar flagellated strains (Vibrio Alginolyticus & Caulobacter Crescentus), local force theory was adequate to describe the swimming of multi-flagellated Esherichia Coli. We performed additional measurements on E. Coli minicells (miniature cells with single polar flagellum) to try and determine the cause of this apparent effect of shielding of long range interactions in multiple flagellated bacteria.

Paramecia Swim with a constant propulsion in Solutions of Varying Viscosity

NASA Astrophysics Data System (ADS)

Valles, James M., Jr.; Jung, Ilyong; Mickalide, Harry; Park, Hojin; Powers, Thomas

2012-02-01

Paramecia swim through the coordinated beating of the 1000's of cilia covering their body. We have measured the swimming speed of populations of Paramecium Caudatam in solutions of different viscosity, η, to see how their propulsion changes with increased drag. We have found the average instantaneous speed, V to decrease monotonically with increasing η. The product ηv is roughly constant over a factor of 7 change in viscosity suggesting that paramecia swim at constant propulsion force. The distribution of swimming speeds is Gaussian. The width appears proportional to the average speed implying that both fast and slow swimmers exert a constant propulsion. We discuss the possibility that this behavior implies that the body cilia beat at constant force with varying viscosity.

Possible involvement of nitric oxide (NO) signaling pathway in the antidepressant-like effect of MK-801(dizocilpine), a NMDA receptor antagonist in mouse forced swim test.

PubMed

Dhir, Ashish; Kulkarni, S K

2008-03-01

L-arginine-nitric oxide (NO)-cyclic guanosine monophosphate (cGMP) is an important signaling pathway involved in depression. With this information, the present study aimed to study the involvement of this signaling pathway in the antidepressant-like action of MK-801 (dizocilpine; N-methyl-d-aspartate receptor antagonist) in the mouse forced-swim test. Total immobility period was recorded in mouse forced swim test for 6 min. MK-801 (5-25 microg/kg., ip) produced a U-shaped curve in reducing the immobility period. The antidepressant-like effect of MK-801 (10 microg/kg, ip) was prevented by pretreatment with L-arginine (750 mg/kg, ip) [substrate for nitric oxide synthase (NOS)]. Pretreatment of mice with 7-nitroindazole (7-NI) (25 mg/kg, ip) [a specific neuronal nitric oxide synthase inhibitor] produced potentiation of the action of subeffective dose of MK-801 (5 microg/kg, ip). In addition, treatment of mice with methylene blue (10 mg/kg, ip) [direct inhibitor of both nitric oxide synthase and soluble guanylate cyclase] potentiated the effect of MK-801 (5 microg/kg, ip) in the forced-swim test. Further, the reduction in the immobility period elicited by MK-801 (10 microg/kg, ip) was also inhibited by pretreatment with sildenafil (5 mg/kg, ip) [phosphodiesterase 5 inhibitor]. The various modulators used in the study and their combination did not produce any changes in locomotor activity per se and in combination with MK-801. MK-801 however, at higher doses (25 microg/kg, ip) produced hyperlocomotion. The results demonstrated the involvement of nitric oxide signaling pathway in the antidepressant-like effect of MK-801 in mouse forced-swim test.

Antidepressant-like effects of a cocoa polyphenolic extract in Wistar-Unilever rats.

PubMed

Messaoudi, Michaël; Bisson, Jean-François; Nejdi, Amine; Rozan, Pascale; Javelot, Hervé

2008-12-01

Depression is a major public health problem affecting about 12% of the world population. Drugs exist but they have many side effects. In the last few years, natural substances (e.g. flavonoids) have been tested to cure such disorders. Cocoa polyphenolic extract is a complex compound prepared from non-roasted cocoa beans containing high levels of flavonoids. The antidepressant-like effect of cocoa polyphenolic extract was evaluated using the forced swimming test in rats. Cocoa polyphenolic extract significantly reduced the duration of immobility at both doses of 24 mg/kg/14 days and 48 mg/kg/14 days, although no change of motor dysfunction was observed with the two doses tested in the open field. The results of the forced swimming test after a subchronic treatment and after an additional locomotor activity test confirm the assumption that the antidepressant-like effect of cocoa polyphenolic extract in the forced swimming test model is specific. Further, it can be speculated that this effect might be related to its content of active polyphenols.

Numerical and experimental investigations of human swimming motions.

PubMed

Takagi, Hideki; Nakashima, Motomu; Sato, Yohei; Matsuuchi, Kazuo; Sanders, Ross H

2016-08-01

This paper reviews unsteady flow conditions in human swimming and identifies the limitations and future potential of the current methods of analysing unsteady flow. The capability of computational fluid dynamics (CFD) has been extended from approaches assuming steady-state conditions to consideration of unsteady/transient conditions associated with the body motion of a swimmer. However, to predict hydrodynamic forces and the swimmer's potential speeds accurately, more robust and efficient numerical methods are necessary, coupled with validation procedures, requiring detailed experimental data reflecting local flow. Experimental data obtained by particle image velocimetry (PIV) in this area are limited, because at present observations are restricted to a two-dimensional 1.0 m(2) area, though this could be improved if the output range of the associated laser sheet increased. Simulations of human swimming are expected to improve competitive swimming, and our review has identified two important advances relating to understanding the flow conditions affecting performance in front crawl swimming: one is a mechanism for generating unsteady fluid forces, and the other is a theory relating to increased speed and efficiency.

Numerical and experimental investigations of human swimming motions

PubMed Central

Takagi, Hideki; Nakashima, Motomu; Sato, Yohei; Matsuuchi, Kazuo; Sanders, Ross H.

2016-01-01

ABSTRACT This paper reviews unsteady flow conditions in human swimming and identifies the limitations and future potential of the current methods of analysing unsteady flow. The capability of computational fluid dynamics (CFD) has been extended from approaches assuming steady-state conditions to consideration of unsteady/transient conditions associated with the body motion of a swimmer. However, to predict hydrodynamic forces and the swimmer’s potential speeds accurately, more robust and efficient numerical methods are necessary, coupled with validation procedures, requiring detailed experimental data reflecting local flow. Experimental data obtained by particle image velocimetry (PIV) in this area are limited, because at present observations are restricted to a two-dimensional 1.0 m2 area, though this could be improved if the output range of the associated laser sheet increased. Simulations of human swimming are expected to improve competitive swimming, and our review has identified two important advances relating to understanding the flow conditions affecting performance in front crawl swimming: one is a mechanism for generating unsteady fluid forces, and the other is a theory relating to increased speed and efficiency. PMID:26699925

Quiet swimming at low Reynolds number

NASA Astrophysics Data System (ADS)

Andersen, Anders; Wadhwa, Navish; Kiørboe, Thomas

2015-04-01

The stresslet provides a simple model of the flow created by a small, freely swimming and neutrally buoyant aquatic organism and shows that the far field fluid disturbance created by such an organism in general decays as one over distance squared. Here we discuss a quieter swimming mode that eliminates the stresslet component of the flow and leads to a faster spatial decay of the fluid disturbance described by a force quadrupole that decays as one over distance cubed. Motivated by recent experimental results on fluid disturbances due to small aquatic organisms, we demonstrate that a three-Stokeslet model of a swimming organism which uses breast stroke type kinematics is an example of such a quiet swimmer. We show that the fluid disturbance in both the near field and the far field is significantly reduced by appropriately arranging the propulsion apparatus, and we find that the far field power laws are valid surprisingly close to the organism. Finally, we discuss point force models as a general framework for hypothesis generation and experimental exploration of fluid mediated predator-prey interactions in the planktonic world.

Quiet swimming at low Reynolds number.

PubMed

Andersen, Anders; Wadhwa, Navish; Kiørboe, Thomas

2015-04-01

The stresslet provides a simple model of the flow created by a small, freely swimming and neutrally buoyant aquatic organism and shows that the far field fluid disturbance created by such an organism in general decays as one over distance squared. Here we discuss a quieter swimming mode that eliminates the stresslet component of the flow and leads to a faster spatial decay of the fluid disturbance described by a force quadrupole that decays as one over distance cubed. Motivated by recent experimental results on fluid disturbances due to small aquatic organisms, we demonstrate that a three-Stokeslet model of a swimming organism which uses breast stroke type kinematics is an example of such a quiet swimmer. We show that the fluid disturbance in both the near field and the far field is significantly reduced by appropriately arranging the propulsion apparatus, and we find that the far field power laws are valid surprisingly close to the organism. Finally, we discuss point force models as a general framework for hypothesis generation and experimental exploration of fluid mediated predator-prey interactions in the planktonic world.

The Effects of Inhaled Pimpinella peregrina Essential Oil on Scopolamine-Induced Memory Impairment, Anxiety, and Depression in Laboratory Rats.

PubMed

Aydin, Emel; Hritcu, Lucian; Dogan, Gulden; Hayta, Sukru; Bagci, Eyup

2016-11-01

In the present study, we identified the effects of inhaled Pimpinella peregrina essential oil (1 and 3 %, for 21 continuous days) on scopolamine-induced memory impairment, anxiety, and depression in laboratory rats. Y-maze and radial arm-maze tests were used for assessing memory processes. Also, the anxiety and depressive responses were studied by means of the elevated plus-maze and forced swimming tests. The scopolamine alone-treated rats exhibited the following: decrease of the spontaneous alternation percentage in Y-maze test, increase of the number of working and reference memory errors in radial arm-maze test, along with decrease of the exploratory activity, the percentage of the time spent and the number of entries in the open arm within elevated plus-maze test and decrease of swimming time and increase of immobility time within forced swimming test. Inhalation of the P. peregrina essential oil significantly improved memory formation and exhibited anxiolytic- and antidepressant-like effects in scopolamine-treated rats. Our results suggest that the P. peregrina essential oil inhalation ameliorates scopolamine-induced memory impairment, anxiety, and depression. Moreover, studies on the P. peregrina essential oil may open a new therapeutic window for the prevention of neurological abnormalities closely related to Alzheimer's disease.

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.

Swimming Training Reduces Neuroma Pain by Regulating Neurotrophins

PubMed Central

TIAN, JINGE; YU, TINGTING; XU, YONGMING; PU, SHAOFENG; LV, YINGYING; ZHANG, XIN; DU, DONGPING

2018-01-01

ABSTRACT Introduction Neuroma formation after peripheral nerve transection leads to severe neuropathic pain in amputees. Previous studies suggested that physical exercise could bring beneficial effect on alleviating neuropathic pain. However, the effect of exercise on neuroma pain still remained unclear. In addition, long-term exercise can affect the expression of neurotrophins (NT), such as nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF), which play key roles in nociceptor sensitization and nerve sprouting after nerve injury. Here, we investigated whether long-term swimming exercise could relieve neuroma pain by modulating NT expression. Methods We used a tibial neuroma transposition (TNT) rat model to mimic neuroma pain. After TNT surgery, rats performed swimming exercise for 5 wk. Neuroma pain and tactile sensitivities were detected using von Frey filaments. Immunofluorescence was applied to analyze neuroma formation. NGF and BDNF expressions in peripheral neuroma, dorsal root ganglion, and the spinal cord were measured using enzyme-linked immunosorbent assay and Western blotting. Results TNT led to neuroma formation, induced neuroma pain, and mechanical allodynia in hind paw. Five-week swimming exercise inhibited neuroma formation and relieved mechanical allodynia in the hind paw and neuroma pain in the lateral ankle. The analgesic effect lasted for at least 1 wk, even when the exercise ceased. TNT elevated the expressions of BDNF and NGF in peripheral neuroma, dorsal root ganglion, and the spinal cord to different extents. Swimming also decreased the elevation of NT expression. Conclusions Swimming exercise not only inhibits neuroma formation induced by nerve transection but also relieves pain behavior. These effects might be associated with the modulation of NT. PMID:28846565

Desipramine and citalopram attenuate pretest swim-induced increases in prodynorphin immunoreactivity in the dorsal bed nucleus of the stria terminalis and the lateral division of the central nucleus of the amygdala in the forced swimming test.

PubMed

Chung, Sung; Kim, Hee Jeong; Kim, Hyun Ju; Choi, Sun Hye; Cho, Jin Hee; Cho, Yun Ha; Kim, Dong-Hoon; Shin, Kyung Ho

2014-10-01

Dynorphin in the nucleus accumbens shell plays an important role in antidepressant-like effect in the forced swimming test (FST), but it is unclear whether desipramine and citalopram treatments alter prodynorphin levels in other brain areas. To explore this possibility, we injected mice with desipramine and citalopram 0.5, 19, and 23 h after a 15-min pretest swim and observed changes in prodynorphin expression before the test swim, which was conducted 24 h after the pretest swim. The pretest swim increased prodynorphin immunoreactivity in the dorsal bed nucleus of the stria terminalis (dBNST) and lateral division of the central nucleus of the amygdala (CeL). This increase in prodynorphin immunoreactivity in the dBNST and CeL was blocked by desipramine and citalopram treatments. Similar changes in prodynorphin mRNA levels were observed in the dBNST and CeL, but these changes did not reach significance. To understand the underlying mechanism, we assessed changes in phosphorylated CREB at Ser(133) (pCREB) immunoreactivity in the dBNST and central nucleus of the amygdala (CeA). Treatment with citalopram but not desipramine after the pretest swim significantly increased pCREB immunoreactivity only in the dBNST. These results suggest that regulation of prodynorphin in the dBNST and CeL before the test swim may be involved in the antidepressant-like effect of desipramine and citalopram in the FST and suggest that changes in pCREB immunoreactivity in these areas may not play an important role in the regulation of prodynorphin in the dBNST and CeA. Copyright © 2014 Elsevier Ltd. All rights reserved.

Mechanisms underlying rhythmic locomotion: body–fluid interaction in undulatory swimming

PubMed Central

Chen, J.; Friesen, W. O.; Iwasaki, T.

2011-01-01

Swimming of fish and other animals results from interactions of rhythmic body movements with the surrounding fluid. This paper develops a model for the body–fluid interaction in undulatory swimming of leeches, where the body is represented by a chain of rigid links and the hydrodynamic force model is based on resistive and reactive force theories. The drag and added-mass coefficients for the fluid force model were determined from experimental data of kinematic variables during intact swimming, measured through video recording and image processing. Parameter optimizations to minimize errors in simulated model behaviors revealed that the resistive force is dominant, and a simple static function of relative velocity captures the essence of hydrodynamic forces acting on the body. The model thus developed, together with the experimental kinematic data, allows us to investigate temporal and spatial (along the body) distributions of muscle actuation, body curvature, hydrodynamic thrust and drag, muscle power supply and energy dissipation into the fluid. We have found that: (1) thrust is generated continuously along the body with increasing magnitude toward the tail, (2) drag is nearly constant along the body, (3) muscle actuation waves travel two or three times faster than the body curvature waves and (4) energy for swimming is supplied primarily by the mid-body muscles, transmitted through the body in the form of elastic energy, and dissipated into the water near the tail. PMID:21270304

Maximum sustained fin-kick thrust in underwater swimming.

PubMed

Yamaguchi, H; Shidara, F; Naraki, N; Mohri, M

1995-09-01

We examined the upper limit of a diver's fin-kick thrust force using a stationary-swimming ergometer. Heart rate, respiratory minute volume, oxygen uptake, and performance rate were measured in four male subjects who swam constantly for 8 min to maintain a horizontal position against an applied force at a depth of 0.7 m. The water temperature was controlled at 26 degrees +/- 1 degree C. The performance rate, which was the parameter of how well the subjects compensated for the applied load, showed an upper limit around 64 N of sustainable thrust force. This meant that the diver could generate the swimming thrust force within 64 N continuously for 8 min in a steady state. Heart rate, respiratory minute volume, and O2 uptake showed almost proportional increases to the applied load within 64 N and tended to plateau about 69 N.

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.

Effects of Methyl Jasmonate on Acute Stress Responses in Mice Subjected to Forced Swim and Anoxic Tests

PubMed Central

Aluko, Oritoke M.; Umukoro, Solomon; Annafi, Olajide S.; Adewole, Folashade A.; Omorogbe, Osarume

2015-01-01

Methyl jasmonate (MJ) is an anti-stress hormone released by plants in response to external stressors and aids adaptation to stress. In this study, we evaluated the anti-stress activity of MJ using the forced swim endurance test (FSET) and anoxic tolerance test in mice. Male Swiss mice were given MJ (25–100 mg/kg, i.p) 30 min before the FSET and anoxic test were carried out. The first occurrence of immobility, duration of immobility, time spent in active swimming, and latency to exhaustion were assessed in the FSET. The onset to anoxic convulsion was measured in the anoxic tolerance test. MJ significantly (p < 0.05) delayed the first occurrence of immobility and shortened the period of immobility, which indicates anti-stress property. MJ also increased the time spent in active swimming and prolonged the latency to exhaustion, which further suggests anti-stress activity. In addition, it also exhibited anti-stress property as evidenced by prolonged latency to first appearance of anoxic convulsions. The results of this study suggest that MJ demonstrated anti-stress activity and may be useful as an energizer in times of body weakness or exhaustion. Although more studies are necessary before concluding on how MJ exerts its anti-stress activity, the present data suggest an action similar to adaptogens in boosting energy and resilience in the face of stress. PMID:26839844

Swimming of an assembly of rigid spheres at low Reynolds number.

PubMed

Felderhof, B U

2014-11-01

A matrix formulation is derived for the calculation of the swimming speed and the power required for swimming of an assembly of rigid spheres immersed in a viscous fluid of infinite extent. The spheres may have arbitrary radii and may interact with elastic forces. The analysis is based on the Stokes mobility matrix of the set of spheres, defined in low Reynolds number hydrodynamics. For small amplitude, swimming optimization of the swimming speed at given power leads to an eigenvalue problem. The method allows straightforward calculation of the swimming performance of structures modeled as assemblies of interacting rigid spheres.

Swimming of Paramecium in confined channels

NASA Astrophysics Data System (ADS)

Jung, Sunghwan

2012-02-01

Many living organisms in nature have developed a few different swimming modes, presumably derived from hydrodynamic advantage. Paramecium is a ciliated protozoan covered by thousands of cilia with a few nanometers in diameter and tens of micro-meters in length and is able to exhibit both ballistic and meandering motions. First, we characterize ballistic swimming behaviors of ciliated microorganisms in glass capillaries of different diameters and explain the trajectories they trace out. We develop a theoretical model of an undulating sheet with a pressure gradient and discuss how it affects the swimming speed. Secondly, investigation into meandering swimmings within rectangular PDMS channels of dimension smaller than Paramecium length. We find that Paramecium executes a body-bend (an elastic buckling) using the cilia while it meanders. By considering an elastic beam model, we estimate and show the universal profile of forces it exerts on the walls. Finally, we discuss a few other locomotion of Paramecium in other extreme environments like gel.

Anxiolytic effects of buspirone and MTEP in the Porsolt Forced Swim Test.

PubMed

Lee, Kaziya M; Coelho, Michal A; Sern, Kimberly R; Class, MacKayla A; Bocz, Mark D; Szumlinski, Karen K

2017-01-01

Traditionally, a reduction in floating behavior or immobility in the Porsolt forced swim test (FST) is employed as a predictor of antidepressant efficacy. However, over the past several years, our studies of alcohol withdrawal-induced negative affect consistently indicate the coincidence of increased anxiety-related behaviors on various behavioral tests with reduced immobility in the FST. Further, this behavioral profile correlates with increased mGlu5 protein expression within limbic brain regions. As the role for mGlu5 in anxiety is well established, we hypothesized that the reduced immobility exhibited by alcohol-withdrawn mice when tested in the FST might reflect anxiety, possibly a hyper-reactivity to the acute swim stressor. Herein, we evaluated whether or not the decreased FST immobility during alcohol withdrawal responds to systemic treatment with a behaviorally-effective dose of the prototypical anxiolytic, buspirone (5 mg/kg). We also determined the functional relevance of the withdrawal-induced increase in mGlu5 expression for FST behavior by comparing the effects of buspirone to a behaviorally effective dose of the mGlu5 negative allosteric modulator MTEP (3 mg/kg). Adult male C57BL/6J mice were subjected to a 14-day, multi-bottle, binge-drinking protocol that elicits hyper-anxiety and increases glutamate-related protein expression during early withdrawal. Control animals received only water. At 24hr withdrawal, animals from each drinking condition were subdivided into groups and treated with an IP injection of buspirone, MTEP, or vehicle, 30min prior to the FST. Drug effects on general locomotor activity were also assessed. As we reported previously, alcohol-withdrawn animals exhibited significantly reduced immobility in the FST compared to water controls. Both buspirone and MTEP significantly increased immobility in alcohol-withdrawn animals, with a modest increase also seen in water controls. No significant group differences were observed for

Inhibitory effects of forced swim stress and corticosterone on the acquisition but not expression of morphine-induced conditioned place preference: involvement of glucocorticoid receptor in the basolateral amygdala.

PubMed

Attarzadeh-Yazdi, Ghassem; Karimi, Sara; Azizi, Pegah; Yazdi-Ravandi, Saeid; Hesam, Soghra; Haghparast, Abbas

2013-09-01

Addiction is a common chronic psychiatric disease which represents a global problem and stress has an important role to increase drug addiction and relapse. In the present study, we investigated the effects of physical stress and exogenous corticosterone on the acquisition and expression of morphine-induced conditioned place preference (CPP). Also, we tried to find out the role of glucocorticoid receptors (GRs) of basolateral amygdala (BLA) in this regard. In the CPP paradigm, conditioning score and locomotion activity were recorded by Ethovision software. Male adult rats received forced swim stress (FSS) as a physical stress or corticosterone (10 mg/kg; ip) as a dominant stress hormone in rodents, 10min before morphine injection (5 mg/kg; sc) during three conditioning days (acquisition) or just prior to CPP test in the post-conditioning day (expression). In FSS procedure, animals were forced to swim for 6 min in cylinder filled with water (24-27 °C). To evaluate the role of glucocorticoid receptors in the BLA, different doses of mifepristone (RU38486) as a GR antagonist were injected into the BLA (0.3, 3 and 30 ng/side) during 3-day conditioning phase before FSS or injection of corticosterone in morphine-CPP paradigm. The results showed that FSS and corticosterone reduce the acquisition but not expression of morphine-induced CPP. Moreover, blockade of GRs in the BLA could diminish the inhibitory effects of FSS or corticosterone on the acquisition of morphine-induced CPP. It seems that stress exerts its effect on reward pathway via glucocorticoid receptors in the BLA. Copyright © 2013 Elsevier B.V. All rights reserved.

Antidepressant-like activity of liposomal formulation containing nimodipine treatment in the tail suspension test, forced swim test and MAOB activity in mice.

PubMed

Moreno, Lina Clara Gayoso E Almendra Ibiapina; Rolim, Hercília Maria Lins; Freitas, Rivelilson Mendes; Santos-Magalhães, Nereide Stela

2016-09-01

Previous studies have shown that intracellular calcium ion dysfunction may be an etiological factor in affective illness. Nimodipine (NMD) is a Ca(2+) channel blocker that has been extensively investigated for therapy of central nervous system (CNS) disorders. In this work, we have evaluated the antidepressant-like activity of nimodipine encapsulated into liposomes (NMD-Lipo) in mice through tail suspension and forced swim assays, as well as MAOB activity. During the tail suspension test, the administration of NMD-Lipo at 0.1, 1 and 10mg/kg was able to promote a reduction in the immobility time of animals greater than the positive control (imipramine). In the forced swim test, the immobility time of mice treated with NMD-Lipo was reduced. This reduction was significantly greater than that found in the animals treated with imipramine and paroxetine. This may suggest that NMD-Lipo provides more antidepressant-like activity than in positive controls. The groups that received a combination of liposomal NMD and antidepressant drugs showed lower immobility time than the groups, which were treated only with imipramine or paroxetine. The mice treated with the combination of NMD-Lipo and reserpine presented an increase in the time of immobility compared with animals treated only with NMD-Lipo. There was a significant decrease in MAOB activity in animals treated with NMD-Lipo compared with untreated animals. The results of the tail suspension test, forced swim test and MAOB activity suggested that the antidepressant activity of NMD-Lipo may be related to an increase in the cerebral monoamine concentrations. Copyright © 2016 Elsevier B.V. All rights reserved.

Tualang honey improves memory performance and decreases depressive-like behavior in rats exposed to loud noise stress.

PubMed

Azman, Khairunnuur Fairuz; Zakaria, Rahimah; AbdAziz, CheBadariah; Othman, Zahiruddin; Al-Rahbi, Badriya

2015-01-01

Recent evidence has exhibited dietary influence on the manifestation of different types of behavior induced by stressor tasks. The present study examined the effects of Tualang honey supplement administered with the goal of preventing or attenuating the occurrence of stress-related behaviors in male rats subjected to noise stress. Forty-eight adult male rats were randomly divided into the following four groups: i) nonstressed with vehicle, ii) nonstressed with Tualang honey, iii) stressed with vehicle, and iv) stressed with honey. The supplement was given once daily via oral gavage at 0.2 g/kg body weight. Two types of behavioral tests were performed, namely, the novel object recognition test to evaluate working memory and the forced swimming test to evaluate depressive-like behavior. Data were analyzed by a two-way analysis of variance (ANOVA) using IBM SPSS 18.0. It was observed that the rats subjected to noise stress expressed higher levels of depressive-like behavior and lower memory functions compared to the unexposed control rats. In addition, our results indicated that the supplementation regimen successfully counteracted the effects of noise stress. The forced swimming test indicated that climbing and swimming times were significantly increased and immobility times significantly decreased in honey-supplemented rats, thereby demonstrating an antidepressant-like effect. Furthermore, cognitive function was shown to be intensely affected by noise stress, but the effects were counteracted by the honey supplement. These findings suggest that subchronic exposure to noise stress induces depressive-like behavior and reduces cognitive functions, and that these effects can be attenuated by Tualang honey supplementation. This warrants further studies to examine the role of Tulang honey in mediating such effects.

Tualang honey improves memory performance and decreases depressive-like behavior in rats exposed to loud noise stress

PubMed Central

Azman, Khairunnuur Fairuz; Zakaria, Rahimah; AbdAziz, CheBadariah; Othman, Zahiruddin; Al-Rahbi, Badriya

2015-01-01

Recent evidence has exhibited dietary influence on the manifestation of different types of behavior induced by stressor tasks. The present study examined the effects of Tualang honey supplement administered with the goal of preventing or attenuating the occurrence of stress-related behaviors in male rats subjected to noise stress. Forty-eight adult male rats were randomly divided into the following four groups: i) nonstressed with vehicle, ii) nonstressed with Tualang honey, iii) stressed with vehicle, and iv) stressed with honey. The supplement was given once daily via oral gavage at 0.2 g/kg body weight. Two types of behavioral tests were performed, namely, the novel object recognition test to evaluate working memory and the forced swimming test to evaluate depressive-like behavior. Data were analyzed by a two-way analysis of variance (ANOVA) using IBM SPSS 18.0. It was observed that the rats subjected to noise stress expressed higher levels of depressive-like behavior and lower memory functions compared to the unexposed control rats. In addition, our results indicated that the supplementation regimen successfully counteracted the effects of noise stress. The forced swimming test indicated that climbing and swimming times were significantly increased and immobility times significantly decreased in honey-supplemented rats, thereby demonstrating an antidepressant-like effect. Furthermore, cognitive function was shown to be intensely affected by noise stress, but the effects were counteracted by the honey supplement. These findings suggest that subchronic exposure to noise stress induces depressive-like behavior and reduces cognitive functions, and that these effects can be attenuated by Tualang honey supplementation. This warrants further studies to examine the role of Tulang honey in mediating such effects. PMID:25774610

Sex differences associated with intermittent swim stress.

PubMed

Warner, Timothy A; Libman, Matthew K; Wooten, Katherine L; Drugan, Robert C

2013-11-01

Various animal models of depression have been used to seek a greater understanding of stress-related disorders. However, there is still a great need for novel research in this area, as many individuals suffering from depression are resistant to current treatment methods. Women have a higher rate of depression, highlighting the need to investigate mechanisms of sex differences. Therefore, we employed a new animal model to assess symptoms of depression, known as intermittent swim stress (ISS). In this model, the animal experiences 100 trials of cold water swim stress. ISS has already been shown to cause signs of behavioral depression in males, but has yet to be assessed in females. Following ISS exposure, we looked at sex differences in the Morris water maze and forced swim test. The results indicated a spatial learning effect only in the hidden platform task between male and female controls, and stressed and control males. A consistent spatial memory effect was only seen for males exposed to ISS. In the forced swim test, both sexes exposed to ISS exhibited greater immobility, and the same males and females also showed attenuated climbing and swimming, respectively. The sex differences could be due to different neural substrates for males and females. The goal of this study was to provide the first behavioral examination of sex differences following ISS exposure, so the stage of estrous cycle was not assessed for the females. This is a necessary future direction for subsequent experiments. The current article highlights the importance of sex differences in response to stress.

Effects of Eleutherococcus senticosus Cortex on Recovery from the Forced Swimming Test and Fatty Acid β-Oxidation in the Liver and Skeletal Muscle of mice.

PubMed

Sumiyoshi, Maho; Kimura, Yoshiyuki

2016-03-01

The root and stem barks of Eleutherococcus senticosus have been used to treat emotional and physical fatigue in China, Russia, Korea, and Japan. The effects of E. senticosus on recovery from physical fatigue and the expenditure of energy currently remain unclear. We herein examined the effects of E. senticosus extract on recovery from physical fatigue after the forced swimming test as well as fatty acid β-oxidation in the liver and skeletal muscle of mice. 1) Physical fatigue; E. senticosus extract (500 and 1000 mg/kg, twice daily) was administered orally to ICR male mice for 7 consecutive days. After swimming had been performed for 15 min, each mouse was placed on the cover of a 100-mm culture plate, and the time for each mouse to move away from the cover was measured. 2) Fatty acid β-oxidation in the liver and skeletal muscle; E. senticosus extract (500 and 1000 mg/kg) was administered orally twice daily to C57BL/6J male mice for 21 consecutive days. The initial and final body and liver weight were measured, and then fatty acid β-oxidation activity in the liver and skeletal muscle was measured by methods using [1- 14 C] palmitic acid. Recovery times after forced swimming were shorter in E. senticosus extract (500 and 1000 mg/kg)-treated mice than in vehicle-treated mice. The body and liver weight had no effect by the oral administration of E. senticosus extract, vitamin mixture and L-carnitine. Fatty acid β-oxidation activity in skeletal muscle was increased by E. senticosus extract (500 and 1000 mg/kg). E. senticosus may enhance recovery from physical fatigue induced by forced swimming by accelerating energy changes through fatty acid β-oxidation in skeletal muscle.

Effects of Swim Stress on Neophobia and Reconditioning Using a Conditioned Taste Aversion Procedure

ERIC Educational Resources Information Center

Walker, Jennifer M.; Ramsey, Ashley K.; Fowler, Stephanie W.; Schachtman, Todd R.

2012-01-01

Previous research has found that swim stress during a classical conditioning trial attenuates conditioned taste aversion (CTA). In the current study, rats were used to examine the effects of inescapable swim stress on the habituation of neophobia to a flavored solution and reacquisition of an extinguished conditioned taste aversion. In Experiment…

Flow-induced attraction of swimming microorganisms by surfaces

NASA Astrophysics Data System (ADS)

Lauga, Eric; Berke, Allison; Turner, Linda; Berg, Howard

2008-03-01

In this talk, we present an experimental and theoretical investigation of the accumulation of swimming cells by nearby surfaces. First, we present results of an experiment aiming at measuring the distribution of smooth-swimming E. coli when moving in a density-matched fluid and between two glass plates; the distribution for the bacteria concentration is found to peak near the glass plates. We then present a physical model for the observed attraction, based on the hydrodynamics interactions between the swimming cells and the walls. We show that such interactions result in a reorientation of the cells in the direction parallel to the surfaces, and an attraction of these (parallel) cells by the nearest wall. Our results are exploited to obtain an estimate of the propulsive force of smooth-swimming E. coli.

Numerical study on the hydrodynamics of thunniform bio-inspired swimming under self-propulsion.

PubMed

Li, Ningyu; Liu, Huanxing; Su, Yumin

2017-01-01

Numerical simulations are employed to study the hydrodynamics of self-propelled thunniform swimming. The swimmer is modeled as a tuna-like flexible body undulating with kinematics of thunniform type. The wake evolution follows the vortex structures arranged nearly vertical to the forward direction, vortex dipole formation resulting in the propulsion motion, and finally a reverse Kármán vortex street. We also carry out a systematic parametric study of various aspects of the fluid dynamics behind the freely swimming behavior, including the swimming speed, hydrodynamic forces, power requirement and wake vortices. The present results show that the fin thrust as well as swimming velocity is an increasing function of both tail undulating amplitude Ap and oscillating amplitude of the caudal fin θm. Whereas change on the propulsive performance with Ap is associated with the strength of wake vortices and the area of suction region on the fin, the swimming performance improves with θm due to the favorable tilting of the fin that make the pressure difference force more oriented toward the thrust direction. Moreover, the energy loss in the transverse direction and the power requirement increase with Ap but decrease with θm, and this indicates that for achieving a desired swimming speed increasing θm seems more efficiently than increasing Ap. Furthermore, we have compared the current simulations with the published experimental studies on undulatory swimming. Comparisons show that our work tackles the flow regime of natural thunniform swimmers and follows the principal scaling law of undulatory locomotion reported. Finally, this study enables a detailed quantitative analysis, which is difficult to obtain by experiments, of the force production of the thunniform mode as well as its connection to the self-propelled swimming kinematics and vortex wake structure. The current findings help provide insights into the swimming performance and mechanisms of self

Numerical study on the hydrodynamics of thunniform bio-inspired swimming under self-propulsion

PubMed Central

Li, Ningyu; Liu, Huanxing

2017-01-01

Numerical simulations are employed to study the hydrodynamics of self-propelled thunniform swimming. The swimmer is modeled as a tuna-like flexible body undulating with kinematics of thunniform type. The wake evolution follows the vortex structures arranged nearly vertical to the forward direction, vortex dipole formation resulting in the propulsion motion, and finally a reverse Kármán vortex street. We also carry out a systematic parametric study of various aspects of the fluid dynamics behind the freely swimming behavior, including the swimming speed, hydrodynamic forces, power requirement and wake vortices. The present results show that the fin thrust as well as swimming velocity is an increasing function of both tail undulating amplitude Ap and oscillating amplitude of the caudal fin θm. Whereas change on the propulsive performance with Ap is associated with the strength of wake vortices and the area of suction region on the fin, the swimming performance improves with θm due to the favorable tilting of the fin that make the pressure difference force more oriented toward the thrust direction. Moreover, the energy loss in the transverse direction and the power requirement increase with Ap but decrease with θm, and this indicates that for achieving a desired swimming speed increasing θm seems more efficiently than increasing Ap. Furthermore, we have compared the current simulations with the published experimental studies on undulatory swimming. Comparisons show that our work tackles the flow regime of natural thunniform swimmers and follows the principal scaling law of undulatory locomotion reported. Finally, this study enables a detailed quantitative analysis, which is difficult to obtain by experiments, of the force production of the thunniform mode as well as its connection to the self-propelled swimming kinematics and vortex wake structure. The current findings help provide insights into the swimming performance and mechanisms of self

The Complex Hydrodynamics of Swimming in the Spanish Dancer

NASA Astrophysics Data System (ADS)

Zhou, Zhuoyu; Mittal, Rajat

2016-11-01

The lack of a vertebra seems to have freed marine gastropods to explore and exploit a stupendous variety of swimming kinematics. In fact, examination of just a few animals in this group reveal locomotory modes ranging from insect-like flapping, to fish-like undulatory swimming, jet propulsion, and rajiform (manta-like) swimming. There are also a number of marine gastropods that have bizarre swimming gaits with no equivalent among fish or marine mammals. In this latter category is the Spanish Dancer (Hexabranchus sanguineus) a sea slug that swims with a complex combination of body undulations and flapping parapodia. While the neurobiology of these animals has been relatively well-studied, less is known about their propulsive mechanism and swimming energetics. In this study, we focus on the hydrodynamics of two distinct swimmers: the Spanish Dancer, and the sea hare Aplysia; the latter adopts a rajiform-like mode of swimming by passing travelling waves along its parapodia. In the present study an immersed boundary method is employed to examine the vortex structures, hydrodynamic forces and energy costs of the swimming in these animals. NSF Grant No. 1246317.

Hydrodynamics of freely swimming flagellates

NASA Astrophysics Data System (ADS)

Dolger, Julia; Nielsen, Lasse Tor; Kiorboe, Thomas; Bohr, Tomas; Andersen, Anders

2016-11-01

Flagellates are a diverse group of unicellular organisms forming an important part of the marine ecosystem. The arrangement of flagella around the cell serves as a key trait optimizing and compromising essential functions. With micro-particle image velocimetry we observed time-resolved near-cell flows around freely swimming flagellates, and we developed an analytical model based on the Stokes flow around a solid sphere propelled by a variable number of differently placed, temporally varying point forces, each representing one flagellum. The model allows us to reproduce the observed flow patterns and swimming dynamics, and to extract quantities such as swimming velocities and prey clearance rates as well as flow disturbances revealing the organism to flow-sensing predators. Our results point to optimal flagellar arrangements and beat patterns, and essential trade-offs. For biflagellates with two symmetrically arranged flagella we contrasted two species using undulatory and ciliary beat patterns, respectively, and found breast-stroke type beat patterns with equatorial power strokes to be favorable for fast as well as quiet swimming. The Centre for Ocean Life is a VKR Centre of Excellence supported by the Villum Foundation.

Forces and energetics of intermittent swimming

NASA Astrophysics Data System (ADS)

Floryan, Daniel; Van Buren, Tyler; Smits, Alexander J.

2017-08-01

Experiments are reported on intermittent swimming motions. Water tunnel experiments on a nominally two-dimensional pitching foil show that the mean thrust and power scale linearly with the duty cycle, from a value of 0.2 all the way up to continuous motions, indicating that individual bursts of activity in intermittent motions are independent of each other. This conclusion is corroborated by particle image velocimetry (PIV) flow visualizations, which show that the main vortical structures in the wake do not change with duty cycle. The experimental data also demonstrate that intermittent motions are generally energetically advantageous over continuous motions. When metabolic energy losses are taken into account, this conclusion is maintained for metabolic power fractions less than 1.

Swimming efficiency of bacterium Escherichia coli

PubMed Central

Chattopadhyay, Suddhashil; Moldovan, Radu; Yeung, Chuck; Wu, X. L.

2006-01-01

We use measurements of swimming bacteria in an optical trap to determine fundamental properties of bacterial propulsion. In particular, we directly measure the force required to hold the bacterium in the optical trap and determine the propulsion matrix, which relates the translational and angular velocity of the flagellum to the torques and forces propelling the bacterium. From the propulsion matrix, dynamical properties such as torques, swimming speed, and power can be obtained by measuring the angular velocity of the motor. We find significant heterogeneities among different individuals even though all bacteria started from a single colony. The propulsive efficiency, defined as the ratio of the propulsive power output to the rotary power input provided by the motors, is found to be ≈2%, which is consistent with the efficiency predicted theoretically for a rigid helical coil. PMID:16954194

The Neurotensin NTS1 Receptor Agonist PD149163 Produces Antidepressant-Like Effects in the Forced Swim Test: Further Support for Neurotensin as a Novel Pharmacologic Strategy for Antidepressant Drugs.

PubMed

Carey, Lawrence M; Rice, Remington J; Prus, Adam J

2017-08-01

Preclinical Research Neurotensin is a nonbrain penetrant neuropeptide neurotransmitter that alters dopaminergic and serotonergic neurotransmission. Previous animal behavioral studies have demonstrated that intra-ventral tegmental administration of neurotensin and system administration of the selective neurotensin NTS 1 receptor agonist, PD149163 produce antidepressant-like effects in a forced swim test and a differential reinforcement of low rate task, respectively. The present study sought to expand upon these past findings by assessing systemic administration of PD149163 in a forced swim test, a primary antidepressant preclinical screening model, in mice. The tricyclic antidepressant drug imipramine was tested for comparison, and both compounds were also assessed in an open field test. Both PD149163 and imipramine reduced time spent immobile, an antidepressant-like effect, in the forced swim test. The highest dose of each compound significantly reduced locomotor activity. These findings provide further evidence for the putative antidepressant effects for PD149163 and suggest that NTS 1 receptor activation may be a novel pharmacologic strategy for antidepressant drug development. Drug Dev Res 78 : 196-202, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Interaction of prenatal stress and morphine alters prolactin and seizure in rat pups.

PubMed

Saboory, Ehsan; Ebrahimi, Loghman; Roshan-Milani, Shiva; Hashemi, Paria

2015-10-01

Prenatal exposure to stress and morphine has complicated effects on epileptic seizure. In the present study, effect of prenatal forced-swim stress and morphine co-administration on pentylenetetrazol (PTZ) induced epileptic behaviors and prolactin blood level (PBL) was investigated in rat offspring. Pregnant Wistar rats were divided to four groups of control-saline, control-morphine, stressed-saline and stressed-morphine. In the stressed group, pregnant rats were placed in 25°C water on gestation days 17, 18 and 19 (GD17, GD18 and GD19) for 30 min. In the morphine/saline group, pregnant rats received morphine (10, 12 and 15 mg/kg, IP, on GD17, GD18 and GD19, respectively) or saline (1 ml, IP). In the morphine/saline-stressed group, the rats received morphine or saline and then exposed to stress. On postnatal days 6 and 15 (P6 and P15), blood samples were obtained and PBL was determined. At P15 and P25, the rest of the pups was injected with PTZ to induce seizure. Then, epileptic behaviors of each rat were observed individually. Latency of first convulsion decreased in control-morphine and stressed-saline groups while increased in stressed-morphine rats compared to control-saline group on P15 (P=0.04). Number of tonic-clonic seizures significantly increased in control-morphine and stressed-saline rats compared to control-saline group at P15 (P=0.02). PBL increased in stressed-saline, control-morphine and stress-morphine groups compared to control-saline rats. It can be concluded that prenatal exposure of rats to forced-swim stress and morphine changed their susceptibility to PTZ-induced seizure and PBL during infancy and prepubertal period. Co-administration of morphine attenuated effect of stress on epileptic behaviors. Copyright © 2015 Elsevier Inc. All rights reserved.

Simultaneous measurement of bacterial flagellar rotation rate and swimming speed.

PubMed Central

Magariyama, Y; Sugiyama, S; Muramoto, K; Kawagishi, I; Imae, Y; Kudo, S

1995-01-01

Swimming speeds and flagellar rotation rates of individual free-swimming Vibrio alginolyticus cells were measured simultaneously by laser dark-field microscopy at 25, 30, and 35 degrees C. A roughly linear relation between swimming speed and flagellar rotation rate was observed. The ratio of swimming speed to flagellar rotation rate was 0.113 microns, which indicated that a cell progressed by 7% of pitch of flagellar helix during one flagellar rotation. At each temperature, however, swimming speed had a tendency to saturate at high flagellar rotation rate. That is, the cell with a faster-rotating flagellum did not always swim faster. To analyze the bacterial motion, we proposed a model in which the torque characteristics of the flagellar motor were considered. The model could be analytically solved, and it qualitatively explained the experimental results. The discrepancy between the experimental and the calculated ratios of swimming speed to flagellar rotation rate was about 20%. The apparent saturation in swimming speed was considered to be caused by shorter flagella that rotated faster but produced less propelling force. Images FIGURE 1 FIGURE 4 PMID:8580359

Sex and age differences in the antidepressant-like effect of fluoxetine in the forced swim test.

PubMed

Fernández-Guasti, Alonso; Olivares-Nazario, Maribel; Reyes, Rebeca; Martínez-Mota, Lucía

2017-01-01

This study compared in males and females of three representative ages: young adults (3-5months old), middle-aged (12-15months old) and senescent (23-25months old) the antidepressant-like effect of fluoxetine (FLX, 5.0 and 10mg/kg) in the forced swim test (FST). Intact (non gonadectomized) rats were evaluated. Young adult females were chosen in proestrus/estrus or in metestrus/diestrus, while middle-aged and senescent females were selected in metestrus/diestrus. Locomotion and motor coordination were also recorded. Under basal conditions (without FLX), young adult and middle-aged females showed less immobility than males. This sex difference disappeared at senescence because males diminished their levels of immobility. Thus, senescent males showed lower immobility than middle-aged and young males. FLX (5 and 10mg/kg) produced similar actions in young females irrespective of their estrous cycle phase, therefore, these subgroups were pooled in a single one. Young adult and middle aged females clearly responded to 5 and 10mg/kg of FLX with a reduction in immobility, while young adult and middle-aged males only did to 10mg/kg. In senescent females 10mg/kg FLX reduced immobility. Remarkably, in senescent males this FLX dose did not produce an antidepressant-like effect. FLX marginally affected locomotion; however, at its highest dose (10mg/kg), and only in senescent males, interfered with motor coordination tested in the rotarod. These data show that sex and aging influence behavioral despair without treatment and after FLX. Copyright © 2016 Elsevier Inc. All rights reserved.

Synergistic effect of estradiol and fluoxetine in young adult and middle-aged female rats in two models of experimental depression.

PubMed

Récamier-Carballo, Soledad; Estrada-Camarena, Erika; Reyes, Rebeca; Fernández-Guasti, Alonso

2012-08-01

The antidepressant effect of estrogens combined with antidepressants is controversial: some preclinical data showed that estrogens facilitate the effect of antidepressants in the forced swimming test (FST) in young adult rats, while others failed to find such effect in middle-aged rats in the chronic mild stress (CMS) model. In clinics similar differences were reported and may be due to the compounds, the depression model or type of depression, the experimental design, and the age of the subjects or the women's menopause stage. The objective of this study was to analyze the antidepressant-like effect of the combination of 17β-estradiol (E(2)) and fluoxetine (FLX) in young adults (2-4 months) and middle-aged (12-14 months) ovariectomized (OVX) rats in two experimental models: FST and CMS. E(2) (5 and 10 μg/rat) and FLX (2.5 and 10 mg/kg) per se dose-dependently reduced immobility in both age groups and, in young adults both compounds increased swimming, whereas in middle-aged rats they increased swimming and climbing. Analysis of the antidepressant-like effect of the combination of suboptimal doses of FLX (1.25 mg/kg) and E(2) (2.5 μg/rat) showed a decrease in immobility and an increase in swimming in both age groups. In the CMS, chronic E(2) (2.5 μg/rat) with FLX (1.25 mg/kg) augmented relative sucrose intake, but middle-aged rats responded 2 weeks earlier than young adults. These results show that the antidepressant-like effect of the combination of E(2) and FLX in young adult and middle-aged female rats is evidenced in the two animal models of depression: FST and CMS. Copyright © 2012 Elsevier B.V. All rights reserved.

Hypobaric Hypoxia Induces Depression-like Behavior in Female Sprague-Dawley Rats, but not in Males

PubMed Central

Bogdanova, Olena V.; Olson, Paul R.; Sung, Young-Hoon; D'Anci, Kristen E.; Renshaw, Perry F.

2015-01-01

Abstract Kanekar, Shami, Olena V. Bogdanova, Paul R. Olson, Young-Hoon Sung, Kristen E. D'Anci, and Perry F. Renshaw. Hypobaric hypoxia induces depression-like behavior in female Sprague-Dawley rats, but not males. High Alt Med Biol 16:52–60, 2015—Rates of depression and suicide are higher in people living at altitude, and in those with chronic hypoxic disorders like asthma, chronic obstructive pulmonary disorder (COPD), and smoking. Living at altitude exposes people to hypobaric hypoxia, which can lower rat brain serotonin levels, and impair brain bioenergetics in both humans and rats. We therefore examined the effect of hypobaric hypoxia on depression-like behavior in rats. After a week of housing at simulated altitudes of 20,000 ft, 10,000 ft, or sea level, or at local conditions of 4500 ft (Salt Lake City, UT), Sprague Dawley rats were tested for depression-like behavior in the forced swim test (FST). Time spent swimming, climbing, or immobile, and latency to immobility were measured. Female rats housed at altitude display more depression-like behavior in the FST, with significantly more immobility, less swimming, and lower latency to immobility than those at sea level. In contrast, males in all four altitude groups were similar in their FST behavior. Locomotor behavior in the open field test did not change with altitude, thus validating immobility in the FST as depression-like behavior. Hypobaric hypoxia exposure therefore induces depression-like behavior in female rats, but not in males. PMID:25803141

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.

Relative Contribution of Arms and Legs in 30 s Fully Tethered Front Crawl Swimming

PubMed Central

Morouço, Pedro G.; Marinho, Daniel A.; Izquierdo, Mikel; Neiva, Henrique; Marques, Mário C.

2015-01-01

The relative contribution of arm stroke and leg kicking to maximal fully tethered front crawl swimming performance remains to be solved. Twenty-three national level young swimmers (12 male and 11 female) randomly performed 3 bouts of 30 s fully tethered swimming (using the whole body, only the arm stroke, and only the leg kicking). A load-cell system permitted the continuous measurement of the exerted forces, and swimming velocity was calculated from the time taken to complete a 50 m front crawl swim. As expected, with no restrictions swimmers were able to exert higher forces than that using only their arm stroke or leg kicking. Estimated relative contributions of arm stroke and leg kicking were 70.3% versus 29.7% for males and 66.6% versus 33.4% for females, with 15.6% and 13.1% force deficits, respectively. To obtain higher velocities, male swimmers are highly dependent on the maximum forces they can exert with the arm stroke (r = 0.77, P < 0.01), whereas female swimmers swimming velocity is more related to whole-body mean forces (r = 0.81, P < 0.01). The obtained results point that leg kicking plays an important role over short duration high intensity bouts and that the used methodology may be useful to identify strength and/or coordination flaws. PMID:26539511

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.

Unsteady propulsion by an intermittent swimming gait

NASA Astrophysics Data System (ADS)

Akoz, Emre; Moored, Keith W.

2018-01-01

Inviscid computational results are presented on a self-propelled swimmer modeled as a virtual body combined with a two-dimensional hydrofoil pitching intermittently about its leading edge. Lighthill (1971) originally proposed that this burst-and-coast behavior can save fish energy during swimming by taking advantage of the viscous Bone-Lighthill boundary layer thinning mechanism. Here, an additional inviscid Garrick mechanism is discovered that allows swimmers to control the ratio of their added mass thrust-producing forces to their circulatory drag-inducing forces by decreasing their duty cycle, DC, of locomotion. This mechanism can save intermittent swimmers as much as 60% of the energy it takes to swim continuously at the same speed. The inviscid energy savings are shown to increase with increasing amplitude of motion, increase with decreasing Lighthill number, Li, and switch to an energetic cost above continuous swimming for sufficiently low DC. Intermittent swimmers are observed to shed four vortices per cycle that form into groups that are self-similar with the DC. In addition, previous thrust and power scaling laws of continuous self-propelled swimming are further generalized to include intermittent swimming. The key is that by averaging the thrust and power coefficients over only the bursting period then the intermittent problem can be transformed into a continuous one. Furthermore, the intermittent thrust and power scaling relations are extended to predict the mean speed and cost of transport of swimmers. By tuning a few coefficients with a handful of simulations these self-propelled relations can become predictive. In the current study, the mean speed and cost of transport are predicted to within 3% and 18% of their full-scale values by using these relations.

Analysis of the swimming activity of Pseudomonas aeruginosa by using photonic force microscope

NASA Astrophysics Data System (ADS)

Chan, Chia-Han; Chang, Bo-Jui; Huang, Ying-Jung; Fan, Chia-Chieh; Peng, Hwei-Ling; Chi, Sien; Hsu, Long

2005-08-01

Swimming activity of flagella is a main factor of the motility of bacteria. Flagella expressed on the surface of bacterial species serve as a primary means of motility including swimming. We propose to use optical tweezers to analyze the swimming activity of bacteria. The sample bacteria in the work is Pseudomonas aeruginosa, and it is a gram-negative bacterium and often causes leading to burn wound infections, urinary-tract infections, and pneumonia. The single polar flagellum of P. aeruginosa has been demonstrated to be important virulence and colonization factor of this opportunistic pathogen. We demonstrate a gene to regulate the bacterial swimming activity in P. aeruginosa PAO1 by biological method. However, the change of flagellar morphology was not observed by electron microscopy analysis, suggesting that the gene regulates the flagellar rotation that could not be detected by biological method. PFM exhibits a spatial resolution of a few nanometers to detect the relative position of the probe at an acquisition rate over 1 MHz. By binding a probe such as a bead or a quantum dot on the flagella, we expect the rotation of the probe due to the flagella could be detected. It is expected that the study of the swimming activity of P. aeruginosa provide potent method for the pathogenic role of the flagella in P. aeruginosa.

Possible involvement of neuropeptide Y Y1 receptors in antidepressant like effect of agmatine in rats.

PubMed

Kotagale, Nandkishor R; Paliwal, Nikhilesh P; Aglawe, Manish M; Umekar, Milind J; Taksande, Brijesh G

2013-09-01

Agmatine and neuropeptide Y (NPY) are widely distributed in central nervous system and critically involved in modulation of depressive behavior in experimental animals. However their mutual interaction, if any, in regulation of depression remain largely unexplored. In the present study we explored the possible interaction between agmatine and neuropeptide Y in regulation of depression like behavior in forced swim test. We found that acute intracerebroventricular (i.c.v.) administration of agmatine (20-40μg/rat), NPY (5 and 10μg/rat) and NPY Y1 receptor agonist, [Leu(31), Pro(34)]-NPY (0.4 and 0.8ng/rat) dose dependently decreased immobility time in forced swim test indicating their antidepressant like effects. In combination studies, the antidepressant like effect of agmatine (10μg/rat) was significantly potentiated by NPY (1 and 5μg/rat, icv) or [Leu(31), Pro(34)]-NPY (0.2 and 0.4ng/rat, icv) pretreatment. Conversely, pretreatment of animals with NPY Y1 receptor antagonist, BIBP3226 (0.1ng/rat, i.c.v.) completely blocked the antidepressant like effect of agmatine (20-40μg/rat) and its synergistic effect with NPY (1μg/rat, icv) or [Leu(31), Pro(34)]-NPY (0.2ng/rat, icv). The results of the present study showed that, agmatine exerts antidepressant like effects via NPYergic system possibly mediated by the NPY Y1 receptor subtypes and suggest that interaction between agmatine and neuropeptide Y may be relevant to generate the therapeutic strategies for the treatment of depression. Copyright © 2013 Elsevier Inc. All rights reserved.

A comparative pharmacological investigation of three samples of 'Guduchi ghrita' for adaptogenic activity against forced swimming induced gastric ulceration and hematological changes in albino rats

PubMed Central

Savrikar, Shriram S.; Dole, Vilas; Ravishankar, B.; Shukla, Vinay J.

2010-01-01

This study was undertaken to investigate the impact of formulation factors and adjuvants on the expression of biological activity of Tinospora cordifolia (Willd.) Miers. The adaptogenic effect of three samples of Guduchi ghrita, prepared using plain ghee (clarified butter) obtained from three different sources was studied in albino rats and compared with expressed juice of stem of Guduchi. The test preparations were evaluated against forced–swimming induced hypothermia, gastric ulceration and changes in the hematological parameters. The test drug given in the form of 'ghrita' produced better effect in comparison to the expressed juice. Among the three 'ghrita' preparations evaluated, only the 'Solapur Guduchi ghrita' (SGG) was found to produce significant inhibition of stress hypothermia and gastric ulceration. The other two preparations 'Nanded Guduchi ghrita' (NGG), and 'Wardha Guduchi ghrita' (WGG) could produce only a marginal effect. In hematological parameters 'Guduchi' juice produced better reversal of the stress-induced changes in comparison to the test 'ghrita' preparations. The present study provides evidence highlighting the importance of formulation factors for the expression of biological activity. PMID:20814518

Anxiogenic effects of brief swim stress are sensitive to stress history.

PubMed

Christianson, John P; Drugan, Robert C; Flyer, Johanna G; Watkins, Linda R; Maier, Steven F

2013-07-01

Stressors that are controllable not only protect an individual from the acute consequences of the stressor, but also the consequences of stressors that occur later. This phenomenon, termed "behavioral immunization", is studied in the rat by first administering tailshocks each of which can be terminated (escapable tailshock) by an instrumental wheel-turn response prior to exposure to a second stressor. Previous research has shown that exposure to escapable tailshock blocks the neurochemical and behavioral consequences of later inescapable tailshock or social defeat stress. Here we explored the generality of behavioral immunization by examining the impact of prior escapable tailshock on the behavioral consequences of cold swim stress. Exposure to a 5min cold-water (19°C) swim caused an anxiety-like reduction in social interaction that was dependent upon 5-HT2C receptor activation. Rats with prior exposure to escapable tailshock did not develop the swim-induced anxiety. Plasticity in the medial prefrontal cortex, a hypothetical neural mechanism underlying behavioral immunization, is discussed. Copyright © 2013 Elsevier Inc. All rights reserved.

Influence of short-term inertial training on swimming performance in young swimmers.

PubMed

Naczk, Mariusz; Lopacinski, Artur; Brzenczek-Owczarzak, Wioletta; Arlet, Jarosław; Naczk, Alicja; Adach, Zdzisław

2017-05-01

The aim of this study was to evaluate the influence of dry-land inertial training (IT) on muscle force, muscle power, and swimming performance. Fourteen young, national-level, competitive swimmers were randomly divided into IT and control (C) groups. The experiment lasted four weeks, during which time both groups underwent their regular swimming training. In addition, the IT group underwent IT using the Inertial Training Measurement System (ITMS) three times per week. The muscle groups involved during the upsweep phase of the arm stroke in front crawl and butterfly stroke were trained. Before and after training, muscle force and power were measured under IT conditions. Simultaneously with the biomechanical measurements on the ITMS, the electrical activity of the triceps brachii was registered. After four weeks of training, a 12.8% increase in the muscle force and 14.2% increase in the muscle power (p < .05) were noted in the IT group. Moreover, electromyography amplitude of triceps brachii recorded during strength measurements increased by 22.7% in the IT group. Moreover, swimming velocity in the 100 m butterfly and 50 m freestyle improved significantly following the four weeks of dry-land IT (-1.86% and -0.76%, respectively). Changes in the C group were trivial. Moreover, values of force and power registered during the ITMS test correlated negatively with the 100 m butterfly and 50 m freestyle swimming times (r value ranged from -.80 to -.91). These results suggest that IT can be useful in swimming practice.

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.

Swimming performance in juvenile shortnose sturgeon (Acipenser brevirostrum): the influence of time interval and velocity increments on critical swimming tests

PubMed Central

Kieffer, James D.

2017-01-01

Abstract The most utilized method to measure swimming performance of fishes has been the critical swimming speed (UCrit) test. In this test, the fish is forced to swim against an incrementally increasing flow of water until fatigue. Before the water velocity is increased, the fish swims at the water velocity for a specific, pre-arranged time interval. The magnitude of the velocity increments and the time interval for each swimming period can vary across studies making the comparison between and within species difficult. This issue has been acknowledged in the literature, however, little empirical evidence exists that tests the importance of velocity and time increments on swimming performance in fish. A practical application for fish performance is through the design of fishways that enable fish to bypass anthropogenic structures (e.g. dams) that block migration routes, which is one of the causes of world-wide decline in sturgeon populations. While fishways will improve sturgeon conservation, they need to be specifically designed to accommodate the swimming capabilities specific for sturgeons, and it is possible that current swimming methodologies have under-estimated the swimming performance of sturgeons. The present study assessed the UCrit of shortnose sturgeon using modified UCrit to determine the importance of velocity increment (5 and 10 cm s−1) and time (5, 15 and 30 min) intervals on swimming performance. UCrit was found to be influenced by both time interval and water velocity. UCrit was generally lower in sturgeon when they were swum using 5cm s−1 compared with 10 cm s−1 increments. Velocity increment influences the UCrit more than time interval. Overall, researchers must consider the impacts of using particular swimming criteria when designing their experiments. PMID:28835841

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)

Attenuation of pCREB and Egr1 expression in the insular and anterior cingulate cortices associated with enhancement of CFA-evoked mechanical hypersensitivity after repeated forced swim stress.

PubMed

Imbe, Hiroki; Kimura, Akihisa

2017-09-01

The perception and response to pain are severely impacted by exposure to stressors. In some animal models, stress increases pain sensitivity, which is termed stress-induced hyperalgesia (SIH). The insular cortex (IC) and anterior cingulate cortex (ACC), which are typically activated by noxious stimuli, affect pain perception through the descending pain modulatory system. In the present study, we examined the expression of phospho-cAMP response element-binding protein (pCREB) and early growth response 1 (Egr1) in the IC and ACC at 3h (the acute phase of peripheral tissue inflammation) after complete Freund's adjuvant (CFA) injection in naïve rats and rats preconditioned with forced swim stress (FS) to clarify the effect of FS, a stressor, on cortical cell activities in the rats showing SIH induced by FS. The CFA injection into the hindpaw induced mechanical hypersensitivity and increased the expression of the pCREB and Egr1 in the IC and ACC at 3h after the injection. FS (day 1, 10min; days 2-3, 20min) prior to the CFA injection enhanced the CFA-induced mechanical hypersensitivity and attenuated the increase in the expression of pCREB and Egr1 in the IC and ACC. These findings suggested that FS modulates the CFA injection-induced neuroplasticity in the IC and ACC to enhance the mechanical hypersensitivity. These findings are thought to signify stressor-induced dysfunction of the descending pain modulatory system. Copyright © 2017 Elsevier Inc. All rights reserved.

Young-Adult Male Rats' Vulnerability to Chronic Mild Stress Is Reflected by Anxious-Like instead of Depressive-Like Behaviors.

PubMed

José Jaime, Herrera-Pérez; Venus, Benítez-Coronel; Graciela, Jiménez-Rubio; Tania, Hernández-Hernández Olivia; Lucía, Martínez-Mota

2016-01-01

In a previous study, we found that chronic mild stress (CMS) paradigm did not induce anhedonia in young-adult male rats but it reduced their body weight gain. These contrasting results encouraged us to explore other indicators of animal's vulnerability to stress such as anxious-like behaviors, since stress is an etiologic factor also for anxiety. Thus, in this study, we evaluated the vulnerability of these animals to CMS using behavioral tests of depression or anxiety and measuring serum corticosterone. Male Wistar rats were exposed to four weeks of CMS; the animals' body weight and sucrose preference (indicator of anhedonia) were assessed after three weeks, and, after the fourth week, some animals were evaluated in a behavioral battery (elevated plus maze, defensive burying behavior, and forced swimming tests); meanwhile, others were used to measure serum corticosterone. We found that CMS (1) did not affect sucrose preference, immobility behavior in the forced swimming test, or serum corticosterone; (2) decreased body weight gain; and (3) increased the rat's entries into closed arms of the plus maze and the cumulative burying behavior. These data indicate that young male rats' vulnerability to CMS is reflected as poor body weight gain and anxious-like instead of depressive-like behaviors.

Young-Adult Male Rats' Vulnerability to Chronic Mild Stress Is Reflected by Anxious-Like instead of Depressive-Like Behaviors

PubMed Central

José Jaime, Herrera-Pérez; Venus, Benítez-Coronel; Graciela, Jiménez-Rubio; Tania, Hernández-Hernández Olivia

2016-01-01

In a previous study, we found that chronic mild stress (CMS) paradigm did not induce anhedonia in young-adult male rats but it reduced their body weight gain. These contrasting results encouraged us to explore other indicators of animal's vulnerability to stress such as anxious-like behaviors, since stress is an etiologic factor also for anxiety. Thus, in this study, we evaluated the vulnerability of these animals to CMS using behavioral tests of depression or anxiety and measuring serum corticosterone. Male Wistar rats were exposed to four weeks of CMS; the animals' body weight and sucrose preference (indicator of anhedonia) were assessed after three weeks, and, after the fourth week, some animals were evaluated in a behavioral battery (elevated plus maze, defensive burying behavior, and forced swimming tests); meanwhile, others were used to measure serum corticosterone. We found that CMS (1) did not affect sucrose preference, immobility behavior in the forced swimming test, or serum corticosterone; (2) decreased body weight gain; and (3) increased the rat's entries into closed arms of the plus maze and the cumulative burying behavior. These data indicate that young male rats' vulnerability to CMS is reflected as poor body weight gain and anxious-like instead of depressive-like behaviors. PMID:27433469

Swimming

MedlinePlus

... or eat while you swim — you could choke. Lakes and Ponds Lots of kids swim in streams, lakes, or ponds. Take extra care when swimming in ... can't always see the bottom of the lake or pond, so you don't always know ...

Scaling the Thrust Production and Energetics of Inviscid Intermittent Swimming

NASA Astrophysics Data System (ADS)

Akoz, Emre; Moored, Keith

2015-11-01

Many fish have adopted an intermittent swimming gait sometimes referred as a burst-and-coast behavior. By using this gait, fish have been estimated at reducing their energetic cost of swimming by about 50%. Lighthill proposed that the skin friction drag of an undulating body can be around 400% greater than a rigidly-held coasting body, which may explain the energetic savings of intermittent swimming. Recent studies have confirmed the increase in skin friction drag over an undulating body, however, the increase is on the order of 20-70%. This more modest gain in skin friction drag is not sufficient to lead to the observed energy savings. Motivated by these observations, we investigate the inviscid mechanisms behind intermittent swimming for parameters typical of biology. We see that there is an energy savings at a fixed swimming speed for intermittent swimming as compared to continuous swimming. Then we consider three questions: What is the nature of the inviscid mechanism that leads to the observed energy savings, how do the forces and energetics of intermittent swimming scale with the swimming parameters, and what are the limitations to the benefit? Supported by the Office of Naval Research under Program Director Dr. Bob Brizzola, MURI grant number N00014-14-1-0533.

Supplemental dietary choline during development exerts antidepressant-like effects in adult female rats.

PubMed

Glenn, Melissa J; Adams, Raven S; McClurg, Lauren

2012-03-14

Perinatal choline supplementation in rats is neuroprotective against insults such as fetal alcohol exposure, seizures, and advanced age. In the present study we explored whether dietary choline supplementation may also confer protection from psychological challenges, like stress, and act as a natural buffer against stress-linked psychological disorders, like depression. We previously found that choline supplementation increased adult hippocampal neurogenesis, a function compromised by stress, lowered in depression, and boosted by antidepressants; and increased levels of growth factors linked to depression, like brain-derived neurotrophic factor. Together, these were compelling reasons to study the role of choline in depressed mood. To do this, we treated rats with a choline supplemented diet (5 mg/kg choline chloride in AIN76A) prenatally on embryonic days 10-22, on postnatal days (PD) 25-50, or as adults from PD75 onward. Outside of these treatment periods rats were fed a standard diet (1.1 mg/kg choline chloride in AIN76A); control rats consumed only this diet throughout the study. Starting on PD100 rats' anxiety-like responses to an open field, learning in a water maze, and reactivity to forced swimming were assessed. Rats given choline supplementation during pre- or post-natal development, but not adult-treated rats, were less anxious in the open field and less immobile in the forced swim test than control rats. These effects were not mediated by a learning deficit as all groups performed comparably and well in the water maze. Thus, we offer compelling support for the hypothesis that supplemental dietary choline, at least when given during development, may inoculate an individual against stress and major psychological disorders, like depression. Copyright © 2012 Elsevier B.V. All rights reserved.

CHARACTER OF THE CHANGES IN FEAR MOTIVATED DECLARATIVE MEMORY IN THE HIGH IMMOBILIZATION "DEPRESSIVE" RATS.

PubMed

Nachkebia, N; Shavgulidze, M; Babilodze, M; Chkhartishvili, E; Rogava, N

2016-10-01

Present study investigated possible differences in the learning and memory of declarative memory task in rats selected according to the differences in immobilization response that is in high immobilization "depressive" and low immobilization "non-depressive" rats. Understanding the character of learning and memory disturbances in basal conditions of animal models of depression is still very topical for more intimate definition of the pathophysiology of major depressive disorder and appropriate searching the ways of its correction. Experiments were carried out on the adult white wild rats (with the weight 200-250 g, n=20). Selection of rats according to the level of immobilization was made by means of forced swim test. Learning and memory disturbances were studied using passive avoidance test that is fear motivated one trial declarative memory task. It was shown by us that 100% of low immobilization "non-depressive" rats remember painful stimulation and therefore they are not enter in the dark compartment during whole period of observation during testing session. Behavior of high immobilization "depressive" rats is not similar in passive avoidance camera; 50% of "depressive" rats, with long escape latency during training session (92±10 sec), remember painful stimulation during testing session and therefore they are not enter in the dark compartment during whole observation period. The remaining 50%, that are not differ significantly from the low immobility "non-depressive" rats by the latency of escape (5±1 sec) during training session, are not able to remember painful stimulation during testing session and therefore they enter in the dark compartment with shortest escape latency (6±1 sec). In conclusion, high immobility "depressive" rats perform passive avoidance declarative memory task at the chance level that is a direct indicator for the serious disturbances of declarative memory mechanisms in "depressive" rats selected in forced swim test according to the

The hydrodynamics of swimming at intermediate Reynolds numbers in the water boatman (Corixidae).

PubMed

Ngo, Victoria; McHenry, Matthew James

2014-08-01

The fluid forces that govern propulsion determine the speed and energetic cost of swimming. These hydrodynamics are scale dependent and it is unclear what forces matter to the tremendous diversity of aquatic animals that are between a millimeter and a centimeter in length. Animals at this scale generally operate within the regime of intermediate Reynolds numbers, where both viscous and inertial fluid forces have the potential to play a role in propulsion. The present study aimed to resolve which forces create thrust and drag in the paddling of the water boatman (Corixidae), an animal that spans much of the intermediate regime (10force generated by tethered water boatmen, we found that thrust is generated primarily by drag on the paddling appendages, with a negligible contribution from the acceleration reaction force. Based on these findings, we developed a forward-dynamic model of propulsion in free swimming that accurately predicted changes in the body's center of mass over time. For both tethered and free swimming, we used non-linear optimization algorithms to determine the force coefficients that best matched our measurements. With this approach, the drag coefficients on the body and paddle were found to be up to three times greater than on static structures in fully developed flow at the same Reynolds numbers. This is likely a partial consequence of unsteady interactions between the paddles or between the paddles and the body. In addition, the maximum values for these coefficients were inversely related to the Reynolds number, which suggests that viscous forces additionally play an important role in the hydrodynamics of small water boatmen. This understanding for the major forces that operate at intermediate Reynolds numbers offers a basis for interpreting the mechanics, energetics and functional morphology of swimming in many small aquatic animals. © 2014. Published by The Company of Biologists Ltd.

C1473G polymorphism in mouse tph2 gene is linked to tryptophan hydroxylase-2 activity in the brain, intermale aggression, and depressive-like behavior in the forced swim test.

PubMed

Osipova, Daria V; Kulikov, Alexander V; Popova, Nina K

2009-04-01

Tryptophan hydroxylase-2 (TPH2) is the rate-limiting enzyme of brain serotonin synthesis. The C1473G polymorphism in the mouse tryptophan hydroxylase-2 gene affects the enzyme's activity. In the present study, we investigated the linkage between the C1473G polymorphism, enzyme activity in the brain, and behavior in the forced swim, intermale aggression, and open field tests using mice of the C57BL/6 (C/C) and CC57BR/Mv (G/G) strains and the B6-1473C (C/C) and B6-1473G (G/G) lines created by three successive backcrossings on C57BL/6. Mice of the CC57BR/Mv strain had decreased brain enzyme activity, aggression intensity, and immobility in the forced swim test, but increased locomotor activity and time spent in the central part of the open field arena compared with animals of the C57BL/6 strain. Mice of the B6-1473G line homozygous for the 1473G allele had lower TPH2 activity in the brain, aggression intensity, and immobility time in the forced swim test compared with animals of the B6-1473C line homozygous for the 1473C allele. No differences were found between the B6-1473G and B6-1473C mice in locomotor activity and time spent in the central part of the arena in the open field test. Thus, the C1473G polymorphism is involved in the determination of TPH2 activity and is linked to aggression intensity and forced-swim immobility in mice. At the same time, the polymorphism does not affect locomotion and anxiety-related behavior in the open field test. The B6-1473C and B6-1473G mice represent a valuable experimental model for investigating molecular mechanisms of serotonin-related behavior.

Three-link Swimming in Sand

NASA Astrophysics Data System (ADS)

Hatton, R. L.; Ding, Yang; Masse, Andrew; Choset, Howie; Goldman, Daniel

2011-11-01

Many animals move within in granular media such as desert sand. Recent biological experiments have revealed that the sandfish lizard uses an undulatory gait to swim within sand. Models reveal that swimming occurs in a frictional fluid in which inertial effects are small and kinematics dominate. To understand the fundamental mechanics of swimming in granular media (GM), we examine a model system that has been well-studied in Newtonian fluids: the three-link swimmer. We create a physical model driven by two servo-motors, and a discrete element simulation of the swimmer. To predict optimal gaits we use a recent geometric mechanics theory combined with empirically determined resistive force laws for GM. We develop a kinematic relationship between the swimmer's shape and position velocities and construct connection vector field and constraint curvature function visualizations of the system dynamics. From these we predict optimal gaits for forward, lateral and rotational motion. Experiment and simulation are in accord with the theoretical predictions; thus geometric tools can be used to study locomotion in GM.

A Single Sub-anesthetic Dose of Ketamine Relieves Depression-like Behaviors Induced by Neuropathic Pain in Rats

PubMed Central

Wang, Jing; Goffer, Yossef; Xu, Duo; Tukey, David S.; Shamir, D. B.; Eberle, Sarah E.; Zou, Anthony H.; Blanck, Thomas J.J.; Ziff, Edward B.

2011-01-01

Background Chronic pain is associated with depression. In rodents, pain is often assessed by sensory hypersensitivity, which does not sufficiently measure affective responses. Low-dose ketamine has been used to treat both pain and depression, but it is not clear whether ketamine can relieve depression associated with chronic pain and whether this antidepressant effect depends on its anti-nociceptive properties. Methods We examined whether the spared nerve injury (SNI) model of neuropathic pain induces depressive behavior in rats, using sucrose preference test and forced swim test, and tested whether a subanesthetic dose of ketamine treats SNI-induced depression. Results SNI-treated rats, compared with control, showed decreased sucrose preference (0.719 ± 0.068 (mean ± SEM) vs. 0.946 ± 0.010) and enhanced immobility in the forced swim test (107.3 ± 14.6s vs. 56.2 ± 12.5s). Further, sham-operated rats demonstrated depressive behaviors in the acute postoperative period (0.790 ± 0.062 on postoperative day 2). A single subanesthetic dose of ketamine (10mg/kg) did not alter SNI-induced hypersensitivity; however, it treated SNI-associated depression-like behaviors (0.896 ± 0.020 for ketamine vs. 0.663 ± 0.080 for control 1 day after administration; 0.858 ± 0.017 for ketamine vs. 0.683 ± 0.077 for control 5 days after administration). Conclusions Chronic neuropathic pain leads to depression-like behaviors. The postoperative period also confers vulnerability to depression, possibly due to acute pain. Sucrose preference test and forced swim test may be used to compliment sensory tests for assessment of pain in animal studies. Low-dose ketamine can treat depression-like behaviors induced by chronic neuropathic pain. PMID:21934410

Supplemental dietary choline during development exerts antidepressant-like effects in adult female rats

PubMed Central

Glenn, Melissa J.; Adams, Raven S.; McClurg, Lauren

2012-01-01

Perinatal choline supplementation in rats is neuroprotective against insults such as fetal alcohol exposure, seizures, and advanced age. In the present study we explored whether dietary choline supplementation may also confer protection from psychological challenges, like stress, and act as a natural buffer against stress-linked psychological disorders, like depression. We previously found that choline supplementation increased adult hippocampal neurogenesis, a function compromised by stress, lowered in depression, and boosted by antidepressants; and increased levels of growth factors linked to depression, like brain-derived neurotrophic factor. Together, these were compelling reasons to study the role of choline in depressed mood. To do this, we treated rats with a choline supplemented diet (5 mg/kg choline chloride in AIN76A) prenatally on embryonic days 10–22, on postnatal days (PD) 25–50, or as adults from PD75 onward. Outside of these treatment periods rats were fed a standard diet (1.1 mg/kg choline chloride in AIN76A); control rats consumed only this diet throughout the study. Starting on PD100 rats’ anxiety-like responses to an open field, learning in a water maze, and reactivity to forced swimming were assessed. Rats given choline supplementation during pre- or post-natal development, but not adult-treated rats, were less anxious in the open field and less immobile in the forced swim test than control rats. These effects were not mediated by a learning deficit as all groups performed comparably and well in the water maze. Thus, we offer compelling support for the hypothesis that supplemental dietary choline, at least when given during development, may inoculate an individual against stress and major psychological disorders, like depression. PMID:22305146

Ingestion of soy-whey blended protein augments sports performance and ameliorates exercise-induced fatigue in a rat exercise model.

PubMed

Ren, Guangxu; Yi, Suqing; Zhang, Hongru; Wang, Jing

2017-02-22

This study sought to determine the effects of soy-whey blended protein supplementation on sports performance and related biochemical parameters after long-term training. After a week of adaptation, eighteen 6-week-old male Wistar rats were randomly assigned to 3 groups: the standard chow diet plus whey protein (Whey) group, the standard chow diet plus soy-whey blended protein (BP) group and the standard chow diet only (control) group. Each group included 6 rats for the seven-week experiment. Before the experiment, the baseline values of body weight, grasping force and time to exhaustion due to the loaded-swimming test were recorded for each group. During the experimental period, all rats performed the loaded-swimming test until exhaustion five days each week. The results showed that the mean maximum grasping force of the BP group significantly increased between the 5 th and the 7 th week (p < 0.05) compared with the other groups. The ingestion of blended protein for 7 weeks significantly increased the mean time to exhaustion due to swimming by 1.5-fold and 1.2-fold compared with the control and Whey groups, respectively. The plasma levels of leucine, isoleucine and valine were significantly higher at 60 min after the blended protein intervention compared with the Whey and control interventions (p < 0.05). Furthermore, the ingestion of soy-whey blended protein enhanced the activities of lactate dehydrogenase and superoxide dismutase and decreased the levels of malondialdehyde in serum. These results collectively suggest that soy-whey blended protein ingestion with resistance exercise can improve sports performance and ameliorate exercise-induced fatigue in rats.

Involvement of central opioid systems in human interferon-α induced immobility in the mouse forced swimming test

PubMed Central

Makino, Mitsuhiro; Kitano, Yutaka; Komiyama, Chika; Hirohashi, Masaaki; Takasuna, Kiyoshi

2000-01-01

We investigated the mechanism by which human interferon-α (IFN-α) increases the immobility time in a forced swimming test, an animal model of depression.Central administration of IFN-α (0.05–50 IU per mouse, i.cist.) increased the immobility time in the forced swimming test in mice in a dose-dependent manner.Neither IFN-β nor -γ possessed any effect under the same experimental conditions.Pre-treatment with an opioid receptor antagonist, naloxone (1 mg kg−1, s.c.) inhibited the prolonged immobility time induced by IFN-α (60 KIU kg−1, i.v. or 50 IU per mouse. i.cist.).Peripheral administration of naloxone methiodide (1 mg kg−1, s.c.), which does not pass the blood–brain barrier, failed to block the effect of IFN-α, while intracisternal administration of naloxone methiodide (1 nmol per mouse) completely blocked.The effect of IFN-α was inhibited by a μ1-specific opioid receptor antagonist, naloxonazine (35 mg kg−1, s.c.) and a μ1/μ2 receptor antagonist, β-FNA (40 mg kg−1, s.c.). A selective δ-opioid receptor antagonist, naltrindole (3 mg kg−1, s.c.) and a κ-opioid receptor antagonist, nor-binaltorphimine (20 mg kg−1, s.c.), both failed to inhibit the increasing effect of IFN-α.These results suggest that the activator of the central opioid receptors of the μ1-subtype might be related to the prolonged immobility time of IFN-α, but δ and κ-opioid receptors most likely are not involved. PMID:10903965

Dynamics of the vortex wakes of flying and swimming vertebrates.

PubMed

Rayner, J M

1995-01-01

The vortex wakes of flying and swimming animals provide evidence of the history of aero- and hydrodynamic force generation during the locomotor cycle. Vortex-induced momentum flux in the wake is the reaction of forces the animal imposes on its environment, which must be in equilibrium with inertial and external forces. In flying birds and bats, the flapping wings generate lift both to provide thrust and to support the weight. Distinct wingbeat and wake movement patterns can be identified as gaits. In flow visualization experiments, only two wake patterns have been identified: a vortex ring gait with inactive upstroke, and a continuous vortex gait with active upstroke. These gaits may be modelled theoretically by free vortex and lifting line theory to predict mechanical energy consumption, aerodynamic forces and muscle activity. Longer-winged birds undergo a distinct gait change with speed, but shorter-winged species use the vortex ring gait at all speeds. In swimming fish, the situation is more complex: the wake vortices form a reversed von Kármán vortex street, but little is known about the mechanism of generation of the wake, or about how it varies with speed and acceleration or with body form and swimming mode. An unresolved complicating factor is the interaction between the drag wake of the flapping fish body and the thrusting wake from the tail.

Efficient swimming of an assembly of rigid spheres at low Reynolds number.

PubMed

Felderhof, B U

2015-08-01

The swimming of an assembly of rigid spheres immersed in a viscous fluid of infinite extent is studied in low-Reynolds-number hydrodynamics. The instantaneous swimming velocity and rate of dissipation are expressed in terms of the time-dependent displacements of sphere centers about their collective motion. For small-amplitude swimming with periodically oscillating displacements, optimization of the mean swimming speed at given mean power leads to an eigenvalue problem involving a velocity matrix and a power matrix. The corresponding optimal stroke permits generalization to large-amplitude motion in a model of spheres with harmonic interactions and corresponding actuating forces. The method allows straightforward calculation of the swimming performance of structures modeled as assemblies of interacting rigid spheres. A model of three collinear spheres with motion along the common axis is studied as an example.

The effect of low-level laser therapy on oxidative stress and functional fitness in aged rats subjected to swimming: an aerobic exercise.

PubMed

Guaraldo, Simone A; Serra, Andrey Jorge; Amadio, Eliane Martins; Antônio, Ednei Luis; Silva, Flávio; Portes, Leslie Andrews; Tucci, Paulo José Ferreira; Leal-Junior, Ernesto Cesar Pinto; de Carvalho, Paulo de Tarso Camillo

2016-07-01

The aim of the present study was to determine whether low-level laser therapy (LLLT) in conjunction with aerobic training interferes with oxidative stress, thereby influencing the performance of old rats participating in swimming. Thirty Wistar rats (Norvegicus albinus) (24 aged and six young) were tested. The older animals were randomly divided into aged-control, aged-exercise, aged-LLLT, aged-LLLT/exercise, and young-control. Aerobic capacity (VO2max(0.75)) was analyzed before and after the training period. The exercise groups were trained for 6 weeks, and the LLLT was applied at 808 nm and 4 J energy. The rats were euthanized, and muscle tissue was collected to analyze the index of lipid peroxidation thiobarbituric acid reactive substances (TBARS), glutathione (GSH), superoxide dismutase (SOD), and catalase (CAT) activities. VO2 (0.75)max values in the aged-LLLT/exercise group were significantly higher from those in the baseline older group (p <0.01) and the LLLT and exercise group (p <0.05). The results indicate that the activities of CAT, SOD, and GPx were higher and statistically significant (p <0.05) in the LLLT/exercise group than those in the LLLT and exercise groups. Young animals presented lesser and statistically significant activities of antioxidant enzymes compared to the aged group. The LLLT/exercise group and the LLLT and exercise group could also mitigate the concentration of TBARS (p > 0.05). Laser therapy in conjunction with aerobic training may reduce oxidative stress, as well as increase VO2 (0.75)max, indicating that an aerobic exercise such as swimming increases speed and improves performance in aged animals treated with LLLT.

Gender-specific and gonadectomy-specific effects upon swim analgesia: role of steroid replacement therapy.

PubMed

Romero, M T; Cooper, M L; Komisaruk, B R; Bodnar, R J

1988-01-01

Both gender-specific and gonadectomy-specific effects have been observed for the analgesic responses following continuous and intermittent cold-water swims (CCWS and ICWS respectively): female rats display significantly less analgesia than males, and gonadectomized rats display significantly less analgesia than sham-operated controls. The present study evaluated the effects of steroid replacement therapy with testosterone propionate (TP: 2 mg/kg, SC) upon CCWS and ICWS analgesia on the tail-flick and jump tests and hypothermia in sham-operated or gonadectomized male and female rats. Thirty days following surgery, rats received either no treatment, a sesame oil vehicle or TP for 14 days prior to, and then during testing. Relative to the no treatment condition, repeated vehicle injections in sham-operated rats eliminated the gender-specific, but did not affect the gonadectomy-specific effects upon CCWS and ICWS analgesia. TP reversed the deficits in CCWS and ICWS analgesia observed in both castrated and ovariectomized rats on both pain tests. TP only potentiated CCWS analgesia in sham-operated males on the tail-flick test. TP potentiated CCWS and ICWS hypothermia in gonadectomized rats and in male sham-operated rats. These data indicate that gonadal steroids play a major modulatory role in the etiology of swim analgesia, and that the observed gender effects are sensitive to possible adaptational variables.

3D Kinematics and Hydrodynamic Analysis of Freely Swimming Cetacean

NASA Astrophysics Data System (ADS)

Ren, Yan; Sheinberg, Dustin; Liu, Geng; Dong, Haibo; Fish, Frank; Javed, Joveria

2015-11-01

It's widely thought that flexibility and the ability to control flexibility are crucial elements in determining the performance of animal swimming. However, there is a lack of quantification of both span-wise and chord-wise deformation of Cetacean's flukes and associated hydrodynamic performance during actively swimming. To fill this gap, we examined the motion and flexure of both dolphin fluke and orca fluke in steady swimming using a combined experimental and computational approach. It is found that the fluke surface morphing can effectively modulate the flow structures and influence the propulsive performance. Findings from this work are fundamental for understanding key kinematic features of effective Cetacean propulsors, and for quantifying the hydrodynamic force production that naturally occurs during different types of swimming. This work is supported by ONR MURI N00014-14-1-0533 and NSF CBET-1313217.

Modeling and simulation of fish swimming with active muscles.

PubMed

Curatolo, Michele; Teresi, Luciano

2016-11-21

Our goal is to reproduce the key features of carangiform swimming by modeling muscle functioning using the notion of active distortions, thus emphasizing the kinematical role of muscle, the generation of movement, rather than the dynamical one, the production of force. This approach, already proposed to model the action of muscles in different contexts, is here tested again for the problem of developing an effective and reliable framework to model and simulate swimming. A proper undulatory movement of a fish-like body is reproduced by defining a pattern of distortions, tuned in both space and time, meant to model the muscles activation which produce the flexural motion of body fish; eventually, interactions with the surrounding water yields the desired thrust. Carangiform swimmers have a relatively inflexible anterior body section and a generally flat, flexible posterior section. Because of this configuration, undulations sent rearward along the body attain a significant amplitude only in the posterior section. We compare the performances of different swimming gaits, and we are able to find some important relations between key parameters such as frequencies, wavelength, tail amplitude, and the achieved swim velocity, or the generated thrust, which summarize the swimming performance. In particular, an interesting relation is found between the Strouhal number and the wavelength of muscles activation. We highlight the muscle function during fish locomotion describing the activation of muscles and the relation between the force production and the shortening-lengthening cycle of muscle. We found a great accordance between results and empirical relations, giving an implicit validation of our models. Copyright © 2016 Elsevier Ltd. All rights reserved.

Swimming performance of young lake trout after chronic exposure to PCBs and DDE

USGS Publications Warehouse

Rottiers, Donald V.; Bergstedt, Roger A.

1981-01-01

Swimming performance was measured in fry of lake trout (Salvelinus namaycush) exposed to PCB's, DDE, and a combination of these two contaminants in both food and water at concentrations equal to, and 5 and 25 times higher than, levels found in Lake Michigan water and plankton. Fry were tested after about 50, 110, and 165 days of exposure. We measured swimming performance by forcing the fry to swim through a continuous series of incrementally increased velocities until the fish were exhausted. Although we observed significant differences in swimming performance between a few test groups, we detected no relation between swimming performance of the fry and exposure to PCB's or DDE, or both, at the concentrations tested. Inasmuch as swimming performance apparently was not affected by the levels of contamination by PCB's and DDE in Lake Michigan, impairment of swimming by these contaminants cannot account for the failure of lake trout reproduction in Lake Michigan.

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

The effects of body properties on sand-swimming

NASA Astrophysics Data System (ADS)

Sharpe, Sarah; Kuckuk, Robyn; Koehler, Stephan; Goldman, Daniel

2014-03-01

Numerous animals locomote effectively within sand, yet few studies have investigated how body properties and kinematics contribute to subsurface performance. We compare the movement strategies of two desert dwelling subsurface sand-swimmers exhibiting disparate body forms: the long-slender limbless shovel-nosed snake (C. occipitalis) and the relatively shorter sandfish lizard (S. scincus). Both animals ``swim'' subsurface using a head-to-tail propagating wave of body curvature. We use a previously developed granular resistive force theory to successfully predict locomotion of performance of both animals; the agreement with theory implies that both animal's swim within a self-generated frictional fluid. We use theory to show that the snake's shape (body length to body radius ratio), low friction and undulatory gait are close to optimal for sand-swimming. In contrast, we find that the sandfish's shape and higher friction are farther from optimal and prevent the sandfish from achieving the same performance as the shovel-nosed snake during sand-swimming. However, the sandfish's kinematics allows it to operate at the highest performance possible given its body properties. NSF PoLS

Sink or Swim: Navigating the Perilous Waters of Promotion and Tenure--What's Diversity Got to Do with It?

ERIC Educational Resources Information Center

Knight, Wanda B.

2010-01-01

The "sink-or-swim" ideology is pervasive in the United States society. At research universities, for example, promotion and tenure are institutional waters in which faculty are forced to sink or swim with respect to publishing. Either they publish ("swim") or they perish ("sink"). In throwing faculty overboard,…

Enduring effects of post-weaning rearing condition on depressive- and anxiety-like behaviors and motor activity in male rats.

PubMed

Mosaferi, Belal; Babri, Shirin; Ebrahimi, Hadi; Mohaddes, Gisou

2015-04-01

Environmental manipulation at early critical periods could have long-lasting effects. In spite of the great interest in the biological effects of the environmental condition so far, its long-lasting effects are less documented. This study looks at the enduring effects of rearing condition on tasks that measure affective responses and exploratory behavior in male Wistar rats. The animals were reared from weaning to adulthood in an enriched environment, standard laboratory condition, or isolated condition. Then, all rats were housed in standard laboratory cages to provide a common environment, and successively exposed to different tests between 0 and 11 weeks post-manipulation. The open field test indicated a more efficient exploratory behavior in the enriched group, and an enhanced spontaneous motor activity in both standard and isolated groups. In addition, rats reared in standard condition showed heightened motor activity in forced swimming test and elevated plus maze. Forced swimming test showed an antidepressive-like effect in the enriched environment group by increased climbing behavior. In respect to the anxiety behavior, environmental enrichment improved threat detection ability. It is concluded that rearing condition from weaning to adulthood has important and long-lasting effects on depressive- and anxiety-like and exploratory behaviors as well as motor activity. Copyright © 2015 Elsevier Inc. All rights reserved.

Effects of 4-hydroxyisoleucine from Fenugreek Seeds on Depression-like Behavior in Socially Isolated Olfactory Bulbectomized Rats

PubMed Central

Kalshetti, Padmaja B.; Alluri, Ramesh; Mohan, Vishwaraman; Thakurdesai, Prasad Arvind

2015-01-01

Context: Antidepressant-like effects of (2S, 3R, 4S)-4-hydroxyisoleucine (4-HI), a major amino acid from fenugreek seeds, has been reported in the animal model of acute depression. Aims: To evaluate effects of subacute administration of 4-HI in animal model of stress-induced depression namely socially isolated olfactory bulbectomized rats. Materials and Methods: Bilateral olfactory bulbectomy (OBX) were induced in 30 Sprague-Dawley rats. After recovery period of 14 days, rats were randomized into five groups of 6 rats each and stressed with social isolation (individual housing). The rats were orally treated with either vehicle (OBX-Iso), positive control, fluoxetine (30 mg/kg) or 4-HI (10, 30, 100 mg/kg) once a day from day 14 onward. Separate group of rats with social isolation but without OBX (Sham-Iso) was also maintained. The behavioral depression and anxiety related parameters using open field test (OFT), sucrose intake test, novelty suppressed feeding (NSF) and forced swim test (FST), and neurochemical estimation (brain monoamines viz., serotonin and nor-adrenaline, serotonin turnover, and serum cortisol) were performed. Statistical Analysis Used: Data was analyzed by either two-way ANOVA (OFT and FST) or one-way ANOVA (sucrose intake test, NSF, and neurochemical estimation) followed by Dunnett's multiple comparisons test. Differences were considered significant at P < 0.05. Results: The significant and dose-dependent protection from behavioral and neurochemical changes were observed in 4-HI co-administrated OBX-Iso rats. Conclusion: 4-HI demonstrated the antidepressant and antianxiety effects in socially isolated stress-induced OBX rats with possible involvement of multiple stress relieving mechanisms. HIGHLIGHTS OF PAPER In this study, the subacute pretreatment of 4-HI showed strong and dose-dependent prevention of isolation stress related behavioral and neurochemical responses in olfactory bulbectomized rats. The prevention of hyperactive HPA axis in OBX

Effects of 4-hydroxyisoleucine from Fenugreek Seeds on Depression-like Behavior in Socially Isolated Olfactory Bulbectomized Rats.

PubMed

Kalshetti, Padmaja B; Alluri, Ramesh; Mohan, Vishwaraman; Thakurdesai, Prasad Arvind

2015-10-01

Antidepressant-like effects of (2S, 3R, 4S)-4-hydroxyisoleucine (4-HI), a major amino acid from fenugreek seeds, has been reported in the animal model of acute depression. To evaluate effects of subacute administration of 4-HI in animal model of stress-induced depression namely socially isolated olfactory bulbectomized rats. Bilateral olfactory bulbectomy (OBX) were induced in 30 Sprague-Dawley rats. After recovery period of 14 days, rats were randomized into five groups of 6 rats each and stressed with social isolation (individual housing). The rats were orally treated with either vehicle (OBX-Iso), positive control, fluoxetine (30 mg/kg) or 4-HI (10, 30, 100 mg/kg) once a day from day 14 onward. Separate group of rats with social isolation but without OBX (Sham-Iso) was also maintained. The behavioral depression and anxiety related parameters using open field test (OFT), sucrose intake test, novelty suppressed feeding (NSF) and forced swim test (FST), and neurochemical estimation (brain monoamines viz., serotonin and nor-adrenaline, serotonin turnover, and serum cortisol) were performed. Data was analyzed by either two-way ANOVA (OFT and FST) or one-way ANOVA (sucrose intake test, NSF, and neurochemical estimation) followed by Dunnett's multiple comparisons test. Differences were considered significant at P < 0.05. The significant and dose-dependent protection from behavioral and neurochemical changes were observed in 4-HI co-administrated OBX-Iso rats. 4-HI demonstrated the antidepressant and antianxiety effects in socially isolated stress-induced OBX rats with possible involvement of multiple stress relieving mechanisms. In this study, the subacute pretreatment of 4-HI showed strong and dose-dependent prevention of isolation stress related behavioral and neurochemical responses in olfactory bulbectomized rats. The prevention of hyperactive HPA axis in OBX-Iso stress-induced rats can be envisaged as probable mechanism of antidepressant and antianxiety effects of

Exercise-training intervention studies in competitive swimming.

PubMed

Aspenes, Stian Thoresen; Karlsen, Trine

2012-06-01

Competitive swimming has a long history and is currently one of the largest Olympic sports, with 16 pool events. Several aspects separate swimming from most other sports such as (i) the prone position; (ii) simultaneous use of arms and legs for propulsion; (iii) water immersion (i.e. hydrostatic pressure on thorax and controlled respiration); (iv) propulsive forces that are applied against a fluctuant element; and (v) minimal influence of equipment on performance. Competitive swimmers are suggested to have specific anthropometrical features compared with other athletes, but are nevertheless dependent on physiological adaptations to enhance their performance. Swimmers thus engage in large volumes of training in the pool and on dry land. Strength training of various forms is widely used, and the energetic systems are addressed by aerobic and anaerobic swimming training. The aim of the current review was to report results from controlled exercise training trials within competitive swimming. From a structured literature search we found 17 controlled intervention studies that covered strength or resistance training, assisted sprint swimming, arms-only training, leg-kick training, respiratory muscle training, training the energy delivery systems and combined interventions across the aforementioned categories. Nine of the included studies were randomized controlled trials. Among the included studies we found indications that heavy strength training on dry land (one to five repetitions maximum with pull-downs for three sets with maximal effort in the concentric phase) or sprint swimming with resistance towards propulsion (maximal pushing with the arms against fixed points or pulling a perforated bowl) may be efficient for enhanced performance, and may also possibly have positive effects on stroke mechanics. The largest effect size (ES) on swimming performance was found in 50 m freestyle after a dry-land strength training regimen of maximum six repetitions across three

Behavioral Sequelae Following Acute Diisopropylfluorophosphate Intoxication in Rats: Comparative Effects of Atropine and Cannabinomimetics

PubMed Central

Wright, Linnzi K. M.; Liu, Jing; Nallapaneni, Anuradha; Pope, Carey N.

2010-01-01

The comparative effects of atropine and the indirect cannabinomimetics URB597 (a fatty acid amide hydrolase inhibitor) and URB602 (a monoacylglycerol lipase inhibitor) on functional and neurobehavioral endpoints following acute diisopropylfluorophosphate intoxication were studied. Male Sprague-Dawley rats were treated with vehicle or DFP (2.5 mg/kg, sc), immediately post-treated with either vehicle, atropine (16 mg/kg), URB597 (3 mg/kg), URB602 (10 mg/kg) or a combination of URB597 and URB602, and functional signs of toxicity as well as nocturnal motor activity were measured daily for seven consecutive days. Performance in the elevated plus maze (for anxiety-like behavior) and the forced swimming test (for depression-like behavior) was measured at days 6-8 and 27-29 after dosing. Twenty-four hours after dosing, DFP markedly reduced cholinesterase activity in selected brain regions and peripheral tissues (diaphragm and plasma). Substantial recovery of cholinesterase activity was noted at both 8 and 29 days after dosing but significant inhibition was still noted in some brain regions at the latest time-point. DFP elicited body weight reductions and typical signs of cholinergic toxicity, and reduced nocturnal ambulation and rearing. Atropine and the cannabinomimetics (alone and in combination) partially attenuated DFP-induced functional signs of toxicity. None of the post-treatments reversed the DFP-induced reduction in ambulation or rearing, however. No significant treatment-related effects on elevated plus maze performance were noted. DFP-treated rats exhibited decreased swimming and increased immobility in the forced swimming test at both time-points. None of the post-treatments had any effect on DFP-induced changes in immobility or swimming at day 8. At day 29, atropine and the combination of URB597/URB602 significantly blocked DFP-induced changes in immobility, while URB597 and the combination reversed DFP-induced changes in swimming. The results suggest that

The antidepressant- and anxiolytic-like effects following co-treatment with escitalopram and risperidone in rats.

PubMed

Kaminska, K; Rogoz, Z

2016-06-01

Several clinical reports have documented a beneficial effect of the addition of a low dose of risperidone to the ongoing treatment with antidepressants, in particular selective serotonin reuptake inhibitors (SSRI), in the treatment of drug-resistant depression and treatment-resistant anxiety disorders. In the present study, we investigated the effect of treatment with the antidepressant escitalopram (SSRI) given separately or jointly with a low dose of risperidone (an atypical antipsychotic) in the forced swim test and in the elevated plus-maze test in rats. The obtained results showed that escitalopram at doses of 2.5 or 5 mg/kg evoked antidepressant-like effect in the forced swim test. Moreover, risperidone at low doses (0.05 or 0.1 mg/kg) enhanced the antidepressant-like activity of escitalopram (1 mg/kg) in this test by increasing the swimming time and decreasing the immobility time in those animals. WAY 100635 (a serotonin 5-HT1A receptor antagonist) at a dose of 0.1 mg/kg abolished the antidepressant-like effect induced by co-administration of escitalopram and risperidone. The active behavior in that test did not reflect an increase in general activity, since the combined treatment with escitalopram and risperidone failed to enhance the exploratory activity of rats. In the following experiment, we showed that escitalopram (5 mg/kg) and mirtazapine (5 or 10 mg/kg) or risperidone (0.1 mg/kg) induced an anxiolytic-like effect in the elevated plus-maze test, and the combined treatment with an ineffective dose of risperidone (0.05 mg/kg) enhanced the anxiolytic-like effects of escitalopram (2.5 mg/kg) or mirtazapine (1 and 2.5 mg/kg) in this test. The obtained results suggest that risperidone applied at a low dose enhances the antidepressant-like activity of escitalopram in the forced swim test, and that 5-HT1A receptors may play some role in these effects. Moreover, a low dose of risperidone may also enhance the anxiolytic-like action of the studied

Modeling hydrodynamic self-propulsion with Stokesian Dynamics. Or teaching Stokesian Dynamics to swim

NASA Astrophysics Data System (ADS)

Swan, James W.; Brady, John F.; Moore, Rachel S.; ChE 174

2011-07-01

We develop a general framework for modeling the hydrodynamic self-propulsion (i.e., swimming) of bodies (e.g., microorganisms) at low Reynolds number via Stokesian Dynamics simulations. The swimming body is composed of many spherical particles constrained to form an assembly that deforms via relative motion of its constituent particles. The resistance tensor describing the hydrodynamic interactions among the individual particles maps directly onto that for the assembly. Specifying a particular swimming gait and imposing the condition that the swimming body is force- and torque-free determine the propulsive speed. The body's translational and rotational velocities computed via this methodology are identical in form to that from the classical theory for the swimming of arbitrary bodies at low Reynolds number. We illustrate the generality of the method through simulations of a wide array of swimming bodies: pushers and pullers, spinners, the Taylor/Purcell swimming toroid, Taylor's helical swimmer, Purcell's three-link swimmer, and an amoeba-like body undergoing large-scale deformation. An open source code is a part of the supplementary material and can be used to simulate the swimming of a body with arbitrary geometry and swimming gait.

Brain effect of insulin and clonazepam in diabetic rats under depressive-like behavior.

PubMed

Wayhs, Carlos Alberto Yasin; Mescka, Caroline Paula; Vanzin, Camila Simioni; Ribas, Graziela Schmitt; Guerreiro, Gilian; Nin, Maurício Schüler; Manfredini, Vanusa; Barros, Helena Maria Tannhauser; Vargas, Carmen Regla

2013-12-01

Diabetes mellitus is characterized by hyperglycemia resulting from defects on insulin secretion, insulin action, or both. It has recently become clear that the central nervous system is not spared from the deleterious effects of diabetes, since diabetic encephalopathy was recognized as a complication of this heterogeneous metabolic disorder. There is a well recognized association between depression and diabetes, once prevalence of depression in diabetic patients is higher than in general population, and clonazepam is being used to treat this complication. Oxidative stress is widely accepted as playing a key mediatory role in the development and progression of diabetes and its complications. In this work we analyzed DNA damage by comet assay and lipid damage in prefrontal cortex, hippocampus and striatum of streptozotocin-induced diabetic rats submitted to the forced swimming test. It was verified that the diabetic group presented DNA and lipid damage in the brain areas evaluated, when compared to the control groups. Additionally, a significant reduction of the DNA and lipid damage in animals treated with insulin and/or clonazepam was observed. These data suggest that the association of these two drugs could protect against DNA and lipid damage in diabetic rats submitted to the forced swimming test, an animal model of depression.

Behavioral benefits of maternal swimming are counteracted by neonatal hypoxia-ischemia in the offspring.