Teaching Rhythmic Movement to Children: "Chock-Let Pie"

ERIC Educational Resources Information Center

Hastie, Peter A.; Martin, Ellen H.; Gibson, Gary S.

2005-01-01

It is doubtful that any teacher would question the value of rhythmic movement in a physical education program. The benefits of being able to move rhythmically and to keep a beat are numerous. First, children with rhythm have an increased kinesthetic awareness of their body in motion and stillness. As most physical activities have an inherent…

Different types of theta rhythmicity are induced by social and fearful stimuli in a network associated with social memory.

PubMed

Tendler, Alex; Wagner, Shlomo

2015-02-16

Rhythmic activity in the theta range is thought to promote neuronal communication between brain regions. In this study, we performed chronic telemetric recordings in socially behaving rats to monitor electrophysiological activity in limbic brain regions linked to social behavior. Social encounters were associated with increased rhythmicity in the high theta range (7-10 Hz) that was proportional to the stimulus degree of novelty. This modulation of theta rhythmicity, which was specific for social stimuli, appeared to reflect a brain-state of social arousal. In contrast, the same network responded to a fearful stimulus by enhancement of rhythmicity in the low theta range (3-7 Hz). Moreover, theta rhythmicity showed different pattern of coherence between the distinct brain regions in response to social and fearful stimuli. We suggest that the two types of stimuli induce distinct arousal states that elicit different patterns of theta rhythmicity, which cause the same brain areas to communicate in different modes.

Body composition and cardiac dimensions in elite rhythmic gymnasts.

PubMed

Galetta, F; Franzoni, F; D'alessandro, C; Piazza, M; Tocchini, L; Fallahi, P; Antonelli, A; Cupisti, F; Santoro, G

2015-09-01

Rhythmic gymnasts are often believed to be a population at risk of malnutrition because of their tendency to keep a low weight and a lean appearance for better athletic performance, and because they start intensive training at a very young age. The purpose of this study was to evaluate in adolescent elite gymnasts the effects of physical activity on body composition and cardiac morphology and function. Sixteen national level rhythmic gymnasts and 16 control adolescent female underwent anthropometric measurements, bioelectric impedance and echocardiography to assess body composition and cardiac morphology and function. As compared to controls, gymnasts had lower body mass index (16.9±1.1 vs. 18.7±1.0, P<0.001), fatty mass (14.2±4.5 vs. 15.8±2.9 %, P<0.05) and greater fat-free mass (84.0±4.7 vs. 80.5±5.0 %, P<0.05), left ventricular end-diastolic dimension (4.7±0.4 vs. 4.4±0.3 cm) and left ventricular mass, as absolute (132.8±21.2 vs. 112.5±22.8 g, P<0.01) and indexed (44.5±9.3 vs. 36.1±8.2 g/m2.7, P<0.01). Left ventricular mass was directly related to fat-free mass as absolute (r=0.37, P<0.05) and indexed (r=0.43, P<0.02). Body composition analysis showed a lower percentage of body fat in the gymnasts, together with a higher percentage of fat-free mass. Echocardiographic findings indicate that elite rhythmic gymnastics present left ventricular remodeling as training-induced cardiac adaptation. Intensive training, dietary attitude and evident leanness of rhythmic gymnasts are not associated with cardiac abnormalities, as it is the case of pathological leanness.

Resveratrol restores the circadian rhythmic disorder of lipid metabolism induced by high-fat diet in mice.

PubMed

Sun, Linjie; Wang, Yan; Song, Yu; Cheng, Xiang-Rong; Xia, Shufang; Rahman, Md Ramim Tanver; Shi, Yonghui; Le, Guowei

2015-02-27

Circadian rhythmic disorders induced by high-fat diet are associated with metabolic diseases. Resveratrol could improve metabolic disorder, but few reports focused on its effects on circadian rhythm disorders in a variety of studies. The aim of the present study was to analyze the potential effects of resveratrol on high-fat diet-induced disorders about the rhythmic expression of clock genes and clock-controlled lipid metabolism. Male C57BL/6 mice were divided into three groups: a standard diet control group (CON), a high-fat diet (HFD) group and HFD supplemented with 0.1% (w/w) resveratrol (RES). The body weight, fasting blood glucose and insulin, plasma lipids and leptin, whole body metabolic status and the expression of clock genes and clock-controlled lipogenic genes were analyzed at four different time points throughout a 24-h cycle (8:00, 14:00, 20:00, 2:00). Resveratrol, being associated with rhythmic restoration of fasting blood glucose and plasma insulin, significantly decreased the body weight in HFD mice after 11 weeks of feeding, as well as ameliorated the rhythmities of plasma leptin, lipid profiles and whole body metabolic status (respiratory exchange ratio, locomotor activity, and heat production). Meanwhile, resveratrol modified the rhythmic expression of clock genes (Clock, Bmal1 and Per2) and clock-controlled lipid metabolism related genes (Sirt1, Pparα, Srebp-1c, Acc1 and Fas). The response pattern of mRNA expression for Acc1 was similar to the plasma triglyceride. All these results indicated that resveratrol reduced lipogenesis and ultimately normalized rhythmic expression of plasma lipids, possibly via its action on clock machinery. Copyright © 2015 Elsevier Inc. All rights reserved.

Passive Transport Disrupts Grid Signals in the Parahippocampal Cortex.

PubMed

Winter, Shawn S; Mehlman, Max L; Clark, Benjamin J; Taube, Jeffrey S

2015-10-05

Navigation is usually thought of relative to landmarks, but neural signals representing space also use information generated by an animal's movements. These signals include grid cells, which fire at multiple locations, forming a repeating grid pattern. Grid cell generation depends upon theta rhythm, a 6-10 Hz electroencephalogram (EEG) oscillation that is modulated by the animals' movement velocity. We passively moved rats in a clear cart to eliminate motor related self-movement cues that drive moment-to-moment changes in theta rhythmicity. We found that passive movement maintained theta power and frequency at levels equivalent to low active movement velocity, spared overall head-direction (HD) cell characteristics, but abolished both velocity modulation of theta rhythmicity and grid cell firing patterns. These results indicate that self-movement motor cues are necessary for generating grid-specific firing patterns, possibly by driving velocity modulation of theta rhythmicity, which may be used as a speed signal to generate the repeating pattern of grid cells. Copyright © 2015 Elsevier Ltd. All rights reserved.

Synthesis of asymmetric movement trajectories in timed rhythmic behaviour by means of frequency modulation.

PubMed

Waadeland, Carl Haakon

2017-01-01

Results from different empirical investigations on gestural aspects of timed rhythmic movements indicate that the production of asymmetric movement trajectories is a feature that seems to be a common characteristic of various performances of repetitive rhythmic patterns. The behavioural or neural origin of these asymmetrical trajectories is, however, not identified. In the present study we outline a theoretical model that is capable of producing syntheses of asymmetric movement trajectories documented in empirical investigations by Balasubramaniam et al. (2004). Characteristic qualities of the extension/flexion profiles in the observed asymmetric trajectories are reproduced, and we conduct an experiment similar to Balasubramaniam et al. (2004) to show that the empirically documented movement trajectories and our modelled approximations share the same spectral components. The model is based on an application of frequency modulated movements, and a theoretical interpretation offered by the model is to view paced rhythmic movements as a result of an unpaced movement being "stretched" and "compressed", caused by the presence of a metronome. We discuss our model construction within the framework of event-based and emergent timing, and argue that a change between these timing modes might be reflected by the strength of the modulation in our model. Copyright © 2016 Elsevier B.V. All rights reserved.

Rhythmic abilities and musical training in Parkinson's disease: do they help?

PubMed

Cochen De Cock, V; Dotov, D G; Ihalainen, P; Bégel, V; Galtier, F; Lebrun, C; Picot, M C; Driss, V; Landragin, N; Geny, C; Bardy, B; Dalla Bella, S

2018-01-01

Rhythmic auditory cues can immediately improve gait in Parkinson's disease. However, this effect varies considerably across patients. The factors associated with this individual variability are not known to date. Patients' rhythmic abilities and musicality (e.g., perceptual and singing abilities, emotional response to music, and musical training) may foster a positive response to rhythmic cues. To examine this hypothesis, we measured gait at baseline and with rhythmic cues in 39 non-demented patients with Parkinson's disease and 39 matched healthy controls. Cognition, rhythmic abilities and general musicality were assessed. A response to cueing was qualified as positive when the stimulation led to a clinically meaningful increase in gait speed. We observed that patients with positive response to cueing ( n  = 17) were more musically trained, aligned more often their steps to the rhythmic cues while walking, and showed better music perception as well as poorer cognitive flexibility than patients with non-positive response ( n  = 22). Gait performance with rhythmic cues worsened in six patients. We concluded that rhythmic and musical skills, which can be modulated by musical training, may increase beneficial effects of rhythmic auditory cueing in Parkinson's disease. Screening patients in terms of musical/rhythmic abilities and musical training may allow teasing apart patients who are likely to benefit from cueing from those who may worsen their performance due to the stimulation.

Increased firing frequency of spontaneous action potentials in cerebellar Purkinje neurons of db/db mice results from altered auto-rhythmicity and diminished GABAergic tonic inhibition.

PubMed

Forero-Vivas, María E; Hernández-Cruz, Arturo

2014-01-01

The hormone leptin, by binding to hypothalamic receptors, suppresses food intake and decreases body adiposity. Leptin receptors are also widely expressed in extra-hypothalamic areas such as hippocampus, amygdala and cerebellum, where leptin modulates synaptic transmission. Here we show that a defective leptin receptor affects the electrophysiological properties of cerebellar Purkinje neurons (PNs). PNs from (db/db) mice recorded in cerebellar slices display a higher firing rate of spontaneous action potentials than PNs from wild type (WT) mice. Blockade of GABAergic tonic inhibition with bicuculline in WT mice changes the firing pattern from continuous, uninterrupted spiking into bursting firing, but bicuculline does not produce these alterations in db/db neurons, suggesting that they receive a weaker GABAergic inhibitory input. Our results also show that the intrinsic firing properties (auto-rhythmicity) of WT and db/db PNs are different. Tonic firing of PNs, the only efferent output from the cerebellar cortex, is a persistent signal to downstream cerebellar targets. The significance of leptin modulation of PNs spontaneous firing is not known. Also, it is not clear if the increased excitability of cerebellar PNs in db/db mice results from hyperglycemia or from the lack of leptin signaling, since both conditions coexist in the db/db strain.

EEG Oscillations Are Modulated in Different Behavior-Related Networks during Rhythmic Finger Movements.

PubMed

Seeber, Martin; Scherer, Reinhold; Müller-Putz, Gernot R

2016-11-16

Sequencing and timing of body movements are essential to perform motoric tasks. In this study, we investigate the temporal relation between cortical oscillations and human motor behavior (i.e., rhythmic finger movements). High-density EEG recordings were used for source imaging based on individual anatomy. We separated sustained and movement phase-related EEG source amplitudes based on the actual finger movements recorded by a data glove. Sustained amplitude modulations in the contralateral hand area show decrease for α (10-12 Hz) and β (18-24 Hz), but increase for high γ (60-80 Hz) frequencies during the entire movement period. Additionally, we found movement phase-related amplitudes, which resembled the flexion and extension sequence of the fingers. Especially for faster movement cadences, movement phase-related amplitudes included high β (24-30 Hz) frequencies in prefrontal areas. Interestingly, the spectral profiles and source patterns of movement phase-related amplitudes differed from sustained activities, suggesting that they represent different frequency-specific large-scale networks. First, networks were signified by the sustained element, which statically modulate their synchrony levels during continuous movements. These networks may upregulate neuronal excitability in brain regions specific to the limb, in this study the right hand area. Second, movement phase-related networks, which modulate their synchrony in relation to the movement sequence. We suggest that these frequency-specific networks are associated with distinct functions, including top-down control, sensorimotor prediction, and integration. The separation of different large-scale networks, we applied in this work, improves the interpretation of EEG sources in relation to human motor behavior. EEG recordings provide high temporal resolution suitable to relate cortical oscillations to actual movements. Investigating EEG sources during rhythmic finger movements, we distinguish sustained from movement phase-related amplitude modulations. We separate these two EEG source elements motivated by our previous findings in gait. Here, we found two types of large-scale networks, representing the right fingers in distinction from the time sequence of the movements. These findings suggest that EEG source amplitudes reconstructed in a cortical patch are the superposition of these simultaneously present network activities. Separating these frequency-specific networks is relevant for studying function and possible dysfunction of the cortical sensorimotor system in humans as well as to provide more advanced features for brain-computer interfaces. Copyright © 2016 the authors 0270-6474/16/3611671-11$15.00/0.

An Exploration of Rhythmic Grouping of Speech Sequences by French- and German-Learning Infants

PubMed Central

Abboub, Nawal; Boll-Avetisyan, Natalie; Bhatara, Anjali; Höhle, Barbara; Nazzi, Thierry

2016-01-01

Rhythm in music and speech can be characterized by a constellation of several acoustic cues. Individually, these cues have different effects on rhythmic perception: sequences of sounds alternating in duration are perceived as short-long pairs (weak-strong/iambic pattern), whereas sequences of sounds alternating in intensity or pitch are perceived as loud-soft, or high-low pairs (strong-weak/trochaic pattern). This perceptual bias—called the Iambic-Trochaic Law (ITL)–has been claimed to be an universal property of the auditory system applying in both the music and the language domains. Recent studies have shown that language experience can modulate the effects of the ITL on rhythmic perception of both speech and non-speech sequences in adults, and of non-speech sequences in 7.5-month-old infants. The goal of the present study was to explore whether language experience also modulates infants’ grouping of speech. To do so, we presented sequences of syllables to monolingual French- and German-learning 7.5-month-olds. Using the Headturn Preference Procedure (HPP), we examined whether they were able to perceive a rhythmic structure in sequences of syllables that alternated in duration, pitch, or intensity. Our findings show that both French- and German-learning infants perceived a rhythmic structure when it was cued by duration or pitch but not intensity. Our findings also show differences in how these infants use duration and pitch cues to group syllable sequences, suggesting that pitch cues were the easier ones to use. Moreover, performance did not differ across languages, failing to reveal early language effects on rhythmic perception. These results contribute to our understanding of the origin of rhythmic perception and perceptual mechanisms shared across music and speech, which may bootstrap language acquisition. PMID:27378887

Proteomic identification of rhythmic proteins in rice seedlings.

PubMed

Hwang, Heeyoun; Cho, Man-Ho; Hahn, Bum-Soo; Lim, Hyemin; Kwon, Yong-Kook; Hahn, Tae-Ryong; Bhoo, Seong Hee

2011-04-01

Many aspects of plant metabolism that are involved in plant growth and development are influenced by light-regulated diurnal rhythms as well as endogenous clock-regulated circadian rhythms. To identify the rhythmic proteins in rice, periodically grown (12h light/12h dark cycle) seedlings were harvested for three days at six-hour intervals. Continuous dark-adapted plants were also harvested for two days. Among approximately 3000 reproducible protein spots on each gel, proteomic analysis ascertained 354 spots (~12%) as light-regulated rhythmic proteins, in which 53 spots showed prolonged rhythm under continuous dark conditions. Of these 354 ascertained rhythmic protein spots, 74 diurnal spots and 10 prolonged rhythmic spots under continuous dark were identified by MALDI-TOF MS analysis. The rhythmic proteins were functionally classified into photosynthesis, central metabolism, protein synthesis, nitrogen metabolism, stress resistance, signal transduction and unknown. Comparative analysis of our proteomic data with the public microarray database (the Plant DIURNAL Project) and RT-PCR analysis of rhythmic proteins showed differences in rhythmic expression phases between mRNA and protein, suggesting that the clock-regulated proteins in rice are modulated by not only transcriptional but also post-transcriptional, translational, and/or post-translational processes. 2011 Elsevier B.V. All rights reserved.

Somatotype of Top-Level Serbian Rhythmic Gymnasts

PubMed Central

Purenović-Ivanović, Tijana; Popović, Ružena

2014-01-01

Body size and build influence performance in many sports, especially in those belonging to the group of female aesthetic sports (rhythmic gymnastics, artistic gymnastics, and figure skating). These sports pose high specific demands upon the functional, energy, motor and psychological capacities of athletes, but also upon the size, body build and composition of the performers, particularly of the top-level female athletes. The study of the top athletes (rhythmic gymnasts, in this case) may provide valuable information on the morphological requirements for achieving success in this sport. Therefore, the main objective of this research was to analyze the somatotype of 40 Serbian top-level rhythmic gymnasts, aged 13.04±2.79, and to form the five age group categories. The anthropometric variables included body height, body mass, the selected diameters, girths and skinfolds, and the Heath-Carter anthropometric somatotype. All of the anthropometric data were collected according to International Biological Programme, and then processed in the Somatotype 1.2. The applied analysis of variance indicated an increase in endomorphic component with age. The obtained results show that the balanced ectomorph is a dominant somatotype, being similar for all of the athletes that took part in the research (3.54-3.24-4.5). These results are in line with the ones obtained in previous studies. PMID:25031686

Somatotype of top-level serbian rhythmic gymnasts.

PubMed

Purenović-Ivanović, Tijana; Popović, Ružena

2014-03-27

Body size and build influence performance in many sports, especially in those belonging to the group of female aesthetic sports (rhythmic gymnastics, artistic gymnastics, and figure skating). These sports pose high specific demands upon the functional, energy, motor and psychological capacities of athletes, but also upon the size, body build and composition of the performers, particularly of the top-level female athletes. The study of the top athletes (rhythmic gymnasts, in this case) may provide valuable information on the morphological requirements for achieving success in this sport. Therefore, the main objective of this research was to analyze the somatotype of 40 Serbian top-level rhythmic gymnasts, aged 13.04±2.79, and to form the five age group categories. The anthropometric variables included body height, body mass, the selected diameters, girths and skinfolds, and the Heath-Carter anthropometric somatotype. All of the anthropometric data were collected according to International Biological Programme, and then processed in the Somatotype 1.2. The applied analysis of variance indicated an increase in endomorphic component with age. The obtained results show that the balanced ectomorph is a dominant somatotype, being similar for all of the athletes that took part in the research (3.54-3.24-4.5). These results are in line with the ones obtained in previous studies.

A theta rhythm in macaque visual cortex and its attentional modulation

PubMed Central

Spyropoulos, Georgios; Fries, Pascal

2018-01-01

Theta rhythms govern rodent sniffing and whisking, and human language processing. Human psychophysics suggests a role for theta also in visual attention. However, little is known about theta in visual areas and its attentional modulation. We used electrocorticography (ECoG) to record local field potentials (LFPs) simultaneously from areas V1, V2, V4, and TEO of two macaque monkeys performing a selective visual attention task. We found a ≈4-Hz theta rhythm within both the V1–V2 and the V4–TEO region, and theta synchronization between them, with a predominantly feedforward directed influence. ECoG coverage of large parts of these regions revealed a surprising spatial correspondence between theta and visually induced gamma. Furthermore, gamma power was modulated with theta phase. Selective attention to the respective visual stimulus strongly reduced these theta-rhythmic processes, leading to an unusually strong attention effect for V1. Microsaccades (MSs) were partly locked to theta. However, neuronal theta rhythms tended to be even more pronounced for epochs devoid of MSs. Thus, we find an MS-independent theta rhythm specific to visually driven parts of V1–V2, which rhythmically modulates local gamma and entrains V4–TEO, and which is strongly reduced by attention. We propose that the less theta-rhythmic and thereby more continuous processing of the attended stimulus serves the exploitation of this behaviorally most relevant information. The theta-rhythmic and thereby intermittent processing of the unattended stimulus likely reflects the ecologically important exploration of less relevant sources of information. PMID:29848632

The Beat Goes on: Rhythmic Modulation of Cortical Potentials by Imagined Tapping

ERIC Educational Resources Information Center

Osman, Allen; Albert, Robert; Ridderinkhof, K. Richard; Band, Guido; van der Molen, Maurits

2006-01-01

A frequency analysis was used to tag cortical activity from imagined rhythmic movements. Participants synchronized overt and imagined taps with brief visual stimuli presented at a constant rate, alternating between left and right index fingers. Brain potentials were recorded from across the scalp and topographic maps made of their power at the…

[Somatic constitution and the ability to maintain dynamic body equilibrium in girls practicing rhythmic gymnastics].

PubMed

Poliszczuk, Tatiana; Broda, Daria

2010-01-01

The greatest similarities in body constitution were noted in competitors practising the same discipline. The similarities increase with the training level. A typical body constitution for a given discipline not only favourably affects athletic performance, but is also the factor preventing sportsrelated contusions. The ability to maintain body equilibrium, together with somatic constitution, are the basic selective criteria in rhythmic gymnastics. The objective of this paper was to determine somatotypes, to evaluate the ability to maintain dynamic body equilibrium in girls practicing rhythmic gymnastics and to develop model characteristics enabling early diagnosis of the disorders equilibrium system function. The sample comprised 19 girls aged 8-11 years, practising rhythmic gymnastics. For the evaluation of the competitors' somatotypes, the Heath-Carter method was used, based on the classic concept of Sheldon's body constitution components. Body equilibrium level was evaluated by means of posturography. The mean values of the endomorphic component I, mesomorphic component II and ectomorphic component III in the gymnasts were 2.65+/-1.29, 2.45+/-0.37 and 3.95+/-0.64 respectively. The mean body mass index (BMI) value for this cohort was 15.32, which means advanced slimness. The level of dynamic equilibrium is determined by the following mean values: the time of reaching the equilibrium, the way of reaching it and the duration of stay at the defined point. The model of above mentioned indicates was developed based on the analysis of it's best results. Body constitution type in the qualified gymnasts is characterised by the prevalence of the ectomorphic component. The study results indicate that female gymnasts are generally slim and lean. It is necessary to monitor BMI in order to exclude weight-related disorders and to observe the changes with age. The poorest result was found when the gymnasts bent in the backward direction as this body position is most difficult to assume and to maintain body equilibrium as compared to all other directions.

Preclinical evidence supporting the clinical development of central pattern generator-modulating therapies for chronic spinal cord-injured patients

PubMed Central

2014-01-01

Ambulation or walking is one of the main gaits of locomotion. In terrestrial animals, it may be defined as a series of rhythmic and bilaterally coordinated movement of the limbs which creates a forward movement of the body. This applies regardless of the number of limbs—from arthropods with six or more limbs to bipedal primates. These fundamental similarities among species may explain why comparable neural systems and cellular properties have been found, thus far, to control in similar ways locomotor rhythm generation in most animal models. The aim of this article is to provide a comprehensive review of the known structural and functional features associated with central nervous system (CNS) networks that are involved in the control of ambulation and other stereotyped motor patterns—specifically Central Pattern Generators (CPGs) that produce basic rhythmic patterned outputs for locomotion, micturition, ejaculation, and defecation. Although there is compelling evidence of their existence in humans, CPGs have been most studied in reduced models including in vitro isolated preparations, genetically-engineered mice and spinal cord-transected animals. Compared with other structures of the CNS, the spinal cord is generally considered as being well-preserved phylogenetically. As such, most animal models of spinal cord-injured (SCI) should be considered as valuable tools for the development of novel pharmacological strategies aimed at modulating spinal activity and restoring corresponding functions in chronic SCI patients. PMID:24910602

High-density EEG characterization of brain responses to auditory rhythmic stimuli during wakefulness and NREM sleep.

PubMed

Lustenberger, Caroline; Patel, Yogi A; Alagapan, Sankaraleengam; Page, Jessica M; Price, Betsy; Boyle, Michael R; Fröhlich, Flavio

2018-04-01

Auditory rhythmic sensory stimulation modulates brain oscillations by increasing phase-locking to the temporal structure of the stimuli and by increasing the power of specific frequency bands, resulting in Auditory Steady State Responses (ASSR). The ASSR is altered in different diseases of the central nervous system such as schizophrenia. However, in order to use the ASSR as biological markers for disease states, it needs to be understood how different vigilance states and underlying brain activity affect the ASSR. Here, we compared the effects of auditory rhythmic stimuli on EEG brain activity during wake and NREM sleep, investigated the influence of the presence of dominant sleep rhythms on the ASSR, and delineated the topographical distribution of these modulations. Participants (14 healthy males, 20-33 years) completed on the same day a 60 min nap session and two 30 min wakefulness sessions (before and after the nap). During these sessions, amplitude modulated (AM) white noise auditory stimuli at different frequencies were applied. High-density EEG was continuously recorded and time-frequency analyses were performed to assess ASSR during wakefulness and NREM periods. Our analysis revealed that depending on the electrode location, stimulation frequency applied and window/frequencies analysed the ASSR was significantly modulated by sleep pressure (before and after sleep), vigilance state (wake vs. NREM sleep), and the presence of slow wave activity and sleep spindles. Furthermore, AM stimuli increased spindle activity during NREM sleep but not during wakefulness. Thus, (1) electrode location, sleep history, vigilance state and ongoing brain activity needs to be carefully considered when investigating ASSR and (2) auditory rhythmic stimuli during sleep might represent a powerful tool to boost sleep spindles. Copyright © 2017 Elsevier Inc. All rights reserved.

Multiple forms of rhythmic movements in an adolescent boy with rhythmic movement disorder.

PubMed

Su, Changjun; Miao, Jianting; Liu, Yu; Liu, Rui; Lei, Gesheng; Zhang, Wei; Yang, Ting; Li, Zhuyi

2009-12-01

Rhythmic movement disorder (RMD) refers to a group of stereotyped, repetitive movements involving large muscles, usually occurring prior to the onset of sleep and persisting into sleep. RMD more commonly exhibits only one or two forms of rhythmic movements (RM) in most reported cases. However, multiple RM forms of RMD occurring in a patient in the same night have rarely been reported. In this report, we present the unique case of a 15-year-old boy with RMD affected by multiple forms of RM in the same night, including four known forms (i.e., body rocking, head banging, leg rolling, and rhythmic feet movements) and two new kinds of RM (bilateral rhythmic arm rocking and rhythmic hands movements). Two video-polysomnographic recordings were performed in this patient before starting pharmacologic treatment and after long-term oral clonazepam treatment (1.0mg nightly for 3 months). The characteristics of RMD with multiple RM forms and the effectiveness of clonazepam on the RM episodes and polysomnographic findings observed in our patient are discussed. This report raises the fact that a patient with RMD may present with multiple complex rhythmic movements disrupting sleep, which emphasizes that better understanding of the clinical features of complex rhythmic movements during sleep in primary care settings is essential for early clinical diagnosis and optimal management.

Substance P modulation of TRPC3/7 channels improves respiratory rhythm regularity and ICAN-dependent pacemaker activity

PubMed Central

Ben-Mabrouk, Faiza; Tryba, Andrew Kieran

2011-01-01

Neuromodulators, such as Substance P (SubP) play an important role in modulating many rhythmic activities driven by central pattern generators (e.g., locomotion, respiration). However, the mechanism by which SubP enhances breathing regularity has not been determined. Here, we used mouse brainstem slices containing the pre-Bötzinger Complex (Pre-BötC) to demonstrate, for the first time, that SubP activates transient receptor protein canonical (TRPC) channels to enhance respiratory rhythm regularity. Moreover, SubP enhancement of network regularity is accomplished via selective enhancement of ICAN-dependent intrinsic bursting properties. In contrast to INaP-dependant pacemakers, ICAN-dependant pacemaker bursting activity is TRPC dependent. Western Blots reveal TRPC3 and TRPC7 channels are expressed in rhythmically active ventral respiratory group (VRG) island preparations. Taken together, these data suggest that SubP-mediated activation of TRPC3/7 channels underlies rhythmic ICAN-dependent pacemaker activity and enhances the regularity of respiratory rhythm activity. PMID:20345918

Substance P modulation of TRPC3/7 channels improves respiratory rhythm regularity and ICAN-dependent pacemaker activity.

PubMed

Ben-Mabrouk, Faiza; Tryba, Andrew K

2010-04-01

Neuromodulators, such as substance P (SubP), play an important role in modulating many rhythmic activities driven by central pattern generators (e.g. locomotion, respiration). However, the mechanism by which SubP enhances breathing regularity has not been determined. Here, we used mouse brainstem slices containing the pre-Bötzinger complex to demonstrate, for the first time, that SubP activates transient receptor protein canonical (TRPC) channels to enhance respiratory rhythm regularity. Moreover, SubP enhancement of network regularity is accomplished via selective enhancement of ICAN (inward non-specific cation current)-dependent intrinsic bursting properties. In contrast to INaP (persistent sodium current)-dependent pacemakers, ICAN-dependent pacemaker bursting activity is TRPC-dependent. Western Blots reveal TRPC3 and TRPC7 channels are expressed in rhythmically active ventral respiratory group island preparations. Taken together, these data suggest that SubP-mediated activation of TRPC3/7 channels underlies rhythmic ICAN-dependent pacemaker activity and enhances the regularity of respiratory rhythm activity.

Regulation of Mammalian Physiology by Interconnected Circadian and Feeding Rhythms

PubMed Central

Atger, Florian; Mauvoisin, Daniel; Weger, Benjamin; Gobet, Cédric; Gachon, Frédéric

2017-01-01

Circadian clocks are endogenous timekeeping systems that adapt in an anticipatory fashion the physiology and behavior of most living organisms. In mammals, the master pacemaker resides in the suprachiasmatic nucleus and entrains peripheral clocks using a wide range of signals that differentially schedule physiology and gene expression in a tissue-specific manner. The peripheral clocks, such as those found in the liver, are particularly sensitive to rhythmic external cues like feeding behavior, which modulate the phase and amplitude of rhythmic gene expression. Consequently, the liver clock temporally tunes the expression of many genes involved in metabolism and physiology. However, the circadian modulation of cellular functions also relies on multiple layers of posttranscriptional and posttranslational regulation. Strikingly, these additional regulatory events may happen independently of any transcriptional oscillations, showing that complex regulatory networks ultimately drive circadian output functions. These rhythmic events also integrate feeding-related cues and adapt various metabolic processes to food availability schedules. The importance of such temporal regulation of metabolism is illustrated by metabolic dysfunctions and diseases resulting from circadian clock disruption or inappropriate feeding patterns. Therefore, the study of circadian clocks and rhythmic feeding behavior should be of interest to further advance our understanding of the prevention and therapy of metabolic diseases. PMID:28337174

Model of rhythmic ball bouncing using a visually controlled neural oscillator.

PubMed

Avrin, Guillaume; Siegler, Isabelle A; Makarov, Maria; Rodriguez-Ayerbe, Pedro

2017-10-01

The present paper investigates the sensory-driven modulations of central pattern generator dynamics that can be expected to reproduce human behavior during rhythmic hybrid tasks. We propose a theoretical model of human sensorimotor behavior able to account for the observed data from the ball-bouncing task. The novel control architecture is composed of a Matsuoka neural oscillator coupled with the environment through visual sensory feedback. The architecture's ability to reproduce human-like performance during the ball-bouncing task in the presence of perturbations is quantified by comparison of simulated and recorded trials. The results suggest that human visual control of the task is achieved online. The adaptive behavior is made possible by a parametric and state control of the limit cycle emerging from the interaction of the rhythmic pattern generator, the musculoskeletal system, and the environment. NEW & NOTEWORTHY The study demonstrates that a behavioral model based on a neural oscillator controlled by visual information is able to accurately reproduce human modulations in a motor action with respect to sensory information during the rhythmic ball-bouncing task. The model attractor dynamics emerging from the interaction between the neuromusculoskeletal system and the environment met task requirements, environmental constraints, and human behavioral choices without relying on movement planning and explicit internal models of the environment. Copyright © 2017 the American Physiological Society.

Individual Differences in Rhythmic Cortical Entrainment Correlate with Predictive Behavior in Sensorimotor Synchronization

PubMed Central

Nozaradan, Sylvie; Peretz, Isabelle; Keller, Peter E.

2016-01-01

The current study aims at characterizing the mechanisms that allow humans to entrain the mind and body to incoming rhythmic sensory inputs in real time. We addressed this unresolved issue by examining the relationship between covert neural processes and overt behavior in the context of musical rhythm. We measured temporal prediction abilities, sensorimotor synchronization accuracy and neural entrainment to auditory rhythms as captured using an EEG frequency-tagging approach. Importantly, movement synchronization accuracy with a rhythmic beat could be explained by the amplitude of neural activity selectively locked with the beat period when listening to the rhythmic inputs. Furthermore, stronger endogenous neural entrainment at the beat frequency was associated with superior temporal prediction abilities. Together, these results reveal a direct link between cortical and behavioral measures of rhythmic entrainment, thus providing evidence that frequency-tagged brain activity has functional relevance for beat perception and synchronization. PMID:26847160

Individual Differences in Rhythmic Cortical Entrainment Correlate with Predictive Behavior in Sensorimotor Synchronization.

PubMed

Nozaradan, Sylvie; Peretz, Isabelle; Keller, Peter E

2016-02-05

The current study aims at characterizing the mechanisms that allow humans to entrain the mind and body to incoming rhythmic sensory inputs in real time. We addressed this unresolved issue by examining the relationship between covert neural processes and overt behavior in the context of musical rhythm. We measured temporal prediction abilities, sensorimotor synchronization accuracy and neural entrainment to auditory rhythms as captured using an EEG frequency-tagging approach. Importantly, movement synchronization accuracy with a rhythmic beat could be explained by the amplitude of neural activity selectively locked with the beat period when listening to the rhythmic inputs. Furthermore, stronger endogenous neural entrainment at the beat frequency was associated with superior temporal prediction abilities. Together, these results reveal a direct link between cortical and behavioral measures of rhythmic entrainment, thus providing evidence that frequency-tagged brain activity has functional relevance for beat perception and synchronization.

Programmable Cadence Timer

NASA Technical Reports Server (NTRS)

Hall, William A.; Gilbert, John

1990-01-01

Electronic metronome paces users through wide range of exercise routines. Conceptual programmable cadence timer provides rhythmic aural and visual cues. Timer automatically changes cadence according to program entered by the user. It also functions as clock, stopwatch, or alarm. Modular pacer operated as single unit or as two units. With audiovisual module moved away from base module, user concentrates on exercise cues without distraction from information appearing on the liquid-crystal display. Variety of uses in rehabilitative medicine, experimental medicine, sports, and gymnastics. Used in intermittent positive-pressure breathing treatment, in which patient must rhythmically inhale and retain medication delivered under positive pressure; and in incentive spirometer treatment, in which patient must inhale maximally at regular intervals.

A little elastic for a better performance: kinesiotaping of the motor effector modulates neural mechanisms for rhythmic movements.

PubMed

Bravi, Riccardo; Quarta, Eros; Cohen, Erez J; Gottard, Anna; Minciacchi, Diego

2014-01-01

A rhythmic motor performance is brought about by an integration of timing information with movements. Investigations on the millisecond time scale distinguish two forms of time control, event-based timing and emergent timing. While event-based timing asserts the existence of a central internal timekeeper for the control of repetitive movements, the emergent timing perspective claims that timing emerges from dynamic control of nontemporal movements parameters. We have recently demonstrated that the precision of an isochronous performance, defined as performance of repeated movements having a uniform duration, was insensible to auditory stimuli of various characteristics (Bravi et al., 2014). Such finding has led us to investigate whether the application of an elastic therapeutic tape (Kinesio® Tex taping; KTT) used for treating athletic injuries and a variety of physical disorders, is able to reduce the timing variability of repetitive rhythmic movement. Young healthy subjects, tested with and without KTT, have participated in sessions in which sets of repeated isochronous wrist's flexion-extensions (IWFEs) were performed under various auditory conditions and during their recall. Kinematics was recorded and temporal parameters were extracted and analyzed. Our results show that the application of KTT decreases the variability of rhythmic movements by a 2-fold effect: on the one hand KTT provides extra proprioceptive information activating cutaneous mechanoreceptors, on the other KTT biases toward the emergent timing thus modulating the processes for rhythmic movements. Therefore, KTT appears able to render movements less audio dependent by relieving, at least partially, the central structures from time control and making available more resources for an augmented performance.

A common neural element receiving rhythmic arm and leg activity as assessed by reflex modulation in arm muscles

PubMed Central

Tazoe, Toshiki; Nakajima, Tsuyoshi; Futatsubashi, Genki; Ohtsuka, Hiroyuki; Suzuki, Shinya; Zehr, E. Paul; Komiyama, Tomoyoshi

2016-01-01

Neural interactions between regulatory systems for rhythmic arm and leg movements are an intriguing issue in locomotor neuroscience. Amplitudes of early latency cutaneous reflexes (ELCRs) in stationary arm muscles are modulated during rhythmic leg or arm cycling but not during limb positioning or voluntary contraction. This suggests that interneurons mediating ELCRs to arm muscles integrate outputs from neural systems controlling rhythmic limb movements. Alternatively, outputs could be integrated at the motoneuron and/or supraspinal levels. We examined whether a separate effect on the ELCR pathways and cortico-motoneuronal excitability during arm and leg cycling is integrated by neural elements common to the lumbo-sacral and cervical spinal cord. The subjects performed bilateral leg cycling (LEG), contralateral arm cycling (ARM), and simultaneous contralateral arm and bilateral leg cycling (A&L), while ELCRs in the wrist flexor and shoulder flexor muscles were evoked by superficial radial (SR) nerve stimulation. ELCR amplitudes were facilitated by cycling tasks and were larger during A&L than during ARM and LEG. A low stimulus intensity during ARM or LEG generated a larger ELCR during A&L than the sum of ELCRs during ARM and LEG. We confirmed this nonlinear increase in single motor unit firing probability following SR nerve stimulation during A&L. Furthermore, motor-evoked potentials following transcranial magnetic and electrical stimulation did not show nonlinear potentiation during A&L. These findings suggest the existence of a common neural element of the ELCR reflex pathway that is active only during rhythmic arm and leg movement and receives convergent input from contralateral arms and legs. PMID:26961103

Pregnancy Suppresses the Daily Rhythmicity of Core Body Temperature and Adipose Metabolic Gene Expression in the Mouse.

PubMed

Wharfe, Michaela D; Wyrwoll, Caitlin S; Waddell, Brendan J; Mark, Peter J

2016-09-01

Maternal adaptations in lipid metabolism are crucial for pregnancy success due to the role of white adipose tissue as an energy store and the dynamic nature of energy needs across gestation. Because lipid metabolism is regulated by the rhythmic expression of clock genes, it was hypothesized that maternal metabolic adaptations involve changes in both adipose clock gene expression and the rhythmic expression of downstream metabolic genes. Maternal core body temperature (Tc) was investigated as a possible mechanism driving pregnancy-induced changes in clock gene expression. Gonadal adipose tissue and plasma were collected from C57BL/6J mice before and on days 6, 10, 14, and 18 of pregnancy (term 19 d) at 4-hour intervals across a 24-hour period. Adipose expression of clock genes and downstream metabolic genes were determined by quantitative RT-PCR, and Tc was measured by intraperitoneal temperature loggers. Adipose clock gene expression showed robust rhythmicity throughout pregnancy, but absolute levels varied substantially across gestation. Rhythmic expression of the metabolic genes Lipe, Pnpla2, and Lpl was clearly evident before pregnancy; however, this rhythmicity was lost with the onset of pregnancy. Tc rhythm was significantly altered by pregnancy, with a 65% decrease in amplitude by term and a 0.61°C decrease in mesor between days 6 and 18. These changes in Tc, however, did not appear to be linked to adipose clock gene expression across pregnancy. Overall, our data show marked adaptations in the adipose clock in pregnancy, with an apparent decoupling of adipose clock and lipolytic/lipogenic gene rhythms from early in gestation.

The Quantifying Analysis of Effectiveness of Music Learning Through the Dalcroze Musical Method

ERIC Educational Resources Information Center

Wang, Dennis Ping-Cheng

2008-01-01

Movement activities can be used to integrate with any other curriculum in childhood education. The movements can inspire the sense of rhythmic concepts for children. This study aims at investigating how children can be motivated and inspired rhythmically by body movement through Dalcroze approach. In this research, the author revealed how physical…

Daily Rhythmic Behaviors and Thermoregulatory Patterns Are Disrupted in Adult Female MeCP2-Deficient Mice

PubMed Central

Wu, Chiping; Bardakjian, Berj L.; Zhang, Liang; Eubanks, James H.

2012-01-01

Mutations in the X-linked gene encoding Methyl-CpG-binding protein 2 (MECP2) have been associated with neurodevelopmental and neuropsychiatric disorders including Rett Syndrome, X-linked mental retardation syndrome, severe neonatal encephalopathy, and Angelman syndrome. Although alterations in the performance of MeCP2-deficient mice in specific behavioral tasks have been documented, it remains unclear whether or not MeCP2 dysfunction affects patterns of periodic behavioral and electroencephalographic (EEG) activity. The aim of the current study was therefore to determine whether a deficiency in MeCP2 is sufficient to alter the normal daily rhythmic patterns of core body temperature, gross motor activity and cortical delta power. To address this, we monitored individual wild-type and MeCP2-deficient mice in their home cage environment via telemetric recording over 24 hour cycles. Our results show that the normal daily rhythmic behavioral patterning of cortical delta wave activity, core body temperature and mobility are disrupted in one-year old female MeCP2-deficient mice. Moreover, female MeCP2-deficient mice display diminished overall motor activity, lower average core body temperature, and significantly greater body temperature fluctuation than wild-type mice in their home-cage environment. Finally, we show that the epileptiform discharge activity in female MeCP2-deficient mice is more predominant during times of behavioral activity compared to inactivity. Collectively, these results indicate that MeCP2 deficiency is sufficient to disrupt the normal patterning of daily biological rhythmic activities. PMID:22523589

Molecular bases of circadian rhythmicity in renal physiology and pathology

PubMed Central

Bonny, Olivier; Vinciguerra, Manlio; Gumz, Michelle L.; Mazzoccoli, Gianluigi

2013-01-01

The physiological processes that maintain body homeostasis oscillate during the day. Diurnal changes characterize kidney functions, comprising regulation of hydro-electrolytic and acid-base balance, reabsorption of small solutes and hormone production. Renal physiology is characterized by 24-h periodicity and contributes to circadian variability of blood pressure levels, related as well to nychthemeral changes of sodium sensitivity, physical activity, vascular tone, autonomic function and neurotransmitter release from sympathetic innervations. The circadian rhythmicity of body physiology is driven by central and peripheral biological clockworks and entrained by the geophysical light/dark cycle. Chronodisruption, defined as the mismatch between environmental–social cues and physiological–behavioral patterns, causes internal desynchronization of periodic functions, leading to pathophysiological mechanisms underlying degenerative, immune related, metabolic and neoplastic diseases. In this review we will address the genetic, molecular and anatomical elements that hardwire circadian rhythmicity in renal physiology and subtend disarray of time–dependent changes in renal pathology. PMID:23901050

Neural control of rhythmic arm cycling after stroke

PubMed Central

Loadman, Pamela M.; Hundza, Sandra R.

2012-01-01

Disordered reflex activity and alterations in the neural control of walking have been observed after stroke. In addition to impairments in leg movement that affect locomotor ability after stroke, significant impairments are also seen in the arms. Altered neural control in the upper limb can often lead to altered tone and spasticity resulting in impaired coordination and flexion contractures. We sought to address the extent to which the neural control of movement is disordered after stroke by examining the modulation pattern of cutaneous reflexes in arm muscles during arm cycling. Twenty-five stroke participants who were at least 6 mo postinfarction and clinically stable, performed rhythmic arm cycling while cutaneous reflexes were evoked with trains (5 × 1.0-ms pulses at 300 Hz) of constant-current electrical stimulation to the superficial radial (SR) nerve at the wrist. Both the more (MA) and less affected (LA) arms were stimulated in separate trials. Bilateral electromyography (EMG) activity was recorded from muscles acting at the shoulder, elbow, and wrist. Analysis was conducted on averaged reflexes in 12 equidistant phases of the movement cycle. Phase-modulated cutaneous reflexes were present, but altered, in both MA and LA arms after stroke. Notably, the pattern was “blunted” in the MA arm in stroke compared with control participants. Differences between stroke and control were progressively more evident moving from shoulder to wrist. The results suggest that a reduced pattern of cutaneous reflex modulation persists during rhythmic arm movement after stroke. The overall implication of this result is that the putative spinal contributions to rhythmic human arm movement remain accessible after stroke, which has translational implications for rehabilitation. PMID:22572949

Biological Inspiration for Agile Autonomous Air Vehicles

DTIC Science & Technology

2007-11-01

rhythmically contract the thorax; the hind wings have become specialized as small body rotation sensors (halteres). Butterflies and moths have two pairs of...orthogonal pairs of power muscles that produce alternating dorso-ventral and longitudinal flexure of the thorax from rhythmic contractions similar to...other physical sciences lend themselves to somewhat reductionist approaches for both analysis and synthesis. Complex engineered systems are built from

Nitric oxide-mediated intersegmental modulation of cycle frequency in the crayfish swimmeret system.

PubMed

Yoshida, Misaki; Nagayama, Toshiki; Newland, Philip

2018-05-21

Crayfish swimmerets are paired appendages located on the ventral side of each abdominal segment that show rhythmic beating during forward swimming produced by central pattern generators in most abdominal segments. For animals with multiple body segments and limbs, intersegmental coordination of central pattern generators in each segment is crucial for the production of effective movements. Here we develop a novel pharmacological approach to analyse intersegmental modulation of swimmeret rhythm by selectively elevating nitric oxide levels and reducing them with pharmacological agents, in specific ganglia. Bath application of L-arginine, the substrate NO synthesis, increased the cyclical spike responses of the power-stroke motor neurons. By contrast the NOS inhibitor, L-NAME decreased them. To determine the role of the different local centres in producing and controlling the swimmeret rhythm, these two drugs were applied locally to two separate ganglia following bath application of carbachol. Results revealed that there was both ascending and descending intersegmental modulation of cycle frequency of the swimmeret rhythm in the abdominal ganglia and that synchrony of cyclical activity between segments of segments was maintained. We also found that there were gradients in the strength effectiveness in modulation, that ascending modulation of the swimmeret rhythm was stronger than descending modulation. © 2018. Published by The Company of Biologists Ltd.

A little elastic for a better performance: kinesiotaping of the motor effector modulates neural mechanisms for rhythmic movements

PubMed Central

Bravi, Riccardo; Quarta, Eros; Cohen, Erez J.; Gottard, Anna; Minciacchi, Diego

2014-01-01

A rhythmic motor performance is brought about by an integration of timing information with movements. Investigations on the millisecond time scale distinguish two forms of time control, event-based timing and emergent timing. While event-based timing asserts the existence of a central internal timekeeper for the control of repetitive movements, the emergent timing perspective claims that timing emerges from dynamic control of nontemporal movements parameters. We have recently demonstrated that the precision of an isochronous performance, defined as performance of repeated movements having a uniform duration, was insensible to auditory stimuli of various characteristics (Bravi et al., 2014). Such finding has led us to investigate whether the application of an elastic therapeutic tape (Kinesio® Tex taping; KTT) used for treating athletic injuries and a variety of physical disorders, is able to reduce the timing variability of repetitive rhythmic movement. Young healthy subjects, tested with and without KTT, have participated in sessions in which sets of repeated isochronous wrist's flexion-extensions (IWFEs) were performed under various auditory conditions and during their recall. Kinematics was recorded and temporal parameters were extracted and analyzed. Our results show that the application of KTT decreases the variability of rhythmic movements by a 2-fold effect: on the one hand KTT provides extra proprioceptive information activating cutaneous mechanoreceptors, on the other KTT biases toward the emergent timing thus modulating the processes for rhythmic movements. Therefore, KTT appears able to render movements less audio dependent by relieving, at least partially, the central structures from time control and making available more resources for an augmented performance. PMID:25309355

A common neural element receiving rhythmic arm and leg activity as assessed by reflex modulation in arm muscles.

PubMed

Sasada, Syusaku; Tazoe, Toshiki; Nakajima, Tsuyoshi; Futatsubashi, Genki; Ohtsuka, Hiroyuki; Suzuki, Shinya; Zehr, E Paul; Komiyama, Tomoyoshi

2016-04-01

Neural interactions between regulatory systems for rhythmic arm and leg movements are an intriguing issue in locomotor neuroscience. Amplitudes of early latency cutaneous reflexes (ELCRs) in stationary arm muscles are modulated during rhythmic leg or arm cycling but not during limb positioning or voluntary contraction. This suggests that interneurons mediating ELCRs to arm muscles integrate outputs from neural systems controlling rhythmic limb movements. Alternatively, outputs could be integrated at the motoneuron and/or supraspinal levels. We examined whether a separate effect on the ELCR pathways and cortico-motoneuronal excitability during arm and leg cycling is integrated by neural elements common to the lumbo-sacral and cervical spinal cord. The subjects performed bilateral leg cycling (LEG), contralateral arm cycling (ARM), and simultaneous contralateral arm and bilateral leg cycling (A&L), while ELCRs in the wrist flexor and shoulder flexor muscles were evoked by superficial radial (SR) nerve stimulation. ELCR amplitudes were facilitated by cycling tasks and were larger during A&L than during ARM and LEG. A low stimulus intensity during ARM or LEG generated a larger ELCR during A&L than the sum of ELCRs during ARM and LEG. We confirmed this nonlinear increase in single motor unit firing probability following SR nerve stimulation during A&L. Furthermore, motor-evoked potentials following transcranial magnetic and electrical stimulation did not show nonlinear potentiation during A&L. These findings suggest the existence of a common neural element of the ELCR reflex pathway that is active only during rhythmic arm and leg movement and receives convergent input from contralateral arms and legs. Copyright © 2016 the American Physiological Society.

Application of a model of the auditory primal sketch to cross-linguistic differences in speech rhythm: Implications for the acquisition and recognition of speech

NASA Astrophysics Data System (ADS)

Todd, Neil P. M.; Lee, Christopher S.

2002-05-01

It has long been noted that the world's languages vary considerably in their rhythmic organization. Different languages seem to privilege different phonological units as their basic rhythmic unit, and there is now a large body of evidence that such differences have important consequences for crucial aspects of language acquisition and processing. The most fundamental finding is that the rhythmic structure of a language strongly influences the process of spoken-word recognition. This finding, together with evidence that infants are sensitive from birth to rhythmic differences between languages, and exploit rhythmic cues to segmentation at an earlier developmental stage than other cues prompted the claim that rhythm is the key which allows infants to begin building a lexicon and then go on to acquire syntax. It is therefore of interest to determine how differences in rhythmic organization arise at the acoustic/auditory level. In this paper, it is shown how an auditory model of the primitive representation of sound provides just such an account of rhythmic differences. Its performance is evaluated on a data set of French and English sentences and compared with the results yielded by the phonetic accounts of Frank Ramus and his colleagues and Esther Grabe and her colleagues.

Cascaded Amplitude Modulations in Sound Texture Perception

PubMed Central

McWalter, Richard; Dau, Torsten

2017-01-01

Sound textures, such as crackling fire or chirping crickets, represent a broad class of sounds defined by their homogeneous temporal structure. It has been suggested that the perception of texture is mediated by time-averaged summary statistics measured from early auditory representations. In this study, we investigated the perception of sound textures that contain rhythmic structure, specifically second-order amplitude modulations that arise from the interaction of different modulation rates, previously described as “beating” in the envelope-frequency domain. We developed an auditory texture model that utilizes a cascade of modulation filterbanks that capture the structure of simple rhythmic patterns. The model was examined in a series of psychophysical listening experiments using synthetic sound textures—stimuli generated using time-averaged statistics measured from real-world textures. In a texture identification task, our results indicated that second-order amplitude modulation sensitivity enhanced recognition. Next, we examined the contribution of the second-order modulation analysis in a preference task, where the proposed auditory texture model was preferred over a range of model deviants that lacked second-order modulation rate sensitivity. Lastly, the discriminability of textures that included second-order amplitude modulations appeared to be perceived using a time-averaging process. Overall, our results demonstrate that the inclusion of second-order modulation analysis generates improvements in the perceived quality of synthetic textures compared to the first-order modulation analysis considered in previous approaches. PMID:28955191

Cascaded Amplitude Modulations in Sound Texture Perception.

PubMed

McWalter, Richard; Dau, Torsten

2017-01-01

Sound textures, such as crackling fire or chirping crickets, represent a broad class of sounds defined by their homogeneous temporal structure. It has been suggested that the perception of texture is mediated by time-averaged summary statistics measured from early auditory representations. In this study, we investigated the perception of sound textures that contain rhythmic structure, specifically second-order amplitude modulations that arise from the interaction of different modulation rates, previously described as "beating" in the envelope-frequency domain. We developed an auditory texture model that utilizes a cascade of modulation filterbanks that capture the structure of simple rhythmic patterns. The model was examined in a series of psychophysical listening experiments using synthetic sound textures-stimuli generated using time-averaged statistics measured from real-world textures. In a texture identification task, our results indicated that second-order amplitude modulation sensitivity enhanced recognition. Next, we examined the contribution of the second-order modulation analysis in a preference task, where the proposed auditory texture model was preferred over a range of model deviants that lacked second-order modulation rate sensitivity. Lastly, the discriminability of textures that included second-order amplitude modulations appeared to be perceived using a time-averaging process. Overall, our results demonstrate that the inclusion of second-order modulation analysis generates improvements in the perceived quality of synthetic textures compared to the first-order modulation analysis considered in previous approaches.

Changes in bone density and bone markers in rhythmic gymnasts and ballet dancers: implications for puberty and leptin levels.

PubMed

Muñoz, María Teresa; de la Piedra, Concepción; Barrios, Vicente; Garrido, Guadalupe; Argente, Jesús

2004-10-01

Our aim was to compare physical activity and biochemical markers with bone mineral acquisition in rhythmic gymnasts and ballet dancers. Weight, height, body mass index, nutritional intake, bone age and menstrual histories were analyzed in nine rhythmic gymnasts, twelve ballet dancers and fourteen controls. Bone mineral density (BMD) was assessed by X-ray absorptiometry at the lumbar spine, hip and radius. Bone alkaline phosphatase (bAP) and amino-terminal propeptide of procollagen I (PNIP) in serum and urinary alpha-isomer of the carboxy-terminal telopeptide of collagen I (alpha-CTX) were measured. Bone age was delayed 2 years and mean age at menarche was 15+/-0.9 years in rhythmic gymnasts and 13.7+/-1 years in ballet dancers, compared with 12.5+/-1 years in controls. Trocanteric and femoral neck BMD was significantly higher in rhythmic gymnasts compared with ballet dancers and controls. Right forearm (non-loaded zone) BMD was significantly decreased in rhythmic gymnasts and ballet dancers compared with controls. All subjects had normal bAP and PNIP levels, but the alpha-CTX/creatinine (Cr) ratio was increased in rhythmic gymnasts (P<0.001) with an inverse correlation between right forearm BMD and the alpha-CTX/Cr ratio (r=-0.74, P<0.001). Serum leptin levels were decreased in rhythmic gymnasts and ballet dancers. Rhythmic gymnasts had a positive correlation between right forearm BMD and leptin levels (r=0.85, P<0.001). Decreased bone mass in rhythmic gymnasts could be partially explained by an increase in bone resorption. Serum leptin levels could be implicated in the pubertal delay and be a good marker of bone mass in these subjects.

Temporal phasing of locomotor activity, heart rate rhythmicity, and core body temperature is disrupted in VIP receptor 2-deficient mice.

PubMed

Hannibal, Jens; Hsiung, Hansen M; Fahrenkrug, Jan

2011-03-01

Neurons of the brain's biological clock located in the hypothalamic suprachiasmatic nucleus (SCN) generate circadian rhythms of physiology (core body temperature, hormone secretion, locomotor activity, sleep/wake, and heart rate) with distinct temporal phasing when entrained by the light/dark (LD) cycle. The neuropeptide vasoactive intestinal polypetide (VIP) and its receptor (VPAC2) are highly expressed in the SCN. Recent studies indicate that VIPergic signaling plays an essential role in the maintenance of ongoing circadian rhythmicity by synchronizing SCN cells and by maintaining rhythmicity within individual neurons. To further increase the understanding of the role of VPAC2 signaling in circadian regulation, we implanted telemetric devices and simultaneously measured core body temperature, spontaneous activity, and heart rate in a strain of VPAC2-deficient mice and compared these observations with observations made from mice examined by wheel-running activity. The study demonstrates that VPAC2 signaling is necessary for a functional circadian clock driving locomotor activity, core body temperature, and heart rate rhythmicity, since VPAC2-deficient mice lose the rhythms in all three parameters when placed under constant conditions (of either light or darkness). Furthermore, although 24-h rhythms for three parameters are retained in VPAC2-deficient mice during the LD cycle, the temperature rhythm displays markedly altered time course and profile, rising earlier and peaking ∼4-6 h prior to that of wild-type mice. The use of telemetric devices to measure circadian locomotor activity, temperature, and heart rate, together with the classical determination of circadian rhythms of wheel-running activity, raises questions about how representative wheel-running activity may be of other behavioral parameters, especially when animals have altered circadian phenotype.

Unpredicted Pitch Modulates Beta Oscillatory Power during Rhythmic Entrainment to a Tone Sequence.

PubMed

Chang, Andrew; Bosnyak, Dan J; Trainor, Laurel J

2016-01-01

Extracting temporal regularities in external stimuli in order to predict upcoming events is an essential aspect of perception. Fluctuations in induced power of beta band (15-25 Hz) oscillations in auditory cortex are involved in predictive timing during rhythmic entrainment, but whether such fluctuations are affected by prediction in the spectral (frequency/pitch) domain remains unclear. We tested whether unpredicted (i.e., unexpected) pitches in a rhythmic tone sequence modulate beta band activity by recording EEG while participants passively listened to isochronous auditory oddball sequences with occasional unpredicted deviant pitches at two different presentation rates. The results showed that the power in low-beta (15-20 Hz) was larger around 200-300 ms following deviant tones compared to standard tones, and this effect was larger when the deviant tones were less predicted. Our results suggest that the induced beta power activities in auditory cortex are consistent with a role in sensory prediction of both "when" (timing) upcoming sounds will occur as well as the prediction precision error of "what" (spectral content in this case). We suggest, further, that both timing and content predictions may co-modulate beta oscillations via attention. These findings extend earlier work on neural oscillations by investigating the functional significance of beta oscillations for sensory prediction. The findings help elucidate the functional significance of beta oscillations in perception.

Serotonin receptor 1A–modulated phosphorylation of glycine receptor α3 controls breathing in mice

PubMed Central

Manzke, Till; Niebert, Marcus; Koch, Uwe R.; Caley, Alex; Vogelgesang, Steffen; Hülsmann, Swen; Ponimaskin, Evgeni; Müller, Ulrike; Smart, Trevor G.; Harvey, Robert J.; Richter, Diethelm W.

2010-01-01

Rhythmic breathing movements originate from a dispersed neuronal network in the medulla and pons. Here, we demonstrate that rhythmic activity of this respiratory network is affected by the phosphorylation status of the inhibitory glycine receptor α3 subtype (GlyRα3), which controls glutamatergic and glycinergic neuronal discharges, subject to serotonergic modulation. Serotonin receptor type 1A–specific (5-HTR1A–specific) modulation directly induced dephosphorylation of GlyRα3 receptors, which augmented inhibitory glycine-activated chloride currents in HEK293 cells coexpressing 5-HTR1A and GlyRα3. The 5-HTR1A–GlyRα3 signaling pathway was distinct from opioid receptor signaling and efficiently counteracted opioid-induced depression of breathing and consequential apnea in mice. Paradoxically, this rescue of breathing originated from enhanced glycinergic synaptic inhibition of glutamatergic and glycinergic neurons and caused disinhibition of their target neurons. Together, these effects changed respiratory phase alternations and ensured rhythmic breathing in vivo. GlyRα3-deficient mice had an irregular respiratory rhythm under baseline conditions, and systemic 5-HTR1A activation failed to remedy opioid-induced respiratory depression in these mice. Delineation of this 5-HTR1A–GlyRα3 signaling pathway offers a mechanistic basis for pharmacological treatment of opioid-induced apnea and other breathing disturbances caused by disorders of inhibitory synaptic transmission, such as hyperekplexia, hypoxia/ischemia, and brainstem infarction. PMID:20978350

Unpredicted Pitch Modulates Beta Oscillatory Power during Rhythmic Entrainment to a Tone Sequence

PubMed Central

Chang, Andrew; Bosnyak, Dan J.; Trainor, Laurel J.

2016-01-01

Extracting temporal regularities in external stimuli in order to predict upcoming events is an essential aspect of perception. Fluctuations in induced power of beta band (15–25 Hz) oscillations in auditory cortex are involved in predictive timing during rhythmic entrainment, but whether such fluctuations are affected by prediction in the spectral (frequency/pitch) domain remains unclear. We tested whether unpredicted (i.e., unexpected) pitches in a rhythmic tone sequence modulate beta band activity by recording EEG while participants passively listened to isochronous auditory oddball sequences with occasional unpredicted deviant pitches at two different presentation rates. The results showed that the power in low-beta (15–20 Hz) was larger around 200–300 ms following deviant tones compared to standard tones, and this effect was larger when the deviant tones were less predicted. Our results suggest that the induced beta power activities in auditory cortex are consistent with a role in sensory prediction of both “when” (timing) upcoming sounds will occur as well as the prediction precision error of “what” (spectral content in this case). We suggest, further, that both timing and content predictions may co-modulate beta oscillations via attention. These findings extend earlier work on neural oscillations by investigating the functional significance of beta oscillations for sensory prediction. The findings help elucidate the functional significance of beta oscillations in perception. PMID:27014138

Autonomous Rhythmic Drug Delivery Systems Based on Chemical and Biochemomechanical Oscillators

NASA Astrophysics Data System (ADS)

Siegel, Ronald A.

While many drug delivery systems target constant, or zero-order drug release, certain drugs and hormones must be delivered in rhythmic pulses in order to achieve their optimal effect. Here we describe studies with two model autonomous rhythmic delivery systems. The first system is driven by a pH oscillator that modulates the ionization state of a model drug, benzoic acid, which can permeate through a lipophilic membrane when the drug is uncharged. The second system is based on a nonlinear negative feedback instability that arises from coupling of swelling of a hydrogel membrane to an enzymatic reaction, with the hydrogel controlling access of substrate to the enzyme, and the enzyme's product controlling the hydrogel's swelling state. The latter system, whose autonomous oscillations are driven by glucose at constant external activity, is shown to deliver gonadotropin releasing hormone (GnRH) in rhythmic pulses, with periodicity of the same order as observed in sexually mature adult humans. Relevant experimental results and some mathematical models are reviewed.

Shared rhythmic subcortical GABAergic input to the entorhinal cortex and presubiculum

PubMed Central

Salib, Minas; Joshi, Abhilasha; Unal, Gunes; Berry, Naomi

2018-01-01

Rhythmic theta frequency (~5–12 Hz) oscillations coordinate neuronal synchrony and higher frequency oscillations across the cortex. Spatial navigation and context-dependent episodic memories are represented in several interconnected regions including the hippocampal and entorhinal cortices, but the cellular mechanisms for their dynamic coupling remain to be defined. Using monosynaptically-restricted retrograde viral tracing in mice, we identified a subcortical GABAergic input from the medial septum that terminated in the entorhinal cortex, with collaterals innervating the dorsal presubiculum. Extracellularly recording and labeling GABAergic entorhinal-projecting neurons in awake behaving mice show that these subcortical neurons, named orchid cells, fire in long rhythmic bursts during immobility and locomotion. Orchid cells discharge near the peak of hippocampal and entorhinal theta oscillations, couple to entorhinal gamma oscillations, and target subpopulations of extra-hippocampal GABAergic interneurons. Thus, orchid cells are a specialized source of rhythmic subcortical GABAergic modulation of ‘upstream’ and ‘downstream’ cortico-cortical circuits involved in mnemonic functions. PMID:29620525

Shared rhythmic subcortical GABAergic input to the entorhinal cortex and presubiculum.

PubMed

Viney, Tim James; Salib, Minas; Joshi, Abhilasha; Unal, Gunes; Berry, Naomi; Somogyi, Peter

2018-04-05

Rhythmic theta frequency (~5-12 Hz) oscillations coordinate neuronal synchrony and higher frequency oscillations across the cortex. Spatial navigation and context-dependent episodic memories are represented in several interconnected regions including the hippocampal and entorhinal cortices, but the cellular mechanisms for their dynamic coupling remain to be defined. Using monosynaptically-restricted retrograde viral tracing in mice, we identified a subcortical GABAergic input from the medial septum that terminated in the entorhinal cortex, with collaterals innervating the dorsal presubiculum. Extracellularly recording and labeling GABAergic entorhinal-projecting neurons in awake behaving mice show that these subcortical neurons, named orchid cells, fire in long rhythmic bursts during immobility and locomotion. Orchid cells discharge near the peak of hippocampal and entorhinal theta oscillations, couple to entorhinal gamma oscillations, and target subpopulations of extra-hippocampal GABAergic interneurons. Thus, orchid cells are a specialized source of rhythmic subcortical GABAergic modulation of 'upstream' and 'downstream' cortico-cortical circuits involved in mnemonic functions. © 2018, Viney et al.

Rhythmic movement disorder in childhood: An integrative review.

PubMed

Gwyther, Amy R M; Walters, Arthur S; Hill, Catherine M

2017-10-01

Rhythmic movement disorder consists of repetitive stereotypic movements, such as head banging or body rocking, that recur every second or so and may last from a few minutes to hours, usually prior to sleep onset. This review of childhood rhythmic movement disorder highlights the lack of systematic research into core aspects of the condition, relying heavily on small case series or case reports. Interpretation is further limited by almost universal failure to confirm the core diagnostic criteria (C) of the International classification of sleep disorders (III), namely that the rhythmic movements should have clinical consequences. Nonetheless, a number of themes emerge. Rhythmic movement disorder is likely to start in infancy and have a developmental course with spontaneous resolution in early childhood in many cases. Factors associated with persistence are, however, unclear. Associations with ADHD and neurodevelopmental disorders are intriguing, require further study and may shed light on the underlying cause of the condition. There is a pressing need for a systematic approach to classify rhythmic movement disorder, to allow standardization of the much needed research into the underlying aetiology and treatment of this relatively neglected sleep disorder. Copyright © 2016 Elsevier Ltd. All rights reserved.

Time-frequency analysis of human motion during rhythmic exercises.

PubMed

Omkar, S N; Vyas, Khushi; Vikranth, H N

2011-01-01

Biomechanical signals due to human movements during exercise are represented in time-frequency domain using Wigner Distribution Function (WDF). Analysis based on WDF reveals instantaneous spectral and power changes during a rhythmic exercise. Investigations were carried out on 11 healthy subjects who performed 5 cycles of sun salutation, with a body-mounted Inertial Measurement Unit (IMU) as a motion sensor. Variance of Instantaneous Frequency (I.F) and Instantaneous Power (I.P) for performance analysis of the subject is estimated using one-way ANOVA model. Results reveal that joint Time-Frequency analysis of biomechanical signals during motion facilitates a better understanding of grace and consistency during rhythmic exercise.

Emotional responses to Hindustani raga music: the role of musical structure

PubMed Central

Mathur, Avantika; Vijayakumar, Suhas H.; Chakrabarti, Bhismadev; Singh, Nandini C.

2015-01-01

In Indian classical music, ragas constitute specific combinations of tonic intervals potentially capable of evoking distinct emotions. A raga composition is typically presented in two modes, namely, alaap and gat. Alaap is the note by note delineation of a raga bound by a slow tempo, but not bound by a rhythmic cycle. Gat on the other hand is rendered at a faster tempo and follows a rhythmic cycle. Our primary objective was to (1) discriminate the emotions experienced across alaap and gat of ragas, (2) investigate the association of tonic intervals, tempo and rhythmic regularity with emotional response. 122 participants rated their experienced emotion across alaap and gat of 12 ragas. Analysis of the emotional responses revealed that (1) ragas elicit distinct emotions across the two presentation modes, and (2) specific tonic intervals are robust predictors of emotional response. Specifically, our results showed that the ‘minor second’ is a direct predictor of negative valence. (3) Tonality determines the emotion experienced for a raga where as rhythmic regularity and tempo modulate levels of arousal. Our findings provide new insights into the emotional response to Indian ragas and the impact of tempo, rhythmic regularity and tonality on it. PMID:25983702

Emotional responses to Hindustani raga music: the role of musical structure.

PubMed

Mathur, Avantika; Vijayakumar, Suhas H; Chakrabarti, Bhismadev; Singh, Nandini C

2015-01-01

In Indian classical music, ragas constitute specific combinations of tonic intervals potentially capable of evoking distinct emotions. A raga composition is typically presented in two modes, namely, alaap and gat. Alaap is the note by note delineation of a raga bound by a slow tempo, but not bound by a rhythmic cycle. Gat on the other hand is rendered at a faster tempo and follows a rhythmic cycle. Our primary objective was to (1) discriminate the emotions experienced across alaap and gat of ragas, (2) investigate the association of tonic intervals, tempo and rhythmic regularity with emotional response. 122 participants rated their experienced emotion across alaap and gat of 12 ragas. Analysis of the emotional responses revealed that (1) ragas elicit distinct emotions across the two presentation modes, and (2) specific tonic intervals are robust predictors of emotional response. Specifically, our results showed that the 'minor second' is a direct predictor of negative valence. (3) Tonality determines the emotion experienced for a raga where as rhythmic regularity and tempo modulate levels of arousal. Our findings provide new insights into the emotional response to Indian ragas and the impact of tempo, rhythmic regularity and tonality on it.

The design of a device for hearer and feeler differentiation, part A. [speech modulated hearing device

NASA Technical Reports Server (NTRS)

Creecy, R.

1974-01-01

A speech modulated white noise device is reported that gives the rhythmic characteristics of a speech signal for intelligible reception by deaf persons. The signal is composed of random amplitudes and frequencies as modulated by the speech envelope characteristics of rhythm and stress. Time intensity parameters of speech are conveyed through the vibro-tactile sensation stimuli.

Jactatio corporis nocturna and dissociative disorder: a case report.

PubMed

Pelin, Zerrin; Karataş, Semra; Kesebir, Sermin

2012-01-01

Jactatio corporis nocturna is a type of parasomnia. Rhythmic body movements during sleep are commonly observed in infancy and early childhood, and spontaneous resolution is expected after the age of 4 years. Rarely, the body movements persist until adulthood. Rhythmic body movements characteristically occur during the wake-sleep transition period, rather than during other sleep stages. Some psychiatric diseases can co-occur with sleep-related movement disorders. A relationship between parasomnias and dissociative disorders has been recently reported. Herein we present a 33-year-old male with nocturnal repetitive rolling body movements and daytime fatigue. The patient also had loss of memory of some important events (such as the day his daughter underwent surgery), and reported that he sometimes confused reality with dreams had fantasies during which he experienced his spirit rising above to watch his body and fantasy. Detailed neuropsychological assessment showed that the patient also had a dissociative disorder. Video-polysomnographic recordings showed repetitive, rolling body movements that occurred only during rapid eye movement (REM) sleep.

Effects of Articulation Styles on Perception of Modulated Tempos in Violin Excerpts

ERIC Educational Resources Information Center

Geringer, John M.; Madsen, Clifford K.; Macleod, Rebecca B.

2007-01-01

We investigated effects of legato, staccato and pizzicato articulation styles on the perception of modulated tempos. Seventy-two music majors served as participants. Two solo violin excerpts were chosen with contrasting rhythmic rates and were recorded in all three articulation styles. Examples were presented to listeners in three conditions of…

A positive feedback at the cellular level promotes robustness and modulation at the circuit level

PubMed Central

Dethier, Julie; Drion, Guillaume; Franci, Alessio

2015-01-01

This article highlights the role of a positive feedback gating mechanism at the cellular level in the robustness and modulation properties of rhythmic activities at the circuit level. The results are presented in the context of half-center oscillators, which are simple rhythmic circuits composed of two reciprocally connected inhibitory neuronal populations. Specifically, we focus on rhythms that rely on a particular excitability property, the postinhibitory rebound, an intrinsic cellular property that elicits transient membrane depolarization when released from hyperpolarization. Two distinct ionic currents can evoke this transient depolarization: a hyperpolarization-activated cation current and a low-threshold T-type calcium current. The presence of a slow activation is specific to the T-type calcium current and provides a slow positive feedback at the cellular level that is absent in the cation current. We show that this slow positive feedback is required to endow the network rhythm with physiological modulation and robustness properties. This study thereby identifies an essential cellular property to be retained at the network level in modeling network robustness and modulation. PMID:26311181

Rate change detection of frequency modulated signals: developmental trends.

PubMed

Cohen-Mimran, Ravit; Sapir, Shimon

2011-08-26

The aim of this study was to examine developmental trends in rate change detection of auditory rhythmic signals (repetitive sinusoidally frequency modulated tones). Two groups of children (9-10 years old and 11-12 years old) and one group of young adults performed a rate change detection (RCD) task using three types of stimuli. The rate of stimulus modulation was either constant (CR), raised by 1 Hz in the middle of the stimulus (RR1) or raised by 2 Hz in the middle of the stimulus (RR2). Performance on the RCD task significantly improved with age. Also, the different stimuli showed different developmental trajectories. When the RR2 stimulus was used, results showed adult-like performance by the age of 10 years but when the RR1 stimulus was used performance continued to improve beyond 12 years of age. Rate change detection of repetitive sinusoidally frequency modulated tones show protracted development beyond the age of 12 years. Given evidence for abnormal processing of auditory rhythmic signals in neurodevelopmental conditions, such as dyslexia, the present methodology might help delineate the nature of these conditions.

Significance of circadian rhythms in severely brain-injured patients

PubMed Central

Lechinger, Julia; Santhi, Nayantara; del Giudice, Renata; Gnjezda, Maria-Teresa; Pichler, Gerald; Scarpatetti, Monika; Donis, Johann; Michitsch, Gabriele; Schabus, Manuel

2017-01-01

Objective: To investigate the relationship between the presence of a circadian body temperature rhythm and behaviorally assessed consciousness levels in patients with disorders of consciousness (DOC; i.e., vegetative state/unresponsive wakefulness syndrome or minimally conscious state). Methods: In a cross-sectional study, we investigated the presence of circadian temperature rhythms across 6 to 7 days using external skin temperature sensors in 18 patients with DOC. Beyond this, we examined the relationship between behaviorally assessed consciousness levels and circadian rhythmicity. Results: Analyses with Lomb-Scargle periodograms revealed significant circadian rhythmicity in all patients (range 23.5–26.3 hours). We found that especially scores on the arousal subscale of the Coma Recovery Scale–Revised were closely linked to the integrity of circadian variations in body temperature. Finally, we piloted whether bright light stimulation could boost circadian rhythmicity and found positive evidence in 2 out of 8 patients. Conclusion: The study provides evidence for an association between circadian body temperature rhythms and arousal as a necessary precondition for consciousness. Our findings also make a case for circadian rhythms as a target for treatment as well as the application of diagnostic and therapeutic means at times when cognitive performance is expected to peak. PMID:28424270

A circadian gene expression atlas in mammals: implications for biology and medicine.

PubMed

Zhang, Ray; Lahens, Nicholas F; Ballance, Heather I; Hughes, Michael E; Hogenesch, John B

2014-11-11

To characterize the role of the circadian clock in mouse physiology and behavior, we used RNA-seq and DNA arrays to quantify the transcriptomes of 12 mouse organs over time. We found 43% of all protein coding genes showed circadian rhythms in transcription somewhere in the body, largely in an organ-specific manner. In most organs, we noticed the expression of many oscillating genes peaked during transcriptional "rush hours" preceding dawn and dusk. Looking at the genomic landscape of rhythmic genes, we saw that they clustered together, were longer, and had more spliceforms than nonoscillating genes. Systems-level analysis revealed intricate rhythmic orchestration of gene pathways throughout the body. We also found oscillations in the expression of more than 1,000 known and novel noncoding RNAs (ncRNAs). Supporting their potential role in mediating clock function, ncRNAs conserved between mouse and human showed rhythmic expression in similar proportions as protein coding genes. Importantly, we also found that the majority of best-selling drugs and World Health Organization essential medicines directly target the products of rhythmic genes. Many of these drugs have short half-lives and may benefit from timed dosage. In sum, this study highlights critical, systemic, and surprising roles of the mammalian circadian clock and provides a blueprint for advancement in chronotherapy.

Rhythmic movement disorder (head banging) in an adult during rapid eye movement sleep.

PubMed

Anderson, Kirstie N; Smith, Ian E; Shneerson, John M

2006-06-01

Sleep-related rhythmic movements (head banging or body rocking) are extremely common in normal infants and young children, but less than 5% of children over the age of 5 years old exhibit these stereotyped motor behaviors. They characteristically occur during drowsiness or sleep onset rather than in deep sleep or rapid eye movement (REM) sleep. We present a 27-year-old man with typical rhythmic movement disorder that had persisted into adult life and was restricted to REM sleep. This man is the oldest subject with this presentation reported to date and highlights the importance of recognizing this nocturnal movement disorder when it does occur in adults.

Daily rhythms of physiological parameters in the dromedary camel under natural and laboratory conditions.

PubMed

Al-Haidary, Ahmed A; Abdoun, Khalid A; Samara, Emad M; Okab, Aly B; Sani, Mamane; Refinetti, Roberto

2016-08-01

Camels are well adapted to hot arid environments and can contribute significantly to the economy of developing countries in arid regions of the world. Full understanding of the physiology of camels requires understanding of the internal temporal order of the body, as reflected in daily or circadian rhythms. In the current study, we investigated the daily rhythmicity of 20 physiological variables in camels exposed to natural oscillations of ambient temperature in a desert environment and compared the daily temporal courses of the variables. We also studied the rhythm of core body temperature under experimental conditions with constant ambient temperature in the presence and absence of a light-dark cycle. The obtained results indicated that different physiological variables exhibit different degrees of daily rhythmicity and reach their daily peaks at different times of the day, starting with plasma cholesterol, which peaks 24min after midnight, and ending with plasma calcium, which peaks 3h before midnight. Furthermore, the rhythm of core body temperature persisted in the absence of environmental rhythmicity, thus confirming its endogenous nature. The observed delay in the acrophase of core body temperature rhythm under constant conditions suggests that the circadian period is longer than 24h. Further studies with more refined experimental manipulation of different variables are needed to fully elucidate the causal network of circadian rhythms in dromedary camels. Copyright © 2016 Elsevier Ltd. All rights reserved.

Paired Synchronous Rhythmic Finger Tapping without an External Timing Cue Shows Greater Speed Increases Relative to Those for Solo Tapping

PubMed Central

Okano, Masahiro; Shinya, Masahiro; Kudo, Kazutoshi

2017-01-01

In solo synchronization-continuation (SC) tasks, intertap intervals (ITI) are known to drift from the initial tempo. It has been demonstrated that people in paired and group contexts modulate their action timing unconsciously in various situations such as choice reaction tasks, rhythmic body sway, and hand clapping in concerts, which suggests the possibility that ITI drift is also affected by paired context. We conducted solo and paired SC tapping experiments with three tempos (75, 120, and 200 bpm) and examined whether tempo-keeping performance changed according to tempo and/or the number of players. Results indicated that those tapping in the paired conditions were faster, relative to those observed in the solo conditions, for all tempos. For the faster participants, the degree of ITI drift in the solo conditions was strongly correlated with that in the paired conditions. Regression analyses suggested that both faster and slower participants adapted their tap timing to that of their partners. A possible explanation for these results is that the participants reset the phase of their internal clocks according to the faster beat between their own tap and the partners’ tap. Our results indicated that paired context could bias the direction of ITI drift toward decreasing. PMID:28276461

Paired Synchronous Rhythmic Finger Tapping without an External Timing Cue Shows Greater Speed Increases Relative to Those for Solo Tapping.

PubMed

Okano, Masahiro; Shinya, Masahiro; Kudo, Kazutoshi

2017-03-09

In solo synchronization-continuation (SC) tasks, intertap intervals (ITI) are known to drift from the initial tempo. It has been demonstrated that people in paired and group contexts modulate their action timing unconsciously in various situations such as choice reaction tasks, rhythmic body sway, and hand clapping in concerts, which suggests the possibility that ITI drift is also affected by paired context. We conducted solo and paired SC tapping experiments with three tempos (75, 120, and 200 bpm) and examined whether tempo-keeping performance changed according to tempo and/or the number of players. Results indicated that those tapping in the paired conditions were faster, relative to those observed in the solo conditions, for all tempos. For the faster participants, the degree of ITI drift in the solo conditions was strongly correlated with that in the paired conditions. Regression analyses suggested that both faster and slower participants adapted their tap timing to that of their partners. A possible explanation for these results is that the participants reset the phase of their internal clocks according to the faster beat between their own tap and the partners' tap. Our results indicated that paired context could bias the direction of ITI drift toward decreasing.

Mechanisms Underlying Adaptation of Respiratory Network Activity to Modulatory Stimuli in the Mouse Embryo.

PubMed

Chevalier, Marc; De Sa, Rafaël; Cardoit, Laura; Thoby-Brisson, Muriel

2016-01-01

Breathing is a rhythmic behavior that requires organized contractions of respiratory effector muscles. This behavior must adapt to constantly changing conditions in order to ensure homeostasis, proper body oxygenation, and CO2/pH regulation. Respiratory rhythmogenesis is controlled by neural networks located in the brainstem. One area considered to be essential for generating the inspiratory phase of the respiratory rhythm is the preBötzinger complex (preBötC). Rhythmogenesis emerges from this network through the interplay between the activation of intrinsic cellular properties (pacemaker properties) and intercellular synaptic connections. Respiratory activity continuously changes under the impact of numerous modulatory substances depending on organismal needs and environmental conditions. The preBötC network has been shown to become active during the last third of gestation. But only little is known regarding the modulation of inspiratory rhythmicity at embryonic stages and even less on a possible role of pacemaker neurons in this functional flexibility during the prenatal period. By combining electrophysiology and calcium imaging performed on embryonic brainstem slice preparations, we provide evidence showing that embryonic inspiratory pacemaker neurons are already intrinsically sensitive to neuromodulation and external conditions (i.e., temperature) affecting respiratory network activity, suggesting a potential role of pacemaker neurons in mediating rhythm adaptation to modulatory stimuli in the embryo.

Mechanisms Underlying Adaptation of Respiratory Network Activity to Modulatory Stimuli in the Mouse Embryo

PubMed Central

Chevalier, Marc; De Sa, Rafaël; Cardoit, Laura; Thoby-Brisson, Muriel

2016-01-01

Breathing is a rhythmic behavior that requires organized contractions of respiratory effector muscles. This behavior must adapt to constantly changing conditions in order to ensure homeostasis, proper body oxygenation, and CO2/pH regulation. Respiratory rhythmogenesis is controlled by neural networks located in the brainstem. One area considered to be essential for generating the inspiratory phase of the respiratory rhythm is the preBötzinger complex (preBötC). Rhythmogenesis emerges from this network through the interplay between the activation of intrinsic cellular properties (pacemaker properties) and intercellular synaptic connections. Respiratory activity continuously changes under the impact of numerous modulatory substances depending on organismal needs and environmental conditions. The preBötC network has been shown to become active during the last third of gestation. But only little is known regarding the modulation of inspiratory rhythmicity at embryonic stages and even less on a possible role of pacemaker neurons in this functional flexibility during the prenatal period. By combining electrophysiology and calcium imaging performed on embryonic brainstem slice preparations, we provide evidence showing that embryonic inspiratory pacemaker neurons are already intrinsically sensitive to neuromodulation and external conditions (i.e., temperature) affecting respiratory network activity, suggesting a potential role of pacemaker neurons in mediating rhythm adaptation to modulatory stimuli in the embryo. PMID:27239348

Genomic Analysis of Circadian Clock-, Light-, and Growth-Correlated Genes Reveals PHYTOCHROME-INTERACTING FACTOR5 as a Modulator of Auxin Signaling in Arabidopsis1[C][W][OA

PubMed Central

Nozue, Kazunari; Harmer, Stacey L.; Maloof, Julin N.

2011-01-01

Plants exhibit daily rhythms in their growth, providing an ideal system for the study of interactions between environmental stimuli such as light and internal regulators such as the circadian clock. We previously found that two basic loop-helix-loop transcription factors, PHYTOCHROME-INTERACTING FACTOR4 (PIF4) and PIF5, integrate light and circadian clock signaling to generate rhythmic plant growth in Arabidopsis (Arabidopsis thaliana). Here, we use expression profiling and real-time growth assays to identify growth regulatory networks downstream of PIF4 and PIF5. Genome-wide analysis of light-, clock-, or growth-correlated genes showed significant overlap between the transcriptomes of clock-, light-, and growth-related pathways. Overrepresentation analysis of growth-correlated genes predicted that the auxin and gibberellic acid (GA) hormone pathways both contribute to diurnal growth control. Indeed, lesions of GA biosynthesis genes retarded rhythmic growth. Surprisingly, GA-responsive genes are not enriched among genes regulated by PIF4 and PIF5, whereas auxin pathway and response genes are. Consistent with this finding, the auxin response is more severely affected than the GA response in pif4 pif5 double mutants and in PIF5-overexpressing lines. We conclude that at least two downstream modules participate in diurnal rhythmic hypocotyl growth: PIF4 and/or PIF5 modulation of auxin-related pathways and PIF-independent regulation of the GA pathway. PMID:21430186

MicroRNAs shape circadian hepatic gene expression on a transcriptome-wide scale

PubMed Central

Du, Ngoc-Hien; Arpat, Alaaddin Bulak; De Matos, Mara; Gatfield, David

2014-01-01

A considerable proportion of mammalian gene expression undergoes circadian oscillations. Post-transcriptional mechanisms likely make important contributions to mRNA abundance rhythms. We have investigated how microRNAs (miRNAs) contribute to core clock and clock-controlled gene expression using mice in which miRNA biogenesis can be inactivated in the liver. While the hepatic core clock was surprisingly resilient to miRNA loss, whole transcriptome sequencing uncovered widespread effects on clock output gene expression. Cyclic transcription paired with miRNA-mediated regulation was thus identified as a frequent phenomenon that affected up to 30% of the rhythmic transcriptome and served to post-transcriptionally adjust the phases and amplitudes of rhythmic mRNA accumulation. However, only few mRNA rhythms were actually generated by miRNAs. Overall, our study suggests that miRNAs function to adapt clock-driven gene expression to tissue-specific requirements. Finally, we pinpoint several miRNAs predicted to act as modulators of rhythmic transcripts, and identify rhythmic pathways particularly prone to miRNA regulation. DOI: http://dx.doi.org/10.7554/eLife.02510.001 PMID:24867642

Circadian and Homeostatic Regulation of Structural Synaptic Plasticity in Hypocretin Neurons

PubMed Central

Appelbaum, Lior; Wang, Gordon; Yokogawa, Tohei; Skariah, Gemini M; Smith, Stephen J; Mourrain, Philippe; Mignot, Emmanuel

2010-01-01

Summary Neurons exhibit rhythmic activity that ultimately affects behavior such as sleep. In living zebrafish larvae, we used time-lapse two-photon imaging of the presynaptic marker synaptophysin (SYP) in hypocretin/orexin (HCRT) neurons to determine the dynamics of synaptic modifications during the day and night. We observed circadian rhythmicity in synapse number in HCRT axons. This rhythm is regulated primarily by the circadian clock but is also affected by sleep deprivation. Furthermore, NPTX2, a protein implicated in AMPA receptor clustering, was found to modulate circadian synaptic changes. In zebrafish, nptx2b is rhythmic gene that is mostly expressed in hypothalamic and pineal gland cells. Arrhythmic transgenic nptx2b overexpression (hcrt:NPTX2b) increases synapse number and abolishes rhythmicity in HCRT axons. Finally, hcrt:NPTX2b fish are resistant to the sleep-promoting effects of melatonin. This behavioral effect is consistent with NPTX2b-mediated increased activity of HCRT circuitry. These data provide real-time in vivo evidence of circadian and homeostatic regulation of structural synaptic plasticity. PMID:20920793

Circadian and homeostatic regulation of structural synaptic plasticity in hypocretin neurons.

PubMed

Appelbaum, Lior; Wang, Gordon; Yokogawa, Tohei; Skariah, Gemini M; Smith, Stephen J; Mourrain, Philippe; Mignot, Emmanuel

2010-10-06

Neurons exhibit rhythmic activity that ultimately affects behavior such as sleep. In living zebrafish larvae, we used time-lapse two-photon imaging of the presynaptic marker synaptophysin in hypocretin/orexin (HCRT) neurons to determine the dynamics of synaptic modifications during the day and night. We observed circadian rhythmicity in synapse number in HCRT axons. This rhythm is regulated primarily by the circadian clock but is also affected by sleep deprivation. Furthermore, NPTX2, a protein implicated in AMPA receptor clustering, modulates circadian synaptic changes. In zebrafish, nptx2b is a rhythmic gene that is mostly expressed in hypothalamic and pineal gland cells. Arrhythmic transgenic nptx2b overexpression (hcrt:NPTX2b) increases synapse number and abolishes rhythmicity in HCRT axons. Finally, hcrt:NPTX2b fish are resistant to the sleep-promoting effects of melatonin. This behavioral effect is consistent with NPTX2b-mediated increased activity of HCRT circuitry. These data provide real-time in vivo evidence of circadian and homeostatic regulation of structural synaptic plasticity. Copyright © 2010 Elsevier Inc. All rights reserved.

Significance of circadian rhythms in severely brain-injured patients: A clue to consciousness?

PubMed

Blume, Christine; Lechinger, Julia; Santhi, Nayantara; del Giudice, Renata; Gnjezda, Maria-Teresa; Pichler, Gerald; Scarpatetti, Monika; Donis, Johann; Michitsch, Gabriele; Schabus, Manuel

2017-05-16

To investigate the relationship between the presence of a circadian body temperature rhythm and behaviorally assessed consciousness levels in patients with disorders of consciousness (DOC; i.e., vegetative state/unresponsive wakefulness syndrome or minimally conscious state). In a cross-sectional study, we investigated the presence of circadian temperature rhythms across 6 to 7 days using external skin temperature sensors in 18 patients with DOC. Beyond this, we examined the relationship between behaviorally assessed consciousness levels and circadian rhythmicity. Analyses with Lomb-Scargle periodograms revealed significant circadian rhythmicity in all patients (range 23.5-26.3 hours). We found that especially scores on the arousal subscale of the Coma Recovery Scale-Revised were closely linked to the integrity of circadian variations in body temperature. Finally, we piloted whether bright light stimulation could boost circadian rhythmicity and found positive evidence in 2 out of 8 patients. The study provides evidence for an association between circadian body temperature rhythms and arousal as a necessary precondition for consciousness. Our findings also make a case for circadian rhythms as a target for treatment as well as the application of diagnostic and therapeutic means at times when cognitive performance is expected to peak. Copyright © 2017 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Academy of Neurology.

Postural trials: expertise in rhythmic gymnastics increases control in lateral directions.

PubMed

Calavalle, A R; Sisti, D; Rocchi, M B L; Panebianco, R; Del Sal, M; Stocchi, V

2008-11-01

The first aim of this paper was to investigate if expertise in rhythmic gymnastics influences postural performance even in an easy non-specific task such as bipedal posture. Rhythmic gymnastics is a unique female sport which encompasses aspects of both artistic gymnastics and ballet and includes the use of a small apparatus (rope, hoop, ball, clubs and ribbon). Most previous studies have shown that expertise achieved by artistic gymnasts and dancers improves postural steadiness only in the situations for which those athletes are trained. Literature has not yet compared rhythmic gymnasts to other athletes in terms of their postural strategies. Hence, the study presented herein tested a group of high level rhythmic gymnasts and a group of female university students, trained in other sports, in the bipedal posture under eyes open and closed conditions. A force platform was used to record body sway. (1) Distance from the centre of sway, (2) lateral and (3) antero-posterior displacements were analyzed in time and frequency domains. Comparing the two groups, it was found that rhythmic gymnasts had better strategies than students in simple postural tasks, especially in lateral directions and in the period from 0.05 to 2 s. The most interesting finding in this study is that rhythmic gymnastics training seems to have a direct effect on the ability to maintain bipedal posture, which may confirm the "transfer" hypothesis of rhythmic gymnastics expertise to bipedal postural sway, especially in medio-lateral displacements. This finding has never been reported in previous studies on artistic gymnasts and ballet dancers. Furthermore, the present study confirmed the visual dependence of all the athletes, irrespective of their disciplines, in their postural trials.

The relative contribution of physical fitness to the technical execution score in youth rhythmic gymnastics.

PubMed

Donti, Olyvia; Bogdanis, Gregory C; Kritikou, Maria; Donti, Anastasia; Theodorakou, Kalliopi

2016-06-01

This study examined the association between physical fitness and a technical execution score in rhythmic gymnasts varying in the performance level. Forty-six young rhythmic gymnasts (age: 9.9 ±1.3 years) were divided into two groups (qualifiers, n=24 and non-qualifiers, n=22) based on the results of the National Championships. Gymnasts underwent a series of physical fitness tests and technical execution was evaluated in a routine without apparatus. There were significant differences between qualifiers and non-qualifiers in the technical execution score (p=0.01, d=1.0), shoulder flexion (p=0.01, d=0.8), straight leg raise (p=0.004, d=0.9), sideways leg extension (p=0.002, d=0.9) and body fat (p=.021, d=0.7), but no differences were found in muscular endurance and jumping performance. The technical execution score for the non-qualifiers was significantly correlated with shoulder extension (r=0.423, p<0.05), sideways leg extension (r=0.687, p<0.01), push ups (r=0.437, p<0.05) and body fat (r=0.642, p<0.01), while there was only one significant correlation with sideways leg extension (r=0.467, p<0.05) for the qualifiers. Multiple regression analysis revealed that sideways leg extension, body fat, and push ups accounted for a large part (62.9%) of the variance in the technical execution score for the non-qualifiers, while for the qualifiers, only 37.3% of the variance in the technical execution score was accounted for by sideways leg extension and spine flexibility. In conclusion, flexibility and body composition can effectively discriminate between qualifiers and non-qualifiers in youth rhythmic gymnastics. At the lower level of performance (non-qualifiers), physical fitness seems to have a greater effect on the technical execution score.

Dietary intake and body composition of prepubescent female aesthetic athletes.

PubMed

Soric, Maroje; Misigoj-Durakovic, Marjeta; Pedisic, Zeljko

2008-06-01

The purpose of this study was to assess dietary intake and body composition of prepubescent girls competing in 3 aesthetic sports (artistic and rhythmic gymnastics and ballet). Because physiological demands of ballet training are similar to those in other aesthetic sports, ballet dancers were, for the purpose of this study, regarded as athletes. The sample consisted of 39 athletes (median age, 11 years, range 9-13) and 15 controls (median age, 11 years, range 10-12). Dietary intake was assessed using a quantitative food frequency questionnaire, and body composition, by means of anthropometry. There was no significant difference in total energy intake between groups, but there was a significant difference in energy substrate distribution. Artistic gymnasts reported significantly higher carbohydrate and lower fat contribution to total energy (57% +/- 6% and 29% +/- 5%, respectively) than rhythmic gymnasts (48% +/- 6% and 36% +/- 5%), ballet dancers (51% +/- 4% and 34% +/- 3%), or controls (51% +/- 5% and 34% +/- 4%). Relative to body weight, artistic gymnasts reported higher intake of carbohydrates (9.1 +/- 4.2 g/kg) than rhythmic gymnasts (5.6 +/- 3.1 g/kg), ballet dancers (6.6 +/- 2.5 g/kg), or controls (5.4 +/- 1.9 g/kg). Artistic gymnasts also had the lowest body-fat percentage among the groups. In all the groups mean reported daily intakes of most nutrients were higher than the current daily recommended intakes. The exceptions were dietary fiber and calcium. The proportion of athletes with an inadequate reported intake was highest for phosphorus (33%), followed by vitamin A and niacin (18%) and zinc (13%).

Neurobiology of rhythmic motor entrainment.

PubMed

Molinari, Marco; Leggio, Maria G; De Martin, Martina; Cerasa, Antonio; Thaut, Michael

2003-11-01

Timing is extremely important for movement, and understanding the neurobiological basis of rhythm perception and reproduction can be helpful in addressing motor recovery after brain lesions. In this quest, the science of music might provide interesting hints for better understanding the brain timing mechanism. The report focuses on the neurobiological substrate of sensorimotor transformation of time data, highlighting the power of auditory rhythmic stimuli in guiding motor acts. The cerebellar role of timing is addressed in subjects with cerebellar damage; subsequently, cerebellar timing processing is highlighted through an fMRI study of professional musicians. The two approaches converge to demonstrate that different levels of time processing exist, one conscious and one not, and to support the idea that timing is a distributed function. The hypothesis that unconscious motor responses to auditory rhythmic stimuli can be relevant in guiding motor recovery and modulating music perception is advanced and discussed.

Differences between the sexes in technical mastery of rhythmic gymnastics.

PubMed

Bozanic, Ana; Miletic, Durdica

2011-02-01

The aims of this study were to determine possible differences between the sexes in specific rhythmic gymnastics techniques, and to examine the influence of various aspects of technique on rhythmic composition performance. Seventy-five students aged 21 ± 2 years (45 males, 30 female) undertook four test sessions to determine: coefficients of asymmetry, stability, versatility, and the two rhythmic compositions (without apparatus and with rope). An independent-sample t-test revealed sex-based differences in technique acquisition: stability for ball (P < 0.05; effect size = 0.65) and club (P < 0.05; effect size = 0.79) performance and rhythmic composition without apparatus (P < 0.05; effect size = 0.66). Multiple regression analysis revealed that the variables for assessing stability (beta = 0.44; P < 0.05) and versatility (beta = 0.61; P < 0.05) explained 61% of the variance in the rhythmic composition performance of females, and the variables for assessing asymmetry (beta = -0.38; P < 0.05), versatility (beta = 0.32; P < 0.05), and stability (beta = 0.29; P < 0.05) explained 52% of the variance in the rhythmic composition performance of males. The results suggest that female students dominate in body skill technique, while male students have the advantage with apparatus. There was a lack of an expressive aesthetic component in performance for males. The need for ambidexterity should be considered in the planning of training programmes.

A cardioid oscillator with asymmetric time ratio for establishing CPG models.

PubMed

Fu, Q; Wang, D H; Xu, L; Yuan, G

2018-01-13

Nonlinear oscillators are usually utilized by bionic scientists for establishing central pattern generator models for imitating rhythmic motions by bionic scientists. In the natural word, many rhythmic motions possess asymmetric time ratios, which means that the forward and the backward motions of an oscillating process sustain different times within one period. In order to model rhythmic motions with asymmetric time ratios, nonlinear oscillators with asymmetric forward and backward trajectories within one period should be studied. In this paper, based on the property of the invariant set, a method to design the closed curve in the phase plane of a dynamic system as its limit cycle is proposed. Utilizing the proposed method and considering that a cardioid curve is a kind of asymmetrical closed curves, a cardioid oscillator with asymmetric time ratios is proposed and realized. Through making the derivation of the closed curve in the phase plane of a dynamic system equal to zero, the closed curve is designed as its limit cycle. Utilizing the proposed limit cycle design method and according to the global invariant set theory, a cardioid oscillator applying a cardioid curve as its limit cycle is achieved. On these bases, the numerical simulations are conducted for analyzing the behaviors of the cardioid oscillator. The example utilizing the established cardioid oscillator to simulate rhythmic motions of the hip joint of a human body in the sagittal plane is presented. The results of the numerical simulations indicate that, whatever the initial condition is and without any outside input, the proposed cardioid oscillator possesses the following properties: (1) The proposed cardioid oscillator is able to generate a series of periodic and anti-interference self-exciting trajectories, (2) the generated trajectories possess an asymmetric time ratio, and (3) the time ratio can be regulated by adjusting the oscillator's parameters. Furthermore, the comparison between the simulated trajectories by the established cardioid oscillator and the measured angle trajectories of the hip angle of a human body show that the proposed cardioid oscillator is fit for imitating the rhythmic motions of the hip of a human body with asymmetric time ratios.

Different mechanisms may generate sustained hypertonic and rhythmic bursting muscle activity in idiopathic dystonia.

PubMed

Liu, Xuguang; Yianni, John; Wang, Shouyan; Bain, Peter G; Stein, John F; Aziz, Tipu Z

2006-03-01

Despite that deep brain stimulation (DBS) of the globus pallidus internus (GPi) is emerging as the favored intervention for patients with medically intractable dystonia, the pathophysiological mechanisms of dystonia are largely unclear. In eight patients with primary dystonia who were treated with bilateral chronic pallidal stimulation, we correlated symptom-related electromyogram (EMG) activity of the most affected muscles with the local field potentials (LFPs) recorded from the globus pallidus electrodes. In 5 dystonic patients with mobile involuntary movements, rhythmic EMG bursts in the contralateral muscles were coherent with the oscillations in the pallidal LFPs at the burst frequency. In contrast, no significant coherence was seen between EMG and LFPs either for the sustained activity separated out from the compound EMGs in those 5 cases, or in the EMGs in 3 other cases without mobile involuntary movements and rhythmic EMG bursts. In comparison with the resting condition, in both active and passive movements, significant modulation in the GPi LFPs was seen in the range of 8-16 Hz. The finding of significant coherence between GPi oscillations and rhythmic EMG bursts but not sustained tonic EMG activity suggests that the synchronized pallidal activity may be directly related to the rhythmic involuntary movements. In contrast, the sustained hypertonic muscle activity may be represented by less synchronized activity in the pallidum. Thus, the pallidum may play different roles in generating different components of the dystonic symptom complex.

Perturbed rhythmic activation of signaling pathways in mice deficient for Sterol Carrier Protein 2-dependent diurnal lipid transport and metabolism

PubMed Central

Jouffe, Céline; Gobet, Cédric; Martin, Eva; Métairon, Sylviane; Morin-Rivron, Delphine; Masoodi, Mojgan; Gachon, Frédéric

2016-01-01

Through evolution, most of the living species have acquired a time keeping system to anticipate daily changes caused by the rotation of the Earth. In all of the systems this pacemaker is based on a molecular transcriptional/translational negative feedback loop able to generate rhythmic gene expression with a period close to 24 hours. Recent evidences suggest that post-transcriptional regulations activated mostly by systemic cues play a fundamental role in the process, fine tuning the time keeping system and linking it to animal physiology. Among these signals, we consider the role of lipid transport and metabolism regulated by SCP2. Mice harboring a deletion of the Scp2 locus present a modulated diurnal accumulation of lipids in the liver and a perturbed activation of several signaling pathways including PPARα, SREBP, LRH-1, TORC1 and its upstream regulators. This defect in signaling pathways activation feedbacks upon the clock by lengthening the circadian period of animals through post-translational regulation of core clock regulators, showing that rhythmic lipid transport is a major player in the establishment of rhythmic mRNA and protein expression landscape. PMID:27097688

Perturbed rhythmic activation of signaling pathways in mice deficient for Sterol Carrier Protein 2-dependent diurnal lipid transport and metabolism.

PubMed

Jouffe, Céline; Gobet, Cédric; Martin, Eva; Métairon, Sylviane; Morin-Rivron, Delphine; Masoodi, Mojgan; Gachon, Frédéric

2016-04-21

Through evolution, most of the living species have acquired a time keeping system to anticipate daily changes caused by the rotation of the Earth. In all of the systems this pacemaker is based on a molecular transcriptional/translational negative feedback loop able to generate rhythmic gene expression with a period close to 24 hours. Recent evidences suggest that post-transcriptional regulations activated mostly by systemic cues play a fundamental role in the process, fine tuning the time keeping system and linking it to animal physiology. Among these signals, we consider the role of lipid transport and metabolism regulated by SCP2. Mice harboring a deletion of the Scp2 locus present a modulated diurnal accumulation of lipids in the liver and a perturbed activation of several signaling pathways including PPARα, SREBP, LRH-1, TORC1 and its upstream regulators. This defect in signaling pathways activation feedbacks upon the clock by lengthening the circadian period of animals through post-translational regulation of core clock regulators, showing that rhythmic lipid transport is a major player in the establishment of rhythmic mRNA and protein expression landscape.

Bimanual Coordination Learning with Different Augmented Feedback Modalities and Information Types

PubMed Central

Chiou, Shiau-Chuen; Chang, Erik Chihhung

2016-01-01

Previous studies have shown that bimanual coordination learning is more resistant to the removal of augmented feedback when acquired with auditory than with visual channel. However, it is unclear whether this differential “guidance effect” between feedback modalities is due to enhanced sensorimotor integration via the non-dominant auditory channel or strengthened linkage to kinesthetic information under rhythmic input. The current study aimed to examine how modalities (visual vs. auditory) and information types (continuous visuospatial vs. discrete rhythmic) of concurrent augmented feedback influence bimanual coordination learning. Participants either learned a 90°-out-of-phase pattern for three consecutive days with Lissajous feedback indicating the integrated position of both arms, or with visual or auditory rhythmic feedback reflecting the relative timing of the movement. The results showed diverse performance change after practice when the feedback was removed between Lissajous and the other two rhythmic groups, indicating that the guidance effect may be modulated by the type of information provided during practice. Moreover, significant performance improvement in the dual-task condition where the irregular rhythm counting task was applied as a secondary task also suggested that lower involvement of conscious control may result in better performance in bimanual coordination. PMID:26895286

Bimanual Coordination Learning with Different Augmented Feedback Modalities and Information Types.

PubMed

Chiou, Shiau-Chuen; Chang, Erik Chihhung

2016-01-01

Previous studies have shown that bimanual coordination learning is more resistant to the removal of augmented feedback when acquired with auditory than with visual channel. However, it is unclear whether this differential "guidance effect" between feedback modalities is due to enhanced sensorimotor integration via the non-dominant auditory channel or strengthened linkage to kinesthetic information under rhythmic input. The current study aimed to examine how modalities (visual vs. auditory) and information types (continuous visuospatial vs. discrete rhythmic) of concurrent augmented feedback influence bimanual coordination learning. Participants either learned a 90°-out-of-phase pattern for three consecutive days with Lissajous feedback indicating the integrated position of both arms, or with visual or auditory rhythmic feedback reflecting the relative timing of the movement. The results showed diverse performance change after practice when the feedback was removed between Lissajous and the other two rhythmic groups, indicating that the guidance effect may be modulated by the type of information provided during practice. Moreover, significant performance improvement in the dual-task condition where the irregular rhythm counting task was applied as a secondary task also suggested that lower involvement of conscious control may result in better performance in bimanual coordination.

Role of the dorsal premotor cortex in rhythmic auditory-motor entrainment: a perturbational approach by rTMS.

PubMed

Giovannelli, Fabio; Innocenti, Iglis; Rossi, Simone; Borgheresi, Alessandra; Ragazzoni, Aldo; Zaccara, Gaetano; Viggiano, Maria Pia; Cincotta, Massimo

2014-04-01

Synchronization of body movements to an external beat is a universal human ability, which has also been recently documented in nonhuman species. The neural substrates of this rhythmic motor entrainment are still under investigation. Correlational neuroimaging data suggest an involvement of the dorsal premotor cortex (dPMC) and the supplementary motor area (SMA). In 14 healthy volunteers, we more specifically investigated the neural network underlying this phenomenon using a causal approach by an established 1-Hz repetitive transcranial magnetic stimulation (rTMS) protocol, which produces a focal suppression of cortical excitability outlasting the stimulation period. Synchronization accuracy between rhythmic cues and right index finger tapping, as measured by the mean time lag (asynchrony) between motor and auditory events, was significantly affected when the right dPMC function was transiently perturbed by "off-line" focal rTMS, whereas the reproduction of the rhythmic sequence per se (inter-tap-interval) was spared. This approach affected metrical rhythms of different complexity, but not non-metrical or isochronous sequences. Conversely, no change in auditory-motor synchronization was observed with rTMS of the SMA, of the left dPMC or over a control site (midline occipital area). Our data strongly support the view that the right dPMC is crucial for rhythmic auditory-motor synchronization in humans.

Rhythmic control of endocannabinoids in the rat pineal gland.

PubMed

Koch, Marco; Ferreirós, Nerea; Geisslinger, Gerd; Dehghani, Faramarz; Korf, Horst-Werner

2015-01-01

Endocannabinoids modulate neuroendocrine networks by directly targeting cannabinoid receptors. The time-hormone melatonin synchronizes these networks with external light condition and guarantees time-sensitive and ecologically well-adapted behaviors. Here, the endocannabinoid arachidonoyl ethanolamide (AEA) showed rhythmic changes in rat pineal glands with higher levels during the light-period and reduced amounts at the onset of darkness. Norepinephrine, the essential stimulus for nocturnal melatonin biosynthesis, acutely down-regulated AEA and other endocannabinoids in cultured pineal glands. These temporal dynamics suggest that AEA exerts time-dependent autocrine and/or paracrine functions within the pineal. Moreover, endocananbinoids may be released from the pineal into the CSF or blood stream.

Assessment of rhythmic entrainment at multiple timescales in dyslexia: evidence for disruption to syllable timing.

PubMed

Leong, Victoria; Goswami, Usha

2014-02-01

Developmental dyslexia is associated with rhythmic difficulties, including impaired perception of beat patterns in music and prosodic stress patterns in speech. Spoken prosodic rhythm is cued by slow (<10 Hz) fluctuations in speech signal amplitude. Impaired neural oscillatory tracking of these slow amplitude modulation (AM) patterns is one plausible source of impaired rhythm tracking in dyslexia. Here, we characterise the temporal profile of the dyslexic rhythm deficit by examining rhythmic entrainment at multiple speech timescales. Adult dyslexic participants completed two experiments aimed at testing the perception and production of speech rhythm. In the perception task, participants tapped along to the beat of 4 metrically-regular nursery rhyme sentences. In the production task, participants produced the same 4 sentences in time to a metronome beat. Rhythmic entrainment was assessed using both traditional rhythmic indices and a novel AM-based measure, which utilised 3 dominant AM timescales in the speech signal each associated with a different phonological grain-sized unit (0.9-2.5 Hz, prosodic stress; 2.5-12 Hz, syllables; 12-40 Hz, phonemes). The AM-based measure revealed atypical rhythmic entrainment by dyslexic participants to syllable patterns in speech, in perception and production. In the perception task, both groups showed equally strong phase-locking to Syllable AM patterns, but dyslexic responses were entrained to a significantly earlier oscillatory phase angle than controls. In the production task, dyslexic utterances showed shorter syllable intervals, and differences in Syllable:Phoneme AM cross-frequency synchronisation. Our data support the view that rhythmic entrainment at slow (∼5 Hz, Syllable) rates is atypical in dyslexia, suggesting that neural mechanisms for syllable perception and production may also be atypical. These syllable timing deficits could contribute to the atypical development of phonological representations for spoken words, the central cognitive characteristic of developmental dyslexia across languages. Copyright © 2013 The Authors. Published by Elsevier B.V. All rights reserved.

Assessment of rhythmic entrainment at multiple timescales in dyslexia: Evidence for disruption to syllable timing☆

PubMed Central

Leong, Victoria; Goswami, Usha

2014-01-01

Developmental dyslexia is associated with rhythmic difficulties, including impaired perception of beat patterns in music and prosodic stress patterns in speech. Spoken prosodic rhythm is cued by slow (<10 Hz) fluctuations in speech signal amplitude. Impaired neural oscillatory tracking of these slow amplitude modulation (AM) patterns is one plausible source of impaired rhythm tracking in dyslexia. Here, we characterise the temporal profile of the dyslexic rhythm deficit by examining rhythmic entrainment at multiple speech timescales. Adult dyslexic participants completed two experiments aimed at testing the perception and production of speech rhythm. In the perception task, participants tapped along to the beat of 4 metrically-regular nursery rhyme sentences. In the production task, participants produced the same 4 sentences in time to a metronome beat. Rhythmic entrainment was assessed using both traditional rhythmic indices and a novel AM-based measure, which utilised 3 dominant AM timescales in the speech signal each associated with a different phonological grain-sized unit (0.9–2.5 Hz, prosodic stress; 2.5–12 Hz, syllables; 12–40 Hz, phonemes). The AM-based measure revealed atypical rhythmic entrainment by dyslexic participants to syllable patterns in speech, in perception and production. In the perception task, both groups showed equally strong phase-locking to Syllable AM patterns, but dyslexic responses were entrained to a significantly earlier oscillatory phase angle than controls. In the production task, dyslexic utterances showed shorter syllable intervals, and differences in Syllable:Phoneme AM cross-frequency synchronisation. Our data support the view that rhythmic entrainment at slow (∼5 Hz, Syllable) rates is atypical in dyslexia, suggesting that neural mechanisms for syllable perception and production may also be atypical. These syllable timing deficits could contribute to the atypical development of phonological representations for spoken words, the central cognitive characteristic of developmental dyslexia across languages. This article is part of a Special Issue entitled . PMID:23916752

Genome-wide profiling of 24 hr diel rhythmicity in the water flea, Daphnia pulex: network analysis reveals rhythmic gene expression and enhances functional gene annotation.

PubMed

Rund, Samuel S C; Yoo, Boyoung; Alam, Camille; Green, Taryn; Stephens, Melissa T; Zeng, Erliang; George, Gary F; Sheppard, Aaron D; Duffield, Giles E; Milenković, Tijana; Pfrender, Michael E

2016-08-18

Marine and freshwater zooplankton exhibit daily rhythmic patterns of behavior and physiology which may be regulated directly by the light:dark (LD) cycle and/or a molecular circadian clock. One of the best-studied zooplankton taxa, the freshwater crustacean Daphnia, has a 24 h diel vertical migration (DVM) behavior whereby the organism travels up and down through the water column daily. DVM plays a critical role in resource tracking and the behavioral avoidance of predators and damaging ultraviolet radiation. However, there is little information at the transcriptional level linking the expression patterns of genes to the rhythmic physiology/behavior of Daphnia. Here we analyzed genome-wide temporal transcriptional patterns from Daphnia pulex collected over a 44 h time period under a 12:12 LD cycle (diel) conditions using a cosine-fitting algorithm. We used a comprehensive network modeling and analysis approach to identify novel co-regulated rhythmic genes that have similar network topological properties and functional annotations as rhythmic genes identified by the cosine-fitting analyses. Furthermore, we used the network approach to predict with high accuracy novel gene-function associations, thus enhancing current functional annotations available for genes in this ecologically relevant model species. Our results reveal that genes in many functional groupings exhibit 24 h rhythms in their expression patterns under diel conditions. We highlight the rhythmic expression of immunity, oxidative detoxification, and sensory process genes. We discuss differences in the chronobiology of D. pulex from other well-characterized terrestrial arthropods. This research adds to a growing body of literature suggesting the genetic mechanisms governing rhythmicity in crustaceans may be divergent from other arthropod lineages including insects. Lastly, these results highlight the power of using a network analysis approach to identify differential gene expression and provide novel functional annotation.

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

Thyroxine differentially modulates the peripheral clock: lessons from the human hair follicle.

PubMed

Hardman, Jonathan A; Haslam, Iain S; Farjo, Nilofer; Farjo, Bessam; Paus, Ralf

2015-01-01

The human hair follicle (HF) exhibits peripheral clock activity, with knock-down of clock genes (BMAL1 and PER1) prolonging active hair growth (anagen) and increasing pigmentation. Similarly, thyroid hormones prolong anagen and stimulate pigmentation in cultured human HFs. In addition they are recognized as key regulators of the central clock that controls circadian rhythmicity. Therefore, we asked whether thyroxine (T4) also influences peripheral clock activity in the human HF. Over 24 hours we found a significant reduction in protein levels of BMAL1 and PER1, with their transcript levels also decreasing significantly. Furthermore, while all clock genes maintained their rhythmicity in both the control and T4 treated HFs, there was a significant reduction in the amplitude of BMAL1 and PER1 in T4 (100 nM) treated HFs. Accompanying this, cell-cycle progression marker Cyclin D1 was also assessed appearing to show an induced circadian rhythmicity by T4 however, this was not significant. Contrary to short term cultures, after 6 days, transcript and/or protein levels of all core clock genes (BMAL1, PER1, clock, CRY1, CRY2) were up-regulated in T4 treated HFs. BMAL1 and PER1 mRNA was also up-regulated in the HF bulge, the location of HF epithelial stem cells. Together this provides the first direct evidence that T4 modulates the expression of the peripheral molecular clock. Thus, patients with thyroid dysfunction may also show a disordered peripheral clock, which raises the possibility that short term, pulsatile treatment with T4 might permit one to modulate circadian activity in peripheral tissues as a target to treat clock-related disease.

Neural Oscillations Carry Speech Rhythm through to Comprehension

PubMed Central

Peelle, Jonathan E.; Davis, Matthew H.

2012-01-01

A key feature of speech is the quasi-regular rhythmic information contained in its slow amplitude modulations. In this article we review the information conveyed by speech rhythm, and the role of ongoing brain oscillations in listeners’ processing of this content. Our starting point is the fact that speech is inherently temporal, and that rhythmic information conveyed by the amplitude envelope contains important markers for place and manner of articulation, segmental information, and speech rate. Behavioral studies demonstrate that amplitude envelope information is relied upon by listeners and plays a key role in speech intelligibility. Extending behavioral findings, data from neuroimaging – particularly electroencephalography (EEG) and magnetoencephalography (MEG) – point to phase locking by ongoing cortical oscillations to low-frequency information (~4–8 Hz) in the speech envelope. This phase modulation effectively encodes a prediction of when important events (such as stressed syllables) are likely to occur, and acts to increase sensitivity to these relevant acoustic cues. We suggest a framework through which such neural entrainment to speech rhythm can explain effects of speech rate on word and segment perception (i.e., that the perception of phonemes and words in connected speech is influenced by preceding speech rate). Neuroanatomically, acoustic amplitude modulations are processed largely bilaterally in auditory cortex, with intelligible speech resulting in differential recruitment of left-hemisphere regions. Notable among these is lateral anterior temporal cortex, which we propose functions in a domain-general fashion to support ongoing memory and integration of meaningful input. Together, the reviewed evidence suggests that low-frequency oscillations in the acoustic speech signal form the foundation of a rhythmic hierarchy supporting spoken language, mirrored by phase-locked oscillations in the human brain. PMID:22973251

Functional PDF Signaling in the Drosophila Circadian Neural Circuit Is Gated by Ral A-Dependent Modulation.

PubMed

Klose, Markus; Duvall, Laura; Li, Weihua; Liang, Xitong; Ren, Chi; Steinbach, Joe Henry; Taghert, Paul H

2016-05-18

The neuropeptide PDF promotes the normal sequencing of circadian behavioral rhythms in Drosophila, but its signaling mechanisms are not well understood. We report daily rhythmicity in responsiveness to PDF in critical pacemakers called small LNvs. There is a daily change in potency, as great as 10-fold higher, around dawn. The rhythm persists in constant darkness and does not require endogenous ligand (PDF) signaling or rhythmic receptor gene transcription. Furthermore, rhythmic responsiveness reflects the properties of the pacemaker cell type, not the receptor. Dopamine responsiveness also cycles, in phase with that of PDF, in the same pacemakers, but does not cycle in large LNv. The activity of RalA GTPase in s-LNv regulates PDF responsiveness and behavioral locomotor rhythms. Additionally, cell-autonomous PDF signaling reversed the circadian behavioral effects of lowered RalA activity. Thus, RalA activity confers high PDF responsiveness, providing a daily gate around the dawn hours to promote functional PDF signaling. Copyright © 2016 Elsevier Inc. All rights reserved.

Functional PDF Signaling in the Drosophila Circadian Neural Circuit is Gated by Ral A-Dependent Modulation

PubMed Central

Liang, Xitong; Ren, Chi; Steinbach, Joe Henry; Taghert, Paul H.

2016-01-01

The neuropeptide PDF promotes the normal sequencing of circadian behavioral rhythms in Drosophila, but its signaling mechanisms are not well understood. We report daily rhythmicity in responsiveness to PDF in critical pacemakers called small LNvs. There is a daily change in potency, as great as 10-fold higher, around dawn. The rhythm persists in constant darkness, does not require endogenous ligand (PDF) signaling, or rhythmic receptor gene transcription. Furthermore, rhythmic responsiveness reflects the properties of the pacemaker cell type, not the receptor. Dopamine responsiveness also cycles, in phase with that of PDF, in the same pacemakers, but does not cycle in large LNv. The activity of RalA GTPase in s-LNv regulates PDF responsiveness and behavioral locomotor rhythms. Additional, cell autonomous PDF signaling reversed the circadian behavioral effects of lowered RalA activity. Thus RalA activity confers high PDF responsiveness, providing a daily gate around the dawn hours to promote functional PDF signaling. PMID:27161526

Daily rhythms in antennal protein and olfactory sensitivity in the malaria mosquito Anopheles gambiae

PubMed Central

Rund, Samuel S. C.; Bonar, Nicolle A.; Champion, Matthew M.; Ghazi, John P.; Houk, Cameron M.; Leming, Matthew T.; Syed, Zainulabeuddin; Duffield, Giles E.

2013-01-01

We recently characterized 24-hr daily rhythmic patterns of gene expression in Anopheles gambiae mosquitoes. These include numerous odorant binding proteins (OBPs), soluble odorant carrying proteins enriched in olfactory organs. Here we demonstrate that multiple rhythmically expressed genes including OBPs and takeout proteins, involved in regulating blood feeding behavior, have corresponding rhythmic protein levels as measured by quantitative proteomics. This includes AgamOBP1, previously shown as important to An. gambiae odorant sensing. Further, electrophysiological investigations demonstrate time-of-day specific differences in olfactory sensitivity of antennae to major host-derived odorants. The pre-dusk/dusk peaks in OBPs and takeout gene expression correspond with peak protein abundance at night, and in turn coincide with the time of increased olfactory sensitivity to odorants requiring OBPs and times of increased blood-feeding behavior. This suggests an important role for OBPs in modulating temporal changes in odorant sensitivity, enabling the olfactory system to coordinate with the circadian niche of An. gambiae. PMID:23986098

Time-lapse imaging of human heart motion with switched array UWB radar.

PubMed

Brovoll, Sverre; Berger, Tor; Paichard, Yoann; Aardal, Øyvind; Lande, Tor Sverre; Hamran, Svein-Erik

2014-10-01

Radar systems for detection of human heartbeats have mostly been single-channel systems with limited spatial resolution. In this paper, a radar system for ultra-wideband (UWB) imaging of the human heart is presented. To make the radar waves penetrate the human tissue the antenna is placed very close to the body. The antenna is an array with eight elements, and an antenna switch system connects the radar to the individual elements in sequence to form an image. Successive images are used to build up time-lapse movies of the beating heart. Measurements on a human test subject are presented and the heart motion is estimated at different locations inside the body. The movies show rhythmic motion consistent with the beating heart, and the location and shape of the reflections correspond well with the expected response form the heart wall. The spatial dependent heart motion is compared to ECG recordings, and it is confirmed that heartbeat modulations are seen in the radar data. This work shows that radar imaging of the human heart may provide valuable information on the mechanical movement of the heart.

Modulation of corticospinal input to the legs by arm and leg cycling in people with incomplete spinal cord injury.

PubMed

Zhou, R; Alvarado, L; Kim, S; Chong, S L; Mushahwar, V K

2017-10-01

The spinal cervico-lumbar interaction during rhythmic movements in humans has recently been studied; however, the role of arm movements in modulating the corticospinal drive to the legs is not well understood. The goals of this study were to investigate the effect of active rhythmic arm movements on the corticospinal drive to the legs ( study 1 ) and assess the effect of simultaneous arm and leg training on the corticospinal pathway after incomplete spinal cord injury (iSCI) ( study 2). In study 1 , neurologically intact (NI) participants or participants with iSCI performed combinations of stationary and rhythmic cycling of the arms and legs while motor evoked potentials (MEPs) were recorded from the vastus lateralis (VL) muscle. In the NI group, arm cycling alone could facilitate the VL MEP amplitude, suggesting that dynamic arm movements strongly modulate the corticospinal pathway to the legs. No significant difference in VL MEP between conditions was found in participants with iSCI. In study 2 , participants with iSCI underwent 12 wk of electrical stimulation-assisted cycling training: one group performed simultaneous arm and leg (A&L) cycling and the other legs-only cycling. MEPs in the tibialis anterior (TA) muscle were compared before and after training. After training, only the A&L group had a significantly larger TA MEP, suggesting increased excitability in the corticospinal pathway. The findings demonstrate the importance of arm movements in modulating the corticospinal drive to the legs and suggest that active engagement of the arms in lower limb rehabilitation may produce better neural regulation and restoration of function. NEW & NOTEWORTHY This study aimed to demonstrate the importance of arm movements in modulating the corticospinal drive to the legs. It provides direct evidence in humans that active movement of the arms could facilitate corticospinal transmission to the legs and, for the first time, shows that facilitation is absent after spinal cord injury. Active engagement of the arms in lower limb rehabilitation increased the excitability of the corticospinal pathway and may produce more effective improvement in leg function. Copyright © 2017 the American Physiological Society.

Cyclic Variations in Sustained Human Performance

ERIC Educational Resources Information Center

Aue, William R.; Arruda, James E.; Kass, Steven J.; Stanny, Claudia J.

2009-01-01

Biological rhythms play a prominent role in the modulation of human physiology and behavior. [Smith, K., Valentino, D., & Arruda, J. (2003). "Rhythmic oscillations in the performance of a sustained attention task." "Journal of Clinical and Experimental Neuropsychology," 25, 561-570] suggested that sustained human performance may systematically…

On the Role of Sensory Feedbacks in Rowat–Selverston CPG to Improve Robot Legged Locomotion

PubMed Central

Amrollah, Elmira; Henaff, Patrick

2010-01-01

This paper presents the use of Rowat and Selverston-type of central pattern generator (CPG) to control locomotion. It focuses on the role of afferent exteroceptive and proprioceptive signals in the dynamic phase synchronization in CPG legged robots. The sensori-motor neural network architecture is evaluated to control a two-joint planar robot leg that slips on a rail. Then, the closed loop between the CPG and the mechanical system allows to study the modulation of rhythmic patterns and the effect of the sensing loop via sensory neurons during the locomotion task. Firstly simulations show that the proposed architecture easily allows to modulate rhythmic patterns of the leg, and therefore the velocity of the robot. Secondly, simulations show that sensori-feedbacks from foot/ground contact of the leg make the hip velocity smoother and larger. The results show that the Rowat–Selverston-type CPG with sensory feedbacks is an effective choice for building adaptive neural CPGs for legged robots. PMID:21228904

Precision of Discrete and Rhythmic Forelimb Movements Requires a Distinct Neuronal Subpopulation in the Interposed Anterior Nucleus.

PubMed

Low, Aloysius Y T; Thanawalla, Ayesha R; Yip, Alaric K K; Kim, Jinsook; Wong, Kelly L L; Tantra, Martesa; Augustine, George J; Chen, Albert I

2018-02-27

The deep cerebellar nuclei (DCN) represent output channels of the cerebellum, and they transmit integrated sensorimotor signals to modulate limb movements. But the functional relevance of identifiable neuronal subpopulations within the DCN remains unclear. Here, we examine a genetically tractable population of neurons in the mouse interposed anterior nucleus (IntA). We show that these neurons represent a subset of glutamatergic neurons in the IntA and constitute a specific element of an internal feedback circuit within the cerebellar cortex and cerebello-thalamo-cortical pathway associated with limb control. Ablation and optogenetic stimulation of these neurons disrupt efficacy of skilled reach and locomotor movement and reveal that they control positioning and timing of the forelimb and hindlimb. Together, our findings uncover the function of a distinct neuronal subpopulation in the deep cerebellum and delineate the anatomical substrates and kinematic parameters through which it modulates precision of discrete and rhythmic limb movements. Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.

Genome-wide profiling of diel and circadian gene expression in the malaria vector Anopheles gambiae.

PubMed

Rund, Samuel S C; Hou, Tim Y; Ward, Sarah M; Collins, Frank H; Duffield, Giles E

2011-08-09

Anopheles gambiae, the primary African vector of malaria parasites, exhibits numerous rhythmic behaviors including flight activity, swarming, mating, host seeking, egg laying, and sugar feeding. However, little work has been performed to elucidate the molecular basis for these daily rhythms. To study how gene expression is regulated globally by diel and circadian mechanisms, we have undertaken a DNA microarray analysis of An. gambiae under light/dark cycle (LD) and constant dark (DD) conditions. Adult mated, non-blood-fed female mosquitoes were collected every 4 h for 48 h, and samples were processed with DNA microarrays. Using a cosine wave-fitting algorithm, we identified 1,293 and 600 rhythmic genes with a period length of 20-28 h in the head and body, respectively, under LD conditions, representing 9.7 and 4.5% of the An. gambiae gene set. A majority of these genes was specific to heads or bodies. Examination of mosquitoes under DD conditions revealed that rhythmic programming of the transcriptome is dependent on an interaction between the endogenous clock and extrinsic regulation by the LD cycle. A subset of genes, including the canonical clock components, was expressed rhythmically under both environmental conditions. A majority of genes had peak expression clustered around the day/night transitions, anticipating dawn and dusk. Genes cover diverse biological processes such as transcription/translation, metabolism, detoxification, olfaction, vision, cuticle regulation, and immunity, and include rate-limiting steps in the pathways. This study highlights the fundamental roles that both the circadian clock and light play in the physiology of this important insect vector and suggests targets for intervention.

Time-varying motor control of autotomized leopard gecko tails: multiple inputs and behavioral modulation.

PubMed

Higham, Timothy E; Russell, Anthony P

2012-02-01

Autotomy (voluntary loss of an appendage) is common among diverse groups of vertebrates and invertebrates, and much attention has been given to ecological and developmental aspects of tail autotomy in lizards. Although most studies have focused on the ramifications for the lizard (behavior, biomechanics, energetics, etc.), the tail itself can exhibit interesting behaviors once segregated from the body. For example, recent work highlighted the ability of leopard gecko tails to jump and flip, in addition to being able to swing back and forth. Little is known, however, about the control mechanisms underlying these movements. Using electromyography, we examined the time-varying in vivo motor patterns at four sites (two proximal and two distal) in the tail of the leopard gecko, Eublepharis macularius, following autotomy. Using these data we tested the hypothesis that the disparity in movements results simply from overlapping pattern generators within the tail. We found that burst duration, but not cycle duration, of the rhythmic swings reached a plateau at approximately 150 s following autotomy. This is likely because of physiological changes related to muscle fatigue and ischemia. For flips and jumps, burst and cycle duration exhibited no regular pattern. The coefficient of variation in motor patterns was significantly greater for jumps and flips than for rhythmic swings. This supports the conclusion that the different tail behaviors do not stem from overlapping pattern generators, but that they rely upon independent neural circuits. The signal controlling jumps and flips may be modified by sensory information from the environment. Finally, we found that jumps and flips are initiated using relatively synchronous activity between the two sides of the tail. In contrast, alternating activation of the right and left sides of the tail result in rhythmic swings. The mechanism underlying this change in tail behavior is comparable to locomotor gait changes in vertebrates.

Circadian rhythms and food anticipatory behavior in Wfs1-deficient mice.

PubMed

Luuk, Hendrik; Fahrenkrug, Jan; Hannibal, Jens

2012-08-10

The dorsomedial hypothalamic nucleus (DMH) has been proposed as a candidate for the neural substrate of a food-entrainable oscillator. The existence of a food-entrainable oscillator in the mammalian nervous system was inferred previously from restricted feeding-induced behavioral rhythmicity in rodents with suprachiasmatic nucleus lesions. In the present study, we have characterized the circadian rhythmicity of behavior in Wfs1-deficient mice during ad libitum and restricted feeding. Based on the expression of Wfs1 protein in the DMH it was hypothesized that Wfs1-deficient mice will display reduced or otherwise altered food anticipatory activity. Wfs1 immunoreactivity in DMH was found almost exclusively in the compact part. Restricted feeding induced c-Fos immunoreactivity primarily in the ventral and lateral aspects of DMH and it was similar in both genotypes. Wfs1-deficiency resulted in significantly lower body weight and reduced wheel-running activity. Circadian rhythmicity of behavior was normal in Wfs1-deficient mice under ad libitum feeding apart from elongated free-running period in constant light. The amount of food anticipatory activity induced by restricted feeding was not significantly different between the genotypes. Present results indicate that the effects of Wfs1-deficiency on behavioral rhythmicity are subtle suggesting that Wfs1 is not a major player in the neural networks responsible for circadian rhythmicity of behavior. Copyright © 2012 Elsevier Inc. All rights reserved.

Biases in rhythmic sensorimotor coordination: effects of modality and intentionality.

PubMed

Debats, Nienke B; Ridderikhoff, Arne; de Boer, Betteco J; Peper, C Lieke E

2013-08-01

Sensorimotor biases were examined for intentional (tracking task) and unintentional (distractor task) rhythmic coordination. The tracking task involved unimanual tracking of either an oscillating visual signal or the passive movements of the contralateral hand (proprioceptive signal). In both conditions the required coordination patterns (isodirectional and mirror-symmetric) were defined relative to the body midline and the hands were not visible. For proprioceptive tracking the two patterns did not differ in stability, whereas for visual tracking the isodirectional pattern was performed more stably than the mirror-symmetric pattern. However, when visual feedback about the unimanual hand movements was provided during visual tracking, the isodirectional pattern ceased to be dominant. Together these results indicated that the stability of the coordination patterns did not depend on the modality of the target signal per se, but on the combination of sensory signals that needed to be processed (unimodal vs. cross-modal). The distractor task entailed rhythmic unimanual movements during which a rhythmic visual or proprioceptive distractor signal had to be ignored. The observed biases were similar as for intentional coordination, suggesting that intentionality did not affect the underlying sensorimotor processes qualitatively. Intentional tracking was characterized by active sensory pursuit, through muscle activity in the passively moved arm (proprioceptive tracking task) and rhythmic eye movements (visual tracking task). Presumably this pursuit afforded predictive information serving the coordination process. Copyright © 2013 Elsevier B.V. All rights reserved.

SRC-2 is an essential coactivator for orchastrating metabolism and circadian rhythm

USDA-ARS?s Scientific Manuscript database

Synchrony of the mammalian circadian clock is achieved by complex transcriptional and translational feedback loops centered on the BMAL1:CLOCK heterodimer. Modulation of circadian feedback loops is essential for maintaining rhythmicity, yet the role of transcriptional coactivators in driving BMAL1:C...

Frequency-dependent tACS modulation of BOLD signal during rhythmic visual stimulation.

PubMed

Chai, Yuhui; Sheng, Jingwei; Bandettini, Peter A; Gao, Jia-Hong

2018-05-01

Transcranial alternating current stimulation (tACS) has emerged as a promising tool for modulating cortical oscillations. In previous electroencephalogram (EEG) studies, tACS has been found to modulate brain oscillatory activity in a frequency-specific manner. However, the spatial distribution and hemodynamic response for this modulation remains poorly understood. Functional magnetic resonance imaging (fMRI) has the advantage of measuring neuronal activity in regions not only below the tACS electrodes but also across the whole brain with high spatial resolution. Here, we measured fMRI signal while applying tACS to modulate rhythmic visual activity. During fMRI acquisition, tACS at different frequencies (4, 8, 16, and 32 Hz) was applied along with visual flicker stimulation at 8 and 16 Hz. We analyzed the blood-oxygen-level-dependent (BOLD) signal difference between tACS-ON vs tACS-OFF, and different frequency combinations (e.g., 4 Hz tACS, 8 Hz flicker vs 8 Hz tACS, 8 Hz flicker). We observed significant tACS modulation effects on BOLD responses when the tACS frequency matched the visual flicker frequency or the second harmonic frequency. The main effects were predominantly seen in regions that were activated by the visual task and targeted by the tACS current distribution. These findings bridge different scientific domains of tACS research and demonstrate that fMRI could localize the tACS effect on stimulus-induced brain rhythms, which could lead to a new approach for understanding the high-level cognitive process shaped by the ongoing oscillatory signal. © 2018 Wiley Periodicals, Inc.

Participation of the Olfactory Bulb in Circadian Organization during Early Postnatal Life in Rabbits

PubMed Central

Navarrete, Erika; Ortega-Bernal, Juan Roberto; Trejo-Muñoz, Lucero; Díaz, Georgina; Montúfar-Chaveznava, Rodrigo; Caldelas, Ivette

2016-01-01

Experimental evidence indicates that during pre-visual stages of development in mammals, circadian regulation is still not under the control of the light-entrainable hypothalamic pacemaker, raising the possibility that the circadian rhythmicity that occurs during postnatal development is under the control of peripheral oscillators, such as the main olfactory bulb (MOB). We evaluated the outcome of olfactory bulbectomy on the temporal pattern of core body temperature and gross locomotor activity in newborn rabbits. From postnatal day 1 (P1), pups were randomly assigned to one of the following conditions: intact pups (INT), intact pups fed by enteral gavage (INT+ENT), sham operated pups (SHAM), pups with unilateral lesions of the olfactory bulb (OBx-UNI), and pups with bilateral lesions of the olfactory bulb (OBx-BI). At the beginning of the experiment, from P1-8, the animals in all groups were fed at 11:00, from P9-13 the feeding schedule was delayed 6 h (17:00), and finally, from P14-15 the animals were subjected to fasting conditions. The rabbit pups of the INT, INT+ENT, SHAM and OBx-UNI groups exhibited a clear circadian rhythmicity in body temperature and locomotor activity, with a conspicuous anticipatory rise hours prior to the nursing or feeding schedule, which persisted even during fasting conditions. In addition, phase delays in the nursing or feeding schedule induced a clear phase shift in both parameters. In contrast, the OBx-BI group exhibited atypical rhythmicity in both parameters under entrained conditions that altered the anticipatory component, as well as deficient phase control of both rhythms. The present results demonstrate that the expression of circadian rhythmicity at behavioral and physiological levels during early stages of rabbit development largely depends on the integrity of the main olfactory bulb. PMID:27305041

Setting the pace: host rhythmic behaviour and gene expression patterns in the facultatively symbiotic cnidarian Aiptasia are determined largely by Symbiodinium.

PubMed

Sorek, Michal; Schnytzer, Yisrael; Ben-Asher, Hiba Waldman; Caspi, Vered Chalifa; Chen, Chii-Shiarng; Miller, David J; Levy, Oren

2018-05-09

All organisms employ biological clocks to anticipate physical changes in the environment; however, the integration of biological clocks in symbiotic systems has received limited attention. In corals, the interpretation of rhythmic behaviours is complicated by the daily oscillations in tissue oxygen tension resulting from the photosynthetic and respiratory activities of the associated algal endosymbiont Symbiodinium. In order to better understand the integration of biological clocks in cnidarian hosts of Symbiodinium, daily rhythms of behaviour and gene expression were studied in symbiotic and aposymbiotic morphs of the sea-anemone Aiptasia diaphana. The results showed that whereas circatidal (approx. 12-h) cycles of activity and gene expression predominated in aposymbiotic morphs, circadian (approx. 24-h) patterns were the more common in symbiotic morphs, where the expression of a significant number of genes shifted from a 12- to 24-h rhythm. The behavioural experiments on symbiotic A. diaphana displayed diel (24-h) rhythmicity in body and tentacle contraction under the light/dark cycles, whereas aposymbiotic morphs showed approximately 12-h (circatidal) rhythmicity. Reinfection experiments represent an important step in understanding the hierarchy of endogenous clocks in symbiotic associations, where the aposymbiotic Aiptasia morphs returned to a 24-h behavioural rhythm after repopulation with algae. Whilst some modification of host metabolism is to be expected, the extent to which the presence of the algae modified host endogenous behavioural and transcriptional rhythms implies that it is the symbionts that influence the pace. Our results clearly demonstrate the importance of the endosymbiotic algae in determining the timing and the duration of the extension and contraction of the body and tentacles and temporal gene expression.

Social Physique Anxiety and Pressure to Be Thin in Adolescent Ballet Dancers, Rhythmic Gymnastics and Swimming Athletes

ERIC Educational Resources Information Center

Kosmidou, Evdoxia; Giannitsopoulou, Evgenia; Moysidou, Dimitra

2017-01-01

Participation in sports may influence negative body image and Social Physique Anxiety (SPA) as there is pressure by significant others to have a certain body image. The aim of the present study was to examine possible differences in SPA and perceived pressure to be thin between female preadolescent and adolescent ballet dancers, rhythmic…

Analysis of the energetic metabolism in cyclic Bedouin goats (Capra hircus): Nychthemeral and seasonal variations of some haematochemical parameters in relation with body and ambient temperatures.

PubMed

Malek, Mouna; Amirat, Zaina; Khammar, Farida; Khaldoun, Mounira

2016-08-01

Several studies have examined changes in some haematochemical parameters as a function of the different physiological status (cyclic, pregnant and lactating) of goats, but no relevant literature has exhaustively investigated these variations from anestrous to estrous stages in cyclic goats. In this paper, we report nychthemeral and seasonal variations in ambient and body temperatures, and in some haematochemical parameters (glycemia, cholesterolemia, triglyceridemia, creatininemia and uremia) measured during summer, winter and spring, in seven (7) experimental cyclic female Bedouin goats (Capra hircus) living in the Béni-Abbès region (Algerian Sahara desert). Cosinor rhythmometry procedure was used to determine the rhythmic parameters of ambient temperature and haematochemical parameters. To determine the effect of time of day on the rhythmicity of the studied parameters, as well as their seasonality, repeated measure analysis of variance (ANOVA) was applied. The results showed that in spite of the nychthemeral profile presented by the ambient temperature for each season, the body temperature remained in a narrow range, thus indicating a successful thermoregulation. The rhythmometry analysis showed a circadian rhythmicity of ambient temperature and haematochemical parameters with diurnal acrophases. A statistically significant effect of the time of day was shown on all studied haematochemical parameters, except on creatininemia. It was also found that only uremia, cholesterolemia and triglyceridemia followed the seasonal sexual activity of the studied ruminant. This study demonstrated the good physiological adaptation developed by this breed in response to the harsh climatic conditions of its natural environment. Copyright © 2016 Elsevier Ltd. All rights reserved.

Rhythmic Haptic Stimuli Improve Short-Term Attention.

PubMed

Zhang, Shusheng; Wang, Dangxiao; Afzal, Naqash; Zhang, Yuru; Wu, Ruilin

2016-01-01

Brainwave entrainment using rhythmic visual and/or auditory stimulation has shown its efficacy in modulating neural activities and cognitive ability. In the presented study, we aim to investigate whether rhythmic haptic stimulation could enhance short-term attention. An experiment with sensorimotor rhythm (SMR) increasing protocol was performed in which participants were presented sinusoidal vibrotactile stimulus of 15 Hz on their palm. Test of Variables of Attention (T.O.V.A.) was performed before and after the stimulating session. Electroencephalograph (EEG) was recorded across the stimulating session and the two attention test sessions. SMR band power manifested a significant increase after stimulation. Results of T.O.V.A. tests indicated an improvement in the attention of participants who had received the stimulation compared to the control group who had not received the stimulation. The D prime score of T.O.V.A. reveals that participants performed better in perceptual sensitivity and sustaining attention level compared to their baseline performance before the stimulating session. These findings highlight the potential value of using haptics-based brainwave entrainment for cognitive training.

Chronodisruption in lung cancer and possible therapeutic approaches.

PubMed

Mazzoccoli, Gianluigi; Tarquini, Roberto; Durfort, Tiphanie; Francois, Jean-Christophe

2011-10-01

A customary temporal organization of physiological functions and biological processes is necessary to maintain body homeostasis and an altered body time structure may favour carcinogenesis. There is growing evidence that GH stimulates cancer growth, IGF1 may have a role in carcinogenesis and cancer promotion, GH-IGF1 axis, TRH, TSH, thyroxine, melatonin and cortisol modulate immune cell function and the immune system is often dysfunctional in patients with malignancies. The aim of our study was to evaluate GH-IGF1 axis, hypothalamus-pituitary-thyroid axis, melatonin, cortisol, lymphocyte subsets and IL2 in lung cancer patients. Peripheral blood samples were collected at 4-hour intervals in a 24-hour period from eleven healthy male subjects (age range 35-53 years) and nine male patients suffering from non-small cell lung cancer (age range 43-63 years). In each blood sample, lymphocyte subpopulations (CD3+, CD4+, CD8+, CD16+, CD20+, CD25+, HLA-DR+, γδTcR bearing cells) were analyzed and GH, IGF1, TRH, TSH, FT4, melatonin, cortisol and IL2 were measured. Circadian rhythmicity was evaluated and MESOR, amplitude and acrophase values were compared. In healthy subjects a significant circadian rhythm could be demonstrated with midday peaks for CD8+, CD16+, γδTCR expressing cells and cortisol, and peaks during the night for CD3+, CD4+, GH, TSH and melatonin. A borderline significant rhythm was also observed for CD20+, with a peak late in the evening. IGF1, TRH, FT4 and IL2 values did not show rhythmic variation. In cancer patients a significant circadian rhythm could be demonstrated with diurnal peak for CD16+ and peaks during the night for CD4+ and melatonin. GH, IGF1, TRH, TSH, FT4, cortisol and IL2 values did not show rhythmic variation. MESOR of CD8+ (P<0.0001), CD20+ (P=0.05), γδTCR expressing cells (P=0.01), IGF1 (P<0.001) and TSH (P=0.032) was higher in healthy subjects, whereas MESOR of CD16+ (P<0.0001), CD25+ (P=0.001), GH (P<0.001), TRH (P=0.002), FT4 (P=0.030), cortisol (P=0.01) and IL2 (P=0.02) was higher in cancer patients. Amplitude of circadian variation of γδTCR expressing cells (P=0.01), TSH (P<0.001) and cortisol (P=0.01) was higher in healthy subjects, whereas amplitude of circadian variation of CD4+ was higher in cancer patients (P=0.02). In conclusion, non-small cell lung cancer patients show severe alterations of periodic and quantitative characteristics of neuroendocrine and immune parameters with loss of circadian rhythmicity and internal desynchronization, leading to chronodisruption. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

Circadian rhythmicity of active GSK3 isoforms modulates molecular clock gene rhythms in the suprachiasmatic nucleus.

PubMed

Besing, Rachel C; Paul, Jodi R; Hablitz, Lauren M; Rogers, Courtney O; Johnson, Russell L; Young, Martin E; Gamble, Karen L

2015-04-01

The suprachiasmatic nucleus (SCN) drives and synchronizes daily rhythms at the cellular level via transcriptional-translational feedback loops comprising clock genes such as Bmal1 and Period (Per). Glycogen synthase kinase 3 (GSK3), a serine/threonine kinase, phosphorylates at least 5 core clock proteins and shows diurnal variation in phosphorylation state (inactivation) of the GSK3β isoform. Whether phosphorylation of the other primary isoform (GSK3α) varies across the subjective day-night cycle is unknown. The purpose of this study was to determine if the endogenous rhythm of GSK3 (α and β) phosphorylation is critical for rhythmic BMAL1 expression and normal amplitude and periodicity of the molecular clock in the SCN. Significant circadian rhythmicity of phosphorylated GSK3 (α and β) was observed in the SCN from wild-type mice housed in constant darkness for 2 weeks. Importantly, chronic activation of both GSK3 isoforms impaired rhythmicity of the GSK3 target BMAL1. Furthermore, chronic pharmacological inhibition of GSK3 with 20 µM CHIR-99021 enhanced the amplitude and shortened the period of PER2::luciferase rhythms in organotypic SCN slice cultures. These results support the model that GSK3 activity status is regulated by the circadian clock and that GSK3 feeds back to regulate the molecular clock amplitude in the SCN. © 2015 The Author(s).

Environmental Coupling Modulates the Attractors of Rhythmic Coordination

ERIC Educational Resources Information Center

Kudo, Kazutoshi; Park, Hyeonsaeng; Kay, Bruce A.; Turvey, M. T.

2006-01-01

A simple instance of coupling behavior to the environment is oscillating the hands in pace with metronome beats. This environmental coupling can be weaker (1 beat per cycle) or stronger (2 beats per cycle). The authors examined whether strength of environmental coupling enhanced the stability of in-phase bimanual coordination. Detuning by…

Breathing as a Fundamental Rhythm of Brain Function.

PubMed

Heck, Detlef H; McAfee, Samuel S; Liu, Yu; Babajani-Feremi, Abbas; Rezaie, Roozbeh; Freeman, Walter J; Wheless, James W; Papanicolaou, Andrew C; Ruszinkó, Miklós; Sokolov, Yury; Kozma, Robert

2016-01-01

Ongoing fluctuations of neuronal activity have long been considered intrinsic noise that introduces unavoidable and unwanted variability into neuronal processing, which the brain eliminates by averaging across population activity (Georgopoulos et al., 1986; Lee et al., 1988; Shadlen and Newsome, 1994; Maynard et al., 1999). It is now understood, that the seemingly random fluctuations of cortical activity form highly structured patterns, including oscillations at various frequencies, that modulate evoked neuronal responses (Arieli et al., 1996; Poulet and Petersen, 2008; He, 2013) and affect sensory perception (Linkenkaer-Hansen et al., 2004; Boly et al., 2007; Sadaghiani et al., 2009; Vinnik et al., 2012; Palva et al., 2013). Ongoing cortical activity is driven by proprioceptive and interoceptive inputs. In addition, it is partially intrinsically generated in which case it may be related to mental processes (Fox and Raichle, 2007; Deco et al., 2011). Here we argue that respiration, via multiple sensory pathways, contributes a rhythmic component to the ongoing cortical activity. We suggest that this rhythmic activity modulates the temporal organization of cortical neurodynamics, thereby linking higher cortical functions to the process of breathing.

Arm coordination in octopus crawling involves unique motor control strategies.

PubMed

Levy, Guy; Flash, Tamar; Hochner, Binyamin

2015-05-04

To cope with the exceptional computational complexity that is involved in the control of its hyper-redundant arms [1], the octopus has adopted unique motor control strategies in which the central brain activates rather autonomous motor programs in the elaborated peripheral nervous system of the arms [2, 3]. How octopuses coordinate their eight long and flexible arms in locomotion is still unknown. Here, we present the first detailed kinematic analysis of octopus arm coordination in crawling. The results are surprising in several respects: (1) despite its bilaterally symmetrical body, the octopus can crawl in any direction relative to its body orientation; (2) body and crawling orientation are monotonically and independently controlled; and (3) contrasting known animal locomotion, octopus crawling lacks any apparent rhythmical patterns in limb coordination, suggesting a unique non-rhythmical output of the octopus central controller. We show that this uncommon maneuverability is derived from the radial symmetry of the arms around the body and the simple pushing-by-elongation mechanism by which the arms create the crawling thrust. These two together enable a mechanism whereby the central controller chooses in a moment-to-moment fashion which arms to recruit for pushing the body in an instantaneous direction. Our findings suggest that the soft molluscan body has affected in an embodied way [4, 5] the emergence of the adaptive motor behavior of the octopus. Copyright © 2015 Elsevier Ltd. All rights reserved.

Effects of Cold-Dry (Harmattan) and Hot-Dry Seasons on Daily Rhythms of Rectal and Body Surface Temperatures in Sheep and Goats in a Natural Tropical Environment

PubMed Central

Ayo, Joseph O.

2016-01-01

Studies on daily rhythmicity in livestock under natural conditions are limited, and there is mounting evidence that rhythm patterns differ between chronobiological studies conducted in the laboratory and studies conducted under pronounced natural seasonality. Here, we investigated the influence of cold-dry (harmattan) and hot-dry seasons on daily rhythmicity of rectal (RT) and body surface temperatures (BST) in indigenous sheep and goats under natural light-dark cycles. The RT and BST of the animals, and the ambient temperature (AT) and relative humidity (RH) inside the pen, were measured every three hours for a period of two days, twice on separate days during the hot-dry and the harmattan seasons, respectively. The AT and RH had minimum values of 16°C and 15% recorded during the harmattan and maximum values of 32°C and 46% recorded during the hot-dry season, respectively. A trigonometric statistical model was applied to characterize the main rhythmic parameters according to the single cosinor procedure. The result showed that RT and BST exhibited different degrees of daily rhythmicity, and their oscillatory patterns differed with the seasons (larger amplitude during the harmattan season than during the hot-dry season). The goats displayed greater (p < 0.05) amplitude of BST than the sheep in all seasons. The acrophases were restricted to the light phase of the light-dark cycle. The mesor of RT in goats was not affected by the season, but mesors of BST in both species were significantly higher (p < 0.05) during the hot-dry than the harmattan season. The goats had a more robust RT rhythm (70%) as compared to the sheep (56%). Overall, the results demonstrated that seasonal changes influenced considerably the daily rhythmicity of RT and BST in sheep and goats under natural light-dark cycle. Awareness of these changes may be useful in the improvement of diagnosis, treatment and prevention of diseases, and welfare and productivity of sheep and goats under cold-dry and hot-dry conditions.

Content congruency and its interplay with temporal synchrony modulate integration between rhythmic audiovisual streams.

PubMed

Su, Yi-Huang

2014-01-01

Both lower-level stimulus factors (e.g., temporal proximity) and higher-level cognitive factors (e.g., content congruency) are known to influence multisensory integration. The former can direct attention in a converging manner, and the latter can indicate whether information from the two modalities belongs together. The present research investigated whether and how these two factors interacted in the perception of rhythmic, audiovisual (AV) streams derived from a human movement scenario. Congruency here was based on sensorimotor correspondence pertaining to rhythm perception. Participants attended to bimodal stimuli consisting of a humanlike figure moving regularly to a sequence of auditory beat, and detected a possible auditory temporal deviant. The figure moved either downwards (congruently) or upwards (incongruently) to the downbeat, while in both situations the movement was either synchronous with the beat, or lagging behind it. Greater cross-modal binding was expected to hinder deviant detection. Results revealed poorer detection for congruent than for incongruent streams, suggesting stronger integration in the former. False alarms increased in asynchronous stimuli only for congruent streams, indicating greater tendency for deviant report due to visual capture of asynchronous auditory events. In addition, a greater increase in perceived synchrony was associated with a greater reduction in false alarms for congruent streams, while the pattern was reversed for incongruent ones. These results demonstrate that content congruency as a top-down factor not only promotes integration, but also modulates bottom-up effects of synchrony. Results are also discussed regarding how theories of integration and attentional entrainment may be combined in the context of rhythmic multisensory stimuli.

Rhythmic Extended Kalman Filter for Gait Rehabilitation Motion Estimation and Segmentation.

PubMed

Joukov, Vladimir; Bonnet, Vincent; Karg, Michelle; Venture, Gentiane; Kulic, Dana

2018-02-01

This paper proposes a method to enable the use of non-intrusive, small, wearable, and wireless sensors to estimate the pose of the lower body during gait and other periodic motions and to extract objective performance measures useful for physiotherapy. The Rhythmic Extended Kalman Filter (Rhythmic-EKF) algorithm is developed to estimate the pose, learn an individualized model of periodic movement over time, and use the learned model to improve pose estimation. The proposed approach learns a canonical dynamical system model of the movement during online observation, which is used to accurately model the acceleration during pose estimation. The canonical dynamical system models the motion as a periodic signal. The estimated phase and frequency of the motion also allow the proposed approach to segment the motion into repetitions and extract useful features, such as gait symmetry, step length, and mean joint movement and variance. The algorithm is shown to outperform the extended Kalman filter in simulation, on healthy participant data, and stroke patient data. For the healthy participant marching dataset, the Rhythmic-EKF improves joint acceleration and velocity estimates over regular EKF by 40% and 37%, respectively, estimates joint angles with 2.4° root mean squared error, and segments the motion into repetitions with 96% accuracy.

Rhythmic complexity and predictive coding: a novel approach to modeling rhythm and meter perception in music

PubMed Central

Vuust, Peter; Witek, Maria A. G.

2014-01-01

Musical rhythm, consisting of apparently abstract intervals of accented temporal events, has a remarkable capacity to move our minds and bodies. How does the cognitive system enable our experiences of rhythmically complex music? In this paper, we describe some common forms of rhythmic complexity in music and propose the theory of predictive coding (PC) as a framework for understanding how rhythm and rhythmic complexity are processed in the brain. We also consider why we feel so compelled by rhythmic tension in music. First, we consider theories of rhythm and meter perception, which provide hierarchical and computational approaches to modeling. Second, we present the theory of PC, which posits a hierarchical organization of brain responses reflecting fundamental, survival-related mechanisms associated with predicting future events. According to this theory, perception and learning is manifested through the brain’s Bayesian minimization of the error between the input to the brain and the brain’s prior expectations. Third, we develop a PC model of musical rhythm, in which rhythm perception is conceptualized as an interaction between what is heard (“rhythm”) and the brain’s anticipatory structuring of music (“meter”). Finally, we review empirical studies of the neural and behavioral effects of syncopation, polyrhythm and groove, and propose how these studies can be seen as special cases of the PC theory. We argue that musical rhythm exploits the brain’s general principles of prediction and propose that pleasure and desire for sensorimotor synchronization from musical rhythm may be a result of such mechanisms. PMID:25324813

Diet-induced obesity reduces core body temperature across the estrous cycle and pregnancy in the rat.

PubMed

Crew, Rachael C; Waddell, Brendan J; Maloney, Shane K; Mark, Peter J

2018-04-16

Obesity during pregnancy causes adverse maternal and fetal health outcomes and programs offspring for adult-onset diseases, including cardiovascular disease. Obesity also disrupts core body temperature (T c ) regulation in nonpregnant rodents; however, it is unknown whether obesity alters normal maternal T c adaptations to pregnancy. Since T c is influenced by the circadian system, and both obesity and pregnancy alter circadian biology, it was hypothesized that obesity disrupts the normal rhythmic patterns of T c before and during gestation. Obesity was induced by cafeteria (CAF) feeding in female Wistar rats for 8 weeks prior to and during gestation, whereas control (CON) animals had free access to chow. Intraperitoneal temperature loggers measured daily T c profiles throughout the study, while maternal body composition and leptin levels were assessed near term. Daily temperature profiles were examined for rhythmic features (mesor, amplitude and acrophase) by cosine regression analysis. CAF animals exhibited increased fat mass (93%) and associated hyperleptinemia (3.2-fold increase) compared to CON animals. CAF consumption reduced the average T c (by up to 0.29°C) across the estrous cycle and most of pregnancy; however, T c for CAF and CON animals converged toward the end of gestation. Obesity reduced the amplitude of T c rhythms at estrus and proestrus and on day 8 of pregnancy, but increased the amplitude at day 20 of pregnancy. Photoperiod analysis revealed that obesity reduced T c exclusively in the light period during pre-pregnancy but only during the dark period in late gestation. In conclusion, obesity alters rhythmic T c profiles and reduces the magnitude of the T c decline late in rat gestation, which may have implications for maternal health and fetal development.

Growth and body composition in Brazilian female rhythmic gymnastics athletes.

PubMed

Camargo, Cristiane Teixeira Amaral; Gomez-Campos, Rossana Anelice; Cossio-Bolaños, Marco Antonio; Barbeta, Vinicius Justino De Oliveira; Arruda, Miguel; Guerra-Junior, Gil

2014-01-01

The aim was to analyse the physical growth and body composition of rhythmic gymnastics athletes relative to their level of somatic maturation. This was a cross-sectional study of 136 athletes on 23 teams from Brazil. Mass, standing height and sitting height were measured. Fat-free and fat masses, body fat percentages and ages of the predicted peak height velocity (PHV) were calculated. The z scores for mass were negative during all ages according to both WHO and Brazilian references, and that for standing height were also negative for all ages according to WHO reference but only until 12 years old according to Brazilian reference. The mean age of the predicted PHV was 12.1 years. The mean mass, standing and sitting heights, body fat percentage, fat-free mass and fat mass increased significantly until 4 to 5 years after the age of the PHV. Menarche was reached in only 26% of these athletes and mean age was 13.2 years. The mass was below the national reference standards, and the standing height was below only for the international reference, but they also had late recovery of mass and standing height during puberty. In conclusion, these athletes had a potential to gain mass and standing height several years after PHV, indicating late maturation.

Ground Reaction Forces Generated During Rhythmical Squats as a Dynamic Loads of the Structure

NASA Astrophysics Data System (ADS)

Pantak, Marek

2017-10-01

Dynamic forces generated by moving persons can lead to excessive vibration of the long span, slender and lightweight structure such as floors, stairs, stadium stands and footbridges. These dynamic forces are generated during walking, running, jumping and rhythmical body swaying in vertical or horizontal direction etc. In the paper the mathematical models of the Ground Reaction Forces (GRFs) generated during squats have been presented. Elaborated models was compared to the GRFs measured during laboratory tests carried out by author in wide range of frequency using force platform. Moreover, the GRFs models were evaluated during dynamic numerical analyses and dynamic field tests of the exemplary structure (steel footbridge).

Entrainment of Breast Cell Lines Results in Rhythmic Fluctuations of MicroRNAs

PubMed Central

Chacolla-Huaringa, Rafael; Trevino, Victor; Scott, Sean-Patrick

2017-01-01

Circadian rhythms are essential for temporal (~24 h) regulation of molecular processes in diverse species. Dysregulation of circadian gene expression has been implicated in the pathogenesis of various disorders, including hypertension, diabetes, depression, and cancer. Recently, microRNAs (miRNAs) have been identified as critical modulators of gene expression post-transcriptionally, and perhaps involved in circadian clock architecture or their output functions. The aim of the present study is to explore the temporal expression of miRNAs among entrained breast cell lines. For this purpose, we evaluated the temporal (28 h) expression of 2006 miRNAs in MCF-10A, MCF-7, and MDA-MB-231 cells using microarrays after serum shock entrainment. We noted hundreds of miRNAs that exhibit rhythmic fluctuations in each breast cell line, and some of them across two or three cell lines. Afterwards, we validated the rhythmic profiles exhibited by miR-141-5p, miR-1225-5p, miR-17-5p, miR-222-5p, miR-769-3p, and miR-548ay-3p in the above cell lines, as well as in ZR-7530 and HCC-1954 using RT-qPCR. Our results show that serum shock entrainment in breast cells lines induces rhythmic fluctuations of distinct sets of miRNAs, which have the potential to be related to endogenous circadian clock, but extensive investigation is required to elucidate that connection. PMID:28704935

The bZIP transcription factor HY5 interacts with the promoter of the monoterpene synthase gene QH6 in modulating its rhythmic expression.

PubMed

Zhou, Fei; Sun, Tian-Hu; Zhao, Lei; Pan, Xi-Wu; Lu, Shan

2015-01-01

The Artemisia annua L. β-pinene synthase QH6 was previously determined to be circadian-regulated at the transcriptional level, showing a rhythmic fluctuation of steady-state transcript abundances. Here we isolated both the genomic sequence and upstream promoter region of QH6. Different regulatory elements, such as G-box (TGACACGTGGCA, -421 bp from the translation initiation site) which might have effects on rhythmic gene expression, were found. Using the yeast one-hybrid and electrophoretic mobility shift assay (EMSA), we confirmed that the bZIP transcription factor HY5 binds to this motif of QH6. Studies with promoter truncations before and after this motif suggested that this G-box was important for the diurnal fluctuation of the transgenic β-glucuronidase gene (GUS) transcript abundance in Arabidopsis thaliana. GUS gene driven by the promoter region immediately after G-box showed an arrhythmic expression in both light/dark (LD) and constant dark (DD) conditions, whereas the control with G-box retained its fluctuation in both LD and DD. We further transformed A. thaliana with the luciferase gene (LUC) driven by an 1400 bp fragment upstream QH6 with its G-box intact or mutated, respectively. The luciferase activity assay showed that a peak in the early morning disappeared in the mutant. Gene expression analysis also demonstrated that the rhythmic expression of LUC was abolished in the hy5-1 mutant.

Causal relationships between neurons of the nucleus incertus and the hippocampal theta activity in the rat.

PubMed

Martínez-Bellver, Sergio; Cervera-Ferri, Ana; Luque-García, Aina; Martínez-Ricós, Joana; Valverde-Navarro, Alfonso; Bataller, Manuel; Guerrero, Juan; Teruel-Marti, Vicent

2017-03-01

The nucleus incertus is a key node of the brainstem circuitry involved in hippocampal theta rhythmicity. Synchronisation exists between the nucleus incertus and hippocampal activities during theta periods. By the Granger causality analysis, we demonstrated a directional information flow between theta rhythmical neurons in the nucleus incertus and the hippocampus in theta-on states. The electrical stimulation of the nucleus incertus is also able to evoke a phase reset of the hippocampal theta wave. Our data suggest that the nucleus incertus is a key node of theta generation and the modulation network. In recent years, a body of evidence has shown that the nucleus incertus (NI), in the dorsal tegmental pons, is a key node of the brainstem circuitry involved in hippocampal theta rhythmicity. Ascending reticular brainstem system activation evokes hippocampal theta rhythm with coupled neuronal activity in the NI. In a recent paper, we showed three populations of neurons in the NI with differential firing during hippocampal theta activation. The objective of this work was to better evaluate the causal relationship between the activity of NI neurons and the hippocampus during theta activation in order to further understand the role of the NI in the theta network. A Granger causality analysis was run to determine whether hippocampal theta activity with sensory-evoked theta depends on the neuronal activity of the NI, or vice versa. The analysis showed causal interdependence between the NI and the hippocampus during theta activity, whose directional flow depended on the different neuronal assemblies of the NI. Whereas type I and II NI neurons mainly acted as receptors of hippocampal information, type III neuronal activity was the predominant source of flow between the NI and the hippocampus in theta states. We further determined that the electrical activation of the NI was able to reset hippocampal waves with enhanced theta-band power, depending on the septal area. Collectively, these data suggest that hippocampal theta oscillations after sensory activation show dependence on NI neuron activity, which could play a key role in establishing optimal conditions for memory encoding. © 2016 The Authors. The Journal of Physiology © 2016 The Physiological Society.

Maternal Olfactory Cues Synchronize the Circadian System of Artificially Raised Newborn Rabbits

PubMed Central

Montúfar-Chaveznava, Rodrigo; Trejo-Muñoz, Lucero; Hernández-Campos, Oscar; Navarrete, Erika; Caldelas, Ivette

2013-01-01

In European newborn rabbits, once-daily nursing acts as a strong non-photic entraining cue for the pre-visual circadian system. Nevertheless, there is a lack of information regarding which of the non-photic cues are capable of modulating pup circadian system. In this study, for the first time, we determined that the mammary pheromone 2-methylbut-2-enal (2MB2) presented in the maternal milk acts as a non-photic entraining cue. We evaluated the effect of once-daily exposure to maternal olfactory cues on the temporal pattern of core body temperature, gross locomotor activity and metabolic variables (liver weight, serum glucose, triacylglycerides, free fatty acids, cholecystokinin and cholesterol levels) in newborn rabbits. Rabbit pups were separated from their mothers from postnatal day 1 (P1) to P8 and were randomly assigned to one of the following conditions: nursed by a lactating doe (NAT); exposed to a 3-min pulse of maternal milk (M-Milk), mammary pheromone (2MB2), or water (H2O). To eliminate maternal stimulation, the pups of the last three groups were artificially fed once every 24-h. On P8, the rabbits were sacrificed at different times of the day. In temperature and activity, the NAT, M-Milk and 2MB2 groups exhibited clear diurnal rhythmicity with a conspicuous anticipatory rise hours prior to nursing. In contrast, the H2O group exhibited atypical rhythmicity in both parameters, lacking the anticipatory component. At the metabolic level, all of the groups exhibited a diurnal pattern with similar phases in liver weight and metabolites examined. The results obtained in this study suggest that during pre-visual stages of development, the circadian system of newborn rabbits is sensitive to the maternal olfactory cues contained in milk, indicating that these cues function as non-photic entraining signals mainly for the central oscillators regulating the expression of temperature and behavior, whereas in metabolic diurnal rhythmicity, these cues lack an effect, indicating that peripheral oscillators respond to milk administration. PMID:24040161

Rise, Sally, Rise: Communication through Dance.

ERIC Educational Resources Information Center

Bell, Davia

1999-01-01

Explores ring games--where participants form a circle, sing, dance, and take turns entering the circle--and how they can be used in the second-language classroom. The playful integration of vocalization and rhythmic body movement can have a powerful influence on speech fluency. (Author/VWL)

Physical Education. Secondary

ERIC Educational Resources Information Center

Molosky, Gerald; And Others

GRADES OR AGES: Grades 7-10. SUBJECT MATTER: Physical education. ORGANIZATION AND PHYSICAL APPEARANCE: The guide is divided into six color-coded units, one each for athletic skills and games, fitness testing and body mechanics, rhythmical activities, simple games and recreational activities, tumbling and apparatus, and swimming. It is mimeographed…

Transcriptome analysis in oak uncovers a strong impact of endogenous rhythmic growth on the interaction with plant-parasitic nematodes.

PubMed

Maboreke, Hazel R; Feldhahn, Lasse; Bönn, Markus; Tarkka, Mika T; Buscot, Francois; Herrmann, Sylvie; Menzel, Ralph; Ruess, Liliane

2016-08-12

Pedunculate oak (Quercus robur L.), an important forest tree in temperate ecosystems, displays an endogenous rhythmic growth pattern, characterized by alternating shoot and root growth flushes paralleled by oscillations in carbon allocation to below- and aboveground tissues. However, these common plant traits so far have largely been neglected as a determining factor for the outcome of plant biotic interactions. This study investigates the response of oak to migratory root-parasitic nematodes in relation to rhythmic growth, and how this plant-nematode interaction is modulated by an ectomycorrhizal symbiont. Oaks roots were inoculated with the nematode Pratylenchus penetrans solely and in combination with the fungus Piloderma croceum, and the systemic impact on oak plants was assessed by RNA transcriptomic profiles in leaves. The response of oaks to the plant-parasitic nematode was strongest during shoot flush, with a 16-fold increase in the number of differentially expressed genes as compared to root flush. Multi-layered defence mechanisms were induced at shoot flush, comprising upregulation of reactive oxygen species formation, hormone signalling (e.g. jasmonic acid synthesis), and proteins involved in the shikimate pathway. In contrast during root flush production of glycerolipids involved in signalling cascades was repressed, suggesting that P. penetrans actively suppressed host defence. With the presence of the mycorrhizal symbiont, the gene expression pattern was vice versa with a distinctly stronger effect of P. penetrans at root flush, including attenuated defence, cell and carbon metabolism, likely a response to the enhanced carbon sink strength in roots induced by the presence of both, nematode and fungus. Meanwhile at shoot flush, when nutrients are retained in aboveground tissue, oak defence reactions, such as altered photosynthesis and sugar pathways, diminished. The results highlight that gene response patterns of plants to biotic interactions, both negative (i.e. plant-parasitic nematodes) and beneficial (i.e. mycorrhiza), are largely modulated by endogenous rhythmic growth, and that such plant traits should be considered as an important driver of these relationships in future studies.

What is orgasm? A model of sexual trance and climax via rhythmic entrainment

PubMed Central

Safron, Adam

2016-01-01

Orgasm is one of the most intense pleasures attainable to an organism, yet its underlying mechanisms remain poorly understood. On the basis of existing literatures, this article introduces a novel mechanistic model of sexual stimulation and orgasm. In doing so, it characterizes the neurophenomenology of sexual trance and climax, describes parallels in dynamics between orgasms and seizures, speculates on possible evolutionary origins of sex differences in orgasmic responding, and proposes avenues for future experimentation. Here, a model is introduced wherein sexual stimulation induces entrainment of coupling mechanical and neuronal oscillatory systems, thus creating synchronized functional networks within which multiple positive feedback processes intersect synergistically to contribute to sexual experience. These processes generate states of deepening sensory absorption and trance, potentially culminating in climax if critical thresholds are surpassed. The centrality of rhythmic stimulation (and its modulation by salience) for surpassing these thresholds suggests ways in which differential orgasmic responding between individuals—or with different partners—may serve as a mechanism for ensuring adaptive mate choice. Because the production of rhythmic stimulation combines honest indicators of fitness with cues relating to potential for investment, differential orgasmic response may serve to influence the probability of continued sexual encounters with specific mates. PMID:27799079

Kinematic analysis of basic rhythmic movements of hip-hop dance: motion characteristics common to expert dancers.

PubMed

Sato, Nahoko; Nunome, Hiroyuki; Ikegami, Yasuo

2015-02-01

In hip-hop dance contests, a procedure for evaluating performances has not been clearly defined, and objective criteria for evaluation are necessary. It is assumed that most hip-hop dance techniques have common motion characteristics by which judges determine the dancer's skill level. This study aimed to extract motion characteristics that may be linked to higher evaluations by judges. Ten expert and 12 nonexpert dancers performed basic rhythmic movements at a rate of 100 beats per minute. Their movements were captured using a motion capture system, and eight judges evaluated the performances. Four kinematic parameters, including the amplitude of the body motions and the phase delay, which indicates the phase difference between two joint angles, were calculated. The two groups showed no significant differences in terms of the amplitudes of the body motions. In contrast, the phase delay between the head motion and the other body parts' motions of expert dancers who received higher scores from the judges, which was approximately a quarter cycle, produced a loop-shaped motion of the head. It is suggested that this slight phase delay was related to the judges' evaluations and that these findings may help in constructing an objective evaluation system.

Part 2: Sedimentary geology of the Valles, Marineris, Mars and Antarctic dry valley lakes

NASA Technical Reports Server (NTRS)

Nedell, Susan S.

1987-01-01

Detailed mapping of the layered deposits in the Valles Marineris, Mars from high-resolution Viking orbiter images revealed that they from plateaus of rhythmically layered material whose bases are in the lowest elevations of the canyon floors, and whose tops are within a few hundred meters in elevation of the surrounding plateaus. Four hypotheses for the origin of the layered deposits were considered: that they are eolian deposits; that they are remnants of the same material as the canyon walls; that they are explosive volcanic deposits; or that they were deposited in standing bodies of water. There are serious morphologic objections to each of the first three. The deposition of the layered deposits in standing bodies of water best explains their lateral continuity, horizontality, great thickness, rhythmic nature, and stratigraphic relationships with other units within the canyons. The Martian climatic history indicated that any ancient lakes were ice covered. Two methods for transporting sediment through a cover of ice on a martian lake appear to be feasible. Based on the presently available data, along with the theoretical calculations presented, it appears most likely that the layered deposits in the Valles Marineris were laid down in standing bodies of water.

Imaging of ultraweak spontaneous photon emission from human body displaying diurnal rhythm.

PubMed

Kobayashi, Masaki; Kikuchi, Daisuke; Okamura, Hitoshi

2009-07-16

The human body literally glimmers. The intensity of the light emitted by the body is 1000 times lower than the sensitivity of our naked eyes. Ultraweak photon emission is known as the energy released as light through the changes in energy metabolism. We successfully imaged the diurnal change of this ultraweak photon emission with an improved highly sensitive imaging system using cryogenic charge-coupled device (CCD) camera. We found that the human body directly and rhythmically emits light. The diurnal changes in photon emission might be linked to changes in energy metabolism.

Spinal Cord Swelling and Alterations in Hydrostatic Pressure after Acute Injury

DTIC Science & Technology

2015-10-01

after SCI, half of the animals that received a duraplasty after SCI (50%) were already capable of weight-supported rhythmic hindlimb movements or...actual force, displacement or velocity at impact. Correlation analysis demonstrated a linear relationship between PTIBS and body weight after SCI

Exploring the Nature of Cortical Recurrent Interactions

NASA Astrophysics Data System (ADS)

Morita, Kenji; Kalra, Rita; Aihara, Kazuyuki; Robinson, Hugh P. C.

2011-09-01

Fast rhythmic activity of neural population has been frequently observed in cortical circuits, and suggested to be associated with various cognitive functions including working memory and selective attention. However, precisely how recurrent synaptic interactions, that are prominent in these circuits, shape and/or modulate such population rhythm has not been fully elucidated. We have addressed this issue by combining electrophysiological and computational approaches.

Sex differences in the circadian regulation of sleep and waking cognition in humans.

PubMed

Santhi, Nayantara; Lazar, Alpar S; McCabe, Patrick J; Lo, June C; Groeger, John A; Dijk, Derk-Jan

2016-05-10

The sleep-wake cycle and circadian rhythmicity both contribute to brain function, but whether this contribution differs between men and women and how it varies across cognitive domains and subjective dimensions has not been established. We examined the circadian and sleep-wake-dependent regulation of cognition in 16 men and 18 women in a forced desynchrony protocol and quantified the separate contributions of circadian phase, prior sleep, and elapsed time awake on cognition and sleep. The largest circadian effects were observed for reported sleepiness, mood, and reported effort; the effects on working memory and temporal processing were smaller. Although these effects were seen in both men and women, there were quantitative differences. The amplitude of the circadian modulation was larger in women in 11 of 39 performance measures so that their performance was more impaired in the early morning hours. Principal components analysis of the performance measures yielded three factors, accuracy, effort, and speed, which reflect core performance characteristics in a range of cognitive tasks and therefore are likely to be important for everyday performance. The largest circadian modulation was observed for effort, whereas accuracy exhibited the largest sex difference in circadian modulation. The sex differences in the circadian modulation of cognition could not be explained by sex differences in the circadian amplitude of plasma melatonin and electroencephalographic slow-wave activity. These data establish the impact of circadian rhythmicity and sex on waking cognition and have implications for understanding the regulation of brain function, cognition, and affect in shift-work, jetlag, and aging.

Sex differences in the circadian regulation of sleep and waking cognition in humans

PubMed Central

Santhi, Nayantara; Lazar, Alpar S.; McCabe, Patrick J.; Lo, June C.; Groeger, John A.; Dijk, Derk-Jan

2016-01-01

The sleep–wake cycle and circadian rhythmicity both contribute to brain function, but whether this contribution differs between men and women and how it varies across cognitive domains and subjective dimensions has not been established. We examined the circadian and sleep–wake-dependent regulation of cognition in 16 men and 18 women in a forced desynchrony protocol and quantified the separate contributions of circadian phase, prior sleep, and elapsed time awake on cognition and sleep. The largest circadian effects were observed for reported sleepiness, mood, and reported effort; the effects on working memory and temporal processing were smaller. Although these effects were seen in both men and women, there were quantitative differences. The amplitude of the circadian modulation was larger in women in 11 of 39 performance measures so that their performance was more impaired in the early morning hours. Principal components analysis of the performance measures yielded three factors, accuracy, effort, and speed, which reflect core performance characteristics in a range of cognitive tasks and therefore are likely to be important for everyday performance. The largest circadian modulation was observed for effort, whereas accuracy exhibited the largest sex difference in circadian modulation. The sex differences in the circadian modulation of cognition could not be explained by sex differences in the circadian amplitude of plasma melatonin and electroencephalographic slow-wave activity. These data establish the impact of circadian rhythmicity and sex on waking cognition and have implications for understanding the regulation of brain function, cognition, and affect in shift-work, jetlag, and aging. PMID:27091961

Dynamic decomposition of spatiotemporal neural signals

PubMed Central

2017-01-01

Neural signals are characterized by rich temporal and spatiotemporal dynamics that reflect the organization of cortical networks. Theoretical research has shown how neural networks can operate at different dynamic ranges that correspond to specific types of information processing. Here we present a data analysis framework that uses a linearized model of these dynamic states in order to decompose the measured neural signal into a series of components that capture both rhythmic and non-rhythmic neural activity. The method is based on stochastic differential equations and Gaussian process regression. Through computer simulations and analysis of magnetoencephalographic data, we demonstrate the efficacy of the method in identifying meaningful modulations of oscillatory signals corrupted by structured temporal and spatiotemporal noise. These results suggest that the method is particularly suitable for the analysis and interpretation of complex temporal and spatiotemporal neural signals. PMID:28558039

Krüppel-like factor 15: Regulator of BCAA metabolism and circadian protein rhythmicity.

PubMed

Fan, Liyan; Hsieh, Paishiun N; Sweet, David R; Jain, Mukesh K

2018-04-01

Regulation of nutrient intake, utilization, and storage exhibits a circadian rhythmicity that allows organisms to anticipate and adequately respond to changes in the environment across day/night cycles. The branched-chain amino acids (BCAAs) leucine, isoleucine, and valine are important modulators of metabolism and metabolic health - for example, their catabolism yields carbon substrates for gluconeogenesis during periods of fasting. Krüppel-like factor 15 (KLF15) has recently emerged as a critical transcriptional regulator of BCAA metabolism, and the absence of this transcription factor contributes to severe pathologies such as Duchenne muscular dystrophy and heart failure. This review highlights KLF15's role as a central regulator of BCAA metabolism during periods of fasting, throughout day/night cycles, and in experimental models of muscle disease. Copyright © 2017 Elsevier Ltd. All rights reserved.

The From Scratch Rhythm Workbook. Revised Edition.

ERIC Educational Resources Information Center

Dadson, Philip; McGlashan, Don

Since its formation in 1974, the renowned performing group, "From Scratch," has developed a distinctive style of music using sophisticated rhythmic language and unique sculptural instruments. The group's experiences have been transformed into the exercises and game forms presented in this workbook. The hands-on workbook uses a body-based…

Temporal modulations in speech and music.

PubMed

Ding, Nai; Patel, Aniruddh D; Chen, Lin; Butler, Henry; Luo, Cheng; Poeppel, David

2017-10-01

Speech and music have structured rhythms. Here we discuss a major acoustic correlate of spoken and musical rhythms, the slow (0.25-32Hz) temporal modulations in sound intensity and compare the modulation properties of speech and music. We analyze these modulations using over 25h of speech and over 39h of recordings of Western music. We show that the speech modulation spectrum is highly consistent across 9 languages (including languages with typologically different rhythmic characteristics). A different, but similarly consistent modulation spectrum is observed for music, including classical music played by single instruments of different types, symphonic, jazz, and rock. The temporal modulations of speech and music show broad but well-separated peaks around 5 and 2Hz, respectively. These acoustically dominant time scales may be intrinsic features of speech and music, a possibility which should be investigated using more culturally diverse samples in each domain. Distinct modulation timescales for speech and music could facilitate their perceptual analysis and its neural processing. Copyright © 2017 Elsevier Ltd. All rights reserved.

Daily regulation of body temperature rhythm in the camel (Camelus dromedarius) exposed to experimental desert conditions

PubMed Central

Bouâouda, Hanan; Achâaban, Mohamed R.; Ouassat, Mohammed; Oukassou, Mohammed; Piro, Mohamed; Challet, Etienne; El Allali, Khalid; Pévet, Paul

2014-01-01

Abstract In the present work, we have studied daily rhythmicity of body temperature (Tb) in Arabian camels challenged with daily heat, combined or not with dehydration. We confirm that Arabian camels use heterothermy to reduce heat gain coupled with evaporative heat loss during the day. Here, we also demonstrate that this mechanism is more complex than previously reported, because it is characterized by a daily alternation (probably of circadian origin) of two periods of poikilothermy and homeothermy. We also show that dehydration induced a decrease in food intake plays a role in this process. Together, these findings highlight that adaptive heterothermy in the Arabian camel varies across the diurnal light–dark cycle and is modulated by timing of daily heat and degrees of water restriction and associated reduction of food intake. The changed phase relationship between the light–dark cycle and the Tb rhythm observed during the dehydration process points to a possible mechanism of internal desynchronization during the process of adaptation to desert environment. During these experimental conditions mimicking the desert environment, it will be possible in the future to determine if induced high‐amplitude ambient temperature (Ta) rhythms are able to compete with the zeitgeber effect of the light–dark cycle. PMID:25263204

Ballroom dance and body size perception.

PubMed

Fonseca, Cristiane Costa; Thurm, Bianca Elisabeth; Vecchi, Rodrigo Luiz; Gama, Eliane Florencio

2014-10-01

Ballroom dancing consists in the performance of rhythmic movements guided by music, which provide sensorimotor integration and stimulate feelings. The body schema is the unconscious sensorimotor representation that allows the individual to perceive his anatomical body in space. Comprising tactile, proprioceptive, kinesthetic, and environmental information, it is directly related to movement. The aim of this study was to investigate the influence of non-competitive practice of ballroom dancing on body perception. The projection point test was applied to 30 volunteers before and after a period of 3 mo.; 15 controls attended lectures on body perception and 15 participants took dance lessons. It was observed that ballroom dancing brought perceptual benefits for those who practiced it.

Tonic and Rhythmic Spinal Activity Underlying Locomotion.

PubMed

Ivanenko, Yury P; Gurfinkel, Victor S; Selionov, Victor A; Solopova, Irina A; Sylos-Labini, Francesca; Guertin, Pierre A; Lacquaniti, Francesco

2017-05-12

In recent years, many researches put significant efforts into understanding and assessing the functional state of the spinal locomotor circuits in humans. Various techniques have been developed to stimulate the spinal cord circuitries, which may include both diffuse and quite specific tuning effects. Overall, the findings indicate that tonic and rhythmic spinal activity control are not separate phenomena but are closely integrated to properly initiate and sustain stepping. The spinal cord does not simply transmit information to and from the brain. Its physiologic state determines reflex, postural and locomotor control and, therefore, may affect the recovery of the locomotor function in individuals with spinal cord and brain injuries. This review summarizes studies that examine the rhythmogenesis capacity of cervical and lumbosacral neuronal circuitries in humans and its importance in developing central pattern generator-modulating therapies. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

The spectrotemporal filter mechanism of auditory selective attention

PubMed Central

Lakatos, Peter; Musacchia, Gabriella; O’Connell, Monica N.; Falchier, Arnaud Y.; Javitt, Daniel C.; Schroeder, Charles E.

2013-01-01

SUMMARY While we have convincing evidence that attention to auditory stimuli modulates neuronal responses at or before the level of primary auditory cortex (A1), the underlying physiological mechanisms are unknown. We found that attending to rhythmic auditory streams resulted in the entrainment of ongoing oscillatory activity reflecting rhythmic excitability fluctuations in A1. Strikingly, while the rhythm of the entrained oscillations in A1 neuronal ensembles reflected the temporal structure of the attended stream, the phase depended on the attended frequency content. Counter-phase entrainment across differently tuned A1 regions resulted in both the amplification and sharpening of responses at attended time points, in essence acting as a spectrotemporal filter mechanism. Our data suggest that selective attention generates a dynamically evolving model of attended auditory stimulus streams in the form of modulatory subthreshold oscillations across tonotopically organized neuronal ensembles in A1 that enhances the representation of attended stimuli. PMID:23439126

Theta oscillations locked to intended actions rhythmically modulate perception.

PubMed

Tomassini, Alice; Ambrogioni, Luca; Medendorp, W Pieter; Maris, Eric

2017-07-07

Ongoing brain oscillations are known to influence perception, and to be reset by exogenous stimulations. Voluntary action is also accompanied by prominent rhythmic activity, and recent behavioral evidence suggests that this might be coupled with perception. Here, we reveal the neurophysiological underpinnings of this sensorimotor coupling in humans. We link the trial-by-trial dynamics of EEG oscillatory activity during movement preparation to the corresponding dynamics in perception, for two unrelated visual and motor tasks. The phase of theta oscillations (~4 Hz) predicts perceptual performance, even >1 s before movement. Moreover, theta oscillations are phase-locked to the onset of the movement. Remarkably, the alignment of theta phase and its perceptual relevance unfold with similar non-monotonic profiles, suggesting their relatedness. The present work shows that perception and movement initiation are automatically synchronized since the early stages of motor planning through neuronal oscillatory activity in the theta range.

Low energy availability and low body fat of female gymnasts before an international competition.

PubMed

Silva, M R G; Paiva, T

2015-01-01

The purpose of the present study was to evaluate dietary intake and body composition of elite rhythmic gymnastics (RG) athletes prior to a competition event. Sixty-seven rhythmic gymnasts (18.7 ± 2.9 years old) of high performance level, with 36.6 ± 7.6 h of training/week were evaluated in order to collect training and competition data, medical and gynaecological history, detailed dietary intake and body composition before an international competition. The majority of the participants (n = 40; 59.7%) had already menstruated, but age of menarche was delayed (15.3 ± 1.3 years) and all revealed menstrual irregularities. Gymnasts' body mass (48.4 ± 4.9 kg) and body mass index (BMI; 17.4 ± 1.1 kg/m(2)) were below the normal for age, and height (1.66 ± 0.05 m) was normal or even slightly above normal for age. Body fat was 9.0 ± 2.0% with no significant differences between age strata. Gymnasts exhibited low energy availability (EA; 31.5 ± 11.9 kcal/kg fat-free mass (FFM)/day). The average carbohydrate and protein intakes were 5.1 ± 2.3 g/kg/day and 1.6 ± 04 g/kg/day, which correspond to 51.4 ± 7.2% and 16.9 ± 3.4% of total energy intakes, respectively; average fat contribution was 33.0 ± 5.3%. Low intakes of pantothenic acid, folate and vitamins D, E and K and of minerals, including calcium, iron and magnesium were reported. Intakes of thiamine, riboflavin, niacin, vitamins A, B-6, B-12, C and manganese and zinc were above-adequate (P < 0.05). Low EA, low body fat and micronutrient deficiencies are common among RG.

Aesthetic appreciation of poetry correlates with ease of processing in event-related potentials.

PubMed

Obermeier, Christian; Kotz, Sonja A; Jessen, Sarah; Raettig, Tim; von Koppenfels, Martin; Menninghaus, Winfried

2016-04-01

Rhetorical theory suggests that rhythmic and metrical features of language substantially contribute to persuading, moving, and pleasing an audience. A potential explanation of these effects is offered by "cognitive fluency theory," which stipulates that recurring patterns (e.g., meter) enhance perceptual fluency and can lead to greater aesthetic appreciation. In this article, we explore these two assertions by investigating the effects of meter and rhyme in the reception of poetry by means of event-related brain potentials (ERPs). Participants listened to four versions of lyrical stanzas that varied in terms of meter and rhyme, and rated the stanzas for rhythmicity and aesthetic liking. The behavioral and ERP results were in accord with enhanced liking and rhythmicity ratings for metered and rhyming stanzas. The metered and rhyming stanzas elicited smaller N400/P600 ERP responses than their nonmetered, nonrhyming, or nonmetered and nonrhyming counterparts. In addition, the N400 and P600 effects for the lyrical stanzas correlated with aesthetic liking effects (metered-nonmetered), implying that modulation of the N400 and P600 has a direct bearing on the aesthetic appreciation of lyrical stanzas. We suggest that these effects are indicative of perceptual-fluency-enhanced aesthetic liking, as postulated by cognitive fluency theory.

Activation of β-noradrenergic receptors enhances rhythmic bursting in mouse olfactory bulb external tufted cells.

PubMed

Zhou, Fu-Wen; Dong, Hong-Wei; Ennis, Matthew

2016-12-01

The main olfactory bulb (MOB) receives a rich noradrenergic innervation from the nucleus locus coeruleus. Despite the well-documented role of norepinephrine and β-adrenergic receptors in neonatal odor preference learning, identified cellular physiological actions of β-receptors in the MOB have remained elusive. β-Receptors are expressed at relatively high levels in the MOB glomeruli, the location of external tufted (ET) cells that exert an excitatory drive on mitral and other cell types. The present study investigated the effects of β-receptor activation on the excitability of ET cells with patch-clamp electrophysiology in mature mouse MOB slices. Isoproterenol and selective β 2 -, but not β 1 -, receptor agonists were found to enhance two key intrinsic currents involved in ET burst initiation: persistent sodium (I NaP ) and hyperpolarization-activated inward (I h ) currents. Together, the positive modulation of these currents increased the frequency and strength of ET cell rhythmic bursting. Rodent sniff frequency and locus coeruleus neuronal firing increase in response to novel stimuli or environments. The increase in ET excitability by β-receptor activation may better enable ET cell rhythmic bursting, and hence glomerular network activity, to pace faster sniff rates during heightened norepinephrine release associated with arousal. Copyright © 2016 the American Physiological Society.

Visual Contrast Sensitivity Improvement by Right Frontal High-Beta Activity Is Mediated by Contrast Gain Mechanisms and Influenced by Fronto-Parietal White Matter Microstructure

PubMed Central

Quentin, Romain; Elkin Frankston, Seth; Vernet, Marine; Toba, Monica N.; Bartolomeo, Paolo; Chanes, Lorena; Valero-Cabré, Antoni

2016-01-01

Behavioral and electrophysiological studies in humans and non-human primates have correlated frontal high-beta activity with the orienting of endogenous attention and shown the ability of the latter function to modulate visual performance. We here combined rhythmic transcranial magnetic stimulation (TMS) and diffusion imaging to study the relation between frontal oscillatory activity and visual performance, and we associated these phenomena to a specific set of white matter pathways that in humans subtend attentional processes. High-beta rhythmic activity on the right frontal eye field (FEF) was induced with TMS and its causal effects on a contrast sensitivity function were recorded to explore its ability to improve visual detection performance across different stimulus contrast levels. Our results show that frequency-specific activity patterns engaged in the right FEF have the ability to induce a leftward shift of the psychometric function. This increase in visual performance across different levels of stimulus contrast is likely mediated by a contrast gain mechanism. Interestingly, microstructural measures of white matter connectivity suggest a strong implication of right fronto-parietal connectivity linking the FEF and the intraparietal sulcus in propagating high-beta rhythmic signals across brain networks and subtending top-down frontal influences on visual performance. PMID:25899709

Transition Probabilities and Different Levels of Prominence in Segmentation

ERIC Educational Resources Information Center

Ordin, Mikhail; Nespor, Marina

2013-01-01

A large body of empirical research demonstrates that people exploit a wide variety of cues for the segmentation of continuous speech in artificial languages, including rhythmic properties, phrase boundary cues, and statistical regularities. However, less is known regarding how the different cues interact. In this study we addressed the question of…

Captured by Motion: Dance, Action Understanding, and Social Cognition

ERIC Educational Resources Information Center

Sevdalis, Vassilis; Keller, Peter E.

2011-01-01

In this review article, we summarize the main findings from empirical studies that used dance-related forms of rhythmical full body movement as a research tool for investigating action understanding and social cognition. This work has proven to be informative about behavioral and brain mechanisms that mediate links between perceptual and motor…

Don't Miss a Beat: Why Rhythm Is Used in Waldorf Education.

ERIC Educational Resources Information Center

Lopata, Peg

2000-01-01

The Waldorf philosophy of education is about awakening and growing an active, inquiring, imaginative mind; a healthy body; and a heart of compassion. This is accomplished by tapping into the natural well of children's rhythmic natures using multisensory approaches. The importance of rhythm in nature, developmental stages, sequencing, and…

Prolonged daily light exposure increases body fat mass through attenuation of brown adipose tissue activity

PubMed Central

Kooijman, Sander; van den Berg, Rosa; Ramkisoensing, Ashna; Boon, Mariëtte R.; Kuipers, Eline N.; Loef, Marieke; Zonneveld, Tom C. M.; Lucassen, Eliane A.; Sips, Hetty C. M.; Chatzispyrou, Iliana A.; Houtkooper, Riekelt H.; Meijer, Johanna H.; Coomans, Claudia P.; Biermasz, Nienke R.; Rensen, Patrick C. N.

2015-01-01

Disruption of circadian rhythmicity is associated with obesity and related disorders, including type 2 diabetes and cardiovascular disease. Specifically, prolonged artificial light exposure associates with obesity in humans, although the underlying mechanism is unclear. Here, we report that increasing the daily hours of light exposure increases body adiposity through attenuation of brown adipose tissue (BAT) activity, a major contributor of energy expenditure. Mice exposed to a prolonged day length of 16- and 24-h light, compared with regular 12-h light, showed increased adiposity without affecting food intake or locomotor activity. Mechanistically, we demonstrated that prolonged day length decreases sympathetic input into BAT and reduces β3-adrenergic intracellular signaling. Concomitantly, prolonging day length decreased the uptake of fatty acids from triglyceride-rich lipoproteins, as well as of glucose from plasma selectively by BAT. We conclude that impaired BAT activity is an important mediator in the association between disturbed circadian rhythm and adiposity, and anticipate that activation of BAT may overcome the adverse metabolic consequences of disturbed circadian rhythmicity. PMID:25964318

The circadian clock stops ticking during deep hibernation in the European hamster

PubMed Central

Revel, Florent G.; Herwig, Annika; Garidou, Marie-Laure; Dardente, Hugues; Menet, Jérôme S.; Masson-Pévet, Mireille; Simonneaux, Valérie; Saboureau, Michel; Pévet, Paul

2007-01-01

Hibernation is a fascinating, yet enigmatic, physiological phenomenon during which body temperature and metabolism are reduced to save energy. During the harsh season, this strategy allows substantial energy saving by reducing body temperature and metabolism. Accordingly, biological processes are considerably slowed down and reduced to a minimum. However, the persistence of a temperature-compensated, functional biological clock in hibernating mammals has long been debated. Here, we show that the master circadian clock no longer displays 24-h molecular oscillations in hibernating European hamsters. The clock genes Per1, Per2, and Bmal1 and the clock-controlled gene arginine vasopressin were constantly expressed in the suprachiasmatic nucleus during deep torpor, as assessed by radioactive in situ hybridization. Finally, the melatonin rhythm-generating enzyme, arylalkylamine N-acetyltransferase, whose rhythmic expression in the pineal gland is controlled by the master circadian clock, no longer exhibits day/night changes of expression but constantly elevated mRNA levels over 24 h. Overall, these data provide strong evidence that in the European hamster the molecular circadian clock is arrested during hibernation and stops delivering rhythmic output signals. PMID:17715068

Post-transcriptional control of the mammalian circadian clock: implications for health and disease.

PubMed

Preußner, Marco; Heyd, Florian

2016-06-01

Many aspects of human physiology and behavior display rhythmicity with a period of approximately 24 h. Rhythmic changes are controlled by an endogenous time keeper, the circadian clock, and include sleep-wake cycles, physical and mental performance capability, blood pressure, and body temperature. Consequently, many diseases, such as metabolic, sleep, autoimmune and mental disorders and cancer, are connected to the circadian rhythm. The development of therapies that take circadian biology into account is thus a promising strategy to improve treatments of diverse disorders, ranging from allergic syndromes to cancer. Circadian alteration of body functions and behavior are, at the molecular level, controlled and mediated by widespread changes in gene expression that happen in anticipation of predictably changing requirements during the day. At the core of the molecular clockwork is a well-studied transcription-translation negative feedback loop. However, evidence is emerging that additional post-transcriptional, RNA-based mechanisms are required to maintain proper clock function. Here, we will discuss recent work implicating regulated mRNA stability, translation and alternative splicing in the control of the mammalian circadian clock, and its role in health and disease.

High post-movement parietal low-beta power during rhythmic tapping facilitates performance in a stop task.

PubMed

Fischer, Petra; Tan, Huiling; Pogosyan, Alek; Brown, Peter

2016-09-01

Voluntary movements are followed by a post-movement electroencephalography (EEG) beta rebound, which increases with practice and confidence in a task. We hypothesized that greater beta modulation reflects less load on cognitive resources and may thus be associated with faster reactions to new stimuli. EEG was recorded in 17 healthy subjects during rhythmically paced index finger tapping. In a STOP condition, participants had to interrupt the upcoming tap in response to an auditory cue, which was timed such that stopping was successful only in ~ 50% of all trials. In a second condition, participants carried on tapping twice after the stop signal (CONTINUE condition). Thus the conditions were distinct in whether abrupt stopping was required as a second task. Modulation of 12-20 Hz power over motor and parietal areas developed with time on each trial and more so in the CONTINUE condition. Reduced modulation in the STOP condition went along with reduced negative mean asynchronies suggesting less confident anticipation of the timing of the next tap. Yet participants were more likely to stop when beta modulation prior to the stop cue was more pronounced. In the STOP condition, expectancy of the stop signal may have increased cognitive load during movement execution given that the task might have to be stopped abruptly. However, within this condition, stopping ability was increased if the preceding tap was followed by a relatively larger beta increase. Significant, albeit weak, correlations confirmed that increased post-movement beta power was associated with faster reactions to new stimuli, consistent with reduced cognitive load. © 2016 The Authors. European Journal of Neuroscience published by Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Modulation of local field potentials by high-frequency stimulation of afferent axons in the hippocampal CA1 region.

PubMed

Yu, Ying; Feng, Zhouyan; Cao, Jiayue; Guo, Zheshan; Wang, Zhaoxiang; Hu, Na; Wei, Xuefeng

2016-03-01

Modulation of the rhythmic activity of local field potentials (LFP) in neuronal networks could be a mechanism of deep brain stimulation (DBS). However, exact changes of LFP during the periods of high-frequency stimulation (HFS) of DBS are unclear because of the interference of dense stimulation artifacts with high amplitudes. In the present study, we investigated LFP changes induced by HFS of afferent axons in the hippocampal CA1 region of urethane-anesthetized rats by using a proper algorithm of artifact removal. Afterward, the LFP changes in the frequency bands of [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text] and [Formula: see text] rhythms were studied by power spectrum analysis and coherence analysis for the recorded signals collected in the pyramidal layer and in the stratum radiatum of CA1 region before, during and after 1-min long 100 and 200[Formula: see text]Hz HFS. Results showed that the power of LFP rhythms in higher-frequency band ([Formula: see text] rhythm) increased in the pyramidal layer and the power of LFP rhythms in lower-frequency bands ([Formula: see text], [Formula: see text] and [Formula: see text] rhythms) decreased in the stratum radiatum during HFS. The synchronization of [Formula: see text] rhythm decreased and the synchronization of [Formula: see text] rhythm increased during HFS in the stratum radiatum. These results suggest that axonal HFS could modulate LFP rhythms in the downstream brain areas with a plausible underlying mechanism of partial axonal blockage induced by HFS. The study provides new evidence to support the mechanism of DBS modulating rhythmic activity of neuronal populations.

Diurnal secretion profiles of growth hormone, thyrotrophin and prolactin in Parkinson's disease.

PubMed

Aziz, N A; Pijl, H; Frölich, M; Roelfsema, F; Roos, R A C

2011-06-01

Recently, a massive loss of both hypocretin and melanin-concentrating hormone (MCH) neurones was found in the hypothalamus of Parkinson's disease (PD) patients. Because both hypocretin and MCH play a key role in the regulation of sleep, energy homeostasis and autonomic function, partly by modulation of the somatotrophic, thyrotrophic and lactotrophic axes, neuroendocrine dysregulation may contribute to some of the non-motor features of PD. In eight de novo, medication-free PD patients and eight age-, sex- and body mass index-matched controls, we measured serum levels of growth hormone (GH), thyroid-stimulating hormone (TSH) and prolactin every 10 min for 24 h. Auto-deconvolution, cosinor and approximate entropy analysis were applied to quantify GH, TSH and prolactin secretion rates, diurnal rhythmicity, as well as regularity of hormone release. Sleep was polygraphically-recorded throughout the night. Total 24-h secretion of GH (191 ± 31 versus 130 ± 39 mU/l/24 h), TSH (38 ± 9 versus 36 ± 2 mU/l/24 h) and prolactin (102 ± 14 versus 116 ± 17 μg/l/24 h), as well as their diurnal rhythmicity and regularity of release, were not significantly different between PD patients and controls (all P ≥ 0.12). Fasting levels of insulin-like growth factor-1 were also unaltered in PD patients. However, free thyroxine (T(4) ) levels were significantly higher in PD patients compared to controls (16.19 ± 0.80 versus 13.88 ± 0.40 pmol/l; P = 0.031). In PD patients, prolactin levels were related to disease duration (r = 0.76, P = 0.028), whereas both GH (r = -0.91, P = 0.002) and free T(4) (r = -0.71, P = 0.050) levels correlated inversely with body fat content. Apart from a mild increase in free T(4) levels, we found no indications for altered somatotrophic, thyrotrophic and lactotrophic axes activity in early-stage PD patients. © 2011 The Authors. Journal of Neuroendocrinology © 2011 Blackwell Publishing Ltd.

Beats produced between a rhythmic applied force and the resting tremor of Parkinsonism.

PubMed Central

Walsh, E G

1979-01-01

Rhythmic forces have been applied to the wrist of patients with Parkinsonism tremor by means of a printed motor. The tremor rate was not altered to that of the applied force. On the contrary, beats were established, the rate of which depended on the difference in rate between the tremor and the applied rhythm. Most of the observations have been for horizontal motion of the hand but similar phenomena have been seen for vertical movements, and for other parts of the body--for example, foot, elbow, finger joint, and head. The observations are regarded as supporting the view that the tremorgenic mechanism is central. There was no electromyographic evidence of servo driving or servo assistance in the genesis of the tremor. PMID:762588

Effects of rhythmic aerobic exercise plus core stability training on serum omentin, chemerin and vaspin levels and insulin resistance of overweight women.

PubMed

Faramarzi, Mohammad; Banitalebi, Ebrahim; Nori, Saba; Farzin, Shiva; Taghavian, Zohreh

2016-04-01

Omentin, chemerin and vaspin are novel adipokines that are secreted from adipose tissue and improved insulin sensitive. The purpose of this study was to examine the effects of rhythmic aerobic exercise plus core stability training on serum omentin, chemerin and vaspin levels and insulin resistance (IR) of overweight women. Forty aged healthy women (age; 25-45 years old, waist circumference [WC]>88 cm; Body Mass Index (BMI)>25 kg/m2) were selected purposely and divided in two control (N.=16) and experimental (N.=19) groups. Five dropped out during the study. The experimental group trained 12 weeks (3 sessions per week, one hr/session). The exercise program consisted of rhythmic aerobic exercise (55-85% maximum heart rate) along with core stability training. Serum chemerin, omentin, vaspin and insulin concentration were assayed by commercially ELISA kit. IR was evaluated according to the Homeostasis Model Assessment of Insulin Resistance Index (HOMA-IR). Data were analyzed by dependent and independent t-test to compare pre-test and post-test in each group and to compare the amount of changes in experimental and control training groups after twelve weeks. The result showed that exercise training had significant effect on BMI (P=0.00), WC (P=0.00), body fat (P=0.05), chemerin (P=0.041) and vaspin (P=0.045). But, this training had non-significant effect on plasma omentin level (P=0.090), plasma glucose level (P=0.670), insulin (P=0.11) and IR (P=0.07). Despite the fact that this kind of intervention could be an effective treatment to improve some adipokine levels and was accompanied by decreased body fat and waist circumference. However, more intense training is required to significantly change IR and serum omentin level in overweight women.

Vocal learning, prosody, and basal ganglia: don't underestimate their complexity.

PubMed

Ravignani, Andrea; Martins, Mauricio; Fitch, W Tecumseh

2014-12-01

Ackermann et al.'s arguments in the target article need sharpening and rethinking at both mechanistic and evolutionary levels. First, the authors' evolutionary arguments are inconsistent with recent evidence concerning nonhuman animal rhythmic abilities. Second, prosodic intonation conveys much more complex linguistic information than mere emotional expression. Finally, human adults' basal ganglia have a considerably wider role in speech modulation than Ackermann et al. surmise.

Cell-Type and State-Dependent Synchronization among Rodent Somatosensory, Visual, Perirhinal Cortex, and Hippocampus CA1

PubMed Central

Vinck, Martin; Bos, Jeroen J.; Van Mourik-Donga, Laura A.; Oplaat, Krista T.; Klein, Gerbrand A.; Jackson, Jadin C.; Gentet, Luc J.; Pennartz, Cyriel M. A.

2016-01-01

Beta and gamma rhythms have been hypothesized to be involved in global and local coordination of neuronal activity, respectively. Here, we investigated how cells in rodent area S1BF are entrained by rhythmic fluctuations at various frequencies within the local area and in connected areas, and how this depends on behavioral state and cell type. We performed simultaneous extracellular field and unit recordings in four connected areas of the freely moving rat (S1BF, V1M, perirhinal cortex, CA1). S1BF spiking activity was strongly entrained by both beta and gamma S1BF oscillations, which were associated with deactivations and activations, respectively. We identified multiple classes of fast spiking and excitatory cells in S1BF, which showed prominent differences in rhythmic entrainment and in the extent to which phase locking was modulated by behavioral state. Using an additional dataset acquired by whole-cell recordings in head-fixed mice, these cell classes could be compared with identified phenotypes showing gamma rhythmicity in their membrane potential. We next examined how S1BF cells were entrained by rhythmic fluctuations in connected brain areas. Gamma-synchronization was detected in all four areas, however we did not detect significant gamma coherence among these areas. Instead, we only found long-range coherence in the theta-beta range among these areas. In contrast to local S1BF synchronization, we found long-range S1BF-spike to CA1–LFP synchronization to be homogeneous across inhibitory and excitatory cell types. These findings suggest distinct, cell-type contributions of low and high-frequency synchronization to intra- and inter-areal neuronal interactions. PMID:26834582

Acoustic-Emergent Phonology in the Amplitude Envelope of Child-Directed Speech

PubMed Central

Leong, Victoria; Goswami, Usha

2015-01-01

When acquiring language, young children may use acoustic spectro-temporal patterns in speech to derive phonological units in spoken language (e.g., prosodic stress patterns, syllables, phonemes). Children appear to learn acoustic-phonological mappings rapidly, without direct instruction, yet the underlying developmental mechanisms remain unclear. Across different languages, a relationship between amplitude envelope sensitivity and phonological development has been found, suggesting that children may make use of amplitude modulation (AM) patterns within the envelope to develop a phonological system. Here we present the Spectral Amplitude Modulation Phase Hierarchy (S-AMPH) model, a set of algorithms for deriving the dominant AM patterns in child-directed speech (CDS). Using Principal Components Analysis, we show that rhythmic CDS contains an AM hierarchy comprising 3 core modulation timescales. These timescales correspond to key phonological units: prosodic stress (Stress AM, ~2 Hz), syllables (Syllable AM, ~5 Hz) and onset-rime units (Phoneme AM, ~20 Hz). We argue that these AM patterns could in principle be used by naïve listeners to compute acoustic-phonological mappings without lexical knowledge. We then demonstrate that the modulation statistics within this AM hierarchy indeed parse the speech signal into a primitive hierarchically-organised phonological system comprising stress feet (proto-words), syllables and onset-rime units. We apply the S-AMPH model to two other CDS corpora, one spontaneous and one deliberately-timed. The model accurately identified 72–82% (freely-read CDS) and 90–98% (rhythmically-regular CDS) stress patterns, syllables and onset-rime units. This in-principle demonstration that primitive phonology can be extracted from speech AMs is termed Acoustic-Emergent Phonology (AEP) theory. AEP theory provides a set of methods for examining how early phonological development is shaped by the temporal modulation structure of speech across languages. The S-AMPH model reveals a crucial developmental role for stress feet (AMs ~2 Hz). Stress feet underpin different linguistic rhythm typologies, and speech rhythm underpins language acquisition by infants in all languages. PMID:26641472

Acoustic-Emergent Phonology in the Amplitude Envelope of Child-Directed Speech.

PubMed

Leong, Victoria; Goswami, Usha

2015-01-01

When acquiring language, young children may use acoustic spectro-temporal patterns in speech to derive phonological units in spoken language (e.g., prosodic stress patterns, syllables, phonemes). Children appear to learn acoustic-phonological mappings rapidly, without direct instruction, yet the underlying developmental mechanisms remain unclear. Across different languages, a relationship between amplitude envelope sensitivity and phonological development has been found, suggesting that children may make use of amplitude modulation (AM) patterns within the envelope to develop a phonological system. Here we present the Spectral Amplitude Modulation Phase Hierarchy (S-AMPH) model, a set of algorithms for deriving the dominant AM patterns in child-directed speech (CDS). Using Principal Components Analysis, we show that rhythmic CDS contains an AM hierarchy comprising 3 core modulation timescales. These timescales correspond to key phonological units: prosodic stress (Stress AM, ~2 Hz), syllables (Syllable AM, ~5 Hz) and onset-rime units (Phoneme AM, ~20 Hz). We argue that these AM patterns could in principle be used by naïve listeners to compute acoustic-phonological mappings without lexical knowledge. We then demonstrate that the modulation statistics within this AM hierarchy indeed parse the speech signal into a primitive hierarchically-organised phonological system comprising stress feet (proto-words), syllables and onset-rime units. We apply the S-AMPH model to two other CDS corpora, one spontaneous and one deliberately-timed. The model accurately identified 72-82% (freely-read CDS) and 90-98% (rhythmically-regular CDS) stress patterns, syllables and onset-rime units. This in-principle demonstration that primitive phonology can be extracted from speech AMs is termed Acoustic-Emergent Phonology (AEP) theory. AEP theory provides a set of methods for examining how early phonological development is shaped by the temporal modulation structure of speech across languages. The S-AMPH model reveals a crucial developmental role for stress feet (AMs ~2 Hz). Stress feet underpin different linguistic rhythm typologies, and speech rhythm underpins language acquisition by infants in all languages.

Movement in Steady Beat: Learning on the Move, Ages 3-7. Second Edition.

ERIC Educational Resources Information Center

Weikart, Phyllis S.

The ability to feel and maintain steady, rhythmic beat is important for children to develop in early childhood and will assist them in mastering concepts in language and literacy, mathematics, and other content areas as well as increase body coordination and related physical abilities. Designed as an activity supplement to High Scope movement and…

The Enhanced Musical Rhythmic Perception in Second Language Learners

PubMed Central

Roncaglia-Denissen, M. Paula; Roor, Drikus A.; Chen, Ao; Sadakata, Makiko

2016-01-01

Previous research suggests that mastering languages with distinct rather than similar rhythmic properties enhances musical rhythmic perception. This study investigates whether learning a second language (L2) contributes to enhanced musical rhythmic perception in general, regardless of first and second languages rhythmic properties. Additionally, we investigated whether this perceptual enhancement could be alternatively explained by exposure to musical rhythmic complexity, such as the use of compound meter in Turkish music. Finally, it investigates if an enhancement of musical rhythmic perception could be observed among L2 learners whose first language relies heavily on pitch information, as is the case with tonal languages. Therefore, we tested Turkish, Dutch and Mandarin L2 learners of English and Turkish monolinguals on their musical rhythmic perception. Participants’ phonological and working memory capacities, melodic aptitude, years of formal musical training and daily exposure to music were assessed to account for cultural and individual differences which could impact their rhythmic ability. Our results suggest that mastering a L2 rather than exposure to musical rhythmic complexity could explain individuals’ enhanced musical rhythmic perception. An even stronger enhancement of musical rhythmic perception was observed for L2 learners whose first and second languages differ regarding their rhythmic properties, as enhanced performance of Turkish in comparison with Dutch L2 learners of English seem to suggest. Such a stronger enhancement of rhythmic perception seems to be found even among L2 learners whose first language relies heavily on pitch information, as the performance of Mandarin L2 learners of English indicates. Our findings provide further support for a cognitive transfer between the language and music domain. PMID:27375469

Rhythmic Gymnastics: A Challenge with Balls and Ropes.

ERIC Educational Resources Information Center

Bennett, John P.

Rhythmic gymnastics is an outgrowth of rhythmic and dance gymnastics and promotes good posture, strength, flexibility, balance, and coordination, along with appreciation of music and movement together. The current status of rhythmic gymnastics and its historical development are briefly discussed. Descriptions are given of rhythmic gymnastic…

Sedimentation rhythmicity as a reflection of astronomical cyclicity

NASA Astrophysics Data System (ADS)

Avsyuk, Yu. N.; Saltykovskii, A. Ya.; Sokolova, Yu. F.

2011-05-01

The Mesozoic-Cenozoic rhythmic continental sedimentary rocks are analyzed for every particular period and epoch from the Triassic to the Pliocene. The maximal distribution areas of rhythmic deposits are within the latitudinal zone of 20°-40°. Investigation of rhythmic Mesozoic-Cenozoic carbonate-containing deposits of Europe and North America enables us to attribute rhythmicity to climate change owing to insolation and eustatic variations of oceanosphere's level, on the one hand, and to compare duration values of the rhythmic unit and rhythmic sequence with cycles of orbital precession, ecliptic plane inclination, and the eccentricity of the Earth's orbit, on the other hand.

Effects of task complexity on rhythmic reproduction performance in adults.

PubMed

Iannarilli, Flora; Vannozzi, Giuseppe; Iosa, Marco; Pesce, Caterina; Capranica, Laura

2013-02-01

The aim of the present study was to investigate the effect of task complexity on the capability to reproduce rhythmic patterns. Sedentary musically illiterate individuals (age: 34.8±4.2 yrs; M±SD) were administered a rhythmic test including three rhythmic patterns to be reproduced by means of finger-tapping, foot-tapping and walking. For the quantification of subjects' ability in the reproduction of rhythmic patterns, qualitative and quantitative parameters were submitted to analysis. A stereophotogrammetric system was used to reconstruct and evaluate individual performances. The findings indicated a good internal stability of the rhythmic reproduction, suggesting that the present experimental design is suitable to discriminate the participants' rhythmic ability. Qualitative aspects of rhythmic reproduction (i.e., speed of execution and temporal ratios between events) varied as a function of the perceptual-motor requirements of the rhythmic reproduction task, with larger reproduction deviations in the walking task. Copyright © 2013 Elsevier B.V. All rights reserved.

Rhythmic arm movements are less affected than discrete ones after a stroke.

PubMed

Leconte, Patricia; Orban de Xivry, Jean-Jacques; Stoquart, Gaëtan; Lejeune, Thierry; Ronsse, Renaud

2016-06-01

Recent reports indicate that rhythmic and discrete upper-limb movements are two different motor primitives which recruit, at least partially, distinct neural circuitries. In particular, rhythmic movements recruit a smaller cortical network than discrete movements. The goal of this paper is to compare the levels of disability in performing rhythmic and discrete movements after a stroke. More precisely, we tested the hypothesis that rhythmic movements should be less affected than discrete ones, because they recruit neural circuitries that are less likely to be damaged by the stroke. Eleven stroke patients and eleven age-matched control subjects performed discrete and rhythmic movements using an end-effector robot (REAplan). The rhythmic movement condition was performed with and without visual targets to further decrease cortical recruitment. Movement kinematics was analyzed through specific metrics, capturing the degree of smoothness and harmonicity. We reported three main observations: (1) the movement smoothness of the paretic arm was more severely degraded for discrete movements than rhythmic movements; (2) most of the patients performed rhythmic movements with a lower harmonicity than controls; and (3) visually guided rhythmic movements were more altered than non-visually guided rhythmic movements. These results suggest a hierarchy in the levels of impairment: Discrete movements are more affected than rhythmic ones, which are more affected if they are visually guided. These results are a new illustration that discrete and rhythmic movements are two fundamental primitives in upper-limb movements. Moreover, this hierarchy of impairment opens new post-stroke rehabilitation perspectives.

Double-wavelet approach to study frequency and amplitude modulation in renal autoregulation

NASA Astrophysics Data System (ADS)

Sosnovtseva, O. V.; Pavlov, A. N.; Mosekilde, E.; Holstein-Rathlou, N.-H.; Marsh, D. J.

2004-09-01

Biological time series often display complex oscillations with several interacting rhythmic components. Renal autoregulation, for instance, involves at least two separate mechanisms both of which can produce oscillatory variations in the pressures and flows of the individual nephrons. Using double-wavelet analysis we propose a method to examine how the instantaneous frequency and amplitude of a fast mode is modulated by the presence of a slower mode. Our method is applied both to experimental data from normotensive and hypertensive rats showing different oscillatory patterns and to simulation results obtained from a physiologically based model of the nephron pressure and flow control. We reveal a nonlinear interaction between the two mechanisms that regulate the renal blood flow in the form of frequency and amplitude modulation of the myogenic oscillations.

Distributed Attention Is Implemented through Theta-Rhythmic Gamma Modulation.

PubMed

Landau, Ayelet Nina; Schreyer, Helene Marianne; van Pelt, Stan; Fries, Pascal

2015-08-31

When subjects monitor a single location, visual target detection depends on the pre-target phase of an ∼8 Hz brain rhythm. When multiple locations are monitored, performance decrements suggest a division of the 8 Hz rhythm over the number of locations, indicating that different locations are sequentially sampled. Indeed, when subjects monitor two locations, performance benefits alternate at a 4 Hz rhythm. These performance alternations were revealed after a reset of attention to one location. Although resets are common and important events for attention, it is unknown whether, in the absence of resets, ongoing attention samples stimuli in alternation. Here, we examined whether spatially specific attentional sampling can be revealed by ongoing pre-target brain rhythms. Visually induced gamma-band activity plays a role in spatial attention. Therefore, we hypothesized that performance on two simultaneously monitored stimuli can be predicted by a 4 Hz modulation of gamma-band activity. Brain rhythms were assessed with magnetoencephalography (MEG) while subjects monitored bilateral grating stimuli for a unilateral target event. The corresponding contralateral gamma-band responses were subtracted from each other to isolate spatially selective, target-related fluctuations. The resulting lateralized gamma-band activity (LGA) showed opposite pre-target 4 Hz phases for detected versus missed targets. The 4 Hz phase of pre-target LGA accounted for a 14.5% modulation in performance. These findings suggest that spatial attention is a theta-rhythmic sampling process that is continuously ongoing, with each sampling cycle being implemented through gamma-band synchrony. Copyright © 2015 Elsevier Ltd. All rights reserved.

Periodic modulation of repetitively elicited monosynaptic reflexes of the human lumbosacral spinal cord

PubMed Central

Danner, Simon M.; Freundl, Brigitta; Binder, Heinrich; Mayr, Winfried; Rattay, Frank; Minassian, Karen

2015-01-01

In individuals with motor-complete spinal cord injury, epidural stimulation of the lumbosacral spinal cord at 2 Hz evokes unmodulated reflexes in the lower limbs, while stimulation at 22–60 Hz can generate rhythmic burstlike activity. Here we elaborated on an output pattern emerging at transitional stimulation frequencies with consecutively elicited reflexes alternating between large and small. We analyzed responses concomitantly elicited in thigh and leg muscle groups bilaterally by epidural stimulation in eight motor-complete spinal cord-injured individuals. Periodic amplitude modulation of at least 20 successive responses occurred in 31.4% of all available data sets with stimulation frequency set at 5–26 Hz, with highest prevalence at 16 Hz. It could be evoked in a single muscle group only but was more strongly expressed and consistent when occurring in pairs of antagonists or in the same muscle group bilaterally. Latencies and waveforms of the modulated reflexes corresponded to those of the unmodulated, monosynaptic responses to 2-Hz stimulation. We suggest that the cyclical changes of reflex excitability resulted from the interaction of facilitatory and inhibitory mechanisms emerging after specific delays and with distinct durations, including postactivation depression, recurrent inhibition and facilitation, as well as reafferent feedback activation. The emergence of large responses within the patterns at a rate of 5.5/s or 8/s may further suggest the entrainment of spinal mechanisms as involved in clonus. The study demonstrates that the human lumbosacral spinal cord can organize a simple form of rhythmicity through the repetitive activation of spinal reflex circuits. PMID:25904708

[Change of character of intersystemic interactions in newborn rat pups under conditions of a decrease of central influences (urethane anesthesia)].

PubMed

Kuznetsov, S V; Sizonov, V A; Dmitrieva, L E

2014-01-01

On newborn rat pups, for the first day after birth, there was studied the character of mutual influences between the slow-wave rhythmical components of the cardiac, respiratory, and motor activities reflecting interactions between the main functional systems of the developing organism. The study was carried out in norm and after pharmacological depression of the spontaneous periodical motor activity (SPMA) performed by narcotization of rat pups with urethane at low (0.5 g/kg, i/p) and maximal (1 g/kg, i/p) doses. Based on the complex of our obtained data, it is possible to conclude that after birth in rat pups the intersystemic interactions are realized mainly by the slow-wave oscillations of the near- and manyminute diapason. The correlational interactions mediated by rhythms of the decasecond diapason do not play essential role in integrative processes. Injection to the animals of urethane producing selective suppression of reaction of consciousness, but not affecting activating influences of reticular formation on cerebral cortex does not cause marked changes of autonomous parameters, but modulates structure and expression of spontaneous periodical motor activity. There occurs an essential decrease of mutual influences between motor and cardiovascular systems. In the case of preservation of motor activity bursts, a tendency for enhancement of correlational relations between the modulating rhythms of motor and somatomotor systems is observed. The cardiorespiratory interactions, more pronounced in intact rat pups in the near- and many-minute modulation diapason, under conditions of urethane, somewhat decrease, whereas the rhythmical components of the decasecond diapason--are weakly enhanced.

Possible Mechanism for Modulating Cardiovascular System During Running in Humans

DTIC Science & Technology

2001-10-25

odulated by rhythmic muscle contractions during running. It cillates when step rate and heart rate are not synchronised but abilises when they are... synchronised . A maximum cardiac output n be achieved by synchronising step rate with heart rate at an timal phase delay. eywords – Cardiovascular model...trained athletes. Researches from [3][4][5] suggest at synchronization between the heart rate and the step rate uring running may favor an athlete with

Reward Expectancy Strengthens CA1 Theta and Beta Band Synchronization and Hippocampal-Ventral Striatal Coupling.

PubMed

Lansink, Carien S; Meijer, Guido T; Lankelma, Jan V; Vinck, Martin A; Jackson, Jadin C; Pennartz, Cyriel M A

2016-10-12

The use of information from the hippocampal memory system in motivated behavior depends on its communication with the ventral striatum. When an animal encounters cues that signal subsequent reward, its reward expectancy is raised. It is unknown, however, how this process affects hippocampal dynamics and their influence on target structures, such as ventral striatum. We show that, in rats, reward-predictive cues result in enhanced hippocampal theta and beta band rhythmic activity during subsequent action, compared with uncued goal-directed navigation. The beta band component, also labeled theta's harmonic, involves selective hippocampal CA1 cell groups showing frequency doubling of firing periodicity relative to theta rhythmicity and it partitions the theta cycle into segments showing clear versus poor spike timing organization. We found that theta phase precession occurred over a wider range than previously reported. This was apparent from spikes emitted near the peak of the theta cycle exhibiting large "phase precessing jumps" relative to spikes in foregoing cycles. Neither this phenomenon nor the regular manifestation of theta phase precession was affected by reward expectancy. Ventral striatal neuronal firing phase-locked not only to hippocampal theta, but also to beta band activity. Both hippocampus and ventral striatum showed increased synchronization between neuronal firing and local field potential activity during cued compared with uncued goal approaches. These results suggest that cue-triggered reward expectancy intensifies hippocampal output to target structures, such as the ventral striatum, by which the hippocampus may gain prioritized access to systems modulating motivated behaviors. Here we show that temporally discrete cues raising reward expectancy enhance both theta and beta band activity in the hippocampus once goal-directed navigation has been initiated. These rhythmic activities are associated with increased synchronization of neuronal firing patterns in the hippocampus and the connected ventral striatum. When transmitted to downstream target structures, this expectancy-related state of intensified processing in the hippocampus may modulate goal-directed action. Copyright © 2016 the authors 0270-6474/16/3610598-13$15.00/0.

Functional contributors to poor movement and balance control in patients with low back pain: A descriptive analysis.

PubMed

Ayhan, Cigdem; Bilgin, Sevil; Aksoy, Songul; Yakut, Yavuz

2016-08-10

Automatic and voluntary body position control is essential for postural stability; however, little is known about individual factors that impair the sensorimotor system associated with low back pain (LBP). To evaluate automatic and voluntary motor control impairments causing postural instability in patients with LBP. Motor control impairments associated with poor movement and balance control were analyzed prospectively in 32 patients with LBP. Numeric Rating Scale (NRS) for pain assessment, Oswestry Disability Index (ODI) for disability measurement, and computerized dynamic posturography (CDP) for analysis of postural responses were used to measure outcomes of all patients. Computerized dynamic posturography tests including Sensory organization test (SOT), limits of stability test (movement velocity, directional control, endpoint, and maximum excursion), rhythmic weight shift (rhythmic movement speed and directional control), and adaptation test (toes-up and toes-down tests) were performed and the results compared with NeuroCom normative data. The mean age of the patients was 40.50 ± 12.28 years. Lower equilibrium scores were observed in SOT (p < 0.05). There was a significant increase in reaction time and decrease in movement velocity, directional control, and endpoint excursion (p < 0.05). Speed of rhythmic movement along the anteroposterior direction decreased, while speed increased along the lateral direction (p < 0.05). Poor directional control was recorded in the anteroposterior direction (p < 0.05). Toes-down test showed an increased COG sway in patients compared with that in the controls (p < 0.05). LBP causes poor voluntary control of body positioning, a reduction in movement control, delays in movement initiation, and a difficulty to adapt to sudden surface changes.

Brain processing of meter and rhythm in music. Electrophysiological evidence of a common network.

PubMed

Kuck, Heleln; Grossbach, Michael; Bangert, Marc; Altenmüller, Eckart

2003-11-01

To determine cortical structures involved in "global" meter and "local" rhythm processing, slow brain potentials (DC potentials) were recorded from the scalp of 18 musically trained subjects while listening to pairs of monophonic sequences with both metric structure and rhythmic variations. The second sequence could be either identical to or different from the first one. Differences were either of a metric or a rhythmic nature. The subjects' task was to judge whether the sequences were identical or not. During processing of the auditory tasks, brain activation patterns along with the subjects' performance were assessed using 32-channel DC electroencephalography. Data were statistically analyzed using MANOVA. Processing of both meter and rhythm produced sustained cortical activation over bilateral frontal and temporal brain regions. A shift towards right hemispheric activation was pronounced during presentation of the second stimulus. Processing of rhythmic differences yielded a more centroparietal activation compared to metric processing. These results do not support Lerdhal and Jackendoff's two-component model, predicting a dissociation of left hemispheric rhythm and right hemispheric meter processing. We suggest that the uniform right temporofrontal predominance reflects auditory working memory and a pattern recognition module, which participates in both rhythm and meter processing. More pronounced parietal activation during rhythm processing may be related to switching of task-solving strategies towards mental imagination of the score.

The in vitro maintenance of clock genes expression within the rat pineal gland under standard and norepinephrine-synchronized stimulation.

PubMed

Andrade-Silva, Jéssica; Cipolla-Neto, José; Peliciari-Garcia, Rodrigo A

2014-01-01

Although the norepinephrine (NE) synchronization protocol was proved to be an important procedure for further modulating in vitro pineal melatonin synthesis, the maintenance of clock genes under the same conditions remained to be investigated. The aim of this study was to investigate the maintenance of the clock genes expression in pineal gland cultures under standard and NE-synchronized stimulation. The glands were separated into three experimental groups: Control, Standard (acute NE-stimulation), and NE-synchronized. The expression of Bmal1, Per2, Cry2, Rev-erbα, the clock controlled gene Dbp and Arylalkylamine-N-acetyltransferase were investigated, as well as melatonin content. No oscillations were observed in the expression of the investigated genes from the control group. Under Standard NE stimulation, the clock genes did not exhibit a rhythmic pattern of expression. However, in the NE-synchronized condition, a rhythmic expression pattern was observed in all cases. An enhancement in pineal gland responsiveness to NE stimulation, reflected in an advanced synthesis of melatonin was also observed. Our results reinforce our previous hypothesis that NE synchronization of pineal gland culture mimics the natural rhythmic release of NE in the gland, increasing melatonin synthesis and keeping the pineal circadian clock synchronized, ensuring the fine adjustments that are relied in the clockwork machinery. Copyright © 2014 Elsevier Ireland Ltd and the Japan Neuroscience Society. All rights reserved.

Differences in circadian rhythmicity in CLOCK 3111T/C genetic variants in moderate obese women as assessed by thermometry, actimetry and body position

USDA-ARS?s Scientific Manuscript database

Genetics is behind our circadian machinery. CLOCK (Circadian Locomotor Output Cycles Kaput) 3111T/C single-nucleotide polymorphism (SNP) has been previously related to obesity and weight loss. However, phenotypic association and functionality of CLOCK 3111 locus is still unknown. The aim of this stu...

Fish Oil Ameliorates High-Fat Diet Induced Male Mouse Reproductive Dysfunction via Modifying the Rhythmic Expression of Testosterone Synthesis Related Genes.

PubMed

Wang, Hualin; Cai, Yazheng; Shao, Yang; Zhang, Xifeng; Li, Na; Zhang, Hongyu; Liu, Zhiguo

2018-04-29

The present study aims to investigate the protective effects of ω-3 polyunsaturated fatty acids (ω-3PUFAs) against high-fat diet induced male mouse reproductive dysfunction and to explore circadian regulation mechanisms. Male C57BL/6 mice were randomly divided into three groups and fed a normal chow diet (control group, CON), a high-fat diet (HFD group) or a HFD supplemented with fish oil (FO group) for 12 weeks. After 12 weeks of feeding, the body weight and the ratio of perinephric and epididymal fat weight to body weight were significantly higher in the HFD group compared with the CON group. The supplement of fish oil rich in ω-3PUFAs only slightly reduced the HFD-induced obesity but remarkably ameliorated HFD-induced dyslipidemia, sexual hormones disorder, testicle lesions and germ cell apoptosis. Fish oil supplementation restored the expression of steroid synthesis associated genes in HFD fed mouse and flattened the HFD-induced oscillations in circadian genes' expression. Fish oil supplementation prevented HFD-induced male mouse reproductive dysfunction and modified the rhythmic expression of testosterone synthesis related genes.

Circadian and feeding cues integrate to drive rhythms of physiology in Drosophila insulin-producing cells.

PubMed

Barber, Annika F; Erion, Renske; Holmes, Todd C; Sehgal, Amita

2016-12-01

Circadian clocks regulate much of behavior and physiology, but the mechanisms by which they do so remain poorly understood. While cyclic gene expression is thought to underlie metabolic rhythms, little is known about cycles in cellular physiology. We found that Drosophila insulin-producing cells (IPCs), which are located in the pars intercerebralis and lack an autonomous circadian clock, are functionally connected to the central circadian clock circuit via DN1 neurons. Insulin mediates circadian output by regulating the rhythmic expression of a metabolic gene (sxe2) in the fat body. Patch clamp electrophysiology reveals that IPCs display circadian clock-regulated daily rhythms in firing event frequency and bursting proportion under light:dark conditions. The activity of IPCs and the rhythmic expression of sxe2 are additionally regulated by feeding, as demonstrated by night feeding-induced changes in IPC firing characteristics and sxe2 levels in the fat body. These findings indicate circuit-level regulation of metabolism by clock cells in Drosophila and support a role for the pars intercerebralis in integrating circadian control of behavior and physiology. © 2016 Barber et al.; Published by Cold Spring Harbor Laboratory Press.

Individualization of music-based rhythmic auditory cueing in Parkinson's disease.

PubMed

Bella, Simone Dalla; Dotov, Dobromir; Bardy, Benoît; de Cock, Valérie Cochen

2018-06-04

Gait dysfunctions in Parkinson's disease can be partly relieved by rhythmic auditory cueing. This consists in asking patients to walk with a rhythmic auditory stimulus such as a metronome or music. The effect on gait is visible immediately in terms of increased speed and stride length. Moreover, training programs based on rhythmic cueing can have long-term benefits. The effect of rhythmic cueing, however, varies from one patient to the other. Patients' response to the stimulation may depend on rhythmic abilities, often deteriorating with the disease. Relatively spared abilities to track the beat favor a positive response to rhythmic cueing. On the other hand, most patients with poor rhythmic abilities either do not respond to the cues or experience gait worsening when walking with cues. An individualized approach to rhythmic auditory cueing with music is proposed to cope with this variability in patients' response. This approach calls for using assistive mobile technologies capable of delivering cues that adapt in real time to patients' gait kinematics, thus affording step synchronization to the beat. Individualized rhythmic cueing can provide a safe and cost-effective alternative to standard cueing that patients may want to use in their everyday lives. © 2018 New York Academy of Sciences.

Altered time structure of neuro-endocrine-immune system function in lung cancer patients.

PubMed

Mazzoccoli, Gianluigi; Vendemiale, Gianluigi; De Cata, Angelo; Carughi, Stefano; Tarquini, Roberto

2010-06-21

The onset and the development of neoplastic disease may be influenced by many physiological, biological and immunological factors. The nervous, endocrine and immune system might act as an integrated unit to maintain body defense against this pathological process and reciprocal influences have been evidenced among hypothalamus, pituitary, thyroid, adrenal, pineal gland and immune system. In this study we evaluated differences among healthy subjects and subjects suffering from lung cancer in the 24-hour secretory profile of melatonin, cortisol, TRH, TSH, FT4, GH, IGF-1 and IL-2 and circadian variations of lymphocyte subpopulations. In ten healthy male volunteers (age range 45-66) and ten male patients with untreated non small cell lung cancer (age range 46-65) we measured melatonin, cortisol, TRH, TSH, FT4, GH, IGF-1 and IL-2 serum levels and percentages of lymphocyte subpopulations on blood samples collected every four hours for 24 hours. One-way ANOVA between the timepoints for each variable and each group was performed to look for a time-effect, the presence of circadian rhythmicity was evaluated, MESOR, amplitude and acrophase values, mean diurnal levels and mean nocturnal levels were compared. A clear circadian rhythm was validated in the control group for hormone serum level and for lymphocyte subsets variation. Melatonin, TRH, TSH, GH, CD3, CD4, HLA-DR, CD20 and CD25 expressing cells presented circadian rhythmicity with acrophase during the night. Cortisol, CD8, CD8(bright), CD8(dim), CD16, TcRdelta1 and deltaTcS1 presented circadian rhythmicity with acrophase in the morning/at noon. FT4, IGF-1 and IL-2 variation did not show circadian rhythmicity. In lung cancer patients cortisol, TRH, TSH and GH serum level and all the lymphocyte subsubsets variation (except for CD4) showed loss of circadian rhythmicity. MESOR of cortisol, TRH, GH, IL-2 and CD16 was increased, whereas MESOR of TSH, IGF-1, CD8, CD8(bright), TcRdelta1 and deltaTcS1 was decreased in cancer patients. The melatonin/cortisol mean nocturnal level ratio was decreased in cancer patients. The altered secretion and loss of circadian rhythmicity of many studied factors observed in the subjects suffering from neoplastic disease may be expression of gradual alteration of the integrated function of the neuro-immune-endocrine system.

Altered time structure of neuro-endocrine-immune system function in lung cancer patients

PubMed Central

2010-01-01

Background The onset and the development of neoplastic disease may be influenced by many physiological, biological and immunological factors. The nervous, endocrine and immune system might act as an integrated unit to mantain body defense against this pathological process and reciprocal influences have been evidenced among hypothalamus, pituitary, thyroid, adrenal, pineal gland and immune system. In this study we evaluated differences among healthy subjects and subjects suffering from lung cancer in the 24-hour secretory profile of melatonin, cortisol, TRH, TSH, FT4, GH, IGF-1 and IL-2 and circadian variations of lymphocyte subpopulations. Methods In ten healthy male volunteers (age range 45-66) and ten male patients with untreated non small cell lung cancer (age range 46-65) we measured melatonin, cortisol, TRH, TSH, FT4, GH, IGF-1 and IL-2 serum levels and percentages of lymphocyte subpopulations on blood samples collected every four hours for 24 hours. One-way ANOVA between the timepoints for each variable and each group was performed to look for a time-effect, the presence of circadian rhythmicity was evaluated, MESOR, amplitude and acrophase values, mean diurnal levels and mean nocturnal levels were compared. Results A clear circadian rhythm was validated in the control group for hormone serum level and for lymphocyte subsets variation. Melatonin, TRH, TSH, GH, CD3, CD4, HLA-DR, CD20 and CD25 expressing cells presented circadian rhythmicity with acrophase during the night. Cortisol, CD8, CD8bright, CD8dim, CD16, TcRδ1 and δTcS1 presented circadian rhythmicity with acrophase in the morning/at noon. FT4, IGF-1 and IL-2 variation did not show circadian rhythmicity. In lung cancer patients cortisol, TRH, TSH and GH serum level and all the lymphocyte subsubsets variation (except for CD4) showed loss of circadian rhythmicity. MESOR of cortisol, TRH, GH, IL-2 and CD16 was increased, whereas MESOR of TSH, IGF-1, CD8, CD8bright, TcRδ1 and δTcS1 was decreased in cancer patients. The melatonin/cortisol mean nocturnal level ratio was decreased in cancer patients. Conclusion The altered secretion and loss of circadian rhythmicity of many studied factors observed in the subjects suffering from neoplastic disease may be expression of gradual alteration of the integrated function of the neuro-immune-endocrine system PMID:20565977

Temporal network analysis identifies early physiological and transcriptomic indicators of mild drought in Brassica rapa

PubMed Central

Gehan, Malia A; Mockler, Todd C; Weinig, Cynthia; Ewers, Brent E

2017-01-01

The dynamics of local climates make development of agricultural strategies challenging. Yield improvement has progressed slowly, especially in drought-prone regions where annual crop production suffers from episodic aridity. Underlying drought responses are circadian and diel control of gene expression that regulate daily variations in metabolic and physiological pathways. To identify transcriptomic changes that occur in the crop Brassica rapa during initial perception of drought, we applied a co-expression network approach to associate rhythmic gene expression changes with physiological responses. Coupled analysis of transcriptome and physiological parameters over a two-day time course in control and drought-stressed plants provided temporal resolution necessary for correlation of network modules with dynamic changes in stomatal conductance, photosynthetic rate, and photosystem II efficiency. This approach enabled the identification of drought-responsive genes based on their differential rhythmic expression profiles in well-watered versus droughted networks and provided new insights into the dynamic physiological changes that occur during drought. PMID:28826479

Circadian actin dynamics drive rhythmic fibroblast mobilisation during wound healing

PubMed Central

Hoyle, Nathaniel P.; Seinkmane, Estere; Putker, Marrit; Feeney, Kevin A.; Krogager, Toke P.; Chesham, Johanna E.; Bray, Liam K.; Thomas, Justyn M.; Dunn, Ken; Blaikley, John; O’Neill, John S.

2017-01-01

Fibroblasts are primary cellular protagonists of wound healing. They also exhibit circadian timekeeping which imparts a ~24-hour rhythm to their biological function. We interrogated the functional consequences of the cell-autonomous clockwork in fibroblasts using a proteome-wide screen for rhythmically expressed proteins. We observed temporal coordination of actin regulators that drives cell-intrinsic rhythms in actin dynamics. In consequence the cellular clock modulates the efficiency of actin-dependent processes such as cell migration and adhesion, which ultimately impact the efficacy of wound healing. Accordingly, skin wounds incurred during a mouse’s active phase exhibited increased fibroblast invasion in vivo and ex vivo, as well as in cultured fibroblasts and keratinocytes. Our experimental results correlate with the observation that the time of injury significantly affects healing after burns in humans, with daytime wounds healing ~60% faster than night-time wounds. We suggest that circadian regulation of the cytoskeleton influences wound healing efficacy from the cellular to the organismal scale. PMID:29118260

Lip movements entrain the observers’ low-frequency brain oscillations to facilitate speech intelligibility

PubMed Central

Park, Hyojin; Kayser, Christoph; Thut, Gregor; Gross, Joachim

2016-01-01

During continuous speech, lip movements provide visual temporal signals that facilitate speech processing. Here, using MEG we directly investigated how these visual signals interact with rhythmic brain activity in participants listening to and seeing the speaker. First, we investigated coherence between oscillatory brain activity and speaker’s lip movements and demonstrated significant entrainment in visual cortex. We then used partial coherence to remove contributions of the coherent auditory speech signal from the lip-brain coherence. Comparing this synchronization between different attention conditions revealed that attending visual speech enhances the coherence between activity in visual cortex and the speaker’s lips. Further, we identified a significant partial coherence between left motor cortex and lip movements and this partial coherence directly predicted comprehension accuracy. Our results emphasize the importance of visually entrained and attention-modulated rhythmic brain activity for the enhancement of audiovisual speech processing. DOI: http://dx.doi.org/10.7554/eLife.14521.001 PMID:27146891

Could transient hypoxia be associated with rhythmic masticatory muscle activity in sleep bruxism in the absence of sleep-disordered breathing? A preliminary report.

PubMed

Dumais, I E; Lavigne, G J; Carra, M C; Rompré, P H; Huynh, N T

2015-11-01

Sleep bruxism (SB) is a repetitive jaw-muscle activity characterised by clenching or grinding of the teeth during sleep. Sleep bruxism activity is characterised by rhythmic masticatory muscle activity (RMMA). Many but not all RMMA episodes are associated with sleep arousal. The aim of this study was to evaluate whether transient oxygen saturation level change can be temporally associated with genesis of RMMA/SB. Sleep laboratory or home recordings data from 22 SB (tooth grinding history in the absence of reported sleep-disordered breathing) and healthy subjects were analysed. A total of 143 RMMA/SB episodes were classified in four categories: (i) no arousal + no body movement; (ii) arousal + no body movement; (iii) no arousal + body movement; (iv) arousal + body movement. Blood oxygen levels (SaO2 ) were assessed from finger oximetry signal at the baseline (before RMMA), and during RMMA. Significant variation in SaO2 over time (P = 0·001) was found after RMMA onset (+7 to +9 s). No difference between categories (P = 0·91) and no interaction between categories and SaO2 variation over time (P = 0·10) were observed. SaO2 of six of 22 subjects (27%) remained equal or slight increase after the RMMA/SB onset (+8 s) compared to baseline; 10 subjects (45%) slightly decreased (drop 0·01-1%) and the remaining (27%) decreased between 1% and 2%. These preliminary findings suggest that a subgroup of SB subjects had (i) a minor transient hypoxia potentially associated with the onset of RMMA episodes, and this (ii) independently of concomitant sleep arousal or body movements. © 2015 John Wiley & Sons Ltd.

Optimal Tempo for Groove: Its Relation to Directions of Body Movement and Japanese nori

PubMed Central

Etani, Takahide; Marui, Atsushi; Kawase, Satoshi; Keller, Peter E.

2018-01-01

The tendency for groove-based music to induce body movements has been linked to multiple acoustical factors. However, it is unclear how or whether tempo affects groove, although tempo significantly affects other aspects of music perception. To address this issue, the present study investigated effects of tempo, specific rhythmic organizations of patterns, and syncopation on groove and the induction of the sensation of wanting to move. We focused on the directions of body movement in particular by taking into account nori, which is an indigenous Japanese musical term used not only synonymously with groove, but also as a spatial metaphor indicating vertical or horizontal movement directions. Thus, the present study explored how groove was felt and defined, as well as how musical factors induced the sensation of wanting to move in cross-cultural context. A listening experiment was conducted using drum breaks as stimuli. Stimuli consisted of various rhythm patterns at six tempi from 60 to 200 BPM. The main findings are that: (1) an optimal tempo for groove existed for drum breaks at around 100–120 BPM, (2) an optimal tempo existed for the sensation of wanting to move the body in specific directions (i.e., back-and-forth and side-to-side), (3) groove and nori shared a similar concept of wanting to move but differed on several points (i.e., association with sense of pulse and fast tempo). Overall, the present study suggests that there is an optimal tempo for body movement related to groove. This finding has implications for the use of music or rhythmic stimuli to induce smooth motion in rehabilitation, therapy, or dance. PMID:29692747

Body movement selectively shapes the neural representation of musical rhythms.

PubMed

Chemin, Baptiste; Mouraux, André; Nozaradan, Sylvie

2014-12-01

It is increasingly recognized that motor routines dynamically shape the processing of sensory inflow (e.g., when hand movements are used to feel a texture or identify an object). In the present research, we captured the shaping of auditory perception by movement in humans by taking advantage of a specific context: music. Participants listened to a repeated rhythmical sequence before and after moving their bodies to this rhythm in a specific meter. We found that the brain responses to the rhythm (as recorded with electroencephalography) after body movement were significantly enhanced at frequencies related to the meter to which the participants had moved. These results provide evidence that body movement can selectively shape the subsequent internal representation of auditory rhythms. © The Author(s) 2014.

Does 'anchor sleep' entrain circadian rhythms? Evidence from constant routine studies.

PubMed Central

Minors, D S; Waterhouse, J M

1983-01-01

Experiments have been performed in an isolation unit to investigate the effects of abnormal sleep-waking schedules upon circadian rhythms of renal excretion and deep-body temperature. In confirmation of previous work, nychthemeral rhythms appeared to be 'anchored' to a 24 h period if 4 h sleep was taken regularly each day, even though another 4 h was taken irregularly. The endogenous components were investigated by assessing circadian rhythmicity under constant routine conditions, that is, when rhythmic influences in the environment and sleep-waking pattern had been minimized. Analysis of the constant routine data indicated the presence of a rhythmic component which had been stabilized to a period of 24 h by the 'anchor sleep'. In addition, a delayed component was also present. The starting time of the constant routines produced a direct effect upon the rhythms, which was presumed to result from removing the 'masking' effect that sleep normally exerts upon rhythms. There was some evidence that the relative importance of the masking effect and the delayed component depended upon the variable under consideration. The implications of these findings, in terms of the effects of anchor sleep, the presence of more than one internal clock and the usefulness of constant routines, are discussed. PMID:6663508

Laminar Profile of Spontaneous and Evoked Theta: Rhythmic Modulation of Cortical Processing During Word Integration

PubMed Central

Halgren, Eric; Kaestner, Erik; Marinkovic, Ksenija; Cash, Sydney S.; Wang, Chunmao; Schomer, Donald L.; Madsen, Joseph R.; Ulbert, Istvan

2015-01-01

Theta may play a central role during language understanding and other extended cognitive processing, providing an envelope for widespread integration of participating cortical areas. We used linear microelectrode arrays in epileptics to define the circuits generating theta in inferotemporal, perirhinal, entorhinal, prefrontal and anterior cingulate cortices. In all locations, theta was generated by excitatory current sinks in middle layers which receive predominantly feedforward inputs, alternating with sinks in superficial layers which receive mainly feedback/associative inputs. Baseline and event-related theta were generated by indistinguishable laminar profiles of transmembrane currents and unit-firing. Word presentation could reset theta phase, permitting theta to contribute to late event-related potentials, even when theta power decreases relative to baseline. Limited recordings during sentence reading are consistent with rhythmic theta activity entrained by a given word modulating the neural background for the following word. These findings show that theta occurs spontaneously, and can be momentarily suppressed, reset and synchronized by words. Theta represents an alternation between feedforward/divergent and associative/convergent processing modes that may temporally organize sustained processing and optimize the timing of memory formation. We suggest that words are initially encoded via a ventral feedforward stream which is lexicosemantic in the anteroventral temporal lobe; its arrival may trigger a widespread theta rhythm which integrates the word within a larger context. PMID:25801916

Competing streams at the cocktail party: Exploring the mechanisms of attention and temporal integration

PubMed Central

Xiang, Juanjuan; Simon, Jonathan; Elhilali, Mounya

2010-01-01

Processing of complex acoustic scenes depends critically on the temporal integration of sensory information as sounds evolve naturally over time. It has been previously speculated that this process is guided by both innate mechanisms of temporal processing in the auditory system, as well as top-down mechanisms of attention, and possibly other schema-based processes. In an effort to unravel the neural underpinnings of these processes and their role in scene analysis, we combine Magnetoencephalography (MEG) with behavioral measures in humans in the context of polyrhythmic tone sequences. While maintaining unchanged sensory input, we manipulate subjects’ attention to one of two competing rhythmic streams in the same sequence. The results reveal that the neural representation of the attended rhythm is significantly enhanced both in its steady-state power and spatial phase coherence relative to its unattended state, closely correlating with its perceptual detectability for each listener. Interestingly, the data reveals a differential efficiency of rhythmic rates of the order of few hertz during the streaming process, closely following known neural and behavioral measures of temporal modulation sensitivity in the auditory system. These findings establish a direct link between known temporal modulation tuning in the auditory system (particularly at the level of auditory cortex) and the temporal integration of perceptual features in a complex acoustic scene, while mediated by processes of attention. PMID:20826671

State-dependencies of learning across brain scales

PubMed Central

Ritter, Petra; Born, Jan; Brecht, Michael; Dinse, Hubert R.; Heinemann, Uwe; Pleger, Burkhard; Schmitz, Dietmar; Schreiber, Susanne; Villringer, Arno; Kempter, Richard

2015-01-01

Learning is a complex brain function operating on different time scales, from milliseconds to years, which induces enduring changes in brain dynamics. The brain also undergoes continuous “spontaneous” shifts in states, which, amongst others, are characterized by rhythmic activity of various frequencies. Besides the most obvious distinct modes of waking and sleep, wake-associated brain states comprise modulations of vigilance and attention. Recent findings show that certain brain states, particularly during sleep, are essential for learning and memory consolidation. Oscillatory activity plays a crucial role on several spatial scales, for example in plasticity at a synaptic level or in communication across brain areas. However, the underlying mechanisms and computational rules linking brain states and rhythms to learning, though relevant for our understanding of brain function and therapeutic approaches in brain disease, have not yet been elucidated. Here we review known mechanisms of how brain states mediate and modulate learning by their characteristic rhythmic signatures. To understand the critical interplay between brain states, brain rhythms, and learning processes, a wide range of experimental and theoretical work in animal models and human subjects from the single synapse to the large-scale cortical level needs to be integrated. By discussing results from experiments and theoretical approaches, we illuminate new avenues for utilizing neuronal learning mechanisms in developing tools and therapies, e.g., for stroke patients and to devise memory enhancement strategies for the elderly. PMID:25767445

Cholinergic modulation of hippocampal network function

PubMed Central

Teles-Grilo Ruivo, Leonor M.; Mellor, Jack R.

2013-01-01

Cholinergic septohippocampal projections from the medial septal area to the hippocampus are proposed to have important roles in cognition by modulating properties of the hippocampal network. However, the precise spatial and temporal profile of acetylcholine release in the hippocampus remains unclear making it difficult to define specific roles for cholinergic transmission in hippocampal dependent behaviors. This is partly due to a lack of tools enabling specific intervention in, and recording of, cholinergic transmission. Here, we review the organization of septohippocampal cholinergic projections and hippocampal acetylcholine receptors as well as the role of cholinergic transmission in modulating cellular excitability, synaptic plasticity, and rhythmic network oscillations. We point to a number of open questions that remain unanswered and discuss the potential for recently developed techniques to provide a radical reappraisal of the function of cholinergic inputs to the hippocampus. PMID:23908628

The Effect of Haptic Guidance on Learning a Hybrid Rhythmic-Discrete Motor Task.

PubMed

Marchal-Crespo, Laura; Bannwart, Mathias; Riener, Robert; Vallery, Heike

2015-01-01

Bouncing a ball with a racket is a hybrid rhythmic-discrete motor task, combining continuous rhythmic racket movements with discrete impact events. Rhythmicity is exceptionally important in motor learning, because it underlies fundamental movements such as walking. Studies suggested that rhythmic and discrete movements are governed by different control mechanisms at different levels of the Central Nervous System. The aim of this study is to evaluate the effect of fixed/fading haptic guidance on learning to bounce a ball to a desired apex in virtual reality with varying gravity. Changing gravity changes dominance of rhythmic versus discrete control: The higher the value of gravity, the more rhythmic the task; lower values reduce the bouncing frequency and increase dwell times, eventually leading to a repetitive discrete task that requires initiation and termination, resembling target-oriented reaching. Although motor learning in the ball-bouncing task with varying gravity has been studied, the effect of haptic guidance on learning such a hybrid rhythmic-discrete motor task has not been addressed. We performed an experiment with thirty healthy subjects and found that the most effective training condition depended on the degree of rhythmicity: Haptic guidance seems to hamper learning of continuous rhythmic tasks, but it seems to promote learning for repetitive tasks that resemble discrete movements.

Eating disorders, energy intake, training volume, and menstrual function in high-level modern rhythmic gymnasts.

PubMed

Sundgot-Borgen, J

1996-06-01

This study examined clinical and subclinical eating disorders (EDs) in young Norwegian modern rhythmic gymnasts. Subjects were 12 members of the national team, age 13-20 years, and individually matched nonathletic controls. All subjects participated in a structured clinical interview for EDs, medical examination, and dietary analysis. Two of the gymnasts met the DSM-III-R criteria for anorexia nervosa, and 2 met the criteria for anorexia athletica (a subclinical ED). All the gymnasts were dieting in spite of the fact that they were all extremely lean. The avoidance of maturity, menstrual irregularities, energy deficit, high training volume, and high frequency of injuries were common features among the gymnasts. Ther is a need to learn more about risk factors and the etiology of EDs in different sports. Coaches, parents, and athletes need more information about principles of proper nutrition and methods to achieve ideal body composition for optional health and athletic performance.

Neural underpinnings of music: the polyrhythmic brain.

PubMed

Vuust, Peter; Gebauer, Line K; Witek, Maria A G

2014-01-01

Musical rhythm, consisting of apparently abstract intervals of accented temporal events, has the remarkable ability to move our minds and bodies. Why do certain rhythms make us want to tap our feet, bop our heads or even get up and dance? And how does the brain process rhythmically complex rhythms during our experiences of music? In this chapter, we describe some common forms of rhythmic complexity in music and propose that the theory of predictive coding can explain how rhythm and rhythmic complexity are processed in the brain. We also consider how this theory may reveal why we feel so compelled by rhythmic tension in music. First, musical-theoretical and neuroscientific frameworks of rhythm are presented, in which rhythm perception is conceptualized as an interaction between what is heard ('rhythm') and the brain's anticipatory structuring of music ('the meter'). Second, three different examples of tension between rhythm and meter in music are described: syncopation, polyrhythm and groove. Third, we present the theory of predictive coding of music, which posits a hierarchical organization of brain responses reflecting fundamental, survival-related mechanisms associated with predicting future events. According to this theory, perception and learning is manifested through the brain's Bayesian minimization of the error between the input to the brain and the brain's prior expectations. Fourth, empirical studies of neural and behavioral effects of syncopation, polyrhythm and groove will be reported, and we propose how these studies can be seen as special cases of the predictive coding theory. Finally, we argue that musical rhythm exploits the brain's general principles of anticipation and propose that pleasure from musical rhythm may be a result of such anticipatory mechanisms.

A rhythmic modulatory gating system in the stomatogastric nervous system of Homarus gammarus. III. Rhythmic control of the pyloric CPG.

PubMed

Cardi, P; Nagy, F

1994-06-01

1. Two modulatory neurons, P and commissural pyloric (CP), known to be involved in the long-term maintenance of pyloric central pattern generator operation in the rock lobster Homarus gammarus, are members of the commissural pyloric oscillator (CPO), a higher-order oscillator influencing the pyloric network. 2. The CP neuron was endogenously oscillating in approximately 30% of the preparations in which its cell body was impaled. Rhythmic inhibitory feedback from the pyloric pacemaker anterior burster (AB) neuron stabilized the CP neuron's endogenous rhythm. 3. The organization of the CPO is described. Follower commissural neurons, the F cells, and the CP neuron receive a common excitatory postsynaptic potential from another commissural neuron, the large exciter (LE). When in oscillatory state, CP in turn excites the LE neuron. This positive feedback may maintain long episodes of CP oscillations. 4. The pyloric pacemaker neurons follow the CPO rhythm with variable coordination modes (i.e., 1:1, 1:2) and switch among these modes when their membrane potential is modified. The CPO inputs strongly constrain the pyloric period, which as a result may adopt only a few discrete values. This effect is based on mechanisms of entrainment between the CPO and the pyloric oscillator. 5. Pyloric constrictor neurons show differential sensitivity from the pyloric pacemaker neurons with respect to the CPO inputs. Consequently, their bursting period can be a shorter harmonic of the bursting period of the pyloric pacemakers neurons. 6. The CPO neurons seem to be the first example of modulatory gating neurons that also give timing cues to a rhythmic pattern generating network.

Examining the Potential of Web-Based Multimedia to Support Complex Fine Motor Skill Learning: An Empirical Study

ERIC Educational Resources Information Center

Papastergiou, Marina; Pollatou, Elisana; Theofylaktou, Ioannis; Karadimou, Konstantina

2014-01-01

Research on the utilization of the Web for complex fine motor skill learning that involves whole body movements is still scarce. The aim of this study was to evaluate the impact of the introduction of a multimedia web-based learning environment, which was targeted at a rhythmic gymnastics routine consisting of eight fine motor skills, into an…

Determining the period, phase and anticipatory component of activity and temperature patterns in newborn rabbits that were maintained under a daily nursing schedule and fasting conditions.

PubMed

Trejo-Muñoz, Lucero; Navarrete, Erika; Montúfar-Chaveznava, Rodrigo; Caldelas, Ivette

2012-07-16

During the last decade, lagomorphs have gained relevance as valuable models for the study of the development of circadian rhythmicity. This relevance is due to both the peculiar behavior of the lactating doe, in which maternal care is limited from 3 to 5 min per day, and the temporal organization that newborn rabbits exhibit during the early stages of development. In this study, we characterized the development of the temporal pattern of core body temperature and locomotor activity of newborn rabbits. This activity was recorded simultaneously for individual newborn rabbits and was maintained under constant light conditions, a 24-h nursing schedule and without access to the lactating doe. In addition, different mathematical algorithms were designed to determine the period, phase and anticipatory component of the time series obtained for the newborn rabbits. During the first two weeks of life, the average gross locomotor activity decreased as age increased; conversely however, the core body temperature exhibited a significant increment during the early stages of postnatal development. The newborn rabbits' circadian patterns of activity and temperature were consolidated as early as the first week of life. Similarly, the acrophase and nadir of both rhythms were settled by postnatal day 5, and the maximum activity consistently occurred approximately 2 h before the animals' maximum body temperature. The anticipation of nursing was evident from postnatal day 2 for both parameters, and the duration and intensity showed changes associated with the stage of development. In addition, the anticipatory component persisted with the same duration and intensity, even when nursing was omitted. The mathematical methods used in this study are suitable for producing unbiased analyses of the time series that are obtained from developing animals in situations during which biological signals generally show variability in frequencies and trends. By using these methods, it was possible to establish that circadian rhythmicity at the behavioral and physiological levels was evident during the first week of age in newborn rabbits. This circadian rhythmicity represents an endogenous rhythm because it persists throughout constant conditions. Copyright © 2012 Elsevier Inc. All rights reserved.

Endocannabinoid Release Modulates Electrical Coupling between CCK Cells Connected via Chemical and Electrical Synapses in CA1

PubMed Central

Iball, Jonathan; Ali, Afia B.

2011-01-01

Electrical coupling between some subclasses of interneurons is thought to promote coordinated firing that generates rhythmic synchronous activity in cortical regions. Synaptic activity of cholecystokinin (CCK) interneurons which co-express cannabinoid type-1 (CB1) receptors are powerful modulators of network activity via the actions of endocannabinoids. We investigated the modulatory actions of endocannabinoids between chemically and electrically connected synapses of CCK cells using paired whole-cell recordings combined with biocytin and double immunofluorescence labeling in acute slices of rat hippocampus at P18–20 days. CA1 stratum radiatum CCK Schaffer collateral-associated cells were coupled electrically with each other as well as CCK basket cells and CCK cells with axonal projections expanding to dentate gyrus. Approximately 50% of electrically coupled cells received facilitating, asynchronously released inhibitory postsynaptic potential (IPSPs) that curtailed the steady-state coupling coefficient by 57%. Tonic CB1 receptor activity which reduces inhibition enhanced electrical coupling between cells that were connected via chemical and electrical synapses. Blocking CB1 receptors with antagonist, AM-251 (5 μM) resulted in the synchronized release of larger IPSPs and this enhanced inhibition further reduced the steady-state coupling coefficient by 85%. Depolarization induced suppression of inhibition (DSI), maintained the asynchronicity of IPSP latency, but reduced IPSP amplitudes by 95% and enhanced the steady-state coupling coefficient by 104% and IPSP duration by 200%. However, DSI did not did not enhance electrical coupling at purely electrical synapses. These data suggest that different morphological subclasses of CCK interneurons are interconnected via gap junctions. The synergy between the chemical and electrical coupling between CCK cells probably plays a role in activity-dependent endocannabinoid modulation of rhythmic synchronization. PMID:22125513

Theta band oscillations reflect more than entrainment: behavioral and neural evidence demonstrates an active chunking process.

PubMed

Teng, Xiangbin; Tian, Xing; Doelling, Keith; Poeppel, David

2017-10-17

Parsing continuous acoustic streams into perceptual units is fundamental to auditory perception. Previous studies have uncovered a cortical entrainment mechanism in the delta and theta bands (~1-8 Hz) that correlates with formation of perceptual units in speech, music, and other quasi-rhythmic stimuli. Whether cortical oscillations in the delta-theta bands are passively entrained by regular acoustic patterns or play an active role in parsing the acoustic stream is debated. Here, we investigate cortical oscillations using novel stimuli with 1/f modulation spectra. These 1/f signals have no rhythmic structure but contain information over many timescales because of their broadband modulation characteristics. We chose 1/f modulation spectra with varying exponents of f, which simulate the dynamics of environmental noise, speech, vocalizations, and music. While undergoing magnetoencephalography (MEG) recording, participants listened to 1/f stimuli and detected embedded target tones. Tone detection performance varied across stimuli of different exponents and can be explained by local signal-to-noise ratio computed using a temporal window around 200 ms. Furthermore, theta band oscillations, surprisingly, were observed for all stimuli, but robust phase coherence was preferentially displayed by stimuli with exponents 1 and 1.5. We constructed an auditory processing model to quantify acoustic information on various timescales and correlated the model outputs with the neural results. We show that cortical oscillations reflect a chunking of segments, > 200 ms. These results suggest an active auditory segmentation mechanism, complementary to entrainment, operating on a timescale of ~200 ms to organize acoustic information. © 2017 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Physiological modules for generating discrete and rhythmic movements: component analysis of EMG signals.

PubMed

Bengoetxea, Ana; Leurs, Françoise; Hoellinger, Thomas; Cebolla, Ana Maria; Dan, Bernard; Cheron, Guy; McIntyre, Joseph

2014-01-01

A central question in Neuroscience is that of how the nervous system generates the spatiotemporal commands needed to realize complex gestures, such as handwriting. A key postulate is that the central nervous system (CNS) builds up complex movements from a set of simpler motor primitives or control modules. In this study we examined the control modules underlying the generation of muscle activations when performing different types of movement: discrete, point-to-point movements in eight different directions and continuous figure-eight movements in both the normal, upright orientation and rotated 90°. To test for the effects of biomechanical constraints, movements were performed in the frontal-parallel or sagittal planes, corresponding to two different nominal flexion/abduction postures of the shoulder. In all cases we measured limb kinematics and surface electromyographic activity (EMG) signals for seven different muscles acting around the shoulder. We first performed principal component analysis (PCA) of the EMG signals on a movement-by-movement basis. We found a surprisingly consistent pattern of muscle groupings across movement types and movement planes, although we could detect systematic differences between the PCs derived from movements performed in each shoulder posture and between the principal components associated with the different orientations of the figure. Unexpectedly we found no systematic differences between the figure eights and the point-to-point movements. The first three principal components could be associated with a general co-contraction of all seven muscles plus two patterns of reciprocal activation. From these results, we surmise that both "discrete-rhythmic movements" such as the figure eight, and discrete point-to-point movement may be constructed from three different fundamental modules, one regulating the impedance of the limb over the time span of the movement and two others operating to generate movement, one aligned with the vertical and the other aligned with the horizontal.

Physiological modules for generating discrete and rhythmic movements: component analysis of EMG signals

PubMed Central

Bengoetxea, Ana; Leurs, Françoise; Hoellinger, Thomas; Cebolla, Ana Maria; Dan, Bernard; Cheron, Guy; McIntyre, Joseph

2015-01-01

A central question in Neuroscience is that of how the nervous system generates the spatiotemporal commands needed to realize complex gestures, such as handwriting. A key postulate is that the central nervous system (CNS) builds up complex movements from a set of simpler motor primitives or control modules. In this study we examined the control modules underlying the generation of muscle activations when performing different types of movement: discrete, point-to-point movements in eight different directions and continuous figure-eight movements in both the normal, upright orientation and rotated 90°. To test for the effects of biomechanical constraints, movements were performed in the frontal-parallel or sagittal planes, corresponding to two different nominal flexion/abduction postures of the shoulder. In all cases we measured limb kinematics and surface electromyographic activity (EMG) signals for seven different muscles acting around the shoulder. We first performed principal component analysis (PCA) of the EMG signals on a movement-by-movement basis. We found a surprisingly consistent pattern of muscle groupings across movement types and movement planes, although we could detect systematic differences between the PCs derived from movements performed in each shoulder posture and between the principal components associated with the different orientations of the figure. Unexpectedly we found no systematic differences between the figure eights and the point-to-point movements. The first three principal components could be associated with a general co-contraction of all seven muscles plus two patterns of reciprocal activation. From these results, we surmise that both “discrete-rhythmic movements” such as the figure eight, and discrete point-to-point movement may be constructed from three different fundamental modules, one regulating the impedance of the limb over the time span of the movement and two others operating to generate movement, one aligned with the vertical and the other aligned with the horizontal. PMID:25620928

High-frequency gamma oscillations coexist with low-frequency gamma oscillations in the rat visual cortex in vitro.

PubMed

Oke, Olaleke O; Magony, Andor; Anver, Himashi; Ward, Peter D; Jiruska, Premysl; Jefferys, John G R; Vreugdenhil, Martin

2010-04-01

Synchronization of neuronal activity in the visual cortex at low (30-70 Hz) and high gamma band frequencies (> 70 Hz) has been associated with distinct visual processes, but mechanisms underlying high-frequency gamma oscillations remain unknown. In rat visual cortex slices, kainate and carbachol induce high-frequency gamma oscillations (fast-gamma; peak frequency approximately 80 Hz at 37 degrees C) that can coexist with low-frequency gamma oscillations (slow-gamma; peak frequency approximately 50 Hz at 37 degrees C) in the same column. Current-source density analysis showed that fast-gamma was associated with rhythmic current sink-source sequences in layer III and slow-gamma with rhythmic current sink-source sequences in layer V. Fast-gamma and slow-gamma were not phase-locked. Slow-gamma power fluctuations were unrelated to fast-gamma power fluctuations, but were modulated by the phase of theta (3-8 Hz) oscillations generated in the deep layers. Fast-gamma was spatially less coherent than slow-gamma. Fast-gamma and slow-gamma were dependent on gamma-aminobutyric acid (GABA)(A) receptors, alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors and gap-junctions, their frequencies were reduced by thiopental and were weakly dependent on cycle amplitude. Fast-gamma and slow-gamma power were differentially modulated by thiopental and adenosine A(1) receptor blockade, and their frequencies were differentially modulated by N-methyl-D-aspartate (NMDA) receptors, GluK1 subunit-containing receptors and persistent sodium currents. Our data indicate that fast-gamma and slow-gamma both depend on and are paced by recurrent inhibition, but have distinct pharmacological modulation profiles. The independent co-existence of fast-gamma and slow-gamma allows parallel processing of distinct aspects of vision and visual perception. The visual cortex slice provides a novel in vitro model to study cortical high-frequency gamma oscillations.

Rhythmic motor entrainment in children with speech and language impairments: tapping to the beat.

PubMed

Corriveau, Kathleen H; Goswami, Usha

2009-01-01

In prior work (Corriveau et al., 2007), we showed that children with speech and language impairments (SLI) were significantly less sensitive than controls to two auditory cues to rhythmic timing, amplitude envelope rise time and duration. Here we explore whether rhythmic problems extend to rhythmic motor entrainment. Tapping in synchrony with a beat has been described as the simplest rhythmic act that humans perform. We explored whether tapping to a beat would be impaired in children for whom auditory rhythmic timing is impaired. Children with SLI were indeed found to be impaired in a range of measures of paced rhythmic tapping, but were not equally impaired in tapping in an unpaced control condition requiring an internally-generated rhythm. The severity of impairment in paced tapping was linked to language and literacy outcomes.

A point process approach to identifying and tracking transitions in neural spiking dynamics in the subthalamic nucleus of Parkinson's patients

NASA Astrophysics Data System (ADS)

Deng, Xinyi; Eskandar, Emad N.; Eden, Uri T.

2013-12-01

Understanding the role of rhythmic dynamics in normal and diseased brain function is an important area of research in neural electrophysiology. Identifying and tracking changes in rhythms associated with spike trains present an additional challenge, because standard approaches for continuous-valued neural recordings—such as local field potential, magnetoencephalography, and electroencephalography data—require assumptions that do not typically hold for point process data. Additionally, subtle changes in the history dependent structure of a spike train have been shown to lead to robust changes in rhythmic firing patterns. Here, we propose a point process modeling framework to characterize the rhythmic spiking dynamics in spike trains, test for statistically significant changes to those dynamics, and track the temporal evolution of such changes. We first construct a two-state point process model incorporating spiking history and develop a likelihood ratio test to detect changes in the firing structure. We then apply adaptive state-space filters and smoothers to track these changes through time. We illustrate our approach with a simulation study as well as with experimental data recorded in the subthalamic nucleus of Parkinson's patients performing an arm movement task. Our analyses show that during the arm movement task, neurons underwent a complex pattern of modulation of spiking intensity characterized initially by a release of inhibitory control at 20-40 ms after a spike, followed by a decrease in excitatory influence at 40-60 ms after a spike.

Rhythmic Behavior Is Controlled by the SRm160 Splicing Factor in Drosophila melanogaster.

PubMed

Beckwith, Esteban J; Hernando, Carlos E; Polcowñuk, Sofía; Bertolin, Agustina P; Mancini, Estefania; Ceriani, M Fernanda; Yanovsky, Marcelo J

2017-10-01

Circadian clocks organize the metabolism, physiology, and behavior of organisms throughout the day-night cycle by controlling daily rhythms in gene expression at the transcriptional and post-transcriptional levels. While many transcription factors underlying circadian oscillations are known, the splicing factors that modulate these rhythms remain largely unexplored. A genome-wide assessment of the alterations of gene expression in a null mutant of the alternative splicing regulator SR-related matrix protein of 160 kDa (SRm160) revealed the extent to which alternative splicing impacts on behavior-related genes. We show that SRm160 affects gene expression in pacemaker neurons of the Drosophila brain to ensure proper oscillations of the molecular clock. A reduced level of SRm160 in adult pacemaker neurons impairs circadian rhythms in locomotor behavior, and this phenotype is caused, at least in part, by a marked reduction in period ( per ) levels. Moreover, rhythmic accumulation of the neuropeptide PIGMENT DISPERSING FACTOR in the dorsal projections of these neurons is abolished after SRm160 depletion. The lack of rhythmicity in SRm160-downregulated flies is reversed by a fully spliced per construct, but not by an extra copy of the endogenous locus, showing that SRm160 positively regulates per levels in a splicing-dependent manner. Our findings highlight the significant effect of alternative splicing on the nervous system and particularly on brain function in an in vivo model. Copyright © 2017 by the Genetics Society of America.

Neural Entrainment to Rhythmically Presented Auditory, Visual, and Audio-Visual Speech in Children

PubMed Central

Power, Alan James; Mead, Natasha; Barnes, Lisa; Goswami, Usha

2012-01-01

Auditory cortical oscillations have been proposed to play an important role in speech perception. It is suggested that the brain may take temporal “samples” of information from the speech stream at different rates, phase resetting ongoing oscillations so that they are aligned with similar frequency bands in the input (“phase locking”). Information from these frequency bands is then bound together for speech perception. To date, there are no explorations of neural phase locking and entrainment to speech input in children. However, it is clear from studies of language acquisition that infants use both visual speech information and auditory speech information in learning. In order to study neural entrainment to speech in typically developing children, we use a rhythmic entrainment paradigm (underlying 2 Hz or delta rate) based on repetition of the syllable “ba,” presented in either the auditory modality alone, the visual modality alone, or as auditory-visual speech (via a “talking head”). To ensure attention to the task, children aged 13 years were asked to press a button as fast as possible when the “ba” stimulus violated the rhythm for each stream type. Rhythmic violation depended on delaying the occurrence of a “ba” in the isochronous stream. Neural entrainment was demonstrated for all stream types, and individual differences in standardized measures of language processing were related to auditory entrainment at the theta rate. Further, there was significant modulation of the preferred phase of auditory entrainment in the theta band when visual speech cues were present, indicating cross-modal phase resetting. The rhythmic entrainment paradigm developed here offers a method for exploring individual differences in oscillatory phase locking during development. In particular, a method for assessing neural entrainment and cross-modal phase resetting would be useful for exploring developmental learning difficulties thought to involve temporal sampling, such as dyslexia. PMID:22833726

Studies of the phase gradient at the boundary of the phase diffusion equation, motivated by peculiar wave patterns of rhythmic contraction in the amoeboid movement of Physarum polycephalum

NASA Astrophysics Data System (ADS)

Iima, Makoto; Kori, Hiroshi; Nakagaki, Toshiyuki

2017-04-01

The boundary of a cell is the interface with its surroundings and plays a key role in controlling the cell movement adaptations to different environments. We propose a study of the boundary effects on the patterns and waves of the rhythmic contractions in plasmodia of Physarum polycephalum, a tractable model organism of the amoeboid type. Boundary effects are defined as the effects of both the boundary conditions and the boundary shape. The rhythmicity of contraction can be modulated by local stimulation of temperature, light and chemicals, and by local deformation of cell shape via mechanosensitive ion channels as well. First, we examined the effects of boundary cell shapes in the case of a special shape resembling a tadpole, while requiring that the natural frequency in the proximity of the boundary is slightly higher and uniform. The simulation model reproduced the approximate propagated wave, from the tail to the head, while the inward waves were observed only near the periphery of the head section of the tadpole-shape. A key finding was that the frequency of the rhythmic contractions depended on the local shape of cell boundary. This implies that the boundary conditions of the phase were not always homogeneous. To understand the dependency, we reduced the two-dimensional model into a one-dimensional continuum model with Neumann boundary conditions. Here, the boundary conditions reflect the frequency distribution at the boundary. We described the analytic solutions and calculated the relationship between the boundary conditions and the wave propagation for a one-dimensional model of the continuous oscillatory field and a discrete coupled oscillator system. The results obtained may not be limited to cell movement of Physarum, but may be applicable to the other physical systems since the analysis used a generic phase diffusion equation.

Parallel evolution of serotonergic neuromodulation underlies independent evolution of rhythmic motor behavior.

PubMed

Lillvis, Joshua L; Katz, Paul S

2013-02-06

Neuromodulation can dynamically alter neuronal and synaptic properties, thereby changing the behavioral output of a neural circuit. It is therefore conceivable that natural selection might act upon neuromodulation as a mechanism for sculpting the behavioral repertoire of a species. Here we report that the presence of neuromodulation is correlated with the production of a behavior that most likely evolved independently in two species: Tritonia diomedea and Pleurobranchaea californica (Mollusca, Gastropoda, Opisthobranchia, Nudipleura). Individuals of both species exhibit escape swimming behaviors consisting of repeated dorsal-ventral whole-body flexions. The central pattern generator (CPG) circuits underlying these behaviors contain homologous identified neurons: DSI and C2 in Tritonia and As and A1 in Pleurobranchaea. Homologs of these neurons also can be found in Hermissenda crassicornis where they are named CPT and C2, respectively. However, members of this species do not exhibit an analogous swimming behavior. In Tritonia and Pleurobranchaea, but not in Hermissenda, the serotonergic DSI homologs modulated the strength of synapses made by C2 homologs. Furthermore, the serotonin receptor antagonist methysergide blocked this neuromodulation and the swimming behavior. Additionally, in Pleurobranchaea, the robustness of swimming correlated with the extent of the synaptic modulation. Finally, injection of serotonin induced the swimming behavior in Tritonia and Pleurobranchaea, but not in Hermissenda. This suggests that the analogous swimming behaviors of Tritonia and Pleurobranchaea share a common dependence on serotonergic neuromodulation. Thus, neuromodulation may provide a mechanism that enables species to acquire analogous behaviors independently using homologous neural circuit components.

Distinct Thalamic Reticular Cell Types Differentially Modulate Normal and Pathological Cortical Rhythms.

PubMed

Clemente-Perez, Alexandra; Makinson, Stefanie Ritter; Higashikubo, Bryan; Brovarney, Scott; Cho, Frances S; Urry, Alexander; Holden, Stephanie S; Wimer, Matthew; Dávid, Csaba; Fenno, Lief E; Acsády, László; Deisseroth, Karl; Paz, Jeanne T

2017-06-06

Integrative brain functions depend on widely distributed, rhythmically coordinated computations. Through its long-ranging connections with cortex and most senses, the thalamus orchestrates the flow of cognitive and sensory information. Essential in this process, the nucleus reticularis thalami (nRT) gates different information streams through its extensive inhibition onto other thalamic nuclei, however, we lack an understanding of how different inhibitory neuron subpopulations in nRT function as gatekeepers. We dissociated the connectivity, physiology, and circuit functions of neurons within rodent nRT, based on parvalbumin (PV) and somatostatin (SOM) expression, and validated the existence of such populations in human nRT. We found that PV, but not SOM, cells are rhythmogenic, and that PV and SOM neurons are connected to and modulate distinct thalamocortical circuits. Notably, PV, but not SOM, neurons modulate somatosensory behavior and disrupt seizures. These results provide a conceptual framework for how nRT may gate incoming information to modulate brain-wide rhythms. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Rhythmic Engagement with Music in Early Childhood: A Replication and Extension

ERIC Educational Resources Information Center

Ilari, Beatriz

2015-01-01

The purpose of this study was to replicate and extend previous findings on spontaneous movement and rhythmic engagement with music in infancy. Using the identical stimuli and procedures from the original study, I investigated spontaneous rhythmic movements in response to music, infant-directed speech, and contrasting rhythmic patterns in 30…

Situational influences on rhythmicity in speech, music, and their interaction

PubMed Central

Hawkins, Sarah

2014-01-01

Brain processes underlying the production and perception of rhythm indicate considerable flexibility in how physical signals are interpreted. This paper explores how that flexibility might play out in rhythmicity in speech and music. There is much in common across the two domains, but there are also significant differences. Interpretations are explored that reconcile some of the differences, particularly with respect to how functional properties modify the rhythmicity of speech, within limits imposed by its structural constraints. Functional and structural differences mean that music is typically more rhythmic than speech, and that speech will be more rhythmic when the emotions are more strongly engaged, or intended to be engaged. The influence of rhythmicity on attention is acknowledged, and it is suggested that local increases in rhythmicity occur at times when attention is required to coordinate joint action, whether in talking or music-making. Evidence is presented which suggests that while these short phases of heightened rhythmical behaviour are crucial to the success of transitions in communicative interaction, their modality is immaterial: they all function to enhance precise temporal prediction and hence tightly coordinated joint action. PMID:25385776

Visual cortex responses reflect temporal structure of continuous quasi-rhythmic sensory stimulation.

PubMed

Keitel, Christian; Thut, Gregor; Gross, Joachim

2017-02-01

Neural processing of dynamic continuous visual input, and cognitive influences thereon, are frequently studied in paradigms employing strictly rhythmic stimulation. However, the temporal structure of natural stimuli is hardly ever fully rhythmic but possesses certain spectral bandwidths (e.g. lip movements in speech, gestures). Examining periodic brain responses elicited by strictly rhythmic stimulation might thus represent ideal, yet isolated cases. Here, we tested how the visual system reflects quasi-rhythmic stimulation with frequencies continuously varying within ranges of classical theta (4-7Hz), alpha (8-13Hz) and beta bands (14-20Hz) using EEG. Our findings substantiate a systematic and sustained neural phase-locking to stimulation in all three frequency ranges. Further, we found that allocation of spatial attention enhances EEG-stimulus locking to theta- and alpha-band stimulation. Our results bridge recent findings regarding phase locking ("entrainment") to quasi-rhythmic visual input and "frequency-tagging" experiments employing strictly rhythmic stimulation. We propose that sustained EEG-stimulus locking can be considered as a continuous neural signature of processing dynamic sensory input in early visual cortices. Accordingly, EEG-stimulus locking serves to trace the temporal evolution of rhythmic as well as quasi-rhythmic visual input and is subject to attentional bias. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Sex Differences in Rhythmic Preferences in the Budgerigar (Melopsittacus undulatus): A Comparative Study with Humans

PubMed Central

Hoeschele, Marisa; Bowling, Daniel L.

2016-01-01

A variety of parrot species have recently gained attention as members of a small group of non-human animals that are capable of coordinating their movements in time with a rhythmic pulse. This capacity is highly developed in humans, who display unparalleled sensitivity to musical beats and appear to prefer rhythmically organized sounds in their music. Do parrots also exhibit a preference for rhythmic over arrhythmic sounds? Here, we presented humans and budgerigars (Melopsittacus undulatus) – a small parrot species that have been shown to be able to align movements with a beat – with rhythmic and arrhythmic sound patterns in an acoustic place preference paradigm. Both species were allowed to explore an environment for 5 min. We quantified how much time they spent in proximity to rhythmic vs. arrhythmic stimuli. The results show that humans spent more time with rhythmic stimuli, and also preferred rhythmic stimuli when directly asked in a post-test survey. Budgerigars did not show any such overall preferences. However, further examination of the budgerigar results showed an effect of sex, such that male budgerigars spent more time with arrthymic stimuli, and female budgerigars spent more time with rhythmic stimuli. Our results support the idea that rhythmic information is interesting to budgerigars. We suggest that future investigations into the temporal characteristics of naturalistic social behaviors in budgerigars, such as courtship vocalizations and head-bobbing displays, may help explain the sex difference we observed. PMID:27757099

Order restricted inference for oscillatory systems for detecting rhythmic signals

PubMed Central

Larriba, Yolanda; Rueda, Cristina; Fernández, Miguel A.; Peddada, Shyamal D.

2016-01-01

Motivation: Many biological processes, such as cell cycle, circadian clock, menstrual cycles, are governed by oscillatory systems consisting of numerous components that exhibit rhythmic patterns over time. It is not always easy to identify such rhythmic components. For example, it is a challenging problem to identify circadian genes in a given tissue using time-course gene expression data. There is a great potential for misclassifying non-rhythmic as rhythmic genes and vice versa. This has been a problem of considerable interest in recent years. In this article we develop a constrained inference based methodology called Order Restricted Inference for Oscillatory Systems (ORIOS) to detect rhythmic signals. Instead of using mathematical functions (e.g. sinusoidal) to describe shape of rhythmic signals, ORIOS uses mathematical inequalities. Consequently, it is robust and not limited by the biologist's choice of the mathematical model. We studied the performance of ORIOS using simulated as well as real data obtained from mouse liver, pituitary gland and data from NIH3T3, U2OS cell lines. Our results suggest that, for a broad collection of patterns of gene expression, ORIOS has substantially higher power to detect true rhythmic genes in comparison to some popular methods, while also declaring substantially fewer non-rhythmic genes as rhythmic. Availability and Implementation: A user friendly code implemented in R language can be downloaded from http://www.niehs.nih.gov/research/atniehs/labs/bb/staff/peddada/index.cfm. Contact: peddada@niehs.nih.gov PMID:27596593

Differential effects of rhythmic auditory stimulation and neurodevelopmental treatment/Bobath on gait patterns in adults with cerebral palsy: a randomized controlled trial.

PubMed

Kim, Soo Ji; Kwak, Eunmi E; Park, Eun Sook; Cho, Sung-Rae

2012-10-01

To investigate the effects of rhythmic auditory stimulation (RAS) on gait patterns in comparison with changes after neurodevelopmental treatment (NDT/Bobath) in adults with cerebral palsy. A repeated-measures analysis between the pretreatment and posttreatment tests and a comparison study between groups. Human gait analysis laboratory. Twenty-eight cerebral palsy patients with bilateral spasticity participated in this study. The subjects were randomly allocated to either neurodevelopmental treatment (n = 13) or rhythmic auditory stimulation (n = 15). Gait training with rhythmic auditory stimulation or neurodevelopmental treatment was performed three sessions per week for three weeks. Temporal and kinematic data were analysed before and after the intervention. Rhythmic auditory stimulation was provided using a combination of a metronome beat set to the individual's cadence and rhythmic cueing from a live keyboard, while neurodevelopmental treatment was implemented following the traditional method. Temporal data, kinematic parameters and gait deviation index as a measure of overall gait pathology were assessed. Temporal gait measures revealed that rhythmic auditory stimulation significantly increased cadence, walking velocity, stride length, and step length (P < 0.05). Kinematic data demonstrated that anterior tilt of the pelvis and hip flexion during a gait cycle was significantly ameliorated after rhythmic auditory stimulation (P < 0.05). Gait deviation index also showed modest improvement in cerebral palsy patients treated with rhythmic auditory stimulation (P < 0.05). However, neurodevelopmental treatment showed that internal and external rotations of hip joints were significantly improved, whereas rhythmic auditory stimulation showed aggravated maximal internal rotation in the transverse plane (P < 0.05). Gait training with rhythmic auditory stimulation or neurodevelopmental treatment elicited differential effects on gait patterns in adults with cerebral palsy.

Comparison of rhythmic masticatory muscle activity during non-rapid eye movement sleep in guinea pigs and humans.

PubMed

Kato, Takafumi; Toyota, Risa; Haraki, Shingo; Yano, Hiroyuki; Higashiyama, Makoto; Ueno, Yoshio; Yano, Hiroshi; Sato, Fumihiko; Yatani, Hirofumi; Yoshida, Atsushi

2017-09-27

Rhythmic masticatory muscle activity can be a normal variant of oromotor activity, which can be exaggerated in patients with sleep bruxism. However, few studies have tested the possibility in naturally sleeping animals to study the neurophysiological mechanisms of rhythmic masticatory muscle activity. This study aimed to investigate the similarity of cortical, cardiac and electromyographic manifestations of rhythmic masticatory muscle activity occurring during non-rapid eye movement sleep between guinea pigs and human subjects. Polysomnographic recordings were made in 30 freely moving guinea pigs and in eight healthy human subjects. Burst cycle length, duration and activity of rhythmic masticatory muscle activity were compared with those for chewing. The time between R-waves in the electrocardiogram (RR interval) and electroencephalogram power spectrum were calculated to assess time-course changes in cardiac and cortical activities in relation to rhythmic masticatory muscle activity. In animals, in comparison with chewing, rhythmic masticatory muscle activity had a lower burst activity, longer burst duration and longer cycle length (P < 0.05), and greater variabilities were observed (P < 0.05). Rhythmic masticatory muscle activity occurring during non-rapid eye movement sleep [median (interquartile range): 5.2 (2.6-8.9) times per h] was preceded by a transient decrease in RR intervals, and was accompanied by a transient decrease in delta elelctroencephalogram power. In humans, masseter bursts of rhythmic masticatory muscle activity were characterized by a lower activity, longer duration and longer cycle length than those of chewing (P < 0.05). Rhythmic masticatory muscle activity during non-rapid eye movement sleep [1.4 (1.18-2.11) times per h] was preceded by a transient decrease in RR intervals and an increase in cortical activity. Rhythmic masticatory muscle activity in animals had common physiological components representing transient arousal-related rhythmic jaw motor activation in comparison to human subjects. © 2017 European Sleep Research Society.

Rhythmic Trafficking of TRPV2 in the Suprachiasmatic Nucleus is Regulated by Prokineticin 2 Signaling.

PubMed

Burton, Katherine J; Li, Xiaohan; Li, Jia-Da; Hu, Wang-Ping; Zhou, Qun-Yong

2015-04-01

The mammalian circadian clock is composed of single-cell oscillators. Neurochemical and electrical signaling among these oscillators is important for the normal expression of circadian rhythms. Prokineticin 2 (PK2), encoding a cysteine-rich secreted protein, has been shown to be a critical signaling molecule for the regulation of circadian rhythms. PK2 expression in the suprachiasmatic nucleus (SCN) is highly rhythmic, peaking during the day and being essentially absent during the night. Mice with disrupted PK2 gene or its receptor PKR2 display greatly reduced rhythmicity of broad circadian parameters such as locomotor activity, body temperature and sleep/wake patterns. PK2 has been shown to increase the firing rate of SCN neurons, with unknown molecular mechanisms. Here we report that TRPV2, an ion channel belonging to the family of TRP, is co-expressed with PKR2 in the SCN neurons. Further, TRPV2 protein, but not TRPV2 mRNA, was shown to oscillate in the SCN in a PK2-dependent manner. Functional studies revealed that TRPV2 enhanced signaling of PKR2 in calcium mobilization or ion current conductance, likely via the increased trafficking of TRPV2 to the cell surface. Taken together, these results indicate that TRPV2 is likely part of the downstream signaling of PK2 in the regulation of the circadian rhythms.

Rhythmic Trafficking of TRPV2 in the Suprachiasmatic Nucleus is Regulated by Prokineticin 2 Signaling

PubMed Central

Burton, Katherine J.; Li, Xiaohan; Li, Jia-Da; Hu, Wang-Ping

2015-01-01

The mammalian circadian clock is composed of single-cell oscillators. Neurochemical and electrical signaling among these oscillators is important for the normal expression of circadian rhythms. Prokineticin 2 (PK2), encoding a cysteine-rich secreted protein, has been shown to be a critical signaling molecule for the regulation of circadian rhythms. PK2 expression in the suprachiasmatic nucleus (SCN) is highly rhythmic, peaking during the day and being essentially absent during the night. Mice with disrupted PK2 gene or its receptor PKR2 display greatly reduced rhythmicity of broad circadian parameters such as locomotor activity, body temperature and sleep/wake patterns. PK2 has been shown to increase the firing rate of SCN neurons, with unknown molecular mechanisms. Here we report that TRPV2, an ion channel belonging to the family of TRP, is co-expressed with PKR2 in the SCN neurons. Further, TRPV2 protein, but not TRPV2 mRNA, was shown to oscillate in the SCN in a PK2-dependent manner. Functional studies revealed that TRPV2 enhanced signaling of PKR2 in calcium mobilization or ion current conductance, likely via the increased trafficking of TRPV2 to the cell surface. Taken together, these results indicate that TRPV2 is likely part of the downstream signaling of PK2 in the regulation of the circadian rhythms. PMID:27103928

Influence of circadian rhythms on the temporal features of motor imagery for older adult inpatients.

PubMed

Rulleau, Thomas; Mauvieux, Benoit; Toussaint, Lucette

2015-07-01

To examine the circadian modulation on motor imagery quality for older adult inpatients to determine the best time of day to use motor imagery in rehabilitation activities. Time series posttest only. Inpatient rehabilitation center. Participants included older adult inpatients (N=34) who were hospitalized for diverse geriatric or neurogeriatric reasons. They were able to sit without assistance, manipulate objects, and walk 10m in <30 seconds without technical help or with a walking stick. None. The executed and imagined durations of writing and walking movements were recorded 7 times a day (9:15 am-4:45 pm), at times compatible with the hours of rehabilitation activities. Motor imagery quality was evaluated by computing the isochrony index (ie, absolute difference between the average duration of executed and imagined actions) for each trial and each inpatient. The cosinor method was used to analyze the time series for circadian rhythmicity. Imagined movements duration and isochrony index exhibited circadian modulations, whereas no such rhythmic changes appeared for executed movements. Motor imagery quality was better late in the morning, at approximately 10:18 am and 12:10 pm for writing and walking, respectively. Cognitive and sensorimotor aspects of motor behaviors differed among the older adults. The temporal features of motor imagery showed a clear circadian variation. From a practical perspective, this study offers information on an effective schedule for motor imagery in rehabilitation activities with older adult inpatients. Copyright © 2015 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Situational influences on rhythmicity in speech, music, and their interaction.

PubMed

Hawkins, Sarah

2014-12-19

Brain processes underlying the production and perception of rhythm indicate considerable flexibility in how physical signals are interpreted. This paper explores how that flexibility might play out in rhythmicity in speech and music. There is much in common across the two domains, but there are also significant differences. Interpretations are explored that reconcile some of the differences, particularly with respect to how functional properties modify the rhythmicity of speech, within limits imposed by its structural constraints. Functional and structural differences mean that music is typically more rhythmic than speech, and that speech will be more rhythmic when the emotions are more strongly engaged, or intended to be engaged. The influence of rhythmicity on attention is acknowledged, and it is suggested that local increases in rhythmicity occur at times when attention is required to coordinate joint action, whether in talking or music-making. Evidence is presented which suggests that while these short phases of heightened rhythmical behaviour are crucial to the success of transitions in communicative interaction, their modality is immaterial: they all function to enhance precise temporal prediction and hence tightly coordinated joint action. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

Rhythmic engagement with music in infancy

PubMed Central

Zentner, Marcel; Eerola, Tuomas

2010-01-01

Humans have a unique ability to coordinate their motor movements to an external auditory stimulus, as in music-induced foot tapping or dancing. This behavior currently engages the attention of scholars across a number of disciplines. However, very little is known about its earliest manifestations. The aim of the current research was to examine whether preverbal infants engage in rhythmic behavior to music. To this end, we carried out two experiments in which we tested 120 infants (aged 5–24 months). Infants were exposed to various excerpts of musical and rhythmic stimuli, including isochronous drumbeats. Control stimuli consisted of adult- and infant-directed speech. Infants’ rhythmic movements were assessed by multiple methods involving manual coding from video excerpts and innovative 3D motion-capture technology. The results show that (i) infants engage in significantly more rhythmic movement to music and other rhythmically regular sounds than to speech; (ii) infants exhibit tempo flexibility to some extent (e.g., faster auditory tempo is associated with faster movement tempo); and (iii) the degree of rhythmic coordination with music is positively related to displays of positive affect. The findings are suggestive of a predisposition for rhythmic movement in response to music and other metrically regular sounds. PMID:20231438

Rhythmic engagement with music in infancy.

PubMed

Zentner, Marcel; Eerola, Tuomas

2010-03-30

Humans have a unique ability to coordinate their motor movements to an external auditory stimulus, as in music-induced foot tapping or dancing. This behavior currently engages the attention of scholars across a number of disciplines. However, very little is known about its earliest manifestations. The aim of the current research was to examine whether preverbal infants engage in rhythmic behavior to music. To this end, we carried out two experiments in which we tested 120 infants (aged 5-24 months). Infants were exposed to various excerpts of musical and rhythmic stimuli, including isochronous drumbeats. Control stimuli consisted of adult- and infant-directed speech. Infants' rhythmic movements were assessed by multiple methods involving manual coding from video excerpts and innovative 3D motion-capture technology. The results show that (i) infants engage in significantly more rhythmic movement to music and other rhythmically regular sounds than to speech; (ii) infants exhibit tempo flexibility to some extent (e.g., faster auditory tempo is associated with faster movement tempo); and (iii) the degree of rhythmic coordination with music is positively related to displays of positive affect. The findings are suggestive of a predisposition for rhythmic movement in response to music and other metrically regular sounds.

Alterations in diurnal rhythmicity in patients treated for nonfunctioning pituitary macroadenoma: a controlled study and literature review.

PubMed

Joustra, S D; Thijs, R D; van den Berg, R; van Dijk, M; Pereira, A M; Lammers, G J; van Someren, E J W; Romijn, J A; Biermasz, N R

2014-08-01

Patients treated for nonfunctioning pituitary macroadenomas (NFMAs) have fatigue and alterations in sleep characteristics and sleep-wake rhythmicity frequently. As NFMAs often compress the optic chiasm, these complaints might be related to dysfunction of the adjacent suprachiasmatic nucleus (SCN). We aimed to explore whether indirect indices of SCN functioning are altered in the long term after surgery for NFMAs. We studied 17 NFMA patients in long-term remission after transsphenoidal surgery, receiving adequate and stable hormone replacement for hypopituitarism, and 17 control subjects matched for age, gender, and BMI. Indirect indices of SCN function were assessed from 24-h ambulatory recordings of skin and core body temperatures, blood pressure, and salivary melatonin levels. Altered melatonin secretion was defined as an absence of evening rise, considerable irregularity, or daytime values >3 pg/ml. We additionally studied eight patients treated for craniopharyngioma. Distal-proximal skin temperature gradient did not differ between NFMAs and control subjects, but proximal skin temperature was decreased during daytime (P=0.006). Core body temperature and non-dipping of blood pressure did not differ, whereas melatonin secretion was often altered in NFMAs (OR 5.3, 95% CI 0.9-30.6). One or more abnormal parameters (≥2.0 SDS of control subjects) were observed during nighttime in 12 NFMA patients and during daytime in seven NFMA patients. Similar patterns were observed in craniopharyngioma patients. Heterogeneous patterns of altered diurnal rhythmicity in skin temperature and melatonin secretion parameters were observed in the majority of patients treated for NFMAs. On a group level, both NFMA and craniopharyngioma patients showed a lower daytime proximal skin temperature than control subjects, but other group averages were not significantly different. The observations suggest altered function of central (or peripheral) clock machinery, possibly by disturbed entrainment or damage of the hypothalamic SCN by the suprasellar macroadenoma or its treatment. © 2014 European Society of Endocrinology.

Changes in neuromagnetic beta-band oscillation after music-supported stroke rehabilitation.

PubMed

Fujioka, Takako; Ween, Jon Erik; Jamali, Shahab; Stuss, Donald T; Ross, Bernhard

2012-04-01

Precise timing of sound is crucial in music for both performing and listening. Indeed, listening to rhythmic sound sequences activates not only the auditory system but also the sensorimotor system. Previously, we showed the significance of neural beta-band oscillations (15-30 Hz) for the timing processing that involves such auditory-motor coordination. Thus, we hypothesized that motor rehabilitation training incorporating music playing will stimulate and enhance auditory-motor interaction in stroke patients. We examined three chronic patients who received Music-Supported Therapy following the protocols practiced by Schneider. Neuromagnetic beta-band activity was remarkably alike during passive listening to a metronome and during finger tapping, with or without the metronome, for either the paretic or nonparetic hand, suggesting a shared mechanism of the beta modulation. In the listening task, the magnitude of the beta decrease after the tone onset was more pronounced at the posttraining time point and was accompanied by improved arm and hand skills. The present case data give insight into the neural underpinnings of rehabilitation with music making and rhythmic auditory stimulation. © 2012 New York Academy of Sciences.

Melodic multi-feature paradigm reveals auditory profiles in music-sound encoding.

PubMed

Tervaniemi, Mari; Huotilainen, Minna; Brattico, Elvira

2014-01-01

Musical expertise modulates preattentive neural sound discrimination. However, this evidence up to great extent originates from paradigms using very simple stimulation. Here we use a novel melody paradigm (revealing the auditory profile for six sound parameters in parallel) to compare memory-related mismatch negativity (MMN) and attention-related P3a responses recorded from non-musicians and Finnish Folk musicians. MMN emerged in both groups of participants for all sound changes (except for rhythmic changes in non-musicians). In Folk musicians, the MMN was enlarged for mistuned sounds when compared with non-musicians. This is taken to reflect their familiarity with pitch information which is in key position in Finnish folk music when compared with e.g., rhythmic information. The MMN was followed by P3a after timbre changes, rhythm changes, and melody transposition. The MMN and P3a topographies differentiated the groups for all sound changes. Thus, the melody paradigm offers a fast and cost-effective means for determining the auditory profile for music-sound encoding and also, importantly, for probing the effects of musical expertise on it.

Fluorescent tagging of rhythmically active respiratory neurons within the pre-Bötzinger complex of rat medullary slice preparations.

PubMed

Pagliardini, Silvia; Adachi, Tadafumi; Ren, Jun; Funk, Gregory D; Greer, John J

2005-03-09

Elucidation of the neuronal mechanisms underlying respiratory rhythmogenesis is a major focal point in respiratory physiology. An area of the ventrolateral medulla, the pre-Bötzinger complex (preBotC), is a critical site. Attention is now focused on understanding the cellular and network properties within the preBotC that underlie this critical function. The inability to clearly identify key "rhythm-generating" neurons within the heterogeneous population of preBotC neurons has been a significant limitation. Here we report an advancement allowing precise targeting of neurons expressing neurokinin-1 receptors (NK1Rs), which are hypothesized to be essential for respiratory rhythmogenesis. The internalization of tetramethylrhodamine conjugated substance P in rhythmically active medullary slice preparations provided clear visualization of NK1R-expressing neurons for subsequent whole-cell patch-clamp recordings. Among labeled neurons, 82% were inspiratory modulated, and 25% had pacemaker properties. We propose that this approach can be used to greatly expedite progress toward understanding the neuronal processes underlying the control of breathing.

Novel aspects of glucocorticoid actions.

PubMed

Uchoa, E T; Aguilera, G; Herman, J P; Fiedler, J L; Deak, T; de Sousa, M B C

2014-09-01

Normal hypothalamic-pituitary-adrenal (HPA) axis activity leading to the rhythmic and episodic release of adrenal glucocorticoids (GCs) is essential for body homeostasis and survival during stress. Acting through specific intracellular receptors in the brain and periphery, GCs regulate behaviour, as well as metabolic, cardiovascular, immune and neuroendocrine activities. By contrast to chronic elevated levels, circadian and acute stress-induced increases in GCs are necessary for hippocampal neuronal survival and memory acquisition and consolidation, as a result of the inhibition of apoptosis, the facilitation of glutamatergic neurotransmission and the formation of excitatory synapses, and the induction of immediate early genes and dendritic spine formation. In addition to metabolic actions leading to increased energy availability, GCs have profound effects on feeding behaviour, mainly via the modulation of orexigenic and anorixegenic neuropeptides. Evidence is also emerging that, in addition to the recognised immune suppressive actions of GCs by counteracting adrenergic pro-inflammatory actions, circadian elevations have priming effects in the immune system, potentiating acute defensive responses. In addition, negative-feedback by GCs involves multiple mechanisms leading to limited HPA axis activation and prevention of the deleterious effects of excessive GC production. Adequate GC secretion to meet body demands is tightly regulated by a complex neural circuitry controlling hypothalamic corticotrophin-releasing hormone (CRH) and vasopressin secretion, which are the main regulators of pituitary adrenocorticotrophic hormone (ACTH). Rapid feedback mechanisms, likely involving nongenomic actions of GCs, mediate the immediate inhibition of hypothalamic CRH and ACTH secretion, whereas intermediate and delayed mechanisms mediated by genomic actions involve the modulation of limbic circuitry and peripheral metabolic messengers. Consistent with their key adaptive roles, HPA axis components are evolutionarily conserved, being present in the earliest vertebrates. An understanding of these basic mechanisms may lead to novel approaches for the development of diagnostic and therapeutic tools for disorders related to stress and alterations of GC secretion. © 2014 British Society for Neuroendocrinology.

The Effects of Rhythmicity and Amplitude on Transfer of Motor Learning

PubMed Central

Ben-Tov, Mor; Levy-Tzedek, Shelly; Karniel, Amir

2012-01-01

We perform rhythmic and discrete arm movements on a daily basis, yet the motor control literature is not conclusive regarding the mechanisms controlling these movements; does a single mechanism generate both movement types, or are they controlled by separate mechanisms? A recent study reported partial asymmetric transfer of learning from discrete movements to rhythmic movements. Other studies have shown transfer of learning between large-amplitude to small-amplitude movements. The goal of this study is to explore which aspect is important for learning to be transferred from one type of movement to another: rhythmicity, amplitude or both. We propose two hypotheses: (1) Rhythmic and discrete movements are generated by different mechanisms; therefore we expect to see a partial or no transfer of learning between the two types of movements; (2) Within each movement type (rhythmic/discrete), there will be asymmetric transition of learning from larger movements to smaller ones. We used a learning-transfer paradigm, in which 70 participants performed flexion/extension movements with their forearm, and switched between types of movement, which differed in amplitude and/or rhythmicity. We found partial transfer of learning between discrete and rhythmic movements, and an asymmetric transfer of learning from larger movements to smaller movements (within the same type of movement). Our findings suggest that there are two different mechanisms underlying the generation of rhythmic and discrete arm movements, and that practicing on larger movements helps perform smaller movements; the latter finding might have implications for rehabilitation. PMID:23056549

The effects of rhythmicity and amplitude on transfer of motor learning.

PubMed

Ben-Tov, Mor; Levy-Tzedek, Shelly; Karniel, Amir

2012-01-01

We perform rhythmic and discrete arm movements on a daily basis, yet the motor control literature is not conclusive regarding the mechanisms controlling these movements; does a single mechanism generate both movement types, or are they controlled by separate mechanisms? A recent study reported partial asymmetric transfer of learning from discrete movements to rhythmic movements. Other studies have shown transfer of learning between large-amplitude to small-amplitude movements. The goal of this study is to explore which aspect is important for learning to be transferred from one type of movement to another: rhythmicity, amplitude or both. We propose two hypotheses: (1) Rhythmic and discrete movements are generated by different mechanisms; therefore we expect to see a partial or no transfer of learning between the two types of movements; (2) Within each movement type (rhythmic/discrete), there will be asymmetric transition of learning from larger movements to smaller ones. We used a learning-transfer paradigm, in which 70 participants performed flexion/extension movements with their forearm, and switched between types of movement, which differed in amplitude and/or rhythmicity. We found partial transfer of learning between discrete and rhythmic movements, and an asymmetric transfer of learning from larger movements to smaller movements (within the same type of movement). Our findings suggest that there are two different mechanisms underlying the generation of rhythmic and discrete arm movements, and that practicing on larger movements helps perform smaller movements; the latter finding might have implications for rehabilitation.

Persistence, period and precision of autonomous cellular oscillators from the zebrafish segmentation clock

PubMed Central

Webb, Alexis B; Lengyel, Iván M; Jörg, David J; Valentin, Guillaume; Jülicher, Frank; Morelli, Luis G; Oates, Andrew C

2016-01-01

In vertebrate development, the sequential and rhythmic segmentation of the body axis is regulated by a “segmentation clock”. This clock is comprised of a population of coordinated oscillating cells that together produce rhythmic gene expression patterns in the embryo. Whether individual cells autonomously maintain oscillations, or whether oscillations depend on signals from neighboring cells is unknown. Using a transgenic zebrafish reporter line for the cyclic transcription factor Her1, we recorded single tailbud cells in vitro. We demonstrate that individual cells can behave as autonomous cellular oscillators. We described the observed variability in cell behavior using a theory of generic oscillators with correlated noise. Single cells have longer periods and lower precision than the tissue, highlighting the role of collective processes in the segmentation clock. Our work reveals a population of cells from the zebrafish segmentation clock that behave as self-sustained, autonomous oscillators with distinctive noisy dynamics. DOI: http://dx.doi.org/10.7554/eLife.08438.001 PMID:26880542

Are non-human primates capable of rhythmic entrainment? Evidence for the gradual audiomotor evolution hypothesis.

PubMed

Merchant, Hugo; Honing, Henkjan

2013-01-01

We propose a decomposition of the neurocognitive mechanisms that might underlie interval-based timing and rhythmic entrainment. Next to reviewing the concepts central to the definition of rhythmic entrainment, we discuss recent studies that suggest rhythmic entrainment to be specific to humans and a selected group of bird species, but, surprisingly, is not obvious in non-human primates. On the basis of these studies we propose the gradual audiomotor evolution hypothesis that suggests that humans fully share interval-based timing with other primates, but only partially share the ability of rhythmic entrainment (or beat-based timing). This hypothesis accommodates the fact that non-human primates (i.e., macaques) performance is comparable to humans in single interval tasks (such as interval reproduction, categorization, and interception), but show differences in multiple interval tasks (such as rhythmic entrainment, synchronization, and continuation). Furthermore, it is in line with the observation that macaques can, apparently, synchronize in the visual domain, but show less sensitivity in the auditory domain. And finally, while macaques are sensitive to interval-based timing and rhythmic grouping, the absence of a strong coupling between the auditory and motor system of non-human primates might be the reason why macaques cannot rhythmically entrain in the way humans do.

Different corticospinal control between discrete and rhythmic movement of the ankle.

PubMed

Goto, Yumeno; Jono, Yasutomo; Hatanaka, Ryota; Nomura, Yoshifumi; Tani, Keisuke; Chujo, Yuta; Hiraoka, Koichi

2014-01-01

We investigated differences in corticospinal and spinal control between discrete and rhythmic ankle movements. Motor evoked potentials (MEPs) in the tibialis anterior and soleus muscles and soleus H-reflex were elicited in the middle of the plantar flexion phase during discrete ankle movement or in the initial or later cycles of rhythmic ankle movement. The H-reflex was evoked at an intensity eliciting a small M-wave and MEPs were elicited at an intensity of 1.2 times the motor threshold of the soleus MEPs. Only trials in which background EMG level, ankle angle, and ankle velocity were similar among the movement conditions were included for data analysis. In addition, only trials with a similar M-wave were included for data analysis in the experiment evoking H-reflexes. Results showed that H reflex and MEP amplitudes in the soleus muscle during discrete movement were not significantly different from those during rhythmic movement. MEP amplitude in the tibialis anterior muscle during the later cycles of rhythmic movement was significantly larger than that during the initial cycle of the rhythmic movement or during discrete movement. Higher corticospinal excitability in the tibialis anterior muscle during the later cycles of rhythmic movement may reflect changes in corticospinal control from the initial cycle to the later cycles of rhythmic movement.

Different corticospinal control between discrete and rhythmic movement of the ankle

PubMed Central

Goto, Yumeno; Jono, Yasutomo; Hatanaka, Ryota; Nomura, Yoshifumi; Tani, Keisuke; Chujo, Yuta; Hiraoka, Koichi

2014-01-01

We investigated differences in corticospinal and spinal control between discrete and rhythmic ankle movements. Motor evoked potentials (MEPs) in the tibialis anterior and soleus muscles and soleus H-reflex were elicited in the middle of the plantar flexion phase during discrete ankle movement or in the initial or later cycles of rhythmic ankle movement. The H-reflex was evoked at an intensity eliciting a small M-wave and MEPs were elicited at an intensity of 1.2 times the motor threshold of the soleus MEPs. Only trials in which background EMG level, ankle angle, and ankle velocity were similar among the movement conditions were included for data analysis. In addition, only trials with a similar M-wave were included for data analysis in the experiment evoking H-reflexes. Results showed that H reflex and MEP amplitudes in the soleus muscle during discrete movement were not significantly different from those during rhythmic movement. MEP amplitude in the tibialis anterior muscle during the later cycles of rhythmic movement was significantly larger than that during the initial cycle of the rhythmic movement or during discrete movement. Higher corticospinal excitability in the tibialis anterior muscle during the later cycles of rhythmic movement may reflect changes in corticospinal control from the initial cycle to the later cycles of rhythmic movement. PMID:25126066

Low-Frequency Components in Rat Pial Arteriolar Rhythmic Diameter Changes.

PubMed

Lapi, Dominga; Mastantuono, Teresa; Di Maro, Martina; Varanini, Maurizio; Colantuoni, Antonio

2017-01-01

This study aimed to analyze the frequency components present in spontaneous rhythmic diameter changes in rat pial arterioles. Pial microcirculation was visualized by fluorescence microscopy. Rhythmic luminal variations were evaluated via computer-assisted methods. Spectral analysis was carried out on 30-min recordings under baseline conditions and after administration of acetylcholine (Ach), papaverine (Pap), Nω-nitro-L-arginine (L-NNA) prior to Ach, indomethacin (INDO), INDO prior to Ach, charybdotoxin and apamin, and charybdotoxin and apamin prior to Ach. Under baseline conditions all arteriolar orders showed 3 frequency components in the ranges of 0.0095-0.02, 0.02-0.06, and 0.06-0.2 Hz, another 2 in the ranges of 0.2-2.0 and 2.5-4.5 Hz, and another ultra-low-frequency component in the range of 0.001-0.0095 Hz. Ach caused a significant increase in the spectral density of the frequency components in the range of 0.001-0.2 Hz. Pap was able to slightly increase spectral density in the ranges of 0.001-0.0095 and 0.0095-0.02 Hz. L-NNA mainly attenuated arteriolar responses to Ach. INDO prior to Ach did not affect the endothelial response to Ach. Charybdotoxin and apamin, suggested as endothelium-derived hyperpolarizing factor inhibitors, reduced spectral density in the range of 0.001-0.0095 Hz before and after Ach administration. In conclusion, regulation of the blood flow distribution is due to several mechanisms, one of which is affected by charibdotoxin and apamin, modulating the vascular tone. © 2017 S. Karger AG, Basel.

Synchronicity and Rhythmicity of Purkinje Cell Firing during Generalized Spike-and-Wave Discharges in a Natural Mouse Model of Absence Epilepsy

PubMed Central

Kros, Lieke; Lindeman, Sander; Eelkman Rooda, Oscar H. J.; Murugesan, Pavithra; Bina, Lorenzo; Bosman, Laurens W. J.; De Zeeuw, Chris I.; Hoebeek, Freek E.

2017-01-01

Absence epilepsy is characterized by the occurrence of generalized spike and wave discharges (GSWDs) in electrocorticographical (ECoG) recordings representing oscillatory activity in thalamocortical networks. The oscillatory nature of GSWDs has been shown to be reflected in the simple spike activity of cerebellar Purkinje cells and in the activity of their target neurons in the cerebellar nuclei, but it is unclear to what extent complex spike activity is implicated in generalized epilepsy. Purkinje cell complex spike firing is elicited by climbing fiber activation and reflects action potential firing in the inferior olive. Here, we investigated to what extent modulation of complex spike firing is reflected in the temporal patterns of seizures. Extracellular single-unit recordings in awake, head-restrained homozygous tottering mice, which suffer from a mutation in the voltage-gated CaV2.1 calcium channel, revealed that a substantial proportion of Purkinje cells (26%) showed increased complex spike activity and rhythmicity during GSWDs. Moreover, Purkinje cells, recorded either electrophysiologically or by using Ca2+-imaging, showed a significant increase in complex spike synchronicity for both adjacent and remote Purkinje cells during ictal events. These seizure-related changes in firing frequency, rhythmicity and synchronicity were most prominent in the lateral cerebellum, a region known to receive cerebral input via the inferior olive. These data indicate profound and widespread changes in olivary firing that are most likely induced by seizure-related activity changes in the thalamocortical network, thereby highlighting the possibility that olivary neurons can compensate for pathological brain-state changes by dampening oscillations. PMID:29163057

Jazz drummers recruit language-specific areas for the processing of rhythmic structure.

PubMed

Herdener, Marcus; Humbel, Thierry; Esposito, Fabrizio; Habermeyer, Benedikt; Cattapan-Ludewig, Katja; Seifritz, Erich

2014-03-01

Rhythm is a central characteristic of music and speech, the most important domains of human communication using acoustic signals. Here, we investigated how rhythmical patterns in music are processed in the human brain, and, in addition, evaluated the impact of musical training on rhythm processing. Using fMRI, we found that deviations from a rule-based regular rhythmic structure activated the left planum temporale together with Broca's area and its right-hemispheric homolog across subjects, that is, a network also crucially involved in the processing of harmonic structure in music and the syntactic analysis of language. Comparing the BOLD responses to rhythmic variations between professional jazz drummers and musical laypersons, we found that only highly trained rhythmic experts show additional activity in left-hemispheric supramarginal gyrus, a higher-order region involved in processing of linguistic syntax. This suggests an additional functional recruitment of brain areas usually dedicated to complex linguistic syntax processing for the analysis of rhythmical patterns only in professional jazz drummers, who are especially trained to use rhythmical cues for communication.

Diel rhythmicity of lipid-body formation in a coral- Symbiodinium endosymbiosis

NASA Astrophysics Data System (ADS)

Chen, W.-N. U.; Kang, H.-J.; Weis, V. M.; Mayfield, A. B.; Jiang, P.-L.; Fang, L.-S.; Chen, C.-S.

2012-06-01

The biogenesis of intracellular lipid bodies (LBs) is dependent upon the symbiotic status between host corals and their intracellular dinoflagellates (genus Symbiodinium), though aside from this observation, little is known about LB behavior and function in this globally important endosymbiosis. The present research aimed to understand how LB formation and density are regulated in the gastrodermal tissue layer of the reef-building coral Euphyllia glabrescens. After tissue fixation and labeling with osmium tetroxide, LB distribution and density were quantified by imaging analysis of serial cryo-sections, and a diel rhythmicity was observed; the onset of solar irradiation at sunrise initiated an increase in LB density and size, which peaked at sunset. Both LB density and size then decreased to basal levels at night. On a seasonal timescale, LB density was found to be significantly positively correlated with seasonal irradiation, with highest densities found in the summer and lowest in the fall. In terms of LB lipid composition, only the concentration of wax esters, and not triglycerides or sterols, exhibited diel variability. This suggests that the metabolism and accumulation of lipids in LBs is at least partially light dependent. Ultrastructural examinations revealed that the LB wax ester concentration correlated with the number of electron-transparent inclusion bodies. Finally, there was a directional redistribution of the LB population across the gastroderm over the diel cycle. Collectively, these data reveal that coral gastrodermal LBs vary in composition and intracellular location over diel cycles, features which may shed light on their function within this coral-dinoflagellate mutualism.

Using an Artificial Neural Bypass to Restore Cortical Control of Rhythmic Movements in a Human with Quadriplegia

NASA Astrophysics Data System (ADS)

Sharma, Gaurav; Friedenberg, David A.; Annetta, Nicholas; Glenn, Bradley; Bockbrader, Marcie; Majstorovic, Connor; Domas, Stephanie; Mysiw, W. Jerry; Rezai, Ali; Bouton, Chad

2016-09-01

Neuroprosthetic technology has been used to restore cortical control of discrete (non-rhythmic) hand movements in a paralyzed person. However, cortical control of rhythmic movements which originate in the brain but are coordinated by Central Pattern Generator (CPG) neural networks in the spinal cord has not been demonstrated previously. Here we show a demonstration of an artificial neural bypass technology that decodes cortical activity and emulates spinal cord CPG function allowing volitional rhythmic hand movement. The technology uses a combination of signals recorded from the brain, machine-learning algorithms to decode the signals, a numerical model of CPG network, and a neuromuscular electrical stimulation system to evoke rhythmic movements. Using the neural bypass, a quadriplegic participant was able to initiate, sustain, and switch between rhythmic and discrete finger movements, using his thoughts alone. These results have implications in advancing neuroprosthetic technology to restore complex movements in people living with paralysis.

Continuous 24-hour intravenous infusion of recombinant human growth hormone (GH)-releasing hormone-(1-44)-amide augments pulsatile, entropic, and daily rhythmic GH secretion in postmenopausal women equally in the estrogen-withdrawn and estrogen-supplemented states.

PubMed

Evans, W S; Anderson, S M; Hull, L T; Azimi, P P; Bowers, C Y; Veldhuis, J D

2001-02-01

How estrogen amplifies GH secretion in the human is not known. The present study tests the clinical hypothesis that estradiol modulates the stimulatory actions of a primary GH feedforward signal, GHRH. To this end, we investigated the ability of short-term (7- to 12-day) supplementation with oral estradiol vs. placebo to modulate basal, pulsatile, entropic, and 24-h rhythmic GH secretion driven by a continuous iv infusion of recombinant human GHRH-(1--44)-amide vs. saline in nine healthy postmenopausal women. Volunteers underwent concurrent blood sampling every 10 min for 24 h on four occasions in a prospectively randomized, single blind, within-subject cross-over design (placebo/saline, placebo/GHRH, estradiol/saline, estradiol/GHRH). Intensively sampled serum GH concentrations were quantitated by ultrasensitive chemiluminescence assay. Basal, pulsatile, entropic (feedback-sensitive), and 24-h rhythmic modes of GH secretion were appraised by deconvolution analysis, the approximate entropy (ApEn) statistic, and cosine regression, respectively. ANOVA revealed that continuous iv infusion of GHRH in the estrogen-withdrawn (control) milieu 1) amplified individual basal (P = 0.00011) and pulsatile (P < 10(-13)) GH secretion rates by 12- and 11-fold, respectively; 2) augmented GH secretory burst mass and amplitude each by 10-fold (P < 10(-11)), without altering GH secretory burst frequency, duration, or half-life; 3) increased the disorderliness (ApEn) of GH release patterns (P = 0.0000002); 4) elevated the mesor (cosine mean) and amplitude of the 24-h rhythm in serum GH concentrations by nearly 30-fold (both P < 10(-12)); 5) induced a phase advance in the clocktime of the GH zenith (P = 0.021); and 6) evoked a new 24-h rhythm in GH secretory burst mass with a maximum at 0018 h GH (P < 10(-3)), while damping the mesor of the 24-h rhythm in GH interpulse intervals (P < 0.025). Estradiol supplementation alone 1) increased the 24-h mean and integrated serum GH concentration (P = 0.047); 2) augmented GH secretory burst mass (P: = 0.025) without influencing pulse frequency, duration, half-life, or basal secretion; 2) stimulated more irregular patterns of GH release (higher ApEn; P = 0.012); and 3) elevated the 24-h rhythmic GH mesor (P = 0.0005), but not amplitude. Notably, combined stimulation of the GH axis with GHRH-(1--44)-amide and estradiol exerted no further effect beyond that evoked by GHRH alone, except for normalizing the acrophase of 24-h GH rhythmic release and elevating the postinfusion plasma insulin-like growth factor I concentration (P = 0.016). Unexpectedly, the two GHRH-infused serum GH concentration profiles monitored after placebo and estradiol pretreatment showed strongly nonrandom synchrony with a 20- to 30-min lag (P < 0.001). In summary, the present clinical investigations unmask a 3-fold (pulsatile, entropic, and daily rhythmic) similitude between the neuroregulatory actions of estradiol and GHRH in healthy postmenopausal women. However, GHRH infusion was multifold more effectual than estradiol, and only GHRH elevated nonpulsatile (basal) GH secretion, shifted the GH acrophase, and synchronized GH profiles. Given the nonadditive nature of the joint effects of estradiol and GHRH on pulsatile and entropic GH release, we hypothesize that estrogen amplifies GH secretion in part by enhancing endogenous GHRH release or actions. In addition, the distinctive ability of GHRH (but not estradiol) to increase basal (nonpulsatile) GH secretion, shift the GH acrophase and synchronize GH output patterns identifies certain divergent hypothalamo-pituitary actions of these two major GH secretagogues.

Neural correlates of cerebellar-mediated timing during finger tapping in children with fetal alcohol spectrum disorders.

PubMed

du Plessis, Lindie; Jacobson, Sandra W; Molteno, Christopher D; Robertson, Frances C; Peterson, Bradley S; Jacobson, Joseph L; Meintjes, Ernesta M

2015-01-01

Classical eyeblink conditioning (EBC), an elemental form of learning, is among the most sensitive indicators of fetal alcohol spectrum disorders. The cerebellum plays a key role in maintaining timed movements with millisecond accuracy required for EBC. Functional MRI (fMRI) was used to identify cerebellar regions that mediate timing in healthy controls and the degree to which these areas are also recruited in children with prenatal alcohol exposure. fMRI data were acquired during an auditory rhythmic/non-rhythmic finger tapping task. We present results for 17 children with fetal alcohol syndrome (FAS) or partial FAS, 17 heavily exposed (HE) nonsyndromal children and 16 non- or minimally exposed controls. Controls showed greater cerebellar blood oxygen level dependent (BOLD) activation in right crus I, vermis IV-VI, and right lobule VI during rhythmic than non-rhythmic finger tapping. The alcohol-exposed children showed smaller activation increases during rhythmic tapping in right crus I than the control children and the most severely affected children with either FAS or PFAS showed smaller increases in vermis IV-V. Higher levels of maternal alcohol intake per occasion during pregnancy were associated with reduced activation increases during rhythmic tapping in all four regions associated with rhythmic tapping in controls. The four cerebellar areas activated by the controls more during rhythmic than non-rhythmic tapping have been implicated in the production of timed responses in several previous studies. These data provide evidence linking binge-like drinking during pregnancy to poorer function in cerebellar regions involved in timing and somatosensory processing needed for complex tasks requiring precise timing.

Rhythmic speech and stuttering reduction in a syllable-timed language.

PubMed

Law, Thomas; Packman, Ann; Onslow, Mark; To, Carol K-S; Tong, Michael C-F; Lee, Kathy Y-S

2018-06-06

Speaking rhythmically, also known as syllable-timed speech (STS), has been known for centuries to be a fluency-inducing condition for people who stutter. Cantonese is a tonal syllable-timed language and it has been shown that, of all languages, Cantonese is the most rhythmic (Mok, 2009). However, it is not known if STS reduces stuttering in Cantonese as it does in English. This is the first study to investigate the effects of STS on stuttering in a syllable-timed language. Nineteen native Cantonese-speaking adults who stutter were engaged in conversational tasks in Cantonese under two conditions: one in their usual speaking style and one using STS. The speakers' percentage syllables stuttered (%SS) and speech rhythmicity were rated. The rhythmicity ratings were used to estimate the extent to which speakers were using STS in the syllable-timed condition. Results revealed a statistically significant reduction in %SS in the STS condition; however, this reduction was not as large as in previous studies in other languages and the amount of stuttering reduction varied across speakers. The rhythmicity ratings showed that some speakers were perceived to be speaking more rhythmically than others and that the perceived rhythmicity correlated positively with reductions in stuttering. The findings were unexpected, as it was anticipated that speakers of a highly rhythmic language such as Cantonese would find STS easy to use and that the consequent reductions in stuttering would be great, even greater perhaps than in a stress-timed language such as English. The theoretical and clinical implications of the findings are discussed.

Identification of a rhythmic firing pattern in the enteric nervous system that generates rhythmic electrical activity in smooth muscle.

PubMed

Spencer, Nick J; Hibberd, Timothy J; Travis, Lee; Wiklendt, Lukasz; Costa, Marcello; Hu, Hongzhen; Brookes, Simon J; Wattchow, David A; Dinning, Phil G; Keating, Damien J; Sorensen, Julian

2018-05-28

The enteric nervous system (ENS) contains millions of neurons essential for organization of motor behaviour of the intestine. It is well established the large intestine requires ENS activity to drive propulsive motor behaviours. However, the firing pattern of the ENS underlying propagating neurogenic contractions of the large intestine remains unknown. To identify this, we used high resolution neuronal imaging with electrophysiology from neighbouring smooth muscle. Myoelectric activity underlying propagating neurogenic contractions along murine large intestine (referred to as colonic migrating motor complexes, CMMCs) consisted of prolonged bursts of rhythmic depolarizations at a frequency of ∼2 Hz. Temporal coordination of this activity in the smooth muscle over large spatial fields (∼7mm, longitudinally) was dependent on the ENS. During quiescent periods between neurogenic contractions, recordings from large populations of enteric neurons, in mice of either sex, revealed ongoing activity. The onset of neurogenic contractions was characterized by the emergence of temporally synchronized activity across large populations of excitatory and inhibitory neurons. This neuronal firing pattern was rhythmic and temporally synchronized across large numbers of ganglia at ∼2 Hz. ENS activation preceded smooth muscle depolarization, indicating rhythmic depolarizations in smooth muscle were controlled by firing of enteric neurons. The cyclical emergence of temporally coordinated firing of large populations of enteric neurons represents a unique neural motor pattern outside the central nervous system. This is the first direct observation of rhythmic firing in the ENS underlying rhythmic electrical depolarizations in smooth muscle. The pattern of neuronal activity we identified underlies the generation of CMMCs. SIGNIFICANCE STATEMENT How the enteric nervous system (ENS) generates neurogenic contractions of smooth muscle in the gastrointestinal (GI) tract has been a long-standing mystery in vertebrates. It is well known that myogenic pacemaker cells exist in the GI-tract (called Interstitial cells of Cajal, ICC) that generate rhythmic myogenic contractions. However, the mechanisms underlying the generation of rhythmic neurogenic contractions of smooth muscle in the GI-tract remains unknown. We developed a high resolution neuronal imaging method with electrophysiology to address this issue. This technique revealed a novel pattern of rhythmic coordinated neuronal firing in the ENS that has never been identified. Rhythmic neuronal firing in the ENS was found to generate rhythmic neurogenic depolarizations in smooth muscle that underlie contraction of the GI-tract. Copyright © 2018 the authors.

Music Games: Potential Application and Considerations for Rhythmic Training

PubMed Central

Bégel, Valentin; Di Loreto, Ines; Seilles, Antoine; Dalla Bella, Simone

2017-01-01

Rhythmic skills are natural and widespread in the general population. The majority can track the beat of music and move along with it. These abilities are meaningful from a cognitive standpoint given their tight links with prominent motor and cognitive functions such as language and memory. When rhythmic skills are challenged by brain damage or neurodevelopmental disorders, remediation strategies based on rhythm can be considered. For example, rhythmic training can be used to improve motor performance (e.g., gait) as well as cognitive and language skills. Here, we review the games readily available in the market and assess whether they are well-suited for rhythmic training. Games that train rhythm skills may serve as useful tools for retraining motor and cognitive functions in patients with motor or neurodevelopmental disorders (e.g., Parkinson’s disease, dyslexia, or ADHD). Our criteria were the peripheral used to capture and record the response, the type of response and the output measure. None of the existing games provides sufficient temporal precision in stimulus presentation and/or data acquisition. In addition, games do not train selectively rhythmic skills. Hence, the available music games, in their present form, are not satisfying for training rhythmic skills. Yet, some features such as the device used, the interface or the game scenario provide good indications for devising efficient training protocols. Guidelines are provided for devising serious music games targeting rhythmic training in the future. PMID:28611610

Music Games: Potential Application and Considerations for Rhythmic Training.

PubMed

Bégel, Valentin; Di Loreto, Ines; Seilles, Antoine; Dalla Bella, Simone

2017-01-01

Rhythmic skills are natural and widespread in the general population. The majority can track the beat of music and move along with it. These abilities are meaningful from a cognitive standpoint given their tight links with prominent motor and cognitive functions such as language and memory. When rhythmic skills are challenged by brain damage or neurodevelopmental disorders, remediation strategies based on rhythm can be considered. For example, rhythmic training can be used to improve motor performance (e.g., gait) as well as cognitive and language skills. Here, we review the games readily available in the market and assess whether they are well-suited for rhythmic training. Games that train rhythm skills may serve as useful tools for retraining motor and cognitive functions in patients with motor or neurodevelopmental disorders (e.g., Parkinson's disease, dyslexia, or ADHD). Our criteria were the peripheral used to capture and record the response, the type of response and the output measure. None of the existing games provides sufficient temporal precision in stimulus presentation and/or data acquisition. In addition, games do not train selectively rhythmic skills. Hence, the available music games, in their present form, are not satisfying for training rhythmic skills. Yet, some features such as the device used, the interface or the game scenario provide good indications for devising efficient training protocols. Guidelines are provided for devising serious music games targeting rhythmic training in the future.

Extensive circadian and light regulation of the transcriptome in the malaria mosquito Anopheles gambiae

PubMed Central

2013-01-01

Background Mosquitoes exhibit 24 hr rhythms in flight activity, feeding, reproduction and development. To better understand the molecular basis for these rhythms in the nocturnal malaria vector Anopheles gambiae, we have utilized microarray analysis on time-of-day specific collections of mosquitoes over 48 hr to explore the coregulation of gene expression rhythms by the circadian clock and light, and compare these with the 24 hr rhythmic gene expression in the diurnal Aedes aegypti dengue vector mosquito. Results In time courses from An. gambiae head and body collected under light:dark cycle (LD) and constant dark (DD) conditions, we applied three algorithms that detect sinusoidal patterns and an algorithm that detects spikes in expression. This revealed across four experimental conditions 393 probes newly scored as rhythmic. These genes correspond to functions such as metabolic detoxification, immunity and nutrient sensing. This includes glutathione S-transferase GSTE5, whose expression pattern and chromosomal location are shared with other genes, suggesting shared chromosomal regulation; and pulsatile expression of the gene encoding CYP6M2, a cytochrome P450 that metabolizes pyrethroid insecticides. We explored the interaction of light and the circadian clock and highlight the regulation of odorant binding proteins (OBPs), important components of the olfactory system. We reveal that OBPs have unique expression patterns as mosquitoes make the transition from LD to DD conditions. We compared rhythmic expression between An. gambiae and Ae. aegypti heads collected under LD conditions using a single cosine fitting algorithm, and report distinct similarities and differences in the temporal regulation of genes involved in tRNA priming, the vesicular-type ATPase, olfaction and vision between the two species. Conclusions These data build on our previous analyses of time-of-day specific regulation of the An. gambiae transcriptome to reveal additional rhythmic genes, an improved understanding of the co-regulation of rhythms in gene expression by the circadian clock and by light, and an understanding of the time-of-day specific regulation of some of these rhythmic processes in comparison with a different species of mosquito. Improved understanding of biological timing at the molecular level that underlies key physiological aspects of mosquito vectors may prove to be important to successful implementation of established and novel insect control methods. PMID:23552056

How musical training affects cognitive development: rhythm, reward and other modulating variables.

PubMed

Miendlarzewska, Ewa A; Trost, Wiebke J

2013-01-01

Musical training has recently gained additional interest in education as increasing neuroscientific research demonstrates its positive effects on brain development. Neuroimaging revealed plastic changes in the brains of adult musicians but it is still unclear to what extent they are the product of intensive music training rather than of other factors, such as preexisting biological markers of musicality. In this review, we synthesize a large body of studies demonstrating that benefits of musical training extend beyond the skills it directly aims to train and last well into adulthood. For example, children who undergo musical training have better verbal memory, second language pronunciation accuracy, reading ability and executive functions. Learning to play an instrument as a child may even predict academic performance and IQ in young adulthood. The degree of observed structural and functional adaptation in the brain correlates with intensity and duration of practice. Importantly, the effects on cognitive development depend on the timing of musical initiation due to sensitive periods during development, as well as on several other modulating variables. Notably, we point to motivation, reward and social context of musical education, which are important yet neglected factors affecting the long-term benefits of musical training. Further, we introduce the notion of rhythmic entrainment and suggest that it may represent a mechanism supporting learning and development of executive functions. It also hones temporal processing and orienting of attention in time that may underlie enhancements observed in reading and verbal memory. We conclude that musical training uniquely engenders near and far transfer effects, preparing a foundation for a range of skills, and thus fostering cognitive development.

Effectiveness of Exercise on Functional Mobility in Adults with Cerebral Palsy: A Systematic Review

PubMed Central

Lawrence, Hillary; Hills, Sara; Kline, Nicole; Weems, Kyra

2016-01-01

Purpose: We identified evidence evaluating the effect of exercise on functional mobility in adults (aged 18 y or older) with cerebral palsy (CP). Method: An exhaustive search was conducted using the electronic databases PubMed, MEDLINE, CINAHL, PsycINFO, SPORTDiscus, and Cochrane Database of Systematic Reviews from the earliest available evidence (1975) to the present (January 2016) for studies whose participants were ambulatory adults with CP receiving conservative treatment to address functional mobility limitations. Two independent reviewers agreed on the eligibility, inclusion, and level of evidence of each study. The Maastricht-Amsterdam List (MAL) was used to assess evidence quality. Results: Five of the six studies included were randomized controlled trials, and one was a pre–post case series. Interventions included whole-body vibration, treadmill training without body-weight support, rhythmic auditory stimulation, dynamic balance and gait activities, progressive resistance training, and interactive serious gaming for balance. All studies were considered high quality, as indicated by their MAL scores. Four studies showed no statistical difference and trivial effect sizes between the intervention and the control group. Rhythmic auditory stimulation and interactive serious gaming were found to be statistically significant in benefiting adults with CP. Conclusions: Evidence of the effect of exercise on functional mobility for ambulatory adults with CP is lacking. A need exists for quality research to determine the best interventions for adults with CP to maximize functional mobility. PMID:27904240

Prefrontal cortex modulates posterior alpha oscillations during top-down guided visual perception

PubMed Central

Helfrich, Randolph F.; Huang, Melody; Wilson, Guy; Knight, Robert T.

2017-01-01

Conscious visual perception is proposed to arise from the selective synchronization of functionally specialized but widely distributed cortical areas. It has been suggested that different frequency bands index distinct canonical computations. Here, we probed visual perception on a fine-grained temporal scale to study the oscillatory dynamics supporting prefrontal-dependent sensory processing. We tested whether a predictive context that was embedded in a rapid visual stream modulated the perception of a subsequent near-threshold target. The rapid stream was presented either rhythmically at 10 Hz, to entrain parietooccipital alpha oscillations, or arrhythmically. We identified a 2- to 4-Hz delta signature that modulated posterior alpha activity and behavior during predictive trials. Importantly, delta-mediated top-down control diminished the behavioral effects of bottom-up alpha entrainment. Simultaneous source-reconstructed EEG and cross-frequency directionality analyses revealed that this delta activity originated from prefrontal areas and modulated posterior alpha power. Taken together, this study presents converging behavioral and electrophysiological evidence for frontal delta-mediated top-down control of posterior alpha activity, selectively facilitating visual perception. PMID:28808023

Low-Frequency Cortical Oscillations Entrain to Subthreshold Rhythmic Auditory Stimuli

PubMed Central

Schroeder, Charles E.; Poeppel, David; van Atteveldt, Nienke

2017-01-01

Many environmental stimuli contain temporal regularities, a feature that can help predict forthcoming input. Phase locking (entrainment) of ongoing low-frequency neuronal oscillations to rhythmic stimuli is proposed as a potential mechanism for enhancing neuronal responses and perceptual sensitivity, by aligning high-excitability phases to events within a stimulus stream. Previous experiments show that rhythmic structure has a behavioral benefit even when the rhythm itself is below perceptual detection thresholds (ten Oever et al., 2014). It is not known whether this “inaudible” rhythmic sound stream also induces entrainment. Here we tested this hypothesis using magnetoencephalography and electrocorticography in humans to record changes in neuronal activity as subthreshold rhythmic stimuli gradually became audible. We found that significant phase locking to the rhythmic sounds preceded participants' detection of them. Moreover, no significant auditory-evoked responses accompanied this prethreshold entrainment. These auditory-evoked responses, distinguished by robust, broad-band increases in intertrial coherence, only appeared after sounds were reported as audible. Taken together with the reduced perceptual thresholds observed for rhythmic sequences, these findings support the proposition that entrainment of low-frequency oscillations serves a mechanistic role in enhancing perceptual sensitivity for temporally predictive sounds. This framework has broad implications for understanding the neural mechanisms involved in generating temporal predictions and their relevance for perception, attention, and awareness. SIGNIFICANCE STATEMENT The environment is full of rhythmically structured signals that the nervous system can exploit for information processing. Thus, it is important to understand how the brain processes such temporally structured, regular features of external stimuli. Here we report the alignment of slowly fluctuating oscillatory brain activity to external rhythmic structure before its behavioral detection. These results indicate that phase alignment is a general mechanism of the brain to process rhythmic structure and can occur without the perceptual detection of this temporal structure. PMID:28411273

GABA-A receptors in mPOAH simultaneously regulate sleep and body temperature in freely moving rats.

PubMed

Jha, S K; Yadav, V; Mallick, B N

2001-09-01

Sleep-wakefulness and body temperature are two circadian rhythmic biological phenomena. The role of GABAergic inputs in the medial preoptico-anterior hypothalamus (mPOAH) on simultaneous regulation of those phenomena was investigated in freely moving normally behaving rats. The GABA-A receptors were blocked by microinjecting picrotoxin, and the effects on electrophysiological parameters signifying sleep-wakefulness, rectal temperature and brain temperature were recorded simultaneously. The results suggest that, normally, GABA in the medial preoptic area acts through GABA-A receptor that induces sleep and prevents an excessive rise in body temperature. However, the results do not allow us to comment on the cause and effect relationship, if any, between changes in sleep-wakefulness and body temperature. The changes in brain and rectal temperatures showed a positive correlation, however, the former varied within a narrower range than that of the latter.

Homeostasis and biological rhythms in the rat during spaceflight

NASA Technical Reports Server (NTRS)

Fuller, C. A.

1985-01-01

The effects of microgravity on the physiological regulation of homeostatic systems is studied. The temperature and heart rate of rats exposed to seven days of microgravity and a 12:12 light/dark cycle are analyzed. A 24-hour nocturnal rhythmicity is observed in the control and in-flight heart rates and body temperatures. The preflight daytime body temperature was calculated as 37.2 + or - 0.03 C and in-flight as 37.4 + or 0.04 C; nighttime body temperature preflight daytime was determined as 38.0 + or - 0.02 C, and in-flight as 37.8 + or 0.06 C. The 24-hour mean heart rate was depressed from 412 + or - 3.3 bpm preflight to 373 + or - 2.4 bpm in-flight; this change is noted in both dark and light conditions. It is detected that microgravity alters the steady state regulation of heart rate and body temperature.

Sensory Regulation of Network Components Underlying Ciliary Locomotion in Hermissenda

PubMed Central

Crow, Terry; Tian, Lian-Ming

2008-01-01

Ciliary locomotion in the nudibranch mollusk Hermissenda is modulated by the visual and graviceptive systems. Components of the neural network mediating ciliary locomotion have been identified including aggregates of polysensory interneurons that receive monosynaptic input from identified photoreceptors and efferent neurons that activate cilia. Illumination produces an inhibition of type Ii (off-cell) spike activity, excitation of type Ie (on-cell) spike activity, decreased spike activity in type IIIi inhibitory interneurons, and increased spike activity of ciliary efferent neurons. Here we show that pairs of type Ii interneurons and pairs of type Ie interneurons are electrically coupled. Neither electrical coupling or synaptic connections were observed between Ie and Ii interneurons. Coupling is effective in synchronizing dark-adapted spontaneous firing between pairs of Ie and pairs of Ii interneurons. Out-of-phase burst activity, occasionally observed in dark-adapted and light-adapted pairs of Ie and Ii interneurons, suggests that they receive synaptic input from a common presynaptic source or sources. Rhythmic activity is typically not a characteristic of dark-adapted, light-adapted, or light-evoked firing of type I interneurons. However, burst activity in Ie and Ii interneurons may be elicited by electrical stimulation of pedal nerves or generated at the offset of light. Our results indicate that type I interneurons can support the generation of both rhythmic activity and changes in tonic firing depending on sensory input. This suggests that the neural network supporting ciliary locomotion may be multifunctional. However, consistent with the nonmuscular and nonrhythmic characteristics of visually modulated ciliary locomotion, type I interneurons exhibit changes in tonic activity evoked by illumination. PMID:18768639

Dynamical entrainment of corticospinal excitability during rhythmic movement observation: a Transcranial Magnetic Stimulation study.

PubMed

Varlet, Manuel; Novembre, Giacomo; Keller, Peter E

2017-06-01

Spontaneous modulations of corticospinal excitability during action observation have been interpreted as evidence for the activation of internal motor representations equivalent to the observed action. Alternatively or complementary to this perspective, growing evidence shows that motor activity during observation of rhythmic movements can be modulated by direct visuomotor couplings and dynamical entrainment. In-phase and anti-phase entrainment spontaneously occur, characterized by cyclic movements proceeding simultaneously in the same (in-phase) or opposite (anti-phase) direction. Here we investigate corticospinal excitability during the observation of vertical oscillations of an index finger using Transcranial Magnetic Stimulation (TMS). Motor-evoked potentials (MEPs) were recorded from participants' flexor and extensor muscles of the right index finger, placed in either a maximal steady flexion or extension position, with stimulations delivered at maximal flexion, maximal extension or mid-trajectory of the observed finger oscillations. Consistent with the occurrence of dynamical motor entrainment, increased and decreased MEP responses - suggesting the facilitation of stable in-phase and anti-phase relations but not an unstable 90° phase relation - were found in participants' flexors. Anti-phase motor facilitation contrasts with the activation of internal motor representation as it involves activity in the motor system opposite from activity required for the execution of the observed movement. These findings demonstrate the relevance of dynamical entrainment theories and methods for understanding spontaneous motor activity in the brain during action observation and the mechanisms underpinning coordinated movements during social interaction. © 2017 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Circadian clock-dependent and -independent posttranscriptional regulation underlies temporal mRNA accumulation in mouse liver

PubMed Central

Wang, Jingkui; Yeung, Jake; Gobet, Cédric; Sobel, Jonathan; Lück, Sarah; Molina, Nacho; Naef, Felix

2018-01-01

The mammalian circadian clock coordinates physiology with environmental cycles through the regulation of daily oscillations of gene expression. Thousands of transcripts exhibit rhythmic accumulations across mouse tissues, as determined by the balance of their synthesis and degradation. While diurnally rhythmic transcription regulation is well studied and often thought to be the main factor generating rhythmic mRNA accumulation, the extent of rhythmic posttranscriptional regulation is debated, and the kinetic parameters (e.g., half-lives), as well as the underlying regulators (e.g., mRNA-binding proteins) are relatively unexplored. Here, we developed a quantitative model for cyclic accumulations of pre-mRNA and mRNA from total RNA-seq data, and applied it to mouse liver. This allowed us to identify that about 20% of mRNA rhythms were driven by rhythmic mRNA degradation, and another 15% of mRNAs regulated by both rhythmic transcription and mRNA degradation. The method could also estimate mRNA half-lives and processing times in intact mouse liver. We then showed that, depending on mRNA half-life, rhythmic mRNA degradation can either amplify or tune phases of mRNA rhythms. By comparing mRNA rhythms in wild-type and Bmal1−/− animals, we found that the rhythmic degradation of many transcripts did not depend on a functional BMAL1. Interestingly clock-dependent and -independent degradation rhythms peaked at distinct times of day. We further predicted mRNA-binding proteins (mRBPs) that were implicated in the posttranscriptional regulation of mRNAs, either through stabilizing or destabilizing activities. Together, our results demonstrate how posttranscriptional regulation temporally shapes rhythmic mRNA accumulation in mouse liver. PMID:29432155

Physiological modules for generating discrete and rhythmic movements: action identification by a dynamic recurrent neural network.

PubMed

Bengoetxea, Ana; Leurs, Françoise; Hoellinger, Thomas; Cebolla, Ana M; Dan, Bernard; McIntyre, Joseph; Cheron, Guy

2014-01-01

In this study we employed a dynamic recurrent neural network (DRNN) in a novel fashion to reveal characteristics of control modules underlying the generation of muscle activations when drawing figures with the outstretched arm. We asked healthy human subjects to perform four different figure-eight movements in each of two workspaces (frontal plane and sagittal plane). We then trained a DRNN to predict the movement of the wrist from information in the EMG signals from seven different muscles. We trained different instances of the same network on a single movement direction, on all four movement directions in a single movement plane, or on all eight possible movement patterns and looked at the ability of the DRNN to generalize and predict movements for trials that were not included in the training set. Within a single movement plane, a DRNN trained on one movement direction was not able to predict movements of the hand for trials in the other three directions, but a DRNN trained simultaneously on all four movement directions could generalize across movement directions within the same plane. Similarly, the DRNN was able to reproduce the kinematics of the hand for both movement planes, but only if it was trained on examples performed in each one. As we will discuss, these results indicate that there are important dynamical constraints on the mapping of EMG to hand movement that depend on both the time sequence of the movement and on the anatomical constraints of the musculoskeletal system. In a second step, we injected EMG signals constructed from different synergies derived by the PCA in order to identify the mechanical significance of each of these components. From these results, one can surmise that discrete-rhythmic movements may be constructed from three different fundamental modules, one regulating the co-activation of all muscles over the time span of the movement and two others elliciting patterns of reciprocal activation operating in orthogonal directions.

Thalamic reticular nucleus induces fast and local modulation of arousal state

PubMed Central

Lewis, Laura D; Voigts, Jakob; Flores, Francisco J; Schmitt, L Ian; Wilson, Matthew A

2015-01-01

During low arousal states such as drowsiness and sleep, cortical neurons exhibit rhythmic slow wave activity associated with periods of neuronal silence. Slow waves are locally regulated, and local slow wave dynamics are important for memory, cognition, and behaviour. While several brainstem structures for controlling global sleep states have now been well characterized, a mechanism underlying fast and local modulation of cortical slow waves has not been identified. Here, using optogenetics and whole cortex electrophysiology, we show that local tonic activation of thalamic reticular nucleus (TRN) rapidly induces slow wave activity in a spatially restricted region of cortex. These slow waves resemble those seen in sleep, as cortical units undergo periods of silence phase-locked to the slow wave. Furthermore, animals exhibit behavioural changes consistent with a decrease in arousal state during TRN stimulation. We conclude that TRN can induce rapid modulation of local cortical state. DOI: http://dx.doi.org/10.7554/eLife.08760.001 PMID:26460547

Using an Artificial Neural Bypass to Restore Cortical Control of Rhythmic Movements in a Human with Quadriplegia

PubMed Central

Sharma, Gaurav; Friedenberg, David A.; Annetta, Nicholas; Glenn, Bradley; Bockbrader, Marcie; Majstorovic, Connor; Domas, Stephanie; Mysiw, W. Jerry; Rezai, Ali; Bouton, Chad

2016-01-01

Neuroprosthetic technology has been used to restore cortical control of discrete (non-rhythmic) hand movements in a paralyzed person. However, cortical control of rhythmic movements which originate in the brain but are coordinated by Central Pattern Generator (CPG) neural networks in the spinal cord has not been demonstrated previously. Here we show a demonstration of an artificial neural bypass technology that decodes cortical activity and emulates spinal cord CPG function allowing volitional rhythmic hand movement. The technology uses a combination of signals recorded from the brain, machine-learning algorithms to decode the signals, a numerical model of CPG network, and a neuromuscular electrical stimulation system to evoke rhythmic movements. Using the neural bypass, a quadriplegic participant was able to initiate, sustain, and switch between rhythmic and discrete finger movements, using his thoughts alone. These results have implications in advancing neuroprosthetic technology to restore complex movements in people living with paralysis. PMID:27658585

Speech rhythm facilitates syntactic ambiguity resolution: ERP evidence.

PubMed

Roncaglia-Denissen, Maria Paula; Schmidt-Kassow, Maren; Kotz, Sonja A

2013-01-01

In the current event-related potential (ERP) study, we investigated how speech rhythm impacts speech segmentation and facilitates the resolution of syntactic ambiguities in auditory sentence processing. Participants listened to syntactically ambiguous German subject- and object-first sentences that were spoken with either regular or irregular speech rhythm. Rhythmicity was established by a constant metric pattern of three unstressed syllables between two stressed ones that created rhythmic groups of constant size. Accuracy rates in a comprehension task revealed that participants understood rhythmically regular sentences better than rhythmically irregular ones. Furthermore, the mean amplitude of the P600 component was reduced in response to object-first sentences only when embedded in rhythmically regular but not rhythmically irregular context. This P600 reduction indicates facilitated processing of sentence structure possibly due to a decrease in processing costs for the less-preferred structure (object-first). Our data suggest an early and continuous use of rhythm by the syntactic parser and support language processing models assuming an interactive and incremental use of linguistic information during language processing.

Speech Rhythm Facilitates Syntactic Ambiguity Resolution: ERP Evidence

PubMed Central

Roncaglia-Denissen, Maria Paula; Schmidt-Kassow, Maren; Kotz, Sonja A.

2013-01-01

In the current event-related potential (ERP) study, we investigated how speech rhythm impacts speech segmentation and facilitates the resolution of syntactic ambiguities in auditory sentence processing. Participants listened to syntactically ambiguous German subject- and object-first sentences that were spoken with either regular or irregular speech rhythm. Rhythmicity was established by a constant metric pattern of three unstressed syllables between two stressed ones that created rhythmic groups of constant size. Accuracy rates in a comprehension task revealed that participants understood rhythmically regular sentences better than rhythmically irregular ones. Furthermore, the mean amplitude of the P600 component was reduced in response to object-first sentences only when embedded in rhythmically regular but not rhythmically irregular context. This P600 reduction indicates facilitated processing of sentence structure possibly due to a decrease in processing costs for the less-preferred structure (object-first). Our data suggest an early and continuous use of rhythm by the syntactic parser and support language processing models assuming an interactive and incremental use of linguistic information during language processing. PMID:23409109

Methodological aspects of shift-work research.

PubMed

Knutsson, Anders

2004-01-01

A major issue in shift-work research is to understand the possible ways in which shift work can impact performance and health. Nearly all body functions, from those of the cellular level to those of the entire body, are circadian rhythmic. Disturbances of these rhythms as well as the social consequences of odd work hours are of importance for the health and well-being of shift workers. This article reviews a number of common methodological issues which are of relevance to epidemiological studies in this area of research. It discusses conceptual problems regarding the use of the term "shift work," and it underscores the need to develop models that explain the mechanisms of disease in shift workers.

Rhythmic expression of DEC2 protein in vitro and in vivo.

PubMed

Sato, Fuyuki; Muragaki, Yasuteru; Kawamoto, Takeshi; Fujimoto, Katsumi; Kato, Yukio; Zhang, Yanping

2016-06-01

Basic helix-loop-helix (bHLH) transcription factor DEC2 (bHLHE41/Sharp1) is one of the clock genes that show a circadian rhythm in various tissues. DEC2 regulates differentiation, sleep length, tumor cell invasion and apoptosis. Although studies have been conducted on the rhythmic expression of DEC2 mRNA in various tissues, the precise molecular mechanism of DEC2 expression is poorly understood. In the present study, we examined whether DEC2 protein had a rhythmic expression. Western blot analysis for DEC2 protein revealed a rhythmic expression in mouse liver, lung and muscle and in MCF-7 and U2OS cells. In addition, AMP-activated protein kinase (AMPK) activity (phosphorylation of AMPK) in mouse embryonic fibroblasts (MEFs) exhibited a rhythmic expression under the condition of medium change or glucose-depleted medium. However, the rhythmic expression of DEC2 in MEF gradually decreased in time under these conditions. The medium change affected the levels of DEC2 protein and phosphorylation of AMPK. In addition, the levels of DEC2 protein showed a rhythmic expression in vivo and in MCF-7 and U2OS cells. The results showed that the phosphorylation of AMPK immunoreactivity was strongly detected in the liver and lung of DEC2 knockout mice compared with that of wild-type mice. These results may provide new insights into rhythmic expression and the regulation between DEC2 protein and AMPK activity.

Effect of rhythmic photostimulation on monkeys with hyperkinesis of post-encephalitic genesis

NASA Technical Reports Server (NTRS)

Danilov, I. V.; Kudrayatseva, N. N.

1979-01-01

In hyperkinetic monkeys a response opposite to that of healthy monkeys was observed during rhythmic photostimulation (frequency 3, 9, 18, 20, and 25/sec), i.e., the hyperkinesis disappeared. The significance of rhythmic excitatory cycles for interconnections between different brain structures is discussed.

Young Children Being Rhythmically Playful: Creating "Musike" Together

ERIC Educational Resources Information Center

Alcock, Sophie

2008-01-01

This article explores young children's rhythmic, musical, aesthetic and playful creative communication in an early childhood education centre. Young children's communication is musically rhythmic and social. The data, presented as "events", formed part of an ethnographic-inspired study conducted by the researcher as a participant observer.…

Endogenous modulation of human visual cortex activity improves perception at twilight.

PubMed

Cordani, Lorenzo; Tagliazucchi, Enzo; Vetter, Céline; Hassemer, Christian; Roenneberg, Till; Stehle, Jörg H; Kell, Christian A

2018-04-10

Perception, particularly in the visual domain, is drastically influenced by rhythmic changes in ambient lighting conditions. Anticipation of daylight changes by the circadian system is critical for survival. However, the neural bases of time-of-day-dependent modulation in human perception are not yet understood. We used fMRI to study brain dynamics during resting-state and close-to-threshold visual perception repeatedly at six times of the day. Here we report that resting-state signal variance drops endogenously at times coinciding with dawn and dusk, notably in sensory cortices only. In parallel, perception-related signal variance in visual cortices decreases and correlates negatively with detection performance, identifying an anticipatory mechanism that compensates for the deteriorated visual signal quality at dawn and dusk. Generally, our findings imply that decreases in spontaneous neural activity improve close-to-threshold perception.

Optogenetic dissection reveals multiple rhythmogenic modules underlying locomotion

PubMed Central

Hägglund, Martin; Dougherty, Kimberly J.; Borgius, Lotta; Itohara, Shigeyoshi; Iwasato, Takuji; Kiehn, Ole

2013-01-01

Neural networks in the spinal cord known as central pattern generators produce the sequential activation of muscles needed for locomotion. The overall locomotor network architectures in limbed vertebrates have been much debated, and no consensus exists as to how they are structured. Here, we use optogenetics to dissect the excitatory and inhibitory neuronal populations and probe the organization of the mammalian central pattern generator. We find that locomotor-like rhythmic bursting can be induced unilaterally or independently in flexor or extensor networks. Furthermore, we show that individual flexor motor neuron pools can be recruited into bursting without any activity in other nearby flexor motor neuron pools. Our experiments differentiate among several proposed models for rhythm generation in the vertebrates and show that the basic structure underlying the locomotor network has a distributed organization with many intrinsically rhythmogenic modules. PMID:23798384

Neural bases of rhythmic entrainment in humans: critical transformation between cortical and lower-level representations of auditory rhythm.

PubMed

Nozaradan, Sylvie; Schönwiesner, Marc; Keller, Peter E; Lenc, Tomas; Lehmann, Alexandre

2018-02-01

The spontaneous ability to entrain to meter periodicities is central to music perception and production across cultures. There is increasing evidence that this ability involves selective neural responses to meter-related frequencies. This phenomenon has been observed in the human auditory cortex, yet it could be the product of evolutionarily older lower-level properties of brainstem auditory neurons, as suggested by recent recordings from rodent midbrain. We addressed this question by taking advantage of a new method to simultaneously record human EEG activity originating from cortical and lower-level sources, in the form of slow (< 20 Hz) and fast (> 150 Hz) responses to auditory rhythms. Cortical responses showed increased amplitudes at meter-related frequencies compared to meter-unrelated frequencies, regardless of the prominence of the meter-related frequencies in the modulation spectrum of the rhythmic inputs. In contrast, frequency-following responses showed increased amplitudes at meter-related frequencies only in rhythms with prominent meter-related frequencies in the input but not for a more complex rhythm requiring more endogenous generation of the meter. This interaction with rhythm complexity suggests that the selective enhancement of meter-related frequencies does not fully rely on subcortical auditory properties, but is critically shaped at the cortical level, possibly through functional connections between the auditory cortex and other, movement-related, brain structures. This process of temporal selection would thus enable endogenous and motor entrainment to emerge with substantial flexibility and invariance with respect to the rhythmic input in humans in contrast with non-human animals. © 2018 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Short-Term Effects of Binaural Beats on EEG Power, Functional Connectivity, Cognition, Gait and Anxiety in Parkinson's Disease.

PubMed

Gálvez, Gerardo; Recuero, Manuel; Canuet, Leonides; Del-Pozo, Francisco

2018-06-01

We applied rhythmic binaural sound to Parkinson's Disease (PD) patients to investigate its influence on several symptoms of this disease and on Electrophysiology (Electrocardiography and Electroencephalography (EEG)). We conducted a double-blind, randomized controlled study in which rhythmic binaural beats and control were administered over two randomized and counterbalanced sessions (within-subjects repeated-measures design). Patients ([Formula: see text], age [Formula: see text], stage I-III Hoehn & Yahr scale) participated in two sessions of sound stimulation for 10[Formula: see text]min separated by a minimum of 7 days. Data were collected immediately before and after both stimulations with the following results: (1) a decrease in theta activity, (2) a general decrease in Functional Connectivity (FC), and (3) an improvement in working memory performance. However, no significant changes were identified in the gait performance, heart rate or anxiety level of the patients. With regard to the control stimulation, we did not identify significant changes in the variables analyzed. The use of binaural-rhythm stimulation for PD, as designed in this study, seems to be an effective, portable, inexpensive and noninvasive method to modulate brain activity. This influence on brain activity did not induce changes in anxiety or gait parameters; however, it resulted in a normalization of EEG power (altered in PD), normalization of brain FC (also altered in PD) and working memory improvement (a normalizing effect). In summary, we consider that sound, particularly binaural-rhythmic sound, may be a co-assistant tool in the treatment of PD, however more research is needed to consider the use of this type of stimulation as an effective therapy.

The Rhythmic Group, Liaison, Nouns and Verbs of French

ERIC Educational Resources Information Center

Ashby, William J.

1975-01-01

The "rhythmic group" in French (noun group or verb group) is described with examples. The aim is to find some relation between the morphophonological phenomena such as "liaison" occurring within such rhythmic groups and the syntactic structure of French. Available from Liber Laeromedel, Box 1205, S-22105 Lund, Sweden. (TL)

Early development of circadian rhythmicity in the suprachiamatic nuclei and pineal gland of teleost, flounder (Paralichthys olivaeus), embryos.

PubMed

Mogi, Makoto; Uji, Susumu; Yokoi, Hayato; Suzuki, Tohru

2015-08-01

Circadian rhythms enable organisms to coordinate multiple physiological processes and behaviors with the earth's rotation. In mammals, the suprachiasmatic nuclei (SCN), the sole master circadian pacemaker, has entrainment mechanisms that set the circadian rhythm to a 24-h cycle with photic signals from retina. In contrast, the zebrafish SCN is not a circadian pacemaker, instead the pineal gland (PG) houses the major circadian oscillator. The SCN of flounder larvae, unlike that of zebrafish, however, expresses per2 with a rhythmicity of daytime/ON and nighttime/OFF. Here, we examined whether the rhythm of per2 expression in the flounder SCN represents the molecular clock. We also examined early development of the circadian rhythmicity in the SCN and PG. Our three major findings were as follows. First, rhythmic per2 expression in the SCN was maintained under 24 h dark (DD) conditions, indicating that a molecular clock exists in the flounder SCN. Second, onset of circadian rhythmicity in the SCN preceded that in the PG. Third, both 24 h light (LL) and DD conditions deeply affected the development of circadian rhythmicity in the SCN and PG. This is the first report dealing with the early development of circadian rhythmicity in the SCN in fish. © 2015 Japanese Society of Developmental Biologists.

Rhythmic cognition in humans and animals: distinguishing meter and pulse perception

PubMed Central

Fitch, W. Tecumseh

2013-01-01

This paper outlines a cognitive and comparative perspective on human rhythmic cognition that emphasizes a key distinction between pulse perception and meter perception. Pulse perception involves the extraction of a regular pulse or “tactus” from a stream of events. Meter perception involves grouping of events into hierarchical trees with differing levels of “strength”, or perceptual prominence. I argue that metrically-structured rhythms are required to either perform or move appropriately to music (e.g., to dance). Rhythms, from this metrical perspective, constitute “trees in time.” Rhythmic syntax represents a neglected form of musical syntax, and warrants more thorough neuroscientific investigation. The recent literature on animal entrainment clearly demonstrates the capacity to extract the pulse from rhythmic music, and to entrain periodic movements to this pulse, in several parrot species and a California sea lion, and a more limited ability to do so in one chimpanzee. However, the ability of these or other species to infer hierarchical rhythmic trees remains, for the most part, unexplored (with some apparent negative results from macaques). The results from this animal comparative research, combined with new methods to explore rhythmic cognition neurally, provide exciting new routes for understanding not just rhythmic cognition, but hierarchical cognition more generally, from a biological and neural perspective. PMID:24198765

Sympathetic network drive during water deprivation does not increase respiratory or cardiac rhythmic sympathetic nerve activity.

PubMed

Holbein, Walter W; Toney, Glenn M

2013-06-15

Effects of water deprivation on rhythmic bursting of sympathetic nerve activity (SNA) were investigated in anesthetized, bilaterally vagotomized, euhydrated (control) and 48-h water-deprived (WD) rats (n = 8/group). Control and WD rats had similar baseline values of mean arterial pressure, heart rate, end-tidal CO2, and central respiratory drive. Although integrated splanchnic SNA (sSNA) was greater in WD rats than controls (P < 0.01), analysis of respiratory rhythmic bursting of sSNA revealed that inspiratory rhythmic burst amplitude was actually smaller (P < 0.005) in WD rats (+68 ± 6%) than controls (+208 ± 20%), and amplitudes of the early expiratory (postinspiratory) trough and late expiratory burst of sSNA were not different between groups. Further analysis revealed that water deprivation had no effect on either the amplitude or periodicity of the cardiac rhythmic oscillation of sSNA. Collectively, these data indicate that the increase of sSNA produced by water deprivation is not attributable to either increased respiratory or cardiac rhythmic burst discharge. Thus the sympathetic network response to acute water deprivation appears to differ from that of chronic sympathoexcitation in neurogenic forms of arterial hypertension, where increased respiratory rhythmic bursting of SNA and baroreflex adaptations have been reported.

Spectral Mixing in Nervous Systems: Experimental Evidenceand Biologically Plausible Circuits

NASA Astrophysics Data System (ADS)

Kleinfeld, D.; Mehta, S. B.

The ability to compute the difference frequency for two periodic signals depends on a nonlinear operation that mixes those signals. Behavioral and psychophysical evidence suggest that such mixing is likely to occur in the vertebrate nervous system as a means to compare rhythmic sensory signals, such as occurs in human audition, and as a means to lock an intrinsic rhythm to a sensory input. Electrophysiological data from electroreceptors in the immobilized electric fish and somatosensory cortex in the anesthetized rat yield direct evidence for such mixing, providing a neurological substrate for the modulation and demodulation of rhythmic neuronal signals. We consider an analytical model of spectral mixing that makes use of the threshold characteristics of neuronal firing and which has features consistent with the experimental observations. This model serves as a guide for constructing circuits that isolate given mixture components. In particular, such circuits can generate nearly pure difference tones from sinusoidal inputs without the use of band-pass filters, in analogy to an image-reject mixer in communications engineering. We speculate that such computations may play a role in coding of sensory input and feedback stabilization of motor output in nervous systems.

Dopamine Attenuates Ketamine-Induced Neuronal Apoptosis in the Developing Rat Retina Independent of Early Synchronized Spontaneous Network Activity.

PubMed

Dong, Jing; Gao, Lingqi; Han, Junde; Zhang, Junjie; Zheng, Jijian

2017-07-01

Deprivation of spontaneous rhythmic electrical activity in early development by anesthesia administration, among other interventions, induces neuronal apoptosis. However, it is unclear whether enhancement of neuronal electrical activity attenuates neuronal apoptosis in either normal development or after anesthesia exposure. The present study investigated the effects of dopamine, an enhancer of spontaneous rhythmic electrical activity, on ketamine-induced neuronal apoptosis in the developing rat retina. TUNEL and immunohistochemical assays indicated that ketamine time- and dose-dependently aggravated physiological and ketamine-induced apoptosis and inhibited early-synchronized spontaneous network activity. Dopamine administration reversed ketamine-induced neuronal apoptosis, but did not reverse the inhibitory effects of ketamine on early synchronized spontaneous network activity despite enhancing it in controls. Blockade of D1, D2, and A2A receptors and inhibition of cAMP/PKA signaling partially antagonized the protective effect of dopamine against ketamine-induced apoptosis. Together, these data indicate that dopamine attenuates ketamine-induced neuronal apoptosis in the developing rat retina by activating the D1, D2, and A2A receptors, and upregulating cAMP/PKA signaling, rather than through modulation of early synchronized spontaneous network activity.

Neural control of locomotion and training-induced plasticity after spinal and cerebral lesions.

PubMed

Knikou, Maria

2010-10-01

Standing and walking require a plethora of sensorimotor interactions that occur throughout the nervous system. Sensory afferent feedback plays a crucial role in the rhythmical muscle activation pattern, as it affects through spinal reflex circuits the spinal neuronal networks responsible for inducing and maintaining rhythmicity, drives short-term and long-term re-organization of the brain and spinal cord circuits, and contributes to recovery of walking after locomotor training. Therefore, spinal circuits integrating sensory signals are adjustable networks with learning capabilities. In this review, I will synthesize the mechanisms underlying phase-dependent modulation of spinal reflexes in healthy humans as well as those with spinal or cerebral lesions along with findings on afferent regulation of spinal reflexes and central pattern generator in reduced animal preparations. Recovery of walking after locomotor training has been documented in numerous studies but the re-organization of spinal interneuronal and cortical circuits need to be further explored at cellular and physiological levels. For maximizing sensorimotor recovery in people with spinal or cerebral lesions, a multidisciplinary approach (rehabilitation, pharmacology, and electrical stimulation) delivered during various sensorimotor constraints is needed. Copyright 2010 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

Dietary heat-killed Lactobacillus brevis SBC8803 promotes voluntary wheel-running and affects sleep rhythms in mice.

PubMed

Miyazaki, Koyomi; Itoh, Nanako; Yamamoto, Saori; Higo-Yamamoto, Sayaka; Nakakita, Yasukazu; Kaneda, Hirotaka; Shigyo, Tatsuro; Oishi, Katsutaka

2014-08-28

We previously reported that heat-killed Lactobacillus brevis SBC8803 enhances appetite via changes in autonomic neurotransmission. Here we assessed whether a diet supplemented with heat-killed SBC8803 affects circadian locomotor rhythmicity and sleep architecture. Daily total activity gradually increased in mice over 4 weeks and supplementation with heat-killed SBC8803 significantly intensified the increase, which reached saturation at 25 days. Electroencephalography revealed that SBC8803 supplementation significantly reduced the total amount of time spent in non-rapid eye movement (NREM) sleep and increased the amount of time spent being awake during the latter half of the nighttime, but tended to increase the total amount of time spent in NREM sleep during the daytime. Dietary supplementation with SBC8803 can extend the duration of activity during the nighttime and of sleep during the daytime. Daily voluntary wheel-running and sleep rhythmicity become intensified when heat-killed SBC8803 is added to the diet. Dietary heat-killed SBC8803 can modulate circadian locomotion and sleep rhythms, which might benefit individuals with circadian rhythms that have been disrupted by stress or ageing. Copyright © 2014 Elsevier Inc. All rights reserved.

Giving speech a hand: gesture modulates activity in auditory cortex during speech perception.

PubMed

Hubbard, Amy L; Wilson, Stephen M; Callan, Daniel E; Dapretto, Mirella

2009-03-01

Viewing hand gestures during face-to-face communication affects speech perception and comprehension. Despite the visible role played by gesture in social interactions, relatively little is known about how the brain integrates hand gestures with co-occurring speech. Here we used functional magnetic resonance imaging (fMRI) and an ecologically valid paradigm to investigate how beat gesture-a fundamental type of hand gesture that marks speech prosody-might impact speech perception at the neural level. Subjects underwent fMRI while listening to spontaneously-produced speech accompanied by beat gesture, nonsense hand movement, or a still body; as additional control conditions, subjects also viewed beat gesture, nonsense hand movement, or a still body all presented without speech. Validating behavioral evidence that gesture affects speech perception, bilateral nonprimary auditory cortex showed greater activity when speech was accompanied by beat gesture than when speech was presented alone. Further, the left superior temporal gyrus/sulcus showed stronger activity when speech was accompanied by beat gesture than when speech was accompanied by nonsense hand movement. Finally, the right planum temporale was identified as a putative multisensory integration site for beat gesture and speech (i.e., here activity in response to speech accompanied by beat gesture was greater than the summed responses to speech alone and beat gesture alone), indicating that this area may be pivotally involved in synthesizing the rhythmic aspects of both speech and gesture. Taken together, these findings suggest a common neural substrate for processing speech and gesture, likely reflecting their joint communicative role in social interactions.

Giving Speech a Hand: Gesture Modulates Activity in Auditory Cortex During Speech Perception

PubMed Central

Hubbard, Amy L.; Wilson, Stephen M.; Callan, Daniel E.; Dapretto, Mirella

2008-01-01

Viewing hand gestures during face-to-face communication affects speech perception and comprehension. Despite the visible role played by gesture in social interactions, relatively little is known about how the brain integrates hand gestures with co-occurring speech. Here we used functional magnetic resonance imaging (fMRI) and an ecologically valid paradigm to investigate how beat gesture – a fundamental type of hand gesture that marks speech prosody – might impact speech perception at the neural level. Subjects underwent fMRI while listening to spontaneously-produced speech accompanied by beat gesture, nonsense hand movement, or a still body; as additional control conditions, subjects also viewed beat gesture, nonsense hand movement, or a still body all presented without speech. Validating behavioral evidence that gesture affects speech perception, bilateral nonprimary auditory cortex showed greater activity when speech was accompanied by beat gesture than when speech was presented alone. Further, the left superior temporal gyrus/sulcus showed stronger activity when speech was accompanied by beat gesture than when speech was accompanied by nonsense hand movement. Finally, the right planum temporale was identified as a putative multisensory integration site for beat gesture and speech (i.e., here activity in response to speech accompanied by beat gesture was greater than the summed responses to speech alone and beat gesture alone), indicating that this area may be pivotally involved in synthesizing the rhythmic aspects of both speech and gesture. Taken together, these findings suggest a common neural substrate for processing speech and gesture, likely reflecting their joint communicative role in social interactions. PMID:18412134

Effects of climatic factors on plasma lipid levels: A 5-year longitudinal study in a large Chinese population.

PubMed

Zhou, Xiaoming; Lin, Haiyan; Zhang, Shigang; Ren, Jianwei; Wang, Zhe; Zhang, Yun; Wang, Mansen; Zhang, Qunye

2016-01-01

The rules and mechanisms of seasonal changes in plasma lipid levels, which may be related to annual rhythmicity of incidence and mortality of cardiovascular diseases, are still controversial. The objectives of this study were to study the effects of climatic factors on plasma lipid levels and to preliminarily reveal mechanisms of annual rhythmicity of plasma lipid levels. A longitudinal study was performed using health examination data of 5 consecutive years (47,270 subjects) in Jinan, China. The climate in Jinan is typical temperate continental monsoon climate with huge temperature difference between winter and summer (>30°C). After considering and adjusting those classical lipid-associated risk factors, such as age, gender, diet, exercise, blood pressure, body weight, change of body weight, body mass index, glycemia, alanine aminotransferase, and creatinine, only air temperature could still significantly affect plasma lipid levels among the main climatic factors (humidity, precipitation, and so forth). For men, total cholesterol, high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol was decreased significantly 0.35, 0.18, and 0.06 mmol/L, respectively, whereas triglyceride was increased significantly 0.12 mmol/L for every 10°C increase in air temperature. For women, total cholesterol and high-density lipoprotein cholesterol were decreased notably 0.73 and 0.32 mmol/L, and low-density lipoprotein cholesterol was increased significantly 0.26 mmol/L for every 10°C increase in air temperature, whereas triglyceride was not significantly affected by air temperature. Air temperature is an independent risk factor for plasma lipid levels besides those classical lipid-associated risk factors. The annual air temperature fluctuations might be an important mechanism of the seasonal changes of lipids. Copyright © 2016 National Lipid Association. Published by Elsevier Inc. All rights reserved.

The Effects of Gravity on the Circadian Timing System

NASA Technical Reports Server (NTRS)

Fuller, Charles A.

1999-01-01

All vertebrates have a physiological control system that regulates the timing of the rhythms of their daily life. Dysfunction of this system, the circadian timing system (CTS), adversely affects an organism's ability to respond to environmental challenges and has been linked to physiological and psychological disorders. Exposure to altered gravitational environments (the microgravity of space and hyperdynamic environments produced via centrifugation) produces changes in both the functioning of the CTS and the rhythmic variables it controls. The earliest record of primate rhythms in a spaceflight environment come from Biosatellite III. The subject, a pig-tailed macaque, showed a loss of synchronization of the body temperature rhythm and a fragmented sleep-wake cycle. Alterations in the rhythm of body temperature were also seen in rhesus macaques flown on COSMOS 1514. Squirrel monkeys exposed to chronic centrifugation showed an initial decrease in the amplitude and mean of their body temperature and activity rhythms. In a microgravity environment, Squirrel monkeys on Spacelab-3 showed a reduction in the mean and amplitude of their feeding rhythms. Since 1992 we have had the opportunity to participate on three US/Russian sponsored biosatellite missions on which a total of six juvenile male rhesus macaques were flown. These animals uniformly exhibited delays in the phasing of their temperature rhythms, but not their heart rate or activity rhythms during spaceflight. There was also a tendency for changes in waveform mean and amplitude. These data suggest that the spaceflight environment may have a differential effect on the different oscillators controlling different rhythmic variables. Ongoing studies are examining the effects of +G on the CTS. The long-term presence of humans in space highlights the need for effective countermeasures to gravitational effects on the CTS.

Menopausal hot flashes: Randomness or rhythmicity

NASA Astrophysics Data System (ADS)

Kronenberg, Fredi

1991-10-01

Menopausal hot flashes are episodes of flushing, increased heart rate, skin blood flow and skin temperature, and a sensation of heat. The thermoregulatory and cardiovascular concomitants of hot flashes are associated with peaks in the levels of various hormones and neurotransmitters in the peripheral circulation. Although hot flashes affect about 75% of women, and are the primary reason that women at menopause seek medical attention, the mechanism of hot flashes is still not understood. Hot flashes vary in frequency and intensity both within and between individuals, and have been thought of as occurring randomly. Yet, some women report that their hot flashes are worse at a particular time of day or year. Initial examination of subjects' recordings of their hot flashes showed diurnal patterns of hot flash occurrence. There also seems to be a diurnal rhythm of hot flash intensity. Continuous physiological monitoring of hot flashes is facilitating the analysis of these patterns, which is revealing circadian and ultradian periodicities. The occurrence of hot flashes can be modulated by external and internal factors, including ambient temperature and fever. Rhythms of thermoregulatory and endocrine functions also may influence hot flash patterns. Examination of the interrelationships between the various systems of the body involved in hot flashes, and a multidisciplinary approach to the analysis of hot flash patterns, will aid our understanding of this complex phenomenon.

Serotonin syndrome following methylene blue administration during cardiothoracic surgery.

PubMed

Smith, Christina J; Wang, Dorothy; Sgambelluri, Anna; Kramer, Robert S; Gagnon, David J

2015-04-01

Despite its favorable safety profile, there have been reports of methylene blue-induced encephalopathy and serotonin syndrome in patients undergoing parathyroidectomy. We report a case of serotonin syndrome following methylene blue administration in a cardiothoracic surgery patient. A 59-year-old woman taking preoperative venlafaxine and trazodone was given a single dose of 2 mg/kg methylene blue (167 mg) during a planned coronary artery bypass and mitral valve repair. Postoperatively, she was febrile to 38.7°C and developed full-body tremors, rhythmic twitching of the perioral muscles, slow conjugate roving eye movements, and spontaneous movements of the upper extremities. Electroencephalography revealed generalized diffuse slowing consistent with toxic encephalopathy, and a computed tomography scan showed no acute process. The patient's symptoms were most consistent with a methylene blue-induced serotonin syndrome. Her motor symptoms resolved within 48 hours and she was eventually discharged home. Only 2 cases of methylene blue-induced serotonin syndrome during cardiothoracic surgery have been described in the literature, with this report representing the third case. Methylene blue and its metabolite, azure B, are potent, reversible inhibitors of monoamine oxidase A which is responsible for serotonin metabolism. Concomitant administration of methylene blue with serotonin-modulating agents may precipitate serotonin syndrome. © The Author(s) 2015.

New findings regarding light intensity and its effects as a zeitgeber in the Sprague-Dawley rat

NASA Technical Reports Server (NTRS)

Tischler, A. C.; Winget, C. M.; Holley, D. C.; Deroshia, C. W.; Gott, J.; Mele, G.; Callahan, P. X.

1993-01-01

In most mammals, the suprachiasmatic nucleus of the anterior hypothalamus has been implicated as the central driving mechanism of circadian rhythmicity. The photic input from the retina, via the retino-hypothalamic tract, and modulation from the pineal gland help regulate the clock. In this study, we investigated the effects of low light intensity on the circadian system of the Sprague-Dawley rat. A series of light intensity experiments were conducted to determine if a light level of 0.1 Lux will maintain entrained circadian rhythms of feeding, drinking, and locomotor activity.

Processing Rhythmic Pattern during Chinese Sentence Reading: An Eye Movement Study

PubMed Central

Luo, Yingyi; Duan, Yunyan; Zhou, Xiaolin

2015-01-01

Prosodic constraints play a fundamental role during both spoken sentence comprehension and silent reading. In Chinese, the rhythmic pattern of the verb-object (V-O) combination has been found to rapidly affect the semantic access/integration process during sentence reading (Luo and Zhou, 2010). Rhythmic pattern refers to the combination of words with different syllabic lengths, with certain combinations disallowed (e.g., [2 + 1]; numbers standing for the number of syllables of the verb and the noun respectively) and certain combinations preferred (e.g., [1 + 1] or [2 + 2]). This constraint extends to the situation in which the combination is used to modify other words. A V-O phrase could modify a noun by simply preceding it, forming a V-O-N compound; when the verb is disyllabic, however, the word order has to be O-V-N and the object is preferred to be disyllabic. In this study, we investigated how the reader processes the rhythmic pattern and word order information by recording the reader's eye-movements. We created four types of sentences by crossing rhythmic pattern and word order in compounding. The compound, embedding a disyllabic verb, could be in the correct O-V-N or the incorrect V-O-N order; the object could be disyllabic or monosyllabic. We found that the reader spent more time and made more regressions on and after the compounds when either type of anomaly was detected during the first pass reading. However, during re-reading (after all the words in the sentence have been viewed), less regressive eye movements were found for the anomalous rhythmic pattern, relative to the correct pattern; moreover, only the abnormal rhythmic pattern, not the violated word order, influenced the regressive eye movements. These results suggest that while the processing of rhythmic pattern and word order information occurs rapidly during the initial reading of the sentence, the process of recovering from the rhythmic pattern anomaly may ease the reanalysis processing at the later stage of sentence integration. Thus, rhythmic pattern in Chinese can dynamically affect both local phrase analysis and global sentence integration during silent reading. PMID:26696942

Processing Rhythmic Pattern during Chinese Sentence Reading: An Eye Movement Study.

PubMed

Luo, Yingyi; Duan, Yunyan; Zhou, Xiaolin

2015-01-01

Prosodic constraints play a fundamental role during both spoken sentence comprehension and silent reading. In Chinese, the rhythmic pattern of the verb-object (V-O) combination has been found to rapidly affect the semantic access/integration process during sentence reading (Luo and Zhou, 2010). Rhythmic pattern refers to the combination of words with different syllabic lengths, with certain combinations disallowed (e.g., [2 + 1]; numbers standing for the number of syllables of the verb and the noun respectively) and certain combinations preferred (e.g., [1 + 1] or [2 + 2]). This constraint extends to the situation in which the combination is used to modify other words. A V-O phrase could modify a noun by simply preceding it, forming a V-O-N compound; when the verb is disyllabic, however, the word order has to be O-V-N and the object is preferred to be disyllabic. In this study, we investigated how the reader processes the rhythmic pattern and word order information by recording the reader's eye-movements. We created four types of sentences by crossing rhythmic pattern and word order in compounding. The compound, embedding a disyllabic verb, could be in the correct O-V-N or the incorrect V-O-N order; the object could be disyllabic or monosyllabic. We found that the reader spent more time and made more regressions on and after the compounds when either type of anomaly was detected during the first pass reading. However, during re-reading (after all the words in the sentence have been viewed), less regressive eye movements were found for the anomalous rhythmic pattern, relative to the correct pattern; moreover, only the abnormal rhythmic pattern, not the violated word order, influenced the regressive eye movements. These results suggest that while the processing of rhythmic pattern and word order information occurs rapidly during the initial reading of the sentence, the process of recovering from the rhythmic pattern anomaly may ease the reanalysis processing at the later stage of sentence integration. Thus, rhythmic pattern in Chinese can dynamically affect both local phrase analysis and global sentence integration during silent reading.

Endogenous rhythmic growth in oak trees is regulated by internal clocks rather than resource availability

PubMed Central

Herrmann, S.; Recht, S.; Boenn, M.; Feldhahn, L.; Angay, O.; Fleischmann, F.; Tarkka, M T.; Grams, T.E.E.; Buscot, F.

2015-01-01

Common oak trees display endogenous rhythmic growth with alternating shoot and root flushes. To explore the mechanisms involved, microcuttings of the Quercus robur L. clone DF159 were used for 13C/15N labelling in combination with RNA sequencing (RNASeq) transcript profiling of shoots and roots. The effect of plant internal resource availability on the rhythmic growth of the cuttings was tested through inoculation with the ectomycorrhizal fungus Piloderma croceum. Shoot and root flushes were related to parallel shifts in above- and below-ground C and, to a lesser extent, N allocation. Increased plant internal resource availability by P. croceum inoculation with enhanced plant growth affected neither the rhythmic growth nor the associated resource allocation patterns. Two shifts in transcript abundance were identified during root and shoot growth cessation, and most concerned genes were down-regulated. Inoculation with P. croceum suppressed these transcript shifts in roots, but not in shoots. To identify core processes governing the rhythmic growth, functions [Gene Ontology (GO) terms] of the genes differentially expressed during the growth cessation in both leaves and roots of non-inoculated plants and leaves of P. croceum-inoculated plants were examined. Besides genes related to resource acquisition and cell development, which might reflect rather than trigger rhythmic growth, genes involved in signalling and/or regulated by the circadian clock were identified. The results indicate that rhythmic growth involves dramatic oscillations in plant metabolism and gene regulation between below- and above-ground parts. Ectomycorrhizal symbiosis may play a previously unsuspected role in smoothing these oscillations without modifying the rhythmic growth pattern. PMID:26320242

Speech Rhythm: Its Relation to Performance Universals and Articulatory Timing

ERIC Educational Resources Information Center

Allen, George D.

1975-01-01

The relationship between the rhythms of spoken language and the rhythms of other human behavior is examined in terms of: (1) types of rhythmic structures observed, (2) rate of succession of rhythmic units, (3) a perceptual tendency equalization of physically unequal intervals, and (4) the variability of rhythmic motor action. (Author/RM)

The Impact of Rhythmic Entrainment on a Person with Autism.

ERIC Educational Resources Information Center

Orr, Tracy Jo; Myles, Brenda Smith; Carlson, Judith K.

1998-01-01

A study investigated the impact of rhythmic entrainment on an 11-year-old girl with autism who engaged in head jerking and screaming. Rhythmic entrainment intervention was more effective when she exhibited behavior that resulted from a moderate level of stress and less effective when stressors were more severe. (CR)

Dietary Habits and Physical Self-Concept of Elite Rhythmic Gymnasts

ERIC Educational Resources Information Center

Boros, Szilvia

2009-01-01

Study aim: To identify main differences in nutrient patterns, food preferences and physical self-concept between the world's elite rhythmic gymnasts and untrained controls. Material and methods: A group of elite rhythmic gymnasts (n = 103) aged 15-21 years volunteered to participate in the study during the 2003 World Championships in Rhythmic…

A Rhythmic Musical Intervention for Poor Readers: A Comparison of Efficacy with a Letter-Based Intervention

ERIC Educational Resources Information Center

Bhide, Adeetee; Power, Alan; Goswami, Usha

2013-01-01

There is growing evidence that children with reading difficulties show impaired auditory rhythm perception and impairments in musical beat perception tasks. Rhythmic musical interventions with poorer readers may thus improve rhythmic entrainment and consequently improve reading and phonological skills. Here we compare the effects of a musical…

Teaching Rhythmic Gymnastics: A Developmentally Appropriate Approach.

ERIC Educational Resources Information Center

Palmer, Heather C.

This book is designed to guide teachers through the process of creating a developmentally appropriate rhythmic gymnastics program for children age 5-11. Rhythmic gymnastics programs develop fitness, inspire creativity, and allow all children to work at their own level. The book features 10 chapters in two parts. Part 1, "Getting Started on a…

Enhanced musical rhythmic perception in Turkish early and late learners of German

PubMed Central

Roncaglia-Denissen, M. Paula; Schmidt-Kassow, Maren; Heine, Angela; Vuust, Peter; Kotz, Sonja A.

2013-01-01

As language rhythm relies partly on general acoustic properties, such as intensity and duration, mastering two languages with distinct rhythmic properties (i.e., stress position) may enhance musical rhythm perception. We investigated whether competence in a second language (L2) with different rhythmic properties than a L1 affects musical rhythm aptitude. Turkish early (TELG) and late learners (TLLG) of German were compared to German late L2 learners of English (GLE) regarding their musical rhythmic aptitude. While Turkish and German present distinct linguistic rhythm and metric properties, German and English are rather similar in this regard. To account for inter-individual differences, we measured participants' short-term and working memory (WM) capacity, melodic aptitude, and time they spent listening to music. Both groups of Turkish L2 learners of German perceived rhythmic variations significantly better than German L2 learners of English. No differences were found between early and late learners' performance. Our findings suggest that mastering two languages with different rhythmic properties enhances musical rhythm perception, providing further evidence of shared cognitive resources between language and music. PMID:24065946

The Effects of Eight-Month Physical Activity Intervention on Vigilance Performance in Adult Obese Population.

PubMed

Monleón, Cristina; Ballester, Rafael; Sanchis, Carlos; Llorens, Francesc; Martín, Marta; Pablos, Ana

2015-01-01

We aim to analyze the effects of an 8-month physical activity intervention on cardiorespiratory fitness, body mass index (BMI), and vigilance performance in an adult obese population. We conducted an 8-month physical activity intervention based on dance and rhythmic activities. The weekly frequency was 2 sessions of 1 hr per day. Training sessions were divided into 3 phases: a 10-min warm-up, 40 min of dance and rhythmic activities, and 10 min to cool-down. To assess cardiorespiratory fitness, participants performed a modified version of the 6-min walk test from the Senior Fitness Test battery (Larsson & Mattsson, 2001; Rikli & Jones, 1999). Vigilance performance was measured by means of the psychomotor vigilance task (PVT). Two measurements were performed immediately before and after the intervention. The results revealed that participants improved their cardiorespiratory fitness, BMI, and vigilance performance after the intervention. All in all, findings contribute new empirical evidence to the field that investigates the benefits of physical activity intervention on cognitive processes in obese population.

Reduced dental calcium expression and dental mass in chronic sleep deprived rats: Combined EDS, TOF-SIMS, and micro-CT analysis

NASA Astrophysics Data System (ADS)

Kuo, Yi-Jie; Huang, Yung-Kai; Chou, Hsiu-Chu; Pai, Man-Hui; Lee, Ai-Wei; Mai, Fu-Der; Chang, Hung-Ming

2015-08-01

Teeth are the hardest tissue in the body. The growth of teeth is closely regulated by circadian rhythmicity. Considering that sleep deprivation (SD) is a severe condition that disrupts normal circadian rhythmicity, this study was conducted to determine whether calcium expression (the major element participating in teeth constitution), and dental mass would be significantly impaired following SD. Adolescent rats subjected to 3 weeks of SD were processed for energy dispersive spectrum (EDS), time-of-flight secondary ion mass spectrometry (TOF-SIMS), and micro-computed tomography (micro-CT) analyses. The EDS and TOF-SIMS results indicated that high calcium intensity was detected in both the upper and lower incisors of untreated rats. Micro-CT analysis corresponded closely with spectral data in which an enhanced dental mass was calculated in intact animals. However, following SD, both calcium expression and the dental mass were remarkably decreased to nearly half those of the untreated values. Because SD plays a detrimental role in impairing dental structure, establishing satisfactory sleep behavior would therefore serve as a crucial strategy for preventing or improving prevalent dental dysfunctions.

Rhythmic Effects of Syntax Processing in Music and Language.

PubMed

Jung, Harim; Sontag, Samuel; Park, YeBin S; Loui, Psyche

2015-01-01

Music and language are human cognitive and neural functions that share many structural similarities. Past theories posit a sharing of neural resources between syntax processing in music and language (Patel, 2003), and a dynamic attention network that governs general temporal processing (Large and Jones, 1999). Both make predictions about music and language processing over time. Experiment 1 of this study investigates the relationship between rhythmic expectancy and musical and linguistic syntax in a reading time paradigm. Stimuli (adapted from Slevc et al., 2009) were sentences broken down into segments; each sentence segment was paired with a musical chord and presented at a fixed inter-onset interval. Linguistic syntax violations appeared in a garden-path design. During the critical region of the garden-path sentence, i.e., the particular segment in which the syntactic unexpectedness was processed, expectancy violations for language, music, and rhythm were each independently manipulated: musical expectation was manipulated by presenting out-of-key chords and rhythmic expectancy was manipulated by perturbing the fixed inter-onset interval such that the sentence segments and musical chords appeared either early or late. Reading times were recorded for each sentence segment and compared for linguistic, musical, and rhythmic expectancy. Results showed main effects of rhythmic expectancy and linguistic syntax expectancy on reading time. There was also an effect of rhythm on the interaction between musical and linguistic syntax: effects of violations in musical and linguistic syntax showed significant interaction only during rhythmically expected trials. To test the effects of our experimental design on rhythmic and linguistic expectancies, independently of musical syntax, Experiment 2 used the same experimental paradigm, but the musical factor was eliminated-linguistic stimuli were simply presented silently, and rhythmic expectancy was manipulated at the critical region. Experiment 2 replicated effects of rhythm and language, without an interaction. Together, results suggest that the interaction of music and language syntax processing depends on rhythmic expectancy, and support a merging of theories of music and language syntax processing with dynamic models of attentional entrainment.

A Bootstrap Based Measure Robust to the Choice of Normalization Methods for Detecting Rhythmic Features in High Dimensional Data.

PubMed

Larriba, Yolanda; Rueda, Cristina; Fernández, Miguel A; Peddada, Shyamal D

2018-01-01

Motivation: Gene-expression data obtained from high throughput technologies are subject to various sources of noise and accordingly the raw data are pre-processed before formally analyzed. Normalization of the data is a key pre-processing step, since it removes systematic variations across arrays. There are numerous normalization methods available in the literature. Based on our experience, in the context of oscillatory systems, such as cell-cycle, circadian clock, etc., the choice of the normalization method may substantially impact the determination of a gene to be rhythmic. Thus rhythmicity of a gene can purely be an artifact of how the data were normalized. Since the determination of rhythmic genes is an important component of modern toxicological and pharmacological studies, it is important to determine truly rhythmic genes that are robust to the choice of a normalization method. Results: In this paper we introduce a rhythmicity measure and a bootstrap methodology to detect rhythmic genes in an oscillatory system. Although the proposed methodology can be used for any high-throughput gene expression data, in this paper we illustrate the proposed methodology using several publicly available circadian clock microarray gene-expression datasets. We demonstrate that the choice of normalization method has very little effect on the proposed methodology. Specifically, for any pair of normalization methods considered in this paper, the resulting values of the rhythmicity measure are highly correlated. Thus it suggests that the proposed measure is robust to the choice of a normalization method. Consequently, the rhythmicity of a gene is potentially not a mere artifact of the normalization method used. Lastly, as demonstrated in the paper, the proposed bootstrap methodology can also be used for simulating data for genes participating in an oscillatory system using a reference dataset. Availability: A user friendly code implemented in R language can be downloaded from http://www.eio.uva.es/~miguel/robustdetectionprocedure.html.

Neuronal activity in the isolated mouse spinal cord during spontaneous deletions in fictive locomotion: insights into locomotor central pattern generator organization

PubMed Central

Zhong, Guisheng; Shevtsova, Natalia A; Rybak, Ilya A; Harris-Warrick, Ronald M

2012-01-01

We explored the organization of the spinal central pattern generator (CPG) for locomotion by analysing the activity of spinal interneurons and motoneurons during spontaneous deletions occurring during fictive locomotion in the isolated neonatal mouse spinal cord, following earlier work on locomotor deletions in the cat. In the isolated mouse spinal cord, most spontaneous deletions were non-resetting, with rhythmic activity resuming after an integer number of cycles. Flexor and extensor deletions showed marked asymmetry: flexor deletions were accompanied by sustained ipsilateral extensor activity, whereas rhythmic flexor bursting was not perturbed during extensor deletions. Rhythmic activity on one side of the cord was not perturbed during non-resetting spontaneous deletions on the other side, and these deletions could occur with no input from the other side of the cord. These results suggest that the locomotor CPG has a two-level organization with rhythm-generating (RG) and pattern-forming (PF) networks, in which only the flexor RG network is intrinsically rhythmic. To further explore the neuronal organization of the CPG, we monitored activity of motoneurons and selected identified interneurons during spontaneous non-resetting deletions. Motoneurons lost rhythmic synaptic drive during ipsilateral deletions. Flexor-related commissural interneurons continued to fire rhythmically during non-resetting ipsilateral flexor deletions. Deletion analysis revealed two classes of rhythmic V2a interneurons. Type I V2a interneurons retained rhythmic synaptic drive and firing during ipsilateral motor deletions, while type II V2a interneurons lost rhythmic synaptic input and fell silent during deletions. This suggests that the type I neurons are components of the RG, whereas the type II neurons are components of the PF network. We propose a computational model of the spinal locomotor CPG that reproduces our experimental results. The results may provide novel insights into the organization of spinal locomotor networks. PMID:22869012

A Bootstrap Based Measure Robust to the Choice of Normalization Methods for Detecting Rhythmic Features in High Dimensional Data

PubMed Central

Larriba, Yolanda; Rueda, Cristina; Fernández, Miguel A.; Peddada, Shyamal D.

2018-01-01

Motivation: Gene-expression data obtained from high throughput technologies are subject to various sources of noise and accordingly the raw data are pre-processed before formally analyzed. Normalization of the data is a key pre-processing step, since it removes systematic variations across arrays. There are numerous normalization methods available in the literature. Based on our experience, in the context of oscillatory systems, such as cell-cycle, circadian clock, etc., the choice of the normalization method may substantially impact the determination of a gene to be rhythmic. Thus rhythmicity of a gene can purely be an artifact of how the data were normalized. Since the determination of rhythmic genes is an important component of modern toxicological and pharmacological studies, it is important to determine truly rhythmic genes that are robust to the choice of a normalization method. Results: In this paper we introduce a rhythmicity measure and a bootstrap methodology to detect rhythmic genes in an oscillatory system. Although the proposed methodology can be used for any high-throughput gene expression data, in this paper we illustrate the proposed methodology using several publicly available circadian clock microarray gene-expression datasets. We demonstrate that the choice of normalization method has very little effect on the proposed methodology. Specifically, for any pair of normalization methods considered in this paper, the resulting values of the rhythmicity measure are highly correlated. Thus it suggests that the proposed measure is robust to the choice of a normalization method. Consequently, the rhythmicity of a gene is potentially not a mere artifact of the normalization method used. Lastly, as demonstrated in the paper, the proposed bootstrap methodology can also be used for simulating data for genes participating in an oscillatory system using a reference dataset. Availability: A user friendly code implemented in R language can be downloaded from http://www.eio.uva.es/~miguel/robustdetectionprocedure.html PMID:29456555

An Approximation to the Temporal Order in Endogenous Circadian Rhythms of Genes Implicated in Human Adipose Tissue Metabolism

PubMed Central

GARAULET, MARTA; ORDOVÁS, JOSÉ M.; GÓMEZ-ABELLÁN, PURIFICACIÓN; MARTÍNEZ, JOSE A.; MADRID, JUAN A.

2015-01-01

Although it is well established that human adipose tissue (AT) shows circadian rhythmicity, published studies have been discussed as if tissues or systems showed only one or few circadian rhythms at a time. To provide an overall view of the internal temporal order of circadian rhythms in human AT including genes implicated in metabolic processes such as energy intake and expenditure, insulin resistance, adipocyte differentiation, dyslipidemia, and body fat distribution. Visceral and subcutaneous abdominal AT biopsies (n = 6) were obtained from morbid obese women (BMI ≥ 40 kg/m2). To investigate rhythmic expression pattern, AT explants were cultured during 24-h and gene expression was analyzed at the following times: 08:00, 14:00, 20:00, 02:00 h using quantitative real-time PCR. Clock genes, glucocorticoid metabolism-related genes, leptin, adiponectin and their receptors were studied. Significant differences were found both in achrophases and relative-amplitude among genes (P <0.05). Amplitude of most genes rhythms was high (>30%). When interpreting the phase map of gene expression in both depots, data indicated that circadian rhythmicity of the genes studied followed a predictable physiological pattern, particularly for subcutaneous AT. Interesting are the relationships between adiponectin, leptin, and glucocorticoid metabolism-related genes circadian profiles. Their metabolic significance is discussed. Visceral AT behaved in a different way than subcutaneous for most of the genes studied. For every gene, protein mRNA levels fluctuated during the day in synchrony with its receptors. We have provided an overall view of the internal temporal order of circadian rhythms in human adipose tissue. PMID:21520059

Circadian processes in the RNA life cycle.

PubMed

Torres, Manon; Becquet, Denis; Franc, Jean-Louis; François-Bellan, Anne-Marie

2018-05-01

The circadian clock drives daily rhythms of multiple physiological processes, allowing organisms to anticipate and adjust to periodic changes in environmental conditions. These physiological rhythms are associated with robust oscillations in the expression of at least 30% of expressed genes. While the ability for the endogenous timekeeping system to generate a 24-hr cycle is a cell-autonomous mechanism based on negative autoregulatory feedback loops of transcription and translation involving core-clock genes and their protein products, it is now increasingly evident that additional mechanisms also govern the circadian oscillations of clock-controlled genes. Such mechanisms can take place post-transcriptionally during the course of the RNA life cycle. It has been shown that many steps during RNA processing are regulated in a circadian manner, thus contributing to circadian gene expression. These steps include mRNA capping, alternative splicing, changes in splicing efficiency, and changes in RNA stability controlled by the tail length of polyadenylation or the use of alternative polyadenylation sites. RNA transport can also follow a circadian pattern, with a circadian nuclear retention driven by rhythmic expression within the nucleus of particular bodies (the paraspeckles) and circadian export to the cytoplasm driven by rhythmic proteins acting like cargo. Finally, RNA degradation may also follow a circadian pattern through the rhythmic involvement of miRNAs. In this review, we summarize the current knowledge of the post-transcriptional circadian mechanisms known to play a prominent role in shaping circadian gene expression in mammals. This article is categorized under: RNA Processing > Splicing Regulation/Alternative Splicing RNA Processing > RNA Editing and Modification RNA Export and Localization > Nuclear Export/Import. © 2018 Wiley Periodicals, Inc.

Changing patterns of daily rhythmicity across reproductive states in diurnal female Nile grass rats (Arvicanthis niloticus)

PubMed Central

Schradera, Jessica A.; Walaszczykb, Erin J.; Smalea, Laura

2009-01-01

SCHRADER, J.A., E. J. WALASZCZYK, AND L. SMALE. Changing patterns of daily rhythmicity across reproductive states in diurnal female Nile grass rats (Arvicanthis niloticus). PHYSIOL BEHAV XX(X) XXX-XXX, XXXX. -- A suite of changes in circadian rhythms have been described in nocturnal rodents as females go through pregnancy and lactation, but there is no information on such patterns in diurnal species. As the challenges faced by these two groups of animals are somewhat different, we characterized changes in activity and core body temperature (Tb) in female diurnal Nile grass rats (Arvicanthis niloticus) as they went through a series of reproductive states: virgin, pregnant, pregnant and lactating, lactating only, and post-weaning. The phase of neither rhythm varied, but the amplitude did. Females increased their overall levels of daily activity from early to late pregnancy, regardless of whether they were also lactating. The pattern of activity was less rhythmic during early than mid-lactation, in both non-pregnant and pregnant females, as a consequence of a decrease in daytime relative to nighttime activity. The Tb rhythm amplitude dropped from mid-pregnancy through mid-lactation, and there were rises in Tb troughs during the mid-light and mid-dark phases of the day, though pregnancy and lactation affected Tb at these times in somewhat different ways. This study demonstrates that rhythms in diurnal grass rats change during pregnancy and lactation in different ways than those of nocturnal species that have been studied to date and that the effects of pregnancy and lactation are not additive in any simple way. PMID:19744504

Elite level rhythmic gymnasts have significantly more and stronger pain than peers of similar age: a prospective study.

PubMed

Sabeti, Manuel; Jeremian, Lusine; Graf, Alexandra; Kandelhart, Robert

2015-01-01

Rhythmic gymnastics (RG) unites aesthetic, ballet-like motion, and all aspects of gymnastics. To reach elite level, girls begin at early age the intensive training. To date it is unclear if such demanding training influences the incidence and intensity of painful overuse injuries. The purpose of this study is to analyze anatomical painful regions and pain intensity in elite level rhythmic gymnasts (elRG) and compare results with an age-matched control group (CG). This prospective field study was carried out at the European Championship in RG 2013 (218 participating athletes, Vienna, Austria). Volunteering athletes were interviewed according to a preformed questionnaire. As CG secondary school pupils without any competitive sports experience were analyzed accordingly. Overall, 243 young females (144 elRG/66 % of all participants and 99 CG) were observed. ElRGs were significantly (s.) smaller, lighter, and had s. stronger pain (p < 0.001). A total of 72 % of athletes reported to have at least one painful body region compared with 52 % of CG (p < 0.001). ElRG had nearly three times more serious injuries than the CG. In all 23 % off all elRG reported to have had no access to professional medical care. ElRGs were s. more frequently (25 vs 9 %) affected at the lumbar spine and the ankle joint (17.4 vs 7 %). To our knowledge, this trial analyzes the largest cohort of elRG to date. Hence, it is clearly alluded that intensive training in RG is a significant factor causing more and stronger pain than in a CG.

Intensive gait training with rhythmic auditory stimulation in individuals with chronic hemiparetic stroke: a pilot randomized controlled study.

PubMed

Cha, Yuri; Kim, Young; Hwang, Sujin; Chung, Yijung

2014-01-01

Motor relearning protocols should involve task-oriented movement, focused attention, and repetition of desired movements. To investigate the effect of intensive gait training with rhythmic auditory stimulation on postural control and gait performance in individuals with chronic hemiparetic stroke. Twenty patients with chronic hemiparetic stroke participated in this study. Subjects in the Rhythmic auditory stimulation training group (10 subjects) underwent intensive gait training with rhythmic auditory stimulation for a period of 6 weeks (30 min/day, five days/week), while those in the control group (10 subjects) underwent intensive gait training for the same duration. Two clinical measures, Berg balance scale and stroke specific quality of life scale, and a 2-demensional gait analysis system, were used as outcome measure. To provide rhythmic auditory stimulation during gait training, the MIDI Cuebase musical instrument digital interface program and a KM Player version 3.3 was utilized for this study. Intensive gait training with rhythmic auditory stimulation resulted in significant improvement in scores on the Berg balance scale, gait velocity, cadence, stride length and double support period in affected side, and stroke specific quality of life scale compared with the control group after training. Findings of this study suggest that intensive gait training with rhythmic auditory stimulation improves balance and gait performance as well as quality of life, in individuals with chronic hemiparetic stroke.

MEG time-frequency analyses for pre- and post-surgical evaluation of patients with epileptic rhythmic fast activity.

PubMed

Sueda, Keitaro; Takeuchi, Fumiya; Shiraishi, Hideaki; Nakane, Shingo; Asahina, Naoko; Kohsaka, Shinobu; Nakama, Hideyuki; Otsuki, Taisuke; Sawamura, Yutaka; Saitoh, Shinji

2010-02-01

To evaluate the effectiveness of surgery for epilepsy, we analyzed rhythmic fast activity by magnetoencephalography (MEG) before and after surgery using time-frequency analysis. To assess reliability, the results obtained by pre-surgical MEG and intraoperative electrocorticography were compared. Four children with symptomatic localization-related epilepsy caused by circumscribed cortical lesion were examined in the present study using 204-channel helmet-shaped MEG with a sampling rate of 600Hz. One patient had dysembryoplastic neuroepithelial tumor (DNT) and three patients had focal cortical dysplasia (FCD). Aberrant areas were superimposed, to reconstruct 3D MRI images, and illustrated as moving images. In three patients, short-time Fourier transform (STFT) analyses of MEG showed rhythmic activities just above the lesion with FCD and in the vicinity of DNT. In one patient with FCD in the medial temporal lobe, rhythmic activity appeared in the ipsilateral frontal lobe and temporal lateral aspect. These findings correlate well with the results obtained by intraoperative electrocorticography. After the surgery, three patients were relieved of their seizures, and the area of rhythmic MEG activity disappeared or become smaller. One patient had residual rhythmic MEG activity, and she suffered from seizure relapse. Time-frequency analyses using STFT successfully depicted MEG rhythmic fast activity, and would provide valuable information for pre- and post-surgical evaluations to define surgical strategies for patients with epilepsy.

New evidence of a rhythmic priming effect that enhances grammaticality judgments in children.

PubMed

Chern, Alexander; Tillmann, Barbara; Vaughan, Chloe; Gordon, Reyna L

2018-09-01

Musical rhythm and the grammatical structure of language share a surprising number of characteristics that may be intrinsically related in child development. The current study aimed to understand the potential influence of musical rhythmic priming on subsequent spoken grammar task performance in children with typical development who were native speakers of English. Participants (ages 5-8 years) listened to rhythmically regular and irregular musical sequences (within-participants design) followed by blocks of grammatically correct and incorrect sentences upon which they were asked to perform a grammaticality judgment task. Rhythmically regular musical sequences improved performance in grammaticality judgment compared with rhythmically irregular musical sequences. No such effect of rhythmic priming was found in two nonlinguistic control tasks, suggesting a neural overlap between rhythm processing and mechanisms recruited during grammar processing. These findings build on previous research investigating the effect of rhythmic priming by extending the paradigm to a different language, testing a younger population, and employing nonlanguage control tasks. These findings of an immediate influence of rhythm on grammar states (temporarily augmented grammaticality judgment performance) also converge with previous findings of associations between rhythm and grammar traits (stable generalized grammar abilities) in children. Taken together, the results of this study provide additional evidence for shared neural processing for language and music and warrant future investigations of potentially beneficial effects of innovative musical material on language processing. Copyright © 2018 Elsevier Inc. All rights reserved.

Rhythmic Rhymes for Boosting Phonological Awareness in Socially Disadvantaged Children

ERIC Educational Resources Information Center

Kuppen, Sarah E. A.; Bourke, Emilie

2017-01-01

This study evaluated the ability for two rhythmic rhyming programs to raise phonological awareness in the early literacy classroom. Year 1 (5-6-year-olds) from low socioeconomic status schools in Bedfordshire, learned a program of sung or spoken rhythmic rhymes, or acted as controls. The project ran with two independent cohorts (Cohort 1 N = 98,…

Prenez le temps. Pour "faire francais" pensez au rhythme! (Take Your Time. To "Make French," Think about Rhythm!)

ERIC Educational Resources Information Center

Wioland, Francois; Wenk, Brian J.

1983-01-01

Transcripts of 11 dialogs based on rhythmic syllable groups, which make clear the rhythmic structures at the base of spoken French, are presented. Phonetic, lexical, and grammatical variation within the same rhythmic structure strengthen the exercise. The exercises are for intermediate and advanced adult students. (MSE)

Motor Performance and Rhythmic Perception of Children with Intellectual and Developmental Disability and Developmental Coordination Disorder

ERIC Educational Resources Information Center

Kartasidou, Lefkothea; Varsamis, Panagiotis; Sampsonidou, Anna

2012-01-01

Professionals who work with children presenting intellectual and developmental disability (IDD) and developmental coordination disorder (DCD) are concerned with their motor development and their rhythmic perception. The aim of this study is to investigate the correlation between a motor performance test and a music rhythmic test that measures…

Connecting Phrasal and Rhythmic Events: Evidence from Second Language Speech

ERIC Educational Resources Information Center

Nava, Emily Anne

2010-01-01

This dissertation investigates the relation between prosodic events at the phrasal level and component events at the rhythmic level. The overarching hypothesis is that the interaction among component rhythmic events gives rise to prosodic patterns at the phrasal level, while at the same time being constrained by the latter, and that in the case of…

Strength Recovery Following Rhythmic or Sustained Exercise as a Function of Time.

ERIC Educational Resources Information Center

Kearney, Jay T.

The relative rates of strength recovery subsequent to bouts of rhythmic or sustained isometric exercise were investigated. The 72 undergraduates who served as subjects were tested seven times within the framework of a repeated measures design. Each testing session involved two bouts of either rhythmic or sustained isometric exercise separated by a…

The clock gene cycle plays an important role in the circadian clock of the cricket Gryllus bimaculatus.

PubMed

Uryu, Outa; Karpova, Svetlana G; Tomioka, Kenji

2013-07-01

To dissect the molecular oscillatory mechanism of the circadian clock in the cricket Gryllus bimaculatus, we have cloned a cDNA of the clock gene cycle (Gb'cyc) and analyzed its structure and function. Gb'cyc contains four functional domains, i.e. bHLH, PAS-A, PAS-B and BCTR domains, and is expressed rhythmically in light dark cycles, peaking at mid night. The RNA interference (RNAi) of Clock (Gb'Clk) and period (Gb'per) reduced the Gb'cyc mRNA levels and abolished the rhythmic expression, suggesting that the rhythmic expression of Gb'cyc is regulated by a mechanism including Gb'Clk and Gb'per. These features are more similar to those of mammalian orthologue of cyc (Bmal1) than those of Drosophila cyc. A single treatment with double-stranded RNA (dsRNA) of Gb'cyc effectively knocked down the Gb'cyc mRNA level and abolished its rhythmic expression. The cyc RNAi failed to disrupt the locomotor rhythm, but lengthened its free-running period in constant darkness (DD). It is thus likely that Gb'cyc is involved in the circadian clock machinery of the cricket. The cyc RNAi crickets showed a rhythmic expression of Gb'per and timeless (Gb'tim) in the optic lobe in DD, explaining the persistence of the locomotor rhythm. Surprisingly, cyc RNAi revealed a rhythmic expression of Gb'Clk in DD which is otherwise rather constitutively expressed in the optic lobe. These facts suggest that the cricket might have a unique clock oscillatory mechanism in which both Gb'cyc and Gb'Clk are rhythmically controlled and that under abundant expression of Gb'cyc the rhythmic expression of Gb'Clk may be concealed. Copyright © 2013 Elsevier Ltd. All rights reserved.

Rhythmic Auditory Cueing in Motor Rehabilitation for Stroke Patients: Systematic Review and Meta-Analysis.

PubMed

Yoo, Ga Eul; Kim, Soo Ji

2016-01-01

Given the increasing evidence demonstrating the effects of rhythmic auditory cueing for motor rehabilitation of stroke patients, this synthesized analysis is needed in order to improve rehabilitative practice and maximize clinical effectiveness. This study aimed to systematically analyze the literature on rhythmic auditory cueing for motor rehabilitation of stroke patients by highlighting the outcome variables, type of cueing, and stage of stroke. A systematic review with meta-analysis of randomized controlled or clinically controlled trials was conducted. Electronic databases and music therapy journals were searched for studies including stroke, the use of rhythmic auditory cueing, and motor outcomes, such as gait and upper-extremity function. A total of 10 studies (RCT or CCT) with 356 individuals were included for meta-analysis. There were large effect sizes (Hedges's g = 0.984 for walking velocity; Hedges's g = 0.840 for cadence; Hedges's g = 0.760 for stride length; and Hedges's g = 0.456 for Fugl-Meyer test scores) in the use of rhythmic auditory cueing. Additional subgroup analysis demonstrated that although the type of rhythmic cueing and stage of stroke did not lead to statistically substantial group differences, the effect sizes and heterogeneity values in each subgroup implied possible differences in treatment effect. This study corroborates the beneficial effects of rhythmic auditory cueing, supporting its expanded application to broadened areas of rehabilitation for stroke patients. Also, it suggests the future investigation of the differential outcomes depending on how rhythmic auditory cueing is provided in terms of type and intensity implemented. © the American Music Therapy Association 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Endogenous rhythmic growth in oak trees is regulated by internal clocks rather than resource availability.

PubMed

Herrmann, S; Recht, S; Boenn, M; Feldhahn, L; Angay, O; Fleischmann, F; Tarkka, M T; Grams, T E E; Buscot, F

2015-12-01

Common oak trees display endogenous rhythmic growth with alternating shoot and root flushes. To explore the mechanisms involved, microcuttings of the Quercus robur L. clone DF159 were used for (13)C/(15)N labelling in combination with RNA sequencing (RNASeq) transcript profiling of shoots and roots. The effect of plant internal resource availability on the rhythmic growth of the cuttings was tested through inoculation with the ectomycorrhizal fungus Piloderma croceum. Shoot and root flushes were related to parallel shifts in above- and below-ground C and, to a lesser extent, N allocation. Increased plant internal resource availability by P. croceum inoculation with enhanced plant growth affected neither the rhythmic growth nor the associated resource allocation patterns. Two shifts in transcript abundance were identified during root and shoot growth cessation, and most concerned genes were down-regulated. Inoculation with P. croceum suppressed these transcript shifts in roots, but not in shoots. To identify core processes governing the rhythmic growth, functions [Gene Ontology (GO) terms] of the genes differentially expressed during the growth cessation in both leaves and roots of non-inoculated plants and leaves of P. croceum-inoculated plants were examined. Besides genes related to resource acquisition and cell development, which might reflect rather than trigger rhythmic growth, genes involved in signalling and/or regulated by the circadian clock were identified. The results indicate that rhythmic growth involves dramatic oscillations in plant metabolism and gene regulation between below- and above-ground parts. Ectomycorrhizal symbiosis may play a previously unsuspected role in smoothing these oscillations without modifying the rhythmic growth pattern. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology.

Automatic Imitation in Rhythmical Actions: Kinematic Fidelity and the Effects of Compatibility, Delay, and Visual Monitoring

PubMed Central

Eaves, Daniel L.; Turgeon, Martine; Vogt, Stefan

2012-01-01

We demonstrate that observation of everyday rhythmical actions biases subsequent motor execution of the same and of different actions, using a paradigm where the observed actions were irrelevant for action execution. The cycle time of the distractor actions was subtly manipulated across trials, and the cycle time of motor responses served as the main dependent measure. Although distractor frequencies reliably biased response cycle times, this imitation bias was only a small fraction of the modulations in distractor speed, as well as of the modulations produced when participants intentionally imitated the observed rhythms. Importantly, this bias was not only present for compatible actions, but was also found, though numerically reduced, when distractor and executed actions were different (e.g., tooth brushing vs. window wiping), or when the dominant plane of movement was different (horizontal vs. vertical). In addition, these effects were equally pronounced for execution at 0, 4, and 8 s after action observation, a finding that contrasts with the more short-lived effects reported in earlier studies. The imitation bias was also unaffected when vision of the hand was occluded during execution, indicating that this effect most likely resulted from visuomotor interactions during distractor observation, rather than from visual monitoring and guidance during execution. Finally, when the distractor was incompatible in both dimensions (action type and plane) the imitation bias was not reduced further, in an additive way, relative to the single-incompatible conditions. This points to a mechanism whereby the observed action’s impact on motor processing is generally reduced whenever this is not useful for motor planning. We interpret these findings in the framework of biased competition, where intended and distractor actions can be represented as competing and quasi-encapsulated sensorimotor streams. PMID:23071623

The Effects of Music Salience on the Gait Performance of Young Adults.

PubMed

de Bruin, Natalie; Kempster, Cody; Doucette, Angelica; Doan, Jon B; Hu, Bin; Brown, Lesley A

2015-01-01

The presence of a rhythmic beat in the form of a metronome tone or beat-accentuated original music can modulate gait performance; however, it has yet to be determined whether gait modulation can be achieved using commercially available music. The current study investigated the effects of commercially available music on the walking of healthy young adults. Specific aims were (a) to determine whether commercially available music can be used to influence gait (i.e., gait velocity, stride length, cadence, stride time variability), (b) to establish the effect of music salience on gait (i.e., gait velocity, stride length, cadence, stride time variability), and (c) to examine whether music tempi differentially effected gait (i.e., gait velocity, stride length, cadence, stride time variability). Twenty-five participants walked the length of an unobstructed walkway while listening to music. Music selections differed with respect to the salience or the tempo of the music. The genre of music and artists were self-selected by participants. Listening to music while walking was an enjoyable activity that influenced gait. Specifically, salient music selections increased measures of cadence, velocity, and stride length; in contrast, gait was unaltered by the presence of non-salient music. Music tempo did not differentially affect gait performance (gait velocity, stride length, cadence, stride time variability) in these participants. Gait performance was differentially influenced by music salience. These results have implications for clinicians considering the use of commercially available music as an alternative to the traditional rhythmic auditory cues used in rehabilitation programs. © the American Music Therapy Association 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Convergent neuromodulation onto a network neuron can have divergent effects at the network level.

PubMed

Kintos, Nickolas; Nusbaum, Michael P; Nadim, Farzan

2016-04-01

Different neuromodulators often target the same ion channel. When such modulators act on different neuron types, this convergent action can enable a rhythmic network to produce distinct outputs. Less clear are the functional consequences when two neuromodulators influence the same ion channel in the same neuron. We examine the consequences of this seeming redundancy using a mathematical model of the crab gastric mill (chewing) network. This network is activated in vitro by the projection neuron MCN1, which elicits a half-center bursting oscillation between the reciprocally-inhibitory neurons LG and Int1. We focus on two neuropeptides which modulate this network, including a MCN1 neurotransmitter and the hormone crustacean cardioactive peptide (CCAP). Both activate the same voltage-gated current (I MI ) in the LG neuron. However, I MI-MCN1 , resulting from MCN1 released neuropeptide, has phasic dynamics in its maximal conductance due to LG presynaptic inhibition of MCN1, while I MI-CCAP retains the same maximal conductance in both phases of the gastric mill rhythm. Separation of time scales allows us to produce a 2D model from which phase plane analysis shows that, as in the biological system, I MI-MCN1 and I MI-CCAP primarily influence the durations of opposing phases of this rhythm. Furthermore, I MI-MCN1 influences the rhythmic output in a manner similar to the Int1-to-LG synapse, whereas I MI-CCAP has an influence similar to the LG-to-Int1 synapse. These results show that distinct neuromodulators which target the same voltage-gated ion channel in the same network neuron can nevertheless produce distinct effects at the network level, providing divergent neuromodulator actions on network activity.

Convergent neuromodulation onto a network neuron can have divergent effects at the network level

PubMed Central

Kintos, Nickolas; Nusbaum, Michael P.; Nadim, Farzan

2016-01-01

Different neuromodulators often target the same ion channel. When such modulators act on different neuron types, this convergent action can enable a rhythmic network to produce distinct outputs. Less clear are the functional consequences when two neuromodulators influence the same ion channel in the same neuron. We examine the consequences of this seeming redundancy using a mathematical model of the crab gastric mill (chewing) network. This network is activated in vitro by the projection neuron MCN1, which elicits a half-center bursting oscillation between the reciprocally-inhibitory neurons LG and Int1. We focus on two neuropeptides which modulate this network, including a MCN1 neurotransmitter and the hormone crustacean cardioactive peptide (CCAP). Both activate the same voltage-gated current (IMI) in the LG neuron. However, IMI-MCN1, resulting from MCN1 released neuropeptide, has phasic dynamics in its maximal conductance due to LG presynaptic inhibition of MCN1, while IMI-CCAP retains the same maximal conductance in both phases of the gastric mill rhythm. Separation of time scales allows us to produce a 2D model from which phase plane analysis shows that, as in the biological system, IMI-MCN1 and IMI-CCAP primarily influence the durations of opposing phases of this rhythm. Furthermore, IMI-MCN1 influences the rhythmic output in a manner similar to the Int1-to-LG synapse, whereas IMI-CCAP has an influence similar to the LG-to-Int1 synapse. These results show that distinct neuromodulators which target the same voltage-gated ion channel in the same network neuron can nevertheless produce distinct effects at the network level, providing divergent neuromodulator actions on network activity. PMID:26798029

Influence of Quercetin in the Temporal Regulation of Redox Homeostasis in Drosophila melanogaster.

PubMed

Subramanian, Perumal; Kaliyamoorthy, Kanimozhi; Jayapalan, Jaime Jacqueline; Abdul-Rahman, Puteri Shafinaz; Haji Hashim, Onn

2017-01-01

Numerous biological processes are governed by the biological clock. Studies using Drosophila melanogaster (L.) are valuable that could be of importance for their effective applications on rodent studies. In this study, the beneficial role of quercetin (a flavonoid) on H2O2 induced stress in D. melanogaster was investigated. D. melanogaster flies were divided into four groups (group I - control, group II - H2O2 (acute exposure), group III - quercetin, and group IV - quercetin + H2O2 treated). Negative geotaxis assay, oxidative stress indicators (protein carbonyls, thiobarbituric reactive substances [TBARS]), and antioxidants (superoxide dismutase [SOD], catalase [CAT], glutathione-S-transferase [GST], glutathione peroxidase, and reduced glutathione [GSH]) were measured at 4 h intervals over 24 h and temporal expression of heat shock protein-70 (Hsp70), Upd1 (homolog of IL-6 in Drosophila), and nitric oxide synthase (Nos) was analyzed by Western blotting. Groups II and IV showed altered biochemical rhythms (compared with controls). Decreased mesor values of negative geotaxis, SOD, CAT, GST, and GSH were noticed in H2O2, increased mesor of oxidative stress indicators (TBARS and protein carbonyl content) and a reversibility of the rhythmic characteristics were conspicuous after quercetin treatment. The expression levels of Hsp70, Upd1, and Nos were noticeably maximum at 04:00. Significant elevation of expression by H2O2 was nearly normalized by quercetin treatment. The possible mechanism by which quercetin modulates oxidant-antioxidant imbalance under oxidative stress could be ascribed to the modulation of the rhythmic properties. Our results will be helpful to understand the molecular interlink between circadian rhythm and oxidative stress mechanism. © The Author 2017. Published by Oxford University Press on behalf of the Entomological Society of America.

Mated Drosophila melanogaster females consume more amino acids during the dark phase

PubMed Central

Uchizono, Shun; Tabuki, Yumi; Kawaguchi, Natsumi; Tanimura, Teiichi; Itoh, Taichi Q.

2017-01-01

To maintain homeostasis, animals must ingest appropriate quantities, determined by their internal nutritional state, of suitable nutrients. In the fruit fly Drosophila melanogaster, an amino acid deficit induces a specific appetite for amino acids and thus results in their increased consumption. Although multiple processes of physiology, metabolism, and behavior are under circadian control in many organisms, it is unclear whether the circadian clock also modulates such motivated behavior driven by an internal need. Differences in levels of amino acid consumption by flies between the light and dark phases of the day:night cycle were examined using a capillary feeder assay following amino acid deprivation. Female flies exhibited increased consumption of amino acids during the dark phase compared with the light phase. Investigation of mutants lacking a functional period gene (per0), a well-characterized clock gene in Drosophila, found no difference between the light and dark phases in amino acid consumption by per0 flies. Furthermore, increased consumption of amino acids during the dark phase was observed in mated but not in virgin females, which strongly suggested that mating is involved in the rhythmic modulation of amino acid intake. Egg production, which is induced by mating, did not affect the rhythmic change in amino acid consumption, although egg-laying behavior showed a per0-dependent change in rhythm. Elevated consumption of amino acids during the dark phase was partly induced by the action of a seminal protein, sex peptide (SP), on the sex peptide receptor (SPR) in females. Moreover, we showed that the increased consumption of amino acids during the dark phase is induced in mated females independently of their internal level of amino acids. These results suggest that a post-mating SP/SPR signal elevates amino acid consumption during the dark phase via the circadian clock. PMID:28241073

Mated Drosophila melanogaster females consume more amino acids during the dark phase.

PubMed

Uchizono, Shun; Tabuki, Yumi; Kawaguchi, Natsumi; Tanimura, Teiichi; Itoh, Taichi Q

2017-01-01

To maintain homeostasis, animals must ingest appropriate quantities, determined by their internal nutritional state, of suitable nutrients. In the fruit fly Drosophila melanogaster, an amino acid deficit induces a specific appetite for amino acids and thus results in their increased consumption. Although multiple processes of physiology, metabolism, and behavior are under circadian control in many organisms, it is unclear whether the circadian clock also modulates such motivated behavior driven by an internal need. Differences in levels of amino acid consumption by flies between the light and dark phases of the day:night cycle were examined using a capillary feeder assay following amino acid deprivation. Female flies exhibited increased consumption of amino acids during the dark phase compared with the light phase. Investigation of mutants lacking a functional period gene (per0), a well-characterized clock gene in Drosophila, found no difference between the light and dark phases in amino acid consumption by per0 flies. Furthermore, increased consumption of amino acids during the dark phase was observed in mated but not in virgin females, which strongly suggested that mating is involved in the rhythmic modulation of amino acid intake. Egg production, which is induced by mating, did not affect the rhythmic change in amino acid consumption, although egg-laying behavior showed a per0-dependent change in rhythm. Elevated consumption of amino acids during the dark phase was partly induced by the action of a seminal protein, sex peptide (SP), on the sex peptide receptor (SPR) in females. Moreover, we showed that the increased consumption of amino acids during the dark phase is induced in mated females independently of their internal level of amino acids. These results suggest that a post-mating SP/SPR signal elevates amino acid consumption during the dark phase via the circadian clock.

Corporal artistic training influences attention: a pilot study.

PubMed

Ribeiro, Mônica Medeiros; Lima, Isabela; Malloy-Diniz, Leandro; Lage, Guilherme; Pimentel, Lucia Gouvêa; Teixeira, Antônio Lúcio

2014-06-01

This study assessed the effect of the Body Rhythmics (BRIM) on actors' attentional processes. BRIM is a combination of exercises using numbers and rules that enact musical parameters in the moving body through displacements. Male actors (N = 22) participated in the study: 7 in the BRIM (Study) group and 15 in the Control group (groups were equivalent on mean Raven's IQ). The Continuous Performance Test (CPT-II) was administered before and after an intensive period of BRIM training. There was no significant difference on the CPT-II before training. Group results for before vs after training showed a significant difference for reaction time for the Study group. There was also a trend to increased errors of commission in the Study group after BRIM training.

Daily rhythms of behavioral and hormonal patterns in male dromedary camels housed in boxes

PubMed Central

Aubè, Lydiane; Fatnassi, Meriem; Monaco, Davide; Khorchani, Touhami; Lacalandra, Giovanni Michele; Hammadi, Mohamed

2017-01-01

Background Daily rhythmicity has been observed for a number of hormonal and behavioral variables in mammals. It can be entrained by several external factors, such as light-dark cycle and scheduled feeding. In dromedary camels, daily rhythmicity has been documented only for melatonin secretion and body temperature. In this study, the daily rhythmicity of behavioral repertoire, cortisol and testosterone levels was investigated in captive male camels. Methods Six clinically healthy male dromedary camels (Camelus dromedarius) were used. The animals were housed in single boxes for 24 h daily and fed twice a day. Over a period of 48 h, behavioral observations were made and blood samples taken every two hours. The data were analyzed using diurnality index, conisor analysis and PROC mixed procedure. Results The diurnality index for rumination and lying down was close to 0 (respectively, 0.09 and 0.19), while the indices for stereotypy, standing, feeding and walking were close to 1 (respectively, 0.74, 0.84, 0.92 and 0.85). Cosinor analysis revealed daily rhythmicity for all behaviors and for cortisol levels (acrophase at 12:57) but not for testosterone. Rumination and lying down (inactive behaviors) reached a peak during the scotophase, whereas feeding, walking and stereotypy (active behaviors) reached a peak during the photophase around midday. Cortisol level and expression of stereotypies peaked before and after food distribution and were negatively correlated (r =  − 0.287, P = 0.005). Testosterone levels and expression of sexual behaviors were stimulated by the visual and olfactory contacts with the females and were positively correlated (r = 0.164, P = 0.040). Testosterone was also negatively correlated with cortisol (r =  − 0.297; P = 0.003). Discussion These preliminary results provided new knowledge about the daily rhythm of behaviors in camels housed in boxes, suggesting that camels exhibit diurnal behavior pattern in the maintenance conditions outlined in the study. Daily rhythmicity seemed to be entrained not only by the light-dark cycle but also by scheduled feeding. The rise in stereotypy after food distribution could be due to the persistence of feeding motivation and frustration after the ingestion of food. Therefore, feeding practices should be improved to satisfy the foraging and feeding motivation of these camels. Behavioral and hormonal daily patterns in camels should be taken in consideration to adapt the management system, giving the animals more freedom during the light period and a diet richer in fiber, so as to improve reproductive performance, health and welfare. PMID:28367365

Pattern formation in diffusive excitable systems under magnetic flow effects

NASA Astrophysics Data System (ADS)

Mvogo, Alain; Takembo, Clovis N.; Ekobena Fouda, H. P.; Kofané, Timoléon C.

2017-07-01

We study the spatiotemporal formation of patterns in a diffusive FitzHugh-Nagumo network where the effect of electromagnetic induction has been introduced in the standard mathematical model by using magnetic flux, and the modulation of magnetic flux on membrane potential is realized by using memristor coupling. We use the multi-scale expansion to show that the system equations can be reduced to a single differential-difference nonlinear equation. The linear stability analysis is performed and discussed with emphasis on the impact of magnetic flux. It is observed that the effect of memristor coupling importantly modifies the features of modulational instability. Our analytical results are supported by the numerical experiments, which reveal that the improved model can lead to nonlinear quasi-periodic spatiotemporal patterns with some features of synchronization. It is observed also the generation of pulses and rhythmics behaviors like breathing or swimming which are important in brain researches.

Sirt3 modulation may be beneficial in the treatment of ejaculation dysfunction.

PubMed

Mandava, Sree Harsha; Hellstrom, Wayne J G

2013-09-01

Disorders of ejaculation are the most common form of sexual dysfunction. The ejaculatory reflex consists of two phases: emission and expulsion. Premature ejaculation (PE) can arise from overactivity of the smooth muscles responsible for ejaculation. On the other side of the spectrum, delayed ejaculation occurs when an individual is unable to either reach orgasm within an adequate time frame or experiences no ejaculation. While premature ejaculation and to a lesser degree delayed ejaculation have been recognized for quite some time, no FDA approved treatment has been developed. Since both types of ejaculatory dysfunction have an underlying neuro-muscular component, this may be a target for future treatment strategies. We thereby hypothesize that modulation of the rhythmic contraction of the ejaculatory smooth muscles with either a Sirt3 activator or inhibitor may prove beneficial in treating either premature or delayed ejaculation. Copyright © 2013 Elsevier Ltd. All rights reserved.

Respiratory modulation of sympathetic nerve activity is enhanced in male rat offspring following uteroplacental insufficiency.

PubMed

Menuet, C; Wlodek, M E; Fong, A Y; Allen, A M

2016-06-01

Sympathetic nerve activity to the cardiovascular system displays prominent respiratory-related modulation which leads to the generation of rhythmic oscillations in blood pressure called Traube-Hering waves. An amplification of this respiratory modulation of sympathetic activity is observed in hypertension of both genetic, the spontaneously hypertensive rat, and induced, chronic intermittent hypoxia or maternal protein restriction during gestation, origin. Male offspring of mothers with uteroplacental insufficiency, induced by bilateral uterine vessel ligation at 18 days of gestation, are also hypertensive in adulthood. In this study we examined whether these male offspring display altered respiratory modulation of sympathetic activity at pre-hypertensive ages compared to controls. Respiratory, cardiovascular and sympathetic parameters were examined using the working heart-brainstem preparation in 35 day old male rats that had reduced birth weight due to uteroplacental insufficiency. Whilst all respiratory parameters were not different between groups, we observed an enhanced respiratory-related burst of thoracic sympathetic nerve activity and amplified Traube-Hering waves in the growth-restricted group. This group also showed an increased sympathetic and bradycardic response to activation of peripheral chemoreceptors. The observations add support to the view that altered respiratory modulation of sympathetic activity represents a common mechanism involved in the development of several forms of hypertension. Copyright © 2015 Elsevier B.V. All rights reserved.

Metabolic heat production, heat loss and the circadian rhythm of body temperature in the rat.

PubMed

Refinetti, Roberto

2003-05-01

Metabolic heat production (calculated from oxygen consumption), dry heat loss (measured in a calorimeter) and body temperature (measured by telemetry) were recorded simultaneously at 6 min intervals over five consecutive days in rats maintained in constant darkness. Robust circadian rhythmicity (confirmed by chi square periodogram analysis) was observed in all three variables. The rhythm of heat production was phase-advanced by about half an hour in relation to the body temperature rhythm, whereas the rhythm of heat loss was phase-delayed by about half an hour. The balance of heat production and heat loss exhibited a daily oscillation 180 deg out of phase with the oscillation in body temperature. Computations indicated that the amount of heat associated with the generation of the body temperature rhythm (1.6 kJ) corresponds to less than 1 % of the total daily energy budget (172 kJ) in this species. Because of the small magnitude of the fraction of heat balance associated with the body temperature rhythm, it is likely that the daily oscillation in heat balance has a very slow effect on body temperature, thus accounting for the 180 deg phase difference between the rhythms of heat balance and body temperature.

How musical training affects cognitive development: rhythm, reward and other modulating variables

PubMed Central

Miendlarzewska, Ewa A.; Trost, Wiebke J.

2014-01-01

Musical training has recently gained additional interest in education as increasing neuroscientific research demonstrates its positive effects on brain development. Neuroimaging revealed plastic changes in the brains of adult musicians but it is still unclear to what extent they are the product of intensive music training rather than of other factors, such as preexisting biological markers of musicality. In this review, we synthesize a large body of studies demonstrating that benefits of musical training extend beyond the skills it directly aims to train and last well into adulthood. For example, children who undergo musical training have better verbal memory, second language pronunciation accuracy, reading ability and executive functions. Learning to play an instrument as a child may even predict academic performance and IQ in young adulthood. The degree of observed structural and functional adaptation in the brain correlates with intensity and duration of practice. Importantly, the effects on cognitive development depend on the timing of musical initiation due to sensitive periods during development, as well as on several other modulating variables. Notably, we point to motivation, reward and social context of musical education, which are important yet neglected factors affecting the long-term benefits of musical training. Further, we introduce the notion of rhythmic entrainment and suggest that it may represent a mechanism supporting learning and development of executive functions. It also hones temporal processing and orienting of attention in time that may underlie enhancements observed in reading and verbal memory. We conclude that musical training uniquely engenders near and far transfer effects, preparing a foundation for a range of skills, and thus fostering cognitive development. PMID:24672420

Circadian Regulation of Pineal Gland Rhythmicity

PubMed Central

Borjigin, Jimo; Zhang, L. Samantha; Calinescu, Anda-Alexandra

2011-01-01

The pineal gland is a neuroendocrine organ of the brain. Its main task is to synthesize and secrete melatonin, a nocturnal hormone with diverse physiological functions. This review will focus on the central and pineal mechanisms in generation of mammalian pineal rhythmicity including melatonin production. In particular, this review covers the following topics: (1) local control of serotonin and melatonin rhythms; (2) neurotransmitters involved in central control of melatonin; (3) plasticity of the neural circuit controlling melatonin production; (4) role of clock genes in melatonin formation; (5) phase control of pineal rhythmicity; (6) impact of light at night on pineal rhythms; and (7) physiological function of the pineal rhythmicity. PMID:21782887

Comparison between treadmill training with rhythmic auditory stimulation and ground walking with rhythmic auditory stimulation on gait ability in chronic stroke patients: A pilot study.

PubMed

Park, Jin; Park, So-yeon; Kim, Yong-wook; Woo, Youngkeun

2015-01-01

Generally, treadmill training is very effective intervention, and rhythmic auditory stimulation is designed to feedback during gait training in stroke patients. The purpose of this study was to compare the gait abilities in chronic stroke patients following either treadmill walking training with rhythmic auditory stimulation (TRAS) or over ground walking training with rhythmic auditory stimulation (ORAS). Nineteen subjects were divided into two groups: a TRAS group (9 subjects) and an ORAS group (10 subjects). Temporal and spatial gait parameters and motor recovery ability were measured before and after the training period. Gait ability was measured by the Biodex Gait trainer treadmill system, Timed up and go test (TUG), 6 meter walking distance (6MWD) and Functional gait assessment (FGA). After the training periods, the TRAS group showed a significant improvement in walking speed, step cycle, step length of the unaffected limb, coefficient of variation, 6MWD, and, FGA when compared to the ORAS group (p <  0.05). Treadmill walking training during the rhythmic auditory stimulation may be useful for rehabilitation of patients with chronic stroke.

Separate representations of dynamics in rhythmic and discrete movements: evidence from motor learning

PubMed Central

Ingram, James N.; Wolpert, Daniel M.

2011-01-01

Rhythmic and discrete arm movements occur ubiquitously in everyday life, and there is a debate as to whether these two classes of movements arise from the same or different underlying neural mechanisms. Here we examine interference in a motor-learning paradigm to test whether rhythmic and discrete movements employ at least partially separate neural representations. Subjects were required to make circular movements of their right hand while they were exposed to a velocity-dependent force field that perturbed the circularity of the movement path. The direction of the force-field perturbation reversed at the end of each block of 20 revolutions. When subjects made only rhythmic or only discrete circular movements, interference was observed when switching between the two opposing force fields. However, when subjects alternated between blocks of rhythmic and discrete movements, such that each was uniquely associated with one of the perturbation directions, interference was significantly reduced. Only in this case did subjects learn to corepresent the two opposing perturbations, suggesting that different neural resources were employed for the two movement types. Our results provide further evidence that rhythmic and discrete movements employ at least partially separate control mechanisms in the motor system. PMID:21273324

Parasympathetic neural control of canine tracheal smooth muscle.

PubMed

Kobayashi, Ichiro; Kondo, Tetsuri; Hayama, Naoki; Tazaki, Gen

2004-12-01

The middle segment of the trachea is innervated by the recurrent laryngeal and pararecurrent nerves. This study determined the pathway that mediated descending commands to the tracheal smooth muscle. Animals used were seven paralyzed and tracheostomized dogs. Tracheal contraction induced either by apnea, mechanical stimulation of the tracheal bifurcation or hypercapnia was always composed of tonic and rhythmic components. The rhythmic contraction developed in synchrony with rhythmic bursts on phrenic nerve activity (PNA). The respiratory-related bursts were also observed on the recurrent laryngeal nerve activity (RNA) and pararecurrent nerve activity (ParaRNA). During apnea there was no tonic activity neither on RNA or PNA, whereas ParaRNA had both tonic and rhythmic activities. Bursts on RNA preceded to correspondent PNA-bursts by 90+/-13 ms. In contrast, ParaRNA-burst always developed later than PNA-burst and it started at almost the same time as that of tracheal rhythmic contraction. During mechanical stimulation of the trachea or CO2-loading, though RNA did not include tonic component, ParaRNA had tonic activity during tracheal tonic contraction. These findings suggested that rhythmic and tonic contractions of the trachea were mediated through the pararecurrent nerve but not through the recurrent laryngeal nerve.

Persistence of a circadian rhythmicity for thyroid hormones in plasma and thyroid of hibernating male Rana ridibunda.

PubMed

Kühn, E R; Delmotte, N M; Darras, V M

1983-06-01

The presence and circadian rhythmicity of thyroid hormones was studied in plasma and the thyroid gland of male Rana ridibunda before and during hibernation. Hibernating January frogs do have a lower T3 and T4 content of their thyroid gland whereas plasma levels of T3 are maintained and of T4 increased compared to fed September or October frogs. It seems likely that the increased photoperiod in January will be responsible for this increased T4 secretion, since controlled laboratory experiments performed in December did not reveal any influence of low temperature on circulating T3 or T4 levels. Also feeding does not influence circulating levels and thyroid content of thyroid hormones in frogs kept at room temperature during the month of January. A circadian rhythmicity of T3 and T4 in the thyroid gland is present in fed October frogs and in non fed December frogs acclimated at 5 degrees C for 12 days with an acrophase for T3 at approximately 1500 h and for T4 at around 1900 h, whereas in plasma only T3 does have circadian variations (acrophase about midnight) but not T4. When December frogs are acclimated to room temperature for 12 days, frogs are active again, but do not eat and have a lower body weight than frogs hibernating at 5 degrees C. Their T3 content of the thyroid gland has disappeared, but T4 thyroid content and plasma levels of T3 and T4 are maintained. As in hibernating frogs, no circadian variations in T4 plasma concentrations are present whereas the circadian thyroid T4 rhythm disappears. At the same time a dampening in rhythmicity for plasma T3 as judged by the significantly lower amplitude occurs. It is concluded that the persistence of circulating levels of thyroid hormones and of a circadian cyclicity for T3 in plasma in non feeding hibernating frogs may reflect the special metabolic state e.g. availability of food reserves in these animals.

The chick embryo: a leading model in somitogenesis studies.

PubMed

Pourquié, Olivier

2004-09-01

The vertebrate body is built on a metameric organization which consists of a repetition of functionally equivalent units, each comprising a vertebra, its associated muscles, peripheral nerves and blood vessels. This periodic pattern is established during embryogenesis by the somitogenesis process. Somites are generated in a rhythmic fashion from the presomitic mesoderm and they subsequently differentiate to give rise to the vertebrae and skeletal muscles of the body. Somitogenesis has been very actively studied in the chick embryo since the 19th century and many of the landmark experiments that led to our current understanding of the vertebrate segmentation process have been performed in this organism. Somite formation involves an oscillator, the segmentation clock whose periodic signal is converted into the periodic array of somite boundaries by a spacing mechanism relying on a traveling threshold of FGF signaling regressing in concert with body axis extension.

Ribosome profiling reveals the rhythmic liver translatome and circadian clock regulation by upstream open reading frames

PubMed Central

Janich, Peggy; Arpat, Alaaddin Bulak; Castelo-Szekely, Violeta; Lopes, Maykel; Gatfield, David

2015-01-01

Mammalian gene expression displays widespread circadian oscillations. Rhythmic transcription underlies the core clock mechanism, but it cannot explain numerous observations made at the level of protein rhythmicity. We have used ribosome profiling in mouse liver to measure the translation of mRNAs into protein around the clock and at high temporal and nucleotide resolution. We discovered, transcriptome-wide, extensive rhythms in ribosome occupancy and identified a core set of approximately 150 mRNAs subject to particularly robust daily changes in translation efficiency. Cycling proteins produced from nonoscillating transcripts revealed thus-far-unknown rhythmic regulation associated with specific pathways (notably in iron metabolism, through the rhythmic translation of transcripts containing iron responsive elements), and indicated feedback to the rhythmic transcriptome through novel rhythmic transcription factors. Moreover, estimates of relative levels of core clock protein biosynthesis that we deduced from the data explained known features of the circadian clock better than did mRNA expression alone. Finally, we identified uORF translation as a novel regulatory mechanism within the clock circuitry. Consistent with the occurrence of translated uORFs in several core clock transcripts, loss-of-function of Denr, a known regulator of reinitiation after uORF usage and of ribosome recycling, led to circadian period shortening in cells. In summary, our data offer a framework for understanding the dynamics of translational regulation, circadian gene expression, and metabolic control in a solid mammalian organ. PMID:26486724

Circadian and feeding rhythms differentially affect rhythmic mRNA transcription and translation in mouse liver

PubMed Central

Atger, Florian; Gobet, Cédric; Marquis, Julien; Martin, Eva; Wang, Jingkui; Weger, Benjamin; Lefebvre, Grégory; Descombes, Patrick; Naef, Felix; Gachon, Frédéric

2015-01-01

Diurnal oscillations of gene expression are a hallmark of rhythmic physiology across most living organisms. Such oscillations are controlled by the interplay between the circadian clock and feeding rhythms. Although rhythmic mRNA accumulation has been extensively studied, comparatively less is known about their transcription and translation. Here, we quantified simultaneously temporal transcription, accumulation, and translation of mouse liver mRNAs under physiological light–dark conditions and ad libitum or night-restricted feeding in WT and brain and muscle Arnt-like 1 (Bmal1)-deficient animals. We found that rhythmic transcription predominantly drives rhythmic mRNA accumulation and translation for a majority of genes. Comparison of wild-type and Bmal1 KO mice shows that circadian clock and feeding rhythms have broad impact on rhythmic gene expression, Bmal1 deletion affecting surprisingly both transcriptional and posttranscriptional levels. Translation efficiency is differentially regulated during the diurnal cycle for genes with 5′-Terminal Oligo Pyrimidine tract (5′-TOP) sequences and for genes involved in mitochondrial activity, many harboring a Translation Initiator of Short 5′-UTR (TISU) motif. The increased translation efficiency of 5′-TOP and TISU genes is mainly driven by feeding rhythms but Bmal1 deletion also affects amplitude and phase of translation, including TISU genes. Together this study emphasizes the complex interconnections between circadian and feeding rhythms at several steps ultimately determining rhythmic gene expression and translation. PMID:26554015

Neuropeptide Secreted from a Pacemaker Activates Neurons to Control a Rhythmic Behavior

PubMed Central

Wang, Han; Girskis, Kelly; Janssen, Tom; Chan, Jason P.; Dasgupta, Krishnakali; Knowles, James A.; Schoofs, Liliane; Sieburth, Derek

2013-01-01

Summary Background Rhythmic behaviors are driven by endogenous biological clocks in pacemakers, which must reliably transmit timing information to target tissues that execute rhythmic outputs. During the defecation motor program in C. elegans, calcium oscillations in the pacemaker (intestine), which occur about every 50 seconds, trigger rhythmic enteric muscle contractions through downstream GABAergic neurons that innervate enteric muscles. However, the identity of the timing signal released by the pacemaker and the mechanism underlying the delivery of timing information to the GABAergic neurons are unknown. Results Here we show that a neuropeptide-like protein (NLP-40) released by the pacemaker triggers a single rapid calcium transient in the GABAergic neurons during each defecation cycle. We find that mutants lacking nlp-40 have normal pacemaker function, but lack enteric muscle contractions. NLP-40 undergoes calcium-dependent release that is mediated by the calcium sensor, SNT-2/synaptotagmin. We identify AEX-2, the G protein-coupled receptor on the GABAergic neurons, as the receptor of NLP-40. Functional calcium imaging reveals that NLP-40 and AEX-2/GPCR are both necessary for rhythmic activation of these neurons. Furthermore, acute application of synthetic NLP-40-derived peptide depolarizes the GABAergic neurons in vivo. Conclusions Our results show that NLP-40 carries the timing information from the pacemaker via calcium-dependent release and delivers it to the GABAergic neurons by instructing their activation. Thus, we propose that rhythmic release of neuropeptides can deliver temporal information from pacemakers to downstream neurons to execute rhythmic behaviors. PMID:23583549

Cerebral CBM1 neuron contributes to synaptic modulation appearing during rejection of seaweed in Aplysia kurodai.

PubMed

Narusuye, Kenji; Nagahama, Tatsumi

2002-11-01

The Japanese species Aplysia kurodai feeds well on Ulva but rejects Gelidium with distinctive rhythmic patterned movements of the jaws and radula. We have previously shown that the patterned jaw movements during the rejection of Gelidium might be caused by long-lasting suppression of the monosynaptic transmission from the multiaction MA neurons to the jaw-closing (JC) motor neurons in the buccal ganglia and that the modulation might be directly produced by some cerebral neurons. In the present paper, we have identified a pair of catecholaminergic neurons (CBM1) in bilateral cerebral M clusters. The CBM1, probably equivalent to CBI-1 in A. californica, simultaneously produced monosynaptic excitatory postsynaptic potentials (EPSPs) in the MA and JC neurons. Firing of the CBM1 reduced the size of the inhibitory postsynaptic currents (IPSCs) in the JC neuron, evoked by the MA spikes, for >100 s. Moreover, the application of dopamine mimicked the CBM1 modulatory effects and pretreatment with a D1 antagonist, SCH23390, blocked the modulatory effects induced by dopamine. It could also largely block the modulatory effects induced by the CBM1 firing. These results suggest that the CBM1 may directly modulate the synaptic transmission by releasing dopamine. Moreover, we explored the CBM1 spike activity induced by taste stimulation of the animal lips with seaweed extracts by the use of calcium imaging. The calcium-sensitive dye, Calcium Green-1, was iontophoretically loaded into a cell body of the CBM1 using a microelectrode. Application of either Ulva or Gelidium extract to the lips increased the fluorescence intensity, but the Gelidium extract always induced a larger change in fluorescence compared with the Ulva extract, although the solution used induced the maximum spike responses of the CBM1 for each of the seaweed extracts. When the firing frequency of the CBM1 activity after taste stimulation was estimated, the Gelidium extract induced a spike activity of ~30 spikes/s while the Ulva extract induced an activity of ~20 spikes/s, consistent with the effective firing frequency (>25 spikes/s) for the synaptic modulation. These results suggest that the CBM1 may be one of the cerebral neurons contributing to the modulation of the basic feeding circuits for rejection induced by the taste of seaweeds such as Gelidium.

Emotional modulation of body-selective visual areas.

PubMed

Peelen, Marius V; Atkinson, Anthony P; Andersson, Frederic; Vuilleumier, Patrik

2007-12-01

Emotionally expressive faces have been shown to modulate activation in visual cortex, including face-selective regions in ventral temporal lobe. Here, we tested whether emotionally expressive bodies similarly modulate activation in body-selective regions. We show that dynamic displays of bodies with various emotional expressions vs neutral bodies, produce significant activation in two distinct body-selective visual areas, the extrastriate body area and the fusiform body area. Multi-voxel pattern analysis showed that the strength of this emotional modulation was related, on a voxel-by-voxel basis, to the degree of body selectivity, while there was no relation with the degree of selectivity for faces. Across subjects, amygdala responses to emotional bodies positively correlated with the modulation of body-selective areas. Together, these results suggest that emotional cues from body movements produce topographically selective influences on category-specific populations of neurons in visual cortex, and these increases may implicate discrete modulatory projections from the amygdala.

Learning and Discrimination of Audiovisual Events in Human Infants: The Hierarchical Relation between Intersensory Temporal Synchrony and Rhythmic Pattern Cues.

ERIC Educational Resources Information Center

Lewkowicz, David J.

2003-01-01

Three experiments examined 4- to 10-month-olds' perception of audio-visual (A-V) temporal synchrony cues in the presence or absence of rhythmic pattern cues. Results established that infants of all ages could discriminate between two different audio-visual rhythmic events. Only 10-month-olds detected a desynchronization of the auditory and visual…

Rhythmic Effects of Syntax Processing in Music and Language

PubMed Central

Jung, Harim; Sontag, Samuel; Park, YeBin S.; Loui, Psyche

2015-01-01

Music and language are human cognitive and neural functions that share many structural similarities. Past theories posit a sharing of neural resources between syntax processing in music and language (Patel, 2003), and a dynamic attention network that governs general temporal processing (Large and Jones, 1999). Both make predictions about music and language processing over time. Experiment 1 of this study investigates the relationship between rhythmic expectancy and musical and linguistic syntax in a reading time paradigm. Stimuli (adapted from Slevc et al., 2009) were sentences broken down into segments; each sentence segment was paired with a musical chord and presented at a fixed inter-onset interval. Linguistic syntax violations appeared in a garden-path design. During the critical region of the garden-path sentence, i.e., the particular segment in which the syntactic unexpectedness was processed, expectancy violations for language, music, and rhythm were each independently manipulated: musical expectation was manipulated by presenting out-of-key chords and rhythmic expectancy was manipulated by perturbing the fixed inter-onset interval such that the sentence segments and musical chords appeared either early or late. Reading times were recorded for each sentence segment and compared for linguistic, musical, and rhythmic expectancy. Results showed main effects of rhythmic expectancy and linguistic syntax expectancy on reading time. There was also an effect of rhythm on the interaction between musical and linguistic syntax: effects of violations in musical and linguistic syntax showed significant interaction only during rhythmically expected trials. To test the effects of our experimental design on rhythmic and linguistic expectancies, independently of musical syntax, Experiment 2 used the same experimental paradigm, but the musical factor was eliminated—linguistic stimuli were simply presented silently, and rhythmic expectancy was manipulated at the critical region. Experiment 2 replicated effects of rhythm and language, without an interaction. Together, results suggest that the interaction of music and language syntax processing depends on rhythmic expectancy, and support a merging of theories of music and language syntax processing with dynamic models of attentional entrainment. PMID:26635672

Stereotypic movement disorders.

PubMed

Singer, Harvey S

2011-01-01

Stereotypic movements are repetitive, rhythmic, fixed, patterned in form, amplitude, and localization, but purposeless (e.g., hand shaking, waving, body rocking, head nodding). They are commonly seen in children; both in normal children (primary stereotypy) and in individuals with additional behavioral or neurological signs and symptoms (secondary stereotypy). They should be differentiated from compulsions (OCD), tics (tic disorders), trichotillomania, skin picking disorder, or the direct physiological effect of a substance. There is increasing evidence to support a neurobiological mechanism. Response to behavioral and pharmacological therapies is variable. Copyright © 2011 Elsevier B.V. All rights reserved.

Head-Directional Tuning and Theta Modulation of Anatomically Identified Neurons in the Presubiculum.

PubMed

Tukker, John J; Tang, Qiusong; Burgalossi, Andrea; Brecht, Michael

2015-11-18

The presubiculum provides a major input to the medial entorhinal cortex (MEC) and contains cells that encode for the animal's head direction (HD), as well as other cells likely to be important for navigation and memory, including grid cells. To understand the mechanisms underlying HD cell firing and its effects on other parts of the circuit, it is important to determine the anatomical identity of these functionally defined cells. Therefore, we juxtacellularly recorded single cells in the presubiculum in freely moving rats, finding two classes of cells based on firing patterns and juxtacellular labeling (of a subset). Regular-firing cells had the anatomical characteristics of pyramidal cells and included most recorded HD cells. Therefore, HD cells are likely to be excitatory pyramidal cells. For one HD cell, we could follow an axon projecting directly to the MEC. Fast-spiking (FS) cells had the anatomical characteristics of interneurons and displayed weak HD tuning. Furthermore, FS cells displayed a surprising lack of theta-rhythmic firing, in strong contrast to the FS cells that we recorded in the MEC. Overall, we show that HD cells in the presubiculum are pyramidal cells, with FS interneurons only showing weak HD tuning; therefore, MEC may receive an excitatory HD input, as previously assumed by many models. The lack of theta rhythmicity in FS interneurons suggests that different mechanisms may underlie theta in different parts of the hippocampal formation. In freely moving rats, we recorded and labeled single neurons in the presubiculum, an area providing one of the major inputs to the medial entorhinal cortex and part of a network involved in spatial navigation and memory. Post hoc identification of labeled cells showed that (fast-spiking, FS) interneurons and pyramidal cells in the presubiculum can be distinguished based on physiological criteria. We found that both moderately and strongly tuned head-direction (HD) cells are pyramidal cells and therefore likely to provide an excitatory HD input to the entorhinal cortex. FS interneurons were weakly head directional and, surprisingly, showed no theta-rhythmic firing. Therefore, the presubiculum appears to encode HD information via excitatory pyramidal cells, possibly also involving FS interneurons, without using a theta-rhythmic temporal code. Copyright © 2015 the authors 0270-6474/15/3515391-05$15.00/0.

Transitions between Multiband Oscillatory Patterns Characterize Memory-Guided Perceptual Decisions in Prefrontal Circuits.

PubMed

Wimmer, Klaus; Ramon, Marc; Pasternak, Tatiana; Compte, Albert

2016-01-13

Neuronal activity in the lateral prefrontal cortex (LPFC) reflects the structure and cognitive demands of memory-guided sensory discrimination tasks. However, we still do not know how neuronal activity articulates in network states involved in perceiving, remembering, and comparing sensory information during such tasks. Oscillations in local field potentials (LFPs) provide fingerprints of such network dynamics. Here, we examined LFPs recorded from LPFC of macaques while they compared the directions or the speeds of two moving random-dot patterns, S1 and S2, separated by a delay. LFP activity in the theta, beta, and gamma bands tracked consecutive components of the task. In response to motion stimuli, LFP theta and gamma power increased, and beta power decreased, but showed only weak motion selectivity. In the delay, LFP beta power modulation anticipated the onset of S2 and encoded the task-relevant S1 feature, suggesting network dynamics associated with memory maintenance. After S2 onset the difference between the current stimulus S2 and the remembered S1 was strongly reflected in broadband LFP activity, with an early sensory-related component proportional to stimulus difference and a later choice-related component reflecting the behavioral decision buildup. Our results demonstrate that individual LFP bands reflect both sensory and cognitive processes engaged independently during different stages of the task. This activation pattern suggests that during elementary cognitive tasks, the prefrontal network transitions dynamically between states and that these transitions are characterized by the conjunction of LFP rhythms rather than by single LFP bands. Neurons in the brain communicate through electrical impulses and coordinate this activity in ensembles that pulsate rhythmically, very much like musical instruments in an orchestra. These rhythms change with "brain state," from sleep to waking, but also signal with different oscillation frequencies rapid changes between sensory and cognitive processing. Here, we studied rhythmic electrical activity in the monkey prefrontal cortex, an area implicated in working memory, decision making, and executive control. Monkeys had to identify and remember a visual motion pattern and compare it to a second pattern. We found orderly transitions between rhythmic activity where the same frequency channels were active in all ongoing prefrontal computations. This supports prefrontal circuit dynamics that transitions rapidly between complex rhythmic patterns during structured cognitive tasks. Copyright © 2016 the authors 0270-6474/16/360489-17$15.00/0.

RGS2 is a feedback inhibitor of melatonin production in the pineal gland

PubMed Central

Matsuo, Masahiro; Coon, Steven L.; Klein, David C.

2014-01-01

The 24-h rhythmic production of melatonin by the pineal gland is essential for coordinating circadian physiology. Melatonin production increases at night in response to the release of norepinephrine from sympathetic nerve processes which innervate the pineal gland. This signal is transduced through G-protein-coupled adrenergic receptors. Here, we found that the abundance of regulator of G-protein signaling 2 (RGS2) increases at night, that expression is increased by norepinephrine and that this protein has a negative feedback effect on melatonin production. These data are consistent with the conclusion that RGS2 functions on a daily basis to negatively modulate melatonin production. PMID:23523917

Rhythmic entrainment as a musical affect induction mechanism.

PubMed

J Trost, W; Labbé, C; Grandjean, D

2017-02-01

One especially important feature of metrical music is that it contains periodicities that listeners' bodily rhythms can adapt to. Recent psychological frameworks have introduced the notion of rhythmic entrainment, among other mechanisms, as an emotion induction principle. In this review paper, we discuss rhythmic entrainment as an affect induction mechanism by differentiating four levels of entrainment in humans-perceptual, autonomic physiological, motor, and social-all of which could contribute to a subjective feeling component. We review the theoretical and empirical literature on rhythmic entrainment to music that supports the existence of these different levels of entrainment by describing the phenomena and characterizing the associated underlying brain processes. The goal of this review is to present the theoretical implications and empirical findings about rhythmic entrainment as an important principle at the basis of affect induction via music, since it rests upon the temporal dimension of music, which is a specificity of music as an affective stimulus. Copyright © 2017 Elsevier Ltd. All rights reserved.

The ecology of entrainment: Foundations of coordinated rhythmic movement.

PubMed

Phillips-Silver, Jessica; Aktipis, C Athena; Bryant, Gregory A

2010-09-01

Entrainment has been studied in a variety of contexts including music perception, dance, verbal communication and motor coordination more generally. Here we seek to provide a unifying framework that incorporates the key aspects of entrainment as it has been studied in these varying domains. We propose that there are a number of types of entrainment that build upon pre-existing adaptations that allow organisms to perceive stimuli as rhythmic, to produce periodic stimuli, and to integrate the two using sensory feedback. We suggest that social entrainment is a special case of spatiotemporal coordination where the rhythmic signal originates from another individual. We use this framework to understand the function and evolutionary basis for coordinated rhythmic movement and to explore questions about the nature of entrainment in music and dance. The framework of entrainment presented here has a number of implications for the vocal learning hypothesis and other proposals for the evolution of coordinated rhythmic behavior across an array of species.

The evolution of locomotor rhythmicity in tetrapods.

PubMed

Ross, Callum F; Blob, Richard W; Carrier, David R; Daley, Monica A; Deban, Stephen M; Demes, Brigitte; Gripper, Janaya L; Iriarte-Diaz, Jose; Kilbourne, Brandon M; Landberg, Tobias; Polk, John D; Schilling, Nadja; Vanhooydonck, Bieke

2013-04-01

Differences in rhythmicity (relative variance in cycle period) among mammal, fish, and lizard feeding systems have been hypothesized to be associated with differences in their sensorimotor control systems. We tested this hypothesis by examining whether the locomotion of tachymetabolic tetrapods (birds and mammals) is more rhythmic than that of bradymetabolic tetrapods (lizards, alligators, turtles, salamanders). Species averages of intraindividual coefficients of variation in cycle period were compared while controlling for gait and substrate. Variance in locomotor cycle periods is significantly lower in tachymetabolic than in bradymetabolic animals for datasets that include treadmill locomotion, non-treadmill locomotion, or both. When phylogenetic relationships are taken into account the pooled analyses remain significant, whereas the non-treadmill and the treadmill analyses become nonsignificant. The co-occurrence of relatively high rhythmicity in both feeding and locomotor systems of tachymetabolic tetrapods suggests that the anatomical substrate of rhythmicity is in the motor control system, not in the musculoskeletal components. © 2012 The Author(s). Evolution© 2012 The Society for the Study of Evolution.

Sleep-Related Rhythmic Movement Disorder and Obstructive Sleep Apnea in Five Adult Patients

PubMed Central

Chiaro, Giacomo; Maestri, Michelangelo; Riccardi, Silvia; Haba-Rubio, José; Miano, Silvia; Bassetti, Claudio L.; Heinzer, Raphaël C.; Manconi, Mauro

2017-01-01

Sleep-related rhythmic movements (SRRMs) are typical in infancy and childhood, where they usually occur at the wake-to-sleep transition. However, they have rarely been observed in adults, where they can be idiopathic or associated with other sleep disorders including sleep apnea. We report a case series of 5 adults with sleep-related rhythmic movement disorder, 4 of whom had a previous history of SRRMs in childhood. SRRMs mostly occurred in consolidated sleep, in association with pathological respiratory events, predominantly longer ones, especially during stage R sleep, and recovered in 1 patient with continuous positive airway pressure therapy. We hypothesize that sleep apneas may act as a trigger of rhythmic motor events through a respiratory-related arousal mechanism in genetically predisposed subjects. Citation: Chiaro G, Maestri M, Riccardi S, Haba-Rubio J, Miano S, Bassetti CL, Heinzer RC, Manconi M. Sleep-related rhythmic movement disorder and obstructive sleep apnea in five adult patients. J Clin Sleep Med. 2017;13(10):1213–1217. PMID:28859719

Computer analysis of the leaf movements of pinto beans.

PubMed

Hoshizaki, T; Hamner, K C

1969-07-01

Computer analysis was used for the detection of rhythmic components and the estimation of period length in leaf movement records. The results of this study indicated that spectral analysis can be profitably used to determine rhythmic components in leaf movements.In Pinto bean plants (Phaseolus vulgaris L.) grown for 28 days under continuous light of 750 ft-c and at a constant temperature of 28 degrees , there was only 1 highly significant rhythmic component in the leaf movements. The period of this rhythm was 27.3 hr. In plants grown at 20 degrees , there were 2 highly significant rhythmic components: 1 of 13.8 hr and a much stronger 1 of 27.3 hr. At 15 degrees , the highly significant rhythmic components were also 27.3 and 13.8 hr in length but were of equal intensity. Random movements less than 9 hr in length became very pronounced at this temperature. At 10 degrees , no significant rhythm was found in the leaf movements. At 5 degrees , the leaf movements ceased within 1 day.

The ecology of entrainment: Foundations of coordinated rhythmic movement

PubMed Central

Phillips-Silver, Jessica; Aktipis, C. Athena; Bryant, Gregory A.

2011-01-01

Entrainment has been studied in a variety of contexts including music perception, dance, verbal communication and motor coordination more generally. Here we seek to provide a unifying framework that incorporates the key aspects of entrainment as it has been studied in these varying domains. We propose that there are a number of types of entrainment that build upon pre-existing adaptations that allow organisms to perceive stimuli as rhythmic, to produce periodic stimuli, and to integrate the two using sensory feedback. We suggest that social entrainment is a special case of spatiotemporal coordination where the rhythmic signal originates from another individual. We use this framework to understand the function and evolutionary basis for coordinated rhythmic movement and to explore questions about the nature of entrainment in music and dance. The framework of entrainment presented here has a number of implications for the vocal learning hypothesis and other proposals for the evolution of coordinated rhythmic behavior across an array of species. PMID:21776183

Abnormal Neurocirculatory Control During Exercise in Humans with Chronic Renal Failure

PubMed Central

Park, Jeanie; Middlekauff, Holly R.

2014-01-01

Abnormal neurocirculatory control during exercise is one important mechanism leading to exercise intolerance in patients with both end-stage renal disease (ESRD) and earlier stages of chronic kidney disease (CKD). This review will provide an overview of mechanisms underlying abnormal neurocirculatory and hemodynamic responses to exercise in patients with kidney disease. Recent studies have shown that ESRD and CKD patients have an exaggerated increase in blood pressure (BP) during both isometric and rhythmic exercise. Subsequent studies examining the role of the exercise pressor reflex in the augmented pressor response revealed that muscle sympathetic nerve activity (MSNA) was not augmented during exercise in these patients, and metaboreflex-mediated increases in MSNA were blunted, while mechanoreflex-mediated increases were preserved under basal conditions. However, normalizing the augmented BP response during exercise via infusion of nitroprusside (NTP), and thereby equalizing baroreflex-mediated suppression of MSNA, an important modulator of the final hemodynamic response to exercise, revealed that CKD patients had an exaggerated increase in MSNA during isometric and rhythmic exercise. In addition, mechanoreflex-mediated control was augmented, and metaboreceptor blunting was no longer apparent in CKD patients with baroreflex normalization. Factors leading to mechanoreceptor sensitization, and other mechanisms underlying the exaggerated exercise pressor response, such as impaired functional sympatholysis, should be investigated in future studies. PMID:25458430

Aging alters circadian regulation of redox in Drosophila

PubMed Central

Klichko, Vladimir I.; Chow, Eileen S.; Kotwica-Rolinska, Joanna; Orr, William C.; Giebultowicz, Jadwiga M.; Radyuk, Svetlana N.

2015-01-01

Circadian coordination of metabolism, physiology, and neural functions contributes to healthy aging and disease prevention. Clock genes govern the daily rhythmic expression of target genes whose activities underlie such broad physiological parameters as maintenance of redox homeostasis. Previously, we reported that glutathione (GSH) biosynthesis is controlled by the circadian system via effects of the clock genes on expression of the catalytic (Gclc) and modulatory (Gclm) subunits comprising the glutamate cysteine ligase (GCL) holoenzyme. The objective of this study was to determine whether and how aging, which leads to weakened circadian oscillations, affects the daily profiles of redox-active biomolecules. We found that fly aging is associated with altered profiles of Gclc and Gclm expression at both the mRNA and protein levels. Analysis of free aminothiols and GCL activity revealed that aging abolishes daily oscillations in GSH levels and alters the activity of glutathione biosynthetic pathways. Unlike GSH, its precursors and products of catabolism, methionine, cysteine and cysteinyl-glycine, were not rhythmic in young or old flies, while rhythms of the glutathione oxidation product, GSSG, were detectable. We conclude that the temporal regulation of GSH biosynthesis is altered in the aging organism and that age-related loss of circadian modulation of pathways involved in glutathione production is likely to impair temporal redox homeostasis. PMID:25806044

Complementary fMRI and EEG evidence for more efficient neural processing of rhythmic vs. unpredictably timed sounds

PubMed Central

van Atteveldt, Nienke; Musacchia, Gabriella; Zion-Golumbic, Elana; Sehatpour, Pejman; Javitt, Daniel C.; Schroeder, Charles

2015-01-01

The brain’s fascinating ability to adapt its internal neural dynamics to the temporal structure of the sensory environment is becoming increasingly clear. It is thought to be metabolically beneficial to align ongoing oscillatory activity to the relevant inputs in a predictable stream, so that they will enter at optimal processing phases of the spontaneously occurring rhythmic excitability fluctuations. However, some contexts have a more predictable temporal structure than others. Here, we tested the hypothesis that the processing of rhythmic sounds is more efficient than the processing of irregularly timed sounds. To do this, we simultaneously measured functional magnetic resonance imaging (fMRI) and electro-encephalograms (EEG) while participants detected oddball target sounds in alternating blocks of rhythmic (e.g., with equal inter-stimulus intervals) or random (e.g., with randomly varied inter-stimulus intervals) tone sequences. Behaviorally, participants detected target sounds faster and more accurately when embedded in rhythmic streams. The fMRI response in the auditory cortex was stronger during random compared to random tone sequence processing. Simultaneously recorded N1 responses showed larger peak amplitudes and longer latencies for tones in the random (vs. the rhythmic) streams. These results reveal complementary evidence for more efficient neural and perceptual processing during temporally predictable sensory contexts. PMID:26579044

Life in a dark biosphere: a review of circadian physiology in "arrhythmic" environments.

PubMed

Beale, Andrew David; Whitmore, David; Moran, Damian

2016-12-01

Most of the life with which humans interact is exposed to highly rhythmic and extremely predictable changes in illumination that occur with the daily events of sunrise and sunset. However, while the influence of the sun feels omnipotent to surface dwellers such as ourselves, life on earth is dominated, in terms of biomass, by organisms isolated from the direct effects of the sun. A limited understanding of what life is like away from the sun can be inferred from our knowledge of physiology and ecology in the light biosphere, but a full understanding can only be gained by studying animals from the dark biosphere, both in the laboratory and in their natural habitats. One of the least understood aspects of life in the dark biosphere is the rhythmicity of physiology and what it means to live in an environment of low or no rhythmicity. Here we describe methods that may be used to understand rhythmic physiology in the dark and summarise some of the studies of rhythmic physiology in "arrhythmic" environments, such as the poles, deep sea and caves. We review what can be understood about the adaptive value of rhythmic physiology on the Earth's surface from studies of animals from arrhythmic environments and what role a circadian clock may play in the dark.

Distinguishing rhythmic from non-rhythmic brain activity during rest in healthy neurocognitive aging.

PubMed

Caplan, Jeremy B; Bottomley, Monica; Kang, Pardeep; Dixon, Roger A

2015-05-15

Rhythmic brain activity at low frequencies (<12Hz) during rest are thought to increase in neurodegenerative disease, but findings in healthy neurocognitive aging are mixed. Here we address two reasons conventional spectral analyses may have led to inconsistent results. First, spectral-power measures are compared to a baseline condition; when resting activity is the signal of interest, it is unclear what the baseline should be. Second, conventional methods do not clearly differentiate power due to rhythmic versus non-rhythmic activity. The Better OSCillation detection method (BOSC; Caplan et al., 2001; Whitten et al., 2011) avoids these problems by using the signal's own spectral characteristics as a reference to detect elevations in power lasting a few cycles. We recorded electroencephalographic (EEG) signal during rest, alternating eyes open and closed, in healthy younger (18-25 years) and older (60-74 years) participants. Topographic plots suggested the conventional and BOSC analyses measured different sources of activity, particularly at frequencies, like delta (1-4Hz), at which rhythms are sporadic; topographies were more similar in the 8-12Hz alpha band. There was little theta-band activity meeting the BOSC method's criteria, suggesting prior findings of theta power in healthy aging may reflect non-rhythmic signal. In contrast, delta oscillations were present at higher levels than theta in both age groups. In summary, applying strict and standardized criteria for rhythmicity, slow rhythms appear present in the resting brain at delta and alpha, but not theta frequencies, and appear unchanged in healthy aging. Copyright © 2015 Elsevier Inc. All rights reserved.

Sequentially allocated clinical trial of rhythmic stabilization exercises and TENS in women with chronic low back pain.

PubMed

Kofotolis, Nikolaos D; Vlachopoulos, Symeon P; Kellis, Eleftherios

2008-02-01

To examine the effectiveness of rhythmic stabilization exercises and transcutaneous electrical nerve stimulation (TENS) and their combination in treating women with chronic low back pain. Sequentially allocated, single-blinded and controlled study, with a two-month follow-up. The data were collected in a patient rehabilitation setting. A total of 92 women (34-46 years old) with chronic low back pain were studied. Sequential allocation was undertaken into four groups: ;rhythmic stabilization' (n=23), ;rhythmic stabilization - TENS' (n=23), TENS (n=23), and a placebo group (n = 23). Each programme lasted for four weeks. All outcome measures were assessed prior to, immediately after, four weeks and eight weeks post intervention. Data were obtained on functional disability, pain intensity, trunk extension range of motion, dynamic endurance of trunk flexion and static endurance of trunk extension. A total of 88 patients provided two-month follow-up data. The ;rhythmic stabilization' and the ;rhythmic stabilization - TENS' groups displayed statistically significant (P<0.05) improvements in functional disability and pain intensity (ranging from 21.2 to 42.8%), trunk extension range of motion (ranging from 6.5 to 25.5%), dynamic endurance of trunk flexion and static endurance of trunk extension (ranging from 13.5 to 74.3%) compared with the remaining groups. The rhythmic stabilization programmes resulted in more gains in women with chronic low back pain regarding the present outcome variables compared with the other groups; therefore, its application in female chronic low back pain patients aged 34-46 years is recommended.

Neuropeptide secreted from a pacemaker activates neurons to control a rhythmic behavior.

PubMed

Wang, Han; Girskis, Kelly; Janssen, Tom; Chan, Jason P; Dasgupta, Krishnakali; Knowles, James A; Schoofs, Liliane; Sieburth, Derek

2013-05-06

Rhythmic behaviors are driven by endogenous biological clocks in pacemakers, which must reliably transmit timing information to target tissues that execute rhythmic outputs. During the defecation motor program in C. elegans, calcium oscillations in the pacemaker (intestine), which occur about every 50 s, trigger rhythmic enteric muscle contractions through downstream GABAergic neurons that innervate enteric muscles. However, the identity of the timing signal released by the pacemaker and the mechanism underlying the delivery of timing information to the GABAergic neurons are unknown. Here, we show that a neuropeptide-like protein (NLP-40) released by the pacemaker triggers a single rapid calcium transient in the GABAergic neurons during each defecation cycle. We find that mutants lacking nlp-40 have normal pacemaker function, but lack enteric muscle contractions. NLP-40 undergoes calcium-dependent release that is mediated by the calcium sensor, SNT-2/synaptotagmin. We identify AEX-2, the G-protein-coupled receptor on the GABAergic neurons, as the receptor for NLP-40. Functional calcium imaging reveals that NLP-40 and AEX-2/GPCR are both necessary for rhythmic activation of these neurons. Furthermore, acute application of synthetic NLP-40-derived peptide depolarizes the GABAergic neurons in vivo. Our results show that NLP-40 carries the timing information from the pacemaker via calcium-dependent release and delivers it to the GABAergic neurons by instructing their activation. Thus, we propose that rhythmic release of neuropeptides can deliver temporal information from pacemakers to downstream neurons to execute rhythmic behaviors. Copyright © 2013 Elsevier Ltd. All rights reserved.

Assessing stability in mild and moderate Parkinson's disease: Can clinical measures provide insight?

PubMed

Hubble, Ryan P; Silburn, Peter A; Naughton, Geraldine A; Cole, Michael H

2016-09-01

This cross-sectional study aimed to investigate the relationship between accelerometer-derived measures of movement rhythmicity and clinical measures of mobility, balance confidence and gait difficulty in people with Parkinson's disease (PD). Twenty-nine independently-living PD patients (Hoehn & Yahr Stages 1-3) with no history of significant injury or orthopaedic/deep brain stimulation surgery were recruited from a database of patients who had expressed an interest to participate in research. Participants completed clinical assessments of mobility, postural stability, balance confidence and symptom severity, while head and trunk rhythmicity was evaluated during gait using accelerometers. Following data collection, patients were stratified based on disease stage into either a Mild (Hoehn & Yahr Stage 1) or Moderate (Hoehn & Yahr Stages 2-3) PD group. The results highlighted that the Moderate PD group had poorer quality of life, reduced balance confidence and increased gait and falls difficulty. Furthermore, for these patients, gait disability and the number of previous falls were both negatively correlated with multiple components of head and trunk rhythmicity. For the Mild PD group, six-meter walk time was positively correlated with ML head rhythmicity and linear regression highlighted a significant predictive relationship between these outcomes. For the Mild and Moderate PD groups, balance confidence respectively predicted anterior-posterior trunk rhythmicity and vertical head rhythmicity. While these findings demonstrate that falls history and the Gait and Falls questionnaire provide moderate insight into head and trunk rhythmicity in Moderate PD patients, objective and clinically-feasible measures of postural instability would assist with the management of these symptoms. Copyright © 2016 Elsevier B.V. All rights reserved.

Distinguishing rhythmic from non-rhythmic brain activity during rest in healthy neurocognitive aging

PubMed Central

Caplan, Jeremy B.; Bottomley, Monica; Kang, Pardeep; Dixon, Roger A.

2015-01-01

Rhythmic brain activity at low frequencies (<12 Hz) during rest are thought to increase in neurodegenerative disease, but findings in healthy neurocognitive aging are mixed. Here we address two reasons conventional spectral analyses may have led to inconsistent results. First, spectral-power measures are compared to a baseline condition; when resting activity is the signal of interest, it is unclear what the baseline should be. Second, conventional methods do not clearly differentiate power due to rhythmic versus non-rhythmic activity. The Better OSCillation detection method (BOSC; [10], [65]) avoids these problems by using the signal’s own spectral characteristics as a reference to detect elevations in power lasting a few cycles. We recorded electroencephalographic (EEG) signal during rest, alternating eyes open and closed, in healthy younger (18–25 years) and older (60–74 years) participants. Topographic plots suggested the conventional and BOSC analyses measured different sources of activity, particularly at frequencies, like delta (1–4 Hz), at which rhythms are sporadic (but topographies were more similar in the 8–12 Hz alpha band). There was little theta-band activity meeting the BOSC method’s criteria, suggesting prior findings of theta power in healthy aging may reflect non-rhythmic signal. In contrast, delta oscillations were present at higher levels than theta in both age groups. In sum, applying strict and standardized criteria for rhythmicity, slow rhythms appear present in the resting brain at delta and alpha, but not theta frequencies, and appear unchanged in healthy aging. PMID:25769279

Investigating the origins of rhythmic major-element zoning in HP/LT garnets from worldwide subduction mélanges

NASA Astrophysics Data System (ADS)

Viete, D. R.; Hacker, B. R.; Seward, G.; Allen, M. B.

2016-12-01

Rhythmic major-element zoning has been documented in garnets from high pressure/low temperature (HP/LT) lenses within a number of worldwide subduction mélanges (e.g. California, Chinese Tianshan, Cuba, Greek Cyclades, Guatemala, Japan, Venezuela). The origin of these features has implications for the nature of subduction-zone processes. Conditions of rhythmic zoning acquirement in HP/LT garnets of California and Venezuela were investigated by use of Raman and FTIR microspectroscopy, and thermodynamic modelling of phase equilibria. Quartz-in-garnet Raman barometry reveals varying P—on the order of 100­-300 MPa, over radial distances of 10s of µm—in association with the high-Mn (and low-Mg) bands that define the fine-scale rhythmic zoning. Results from FTIR microspectroscopy demonstrate association between the high-Mn bands and locally depressed (structural) OH and elevated (molecular) H2O concentrations. The microspectroscopy results suggest changes in P and fluid activity attended development of the cryptic rhythmic zoning. Perple_X modelling of phase equilibria shows that, for specific rock chemistry and subduction P-T conditions, garnet modal abundance is extremely sensitive to changes in P (e.g. 10-20 vol.% growth/dissolution for ΔP = 200 MPa). Rhythmic major-element zoning may reflect P- and/or fluid-driven cycles of garnet stability-instability and/or varying reaction progress/kinetics during subduction. Steep compositional gradients that define the rhythmic major-element zoning limit time scales at subduction T, requiring that such individual stability-instability and/or accelerated reaction cycles were extremely brief. Seismic cycles or porosity waves represent ephemeral phenomena capable of accounting for development of rhythmic major-element zoning in HP/LT garnet, during subduction, as a result of fluctuations in both P and fluids. Metamorphic rocks may well carry detailed records of the catastrophism that punctuates longer-term tectonometamorphic processes.

[Rhythmic beating cardiomyocytes derived from human embryonic germ (EG) cells in vitro].

PubMed

Hua, Jinlian; Xu, Xiaoming; Dou, Zhongying

2006-10-01

Embryonic germ (EG) cells are pluripotent cells derived from primordial germ cells (PGCs) of gonads, gonadal ridges and mesenteries, analogies of fetuses,with the ability to undergo both highly self-renewal and multiple differentiation. These cells in vitro can differentiate into derivatives of all three embryonic germ layers when transferred to an in vitro environment and have the ability to form any fully differentiated cells of the body. The aim of this study is to investigate the potentiality of human EG cells differentiation into cardiomyocytes. Inducing human EG cells with the method of murine ES cells differentiation into cardiomyocytes, supplemented with 0.75%-1% DMSO, 20% NBS, 10(-7) mM RA and 20% cardiomyocytes conditioned medium. 20 heart-like (rhythmic beating cell masses were observed in vitro culture and delayed human EG cells, which beat spontaneously from 20-120 times per minute and maintained beating for 2-15 days, periodic acid's staining (PAS), Myoglobin and a-actin immunological histology positive were all positive and reacted with K+, Ca2+ and adrenalin. Relatively unorganized myofibrillar bundles or more organized sarcomeres, z-bands or a gap junction, the presence of desmosomes in a few cells of the cell masses was observed with transmision electron microscope, which initially demonstrated that these cells were cardiomyocytes. We could not get rhythmly beating cardiomyocytes with 0.75%-1% DMSO, 10-7 mM RA and 20% cardiomyocytes conditioned medium,but in which the percentage of cardiac alpha-actin immunostaining positive cells were increased. The results first demonstrated that human EG cells can differentiate into rhythmic beating cardiomyocytes in vitro and suggests that human EG cells may represent a new potent resource for cardiomyocytes transplantation therapy for myocardium infarction.

Use of Sine Shaped High-Frequency Rhythmic Visual Stimuli Patterns for SSVEP Response Analysis and Fatigue Rate Evaluation in Normal Subjects

PubMed Central

Keihani, Ahmadreza; Shirzhiyan, Zahra; Farahi, Morteza; Shamsi, Elham; Mahnam, Amin; Makkiabadi, Bahador; Haidari, Mohsen R.; Jafari, Amir H.

2018-01-01

Background: Recent EEG-SSVEP signal based BCI studies have used high frequency square pulse visual stimuli to reduce subjective fatigue. However, the effect of total harmonic distortion (THD) has not been considered. Compared to CRT and LCD monitors, LED screen displays high-frequency wave with better refresh rate. In this study, we present high frequency sine wave simple and rhythmic patterns with low THD rate by LED to analyze SSVEP responses and evaluate subjective fatigue in normal subjects. Materials and Methods: We used patterns of 3-sequence high-frequency sine waves (25, 30, and 35 Hz) to design our visual stimuli. Nine stimuli patterns, 3 simple (repetition of each of above 3 frequencies e.g., P25-25-25) and 6 rhythmic (all of the frequencies in 6 different sequences e.g., P25-30-35) were chosen. A hardware setup with low THD rate (<0.1%) was designed to present these patterns on LED. Twenty two normal subjects (aged 23–30 (25 ± 2.1) yrs) were enrolled. Visual analog scale (VAS) was used for subjective fatigue evaluation after presentation of each stimulus pattern. PSD, CCA, and LASSO methods were employed to analyze SSVEP responses. The data including SSVEP features and fatigue rate for different visual stimuli patterns were statistically evaluated. Results: All 9 visual stimuli patterns elicited SSVEP responses. Overall, obtained accuracy rates were 88.35% for PSD and > 90% for CCA and LASSO (for TWs > 1 s). High frequency rhythmic patterns group with low THD rate showed higher accuracy rate (99.24%) than simple patterns group (98.48%). Repeated measure ANOVA showed significant difference between rhythmic pattern features (P < 0.0005). Overall, there was no significant difference between the VAS of rhythmic [3.85 ± 2.13] compared to the simple patterns group [3.96 ± 2.21], (P = 0.63). Rhythmic group had lower within group VAS variation (min = P25-30-35 [2.90 ± 2.45], max = P35-25-30 [4.81 ± 2.65]) as well as least individual pattern VAS (P25-30-35). Discussion and Conclusion: Overall, rhythmic and simple pattern groups had higher and similar accuracy rates. Rhythmic stimuli patterns showed insignificantly lower fatigue rate than simple patterns. We conclude that both rhythmic and simple visual high frequency sine wave stimuli require further research for human subject SSVEP-BCI studies. PMID:29892219

Use of Sine Shaped High-Frequency Rhythmic Visual Stimuli Patterns for SSVEP Response Analysis and Fatigue Rate Evaluation in Normal Subjects.

PubMed

Keihani, Ahmadreza; Shirzhiyan, Zahra; Farahi, Morteza; Shamsi, Elham; Mahnam, Amin; Makkiabadi, Bahador; Haidari, Mohsen R; Jafari, Amir H

2018-01-01

Background: Recent EEG-SSVEP signal based BCI studies have used high frequency square pulse visual stimuli to reduce subjective fatigue. However, the effect of total harmonic distortion (THD) has not been considered. Compared to CRT and LCD monitors, LED screen displays high-frequency wave with better refresh rate. In this study, we present high frequency sine wave simple and rhythmic patterns with low THD rate by LED to analyze SSVEP responses and evaluate subjective fatigue in normal subjects. Materials and Methods: We used patterns of 3-sequence high-frequency sine waves (25, 30, and 35 Hz) to design our visual stimuli. Nine stimuli patterns, 3 simple (repetition of each of above 3 frequencies e.g., P25-25-25) and 6 rhythmic (all of the frequencies in 6 different sequences e.g., P25-30-35) were chosen. A hardware setup with low THD rate (<0.1%) was designed to present these patterns on LED. Twenty two normal subjects (aged 23-30 (25 ± 2.1) yrs) were enrolled. Visual analog scale (VAS) was used for subjective fatigue evaluation after presentation of each stimulus pattern. PSD, CCA, and LASSO methods were employed to analyze SSVEP responses. The data including SSVEP features and fatigue rate for different visual stimuli patterns were statistically evaluated. Results: All 9 visual stimuli patterns elicited SSVEP responses. Overall, obtained accuracy rates were 88.35% for PSD and > 90% for CCA and LASSO (for TWs > 1 s). High frequency rhythmic patterns group with low THD rate showed higher accuracy rate (99.24%) than simple patterns group (98.48%). Repeated measure ANOVA showed significant difference between rhythmic pattern features ( P < 0.0005). Overall, there was no significant difference between the VAS of rhythmic [3.85 ± 2.13] compared to the simple patterns group [3.96 ± 2.21], ( P = 0.63). Rhythmic group had lower within group VAS variation (min = P25-30-35 [2.90 ± 2.45], max = P35-25-30 [4.81 ± 2.65]) as well as least individual pattern VAS (P25-30-35). Discussion and Conclusion: Overall, rhythmic and simple pattern groups had higher and similar accuracy rates. Rhythmic stimuli patterns showed insignificantly lower fatigue rate than simple patterns. We conclude that both rhythmic and simple visual high frequency sine wave stimuli require further research for human subject SSVEP-BCI studies.

Global Profiling of Rice and Poplar Transcriptomes Highlights Key Conserved Circadian-Controlled Pathways and cis-Regulatory Modules

PubMed Central

Filichkin, Sergei A.; Breton, Ghislain; Priest, Henry D.; Dharmawardhana, Palitha; Jaiswal, Pankaj; Fox, Samuel E.; Michael, Todd P.; Chory, Joanne; Kay, Steve A.; Mockler, Todd C.

2011-01-01

Background Circadian clocks provide an adaptive advantage through anticipation of daily and seasonal environmental changes. In plants, the central clock oscillator is regulated by several interlocking feedback loops. It was shown that a substantial proportion of the Arabidopsis genome cycles with phases of peak expression covering the entire day. Synchronized transcriptome cycling is driven through an extensive network of diurnal and clock-regulated transcription factors and their target cis-regulatory elements. Study of the cycling transcriptome in other plant species could thus help elucidate the similarities and differences and identify hubs of regulation common to monocot and dicot plants. Methodology/Principal Findings Using a combination of oligonucleotide microarrays and data mining pipelines, we examined daily rhythms in gene expression in one monocotyledonous and one dicotyledonous plant, rice and poplar, respectively. Cycling transcriptomes were interrogated under different diurnal (driven) and circadian (free running) light and temperature conditions. Collectively, photocycles and thermocycles regulated about 60% of the expressed nuclear genes in rice and poplar. Depending on the condition tested, up to one third of oscillating Arabidopsis-poplar-rice orthologs were phased within three hours of each other suggesting a high degree of conservation in terms of rhythmic gene expression. We identified clusters of rhythmically co-expressed genes and searched their promoter sequences to identify phase-specific cis-elements, including elements that were conserved in the promoters of Arabidopsis, poplar, and rice. Conclusions/Significance Our results show that the cycling patterns of many circadian clock genes are highly conserved across poplar, rice, and Arabidopsis. The expression of many orthologous genes in key metabolic and regulatory pathways is diurnal and/or circadian regulated and phased to similar times of day. Our results confirm previous findings in Arabidopsis of three major classes of cis-regulatory modules within the plant circadian network: the morning (ME, GBOX), evening (EE, GATA), and midnight (PBX/TBX/SBX) modules. Identification of identical overrepresented motifs in the promoters of cycling genes from different species suggests that the core diurnal/circadian cis-regulatory network is deeply conserved between mono- and dicotyledonous species. PMID:21694767

Proceedings of the 1972 Lyndon B. Johnson Space Center Endocrine Program Conference

NASA Technical Reports Server (NTRS)

1974-01-01

Subjects covered during the Endocrine Program Conference include the following: (1) endocrine/metabolic studies on the Apollo 16 crewmen; (2) changes in glucose, insulin, and growth hormone levels associated with bed rest; (3) circadian rhythms of heart rate and body temperature during 56 days of bed rest; (4) stress-induced changes in corticosteroid metabolism in man; (5) present status of physiological studies on parathyroid hormone and vitamin D; (6) antagonistic effect of lithium on antidiuretic hormone action; (7) proposed Skylab body-fluid volumes study; (8) daily rhythmic changes in serotonin content in areas of the mouse brain and norepinephrine content in areas of the hamster brain; (9) studies of sodium homeostasis during simulated weightlessness; and (10) application of the water immersion model to man.

The use of many-body physics and thermodynamics to describe the dynamics of rhythmic generators in sensory cortices engaged in memory and learning.

PubMed

Vitiello, Giuseppe

2015-04-01

The problem of the transition from the molecular and cellular level to the macroscopic level of observed assemblies of myriads of neurons is the subject addressed in this report. The great amount of detailed information available at molecular and cellular level seems not sufficient to account for the high effectiveness and reliability observed in the brain macroscopic functioning. It is suggested that the dissipative many-body model and thermodynamics might offer the dynamical frame underlying the rich phenomenology observed at microscopic and macroscopic level and help in the understanding on how to fill the gap between the bio-molecular and cellular level and the one of brain macroscopic functioning. Copyright © 2014 Elsevier Ltd. All rights reserved.

Regulation of the Rhythmic Emission of Plant Volatiles by the Circadian Clock.

PubMed

Zeng, Lanting; Wang, Xiaoqin; Kang, Ming; Dong, Fang; Yang, Ziyin

2017-11-13

Like other organisms, plants have endogenous biological clocks that enable them to organize their metabolic, physiological, and developmental processes. The representative biological clock is the circadian system that regulates daily (24-h) rhythms. Circadian-regulated changes in growth have been observed in numerous plants. Evidence from many recent studies indicates that the circadian clock regulates a multitude of factors that affect plant metabolites, especially emitted volatiles that have important ecological functions. Here, we review recent progress in research on plant volatiles showing rhythmic emission under the regulation of the circadian clock, and on how the circadian clock controls the rhythmic emission of plant volatiles. We also discuss the potential impact of other factors on the circadian rhythmic emission of plant volatiles.

Quadruped robots' modular trajectories: Stability issues

NASA Astrophysics Data System (ADS)

Pinto, Carla M. A.

2012-09-01

Pinto, Santos, Rocha and Matos [13, 12] study a CPG model for the generation of modular trajectories of quadruped robots. They consider that each movement is composed of two types of primitives: rhythmic and discrete. The rhythmic primitive models the periodic patterns and the discrete primitive is inserted as a perturbation of those patterns. In this paper we begin to tackle numerically the problem of the stability of that mathematical model. We observe that if the discrete part is inserted in all limbs, with equal values, and as an offset of the rhythmic part, the obtained gait is stable and has the same spatial and spatio-temporal symmetry groups as the purely rhythmic gait, differing only on the value of the offset.

Electrical stunning effectiveness with current levels lower than 1 A in lambs and kid goats.

PubMed

Llonch, P; Rodríguez, P; Casal, N; Carreras, R; Muñoz, I; Dalmau, A; Velarde, A

2015-02-01

An experiment with 360 lambs grouped into three Spanish commercial categories, (Pascual, 13-16 kg; Recental, 9-13 kg and Lechal <7 kg carcass weight) and kid goats (7 kg) was performed to assess stunning effectiveness after head-only (HO) and head-to-body (HB) electrical stunning with intensity currents of 0.3, 0.5 and 0.7 Amperes (A) compared to 1.0 A. After stunning, all animals showed tonic-clonic muscular activity and epileptiform EEG, absence of rhythmic breathing, corneal reflex, spontaneous blinking and pain sensibility. The quiescent EEG occurred earlier (P < 0.05) in HB compared to HO in all categories. More animals recovered corneal reflex and rhythmic breathing before onset of the quiescent activity after HO (from 15 to 50%) compared to HB (from 0 to 15%) (P < 0.05). Concluding, HO and HB electrical stunning with 0.3, 0.5 and 0.7 A induce effective stunning similar to 1.0 A in lambs and kid goats. After stunning and sticking, brain failure occurs earlier in HB than HO system. Copyright © 2014 Elsevier Ltd. All rights reserved.

Homology and homoplasy of swimming behaviors and neural circuits in the Nudipleura (Mollusca, Gastropoda, Opisthobranchia)

PubMed Central

Newcomb, James M.; Sakurai, Akira; Lillvis, Joshua L.; Gunaratne, Charuni A.; Katz, Paul S.

2012-01-01

How neural circuit evolution relates to behavioral evolution is not well understood. Here the relationship between neural circuits and behavior is explored with respect to the swimming behaviors of the Nudipleura (Mollusca, Gastropoda, Opithobranchia). Nudipleura is a diverse monophyletic clade of sea slugs among which only a small percentage of species can swim. Swimming falls into a limited number of categories, the most prevalent of which are rhythmic left–right body flexions (LR) and rhythmic dorsal–ventral body flexions (DV). The phylogenetic distribution of these behaviors suggests a high degree of homoplasy. The central pattern generator (CPG) underlying DV swimming has been well characterized in Tritonia diomedea and in Pleurobranchaea californica. The CPG for LR swimming has been elucidated in Melibe leonina and Dendronotus iris, which are more closely related. The CPGs for the categorically distinct DV and LR swimming behaviors consist of nonoverlapping sets of homologous identified neurons, whereas the categorically similar behaviors share some homologous identified neurons, although the exact composition of neurons and synapses in the neural circuits differ. The roles played by homologous identified neurons in categorically distinct behaviors differ. However, homologous identified neurons also play different roles even in the swim CPGs of the two LR swimming species. Individual neurons can be multifunctional within a species. Some of those functions are shared across species, whereas others are not. The pattern of use and reuse of homologous neurons in various forms of swimming and other behaviors further demonstrates that the composition of neural circuits influences the evolution of behaviors. PMID:22723353

Cryptic forcible insemination: male snakes exploit female physiology, anatomy, and behavior to obtain coercive matings.

PubMed

Shine, Richard; Langkilde, Tracy; Mason, Robert T

2003-11-01

Whether males can inseminate uncooperative females is a central determinant of mating system evolution that profoundly affects the interpretation of phenomena such as multiple mating by females, mate choice, reproductive seasonality, and courtship tactics. Forcible insemination is usually inferred from direct physical battles between the sexes and has been dismissed on intuitive grounds for many kinds of animals. For example, snakes have elongate flexible bodies (making it difficult for a male to restrain a female physically), males are typically smaller than females, and copulation requires female cloacal gaping to enable intromission. Male garter snakes (Thamnophis sirtalis) do not display any overt aggression during courtship and simply lie over the female and exhibit rhythmic pulsating caudocephalic waves of muscular contraction; previous studies have interpreted this behavior as a mechanism for eliciting female receptivity. In contrast, we show that male garter snakes forcibly inseminate females. They do so by taking advantage of specific features of snake physiology, respiratory anatomy, and antipredator behavior. The snake lung extends along most of the body, with the large posterior section (the saccular lung) lacking any respiratory exchange surface. Rhythmic caudocephalic waves by courting male garter snakes push anoxic air from the saccular lung forward and across the respiratory surfaces such that females cannot obtain oxygen. Their stress response involves cloacal gaping, which functions in other contexts to repel predators by extruding feces and musk but in this situation permits male intromission. Thus, superficially benign courtship behaviors may involve cryptic coercion even in species for which intuition dismisses any possibility of forcible insemination.

Effects of Gravity on Insect Circadian Rhythmicity

NASA Technical Reports Server (NTRS)

Hoban-Higgins, Tana M.

2000-01-01

Circadian rhythms - endogenous daily rhythmic fluctuations in virtually all characteristics of life - are generated and coordinated by the circadian timing system (CTS). The CTS is synchronized to the external 24-hour day by time cues such as the light/dark cycle. In an environment without time cues, the length of an animal's day is determined by the period of its internal pacemaker (tau) and the animal is said to be free-running. All life on earth evolved under the solar day; the CTS exists as an adaptation that allows organisms to anticipate and to prepare for rhythmic environmental fluctuations. All life on earth also evolved under the force of earth's gravitational environment. While it is therefore not surprising that changes in the lighting environment affect the CTS, it is surprising that changes in the gravitational environment would do so. However, recent data from one of our laboratories using the brn-3.1 knockout mouse revealed that this model, which lacks the sensory receptor hair cells within the neurovestibular system, does not respond to exposure to a hyperdynamic environment in the same fashion as normal mice. The brn-3.1 mice did not show the expected suppression of circadian rhythmicity shown by control mice exposed to 2G. Exposure to altered ambient force environments affects the amplitude, mean and timing of circadian rhythms in species from unicellular organisms to man. In addition, there is a circadian influence on the homeostatic response to acute 2G acceleration and pulses of 2G can act as a time cue, synchronizing the CTS. This is of significance because maintenance of internal and external temporal coordination is critical for normal physiological and psychological function. Typically, during adaptation to an increased gravitational environment (+G), an initial acute reaction is followed by adaptation and, eventually, a new steady state (14-16), which can take weeks to months to establish. Until the development of space stations, exposure to microgravity was, of necessity, relatively short in duration. In early spaceflight experiments an organism's internal rhythms often expressed periods that were different from each other, even in the presence of a 24.0 hour light-dark cycle, suggesting that the organism was experiencing internal desynchronization (17, 18). In (micro)G, the body temperature rhythm was delayed with respect to other body rhythms and to the light-dark cycle in rhesus macaques (19) and man (20, 21). In the absence of a light-dark cycle, the circadian rhythm of spore formation persisted in Neurospora crassa, however, both the variability and average period of the rhythm increased (22). The beetle Trigonoscelis gigas, exhibited changes in period during and following 11-13 days in (micro)G (23, 24). Resynchronization of the urinary calcium rhythm following a 1800 phase shift of the LID cycle was retarded in rats exposed to (micro)G compared to 1G controls (25). With the development of the Russian Mir Space Station, long-term controlled microgravity exposure became possible. We recorded activity rhythms from black-bodied Tenebrionid beetles, Trigonoscelis gigas, in (micro)G (spaceflight). Each insect was housed individually within an activity monitor (26) and data (activity counts) were collected and stored in five-minute bins. Thirty-two individual activity monitors were housed within each of 2 experimental kits. The beetles within each kit were divided into two groups and the lighting was controlled separately for each group.

Neural mechanisms of rhythm-based temporal prediction: Delta phase-locking reflects temporal predictability but not rhythmic entrainment.

PubMed

Breska, Assaf; Deouell, Leon Y

2017-02-01

Predicting the timing of upcoming events enables efficient resource allocation and action preparation. Rhythmic streams, such as music, speech, and biological motion, constitute a pervasive source for temporal predictions. Widely accepted entrainment theories postulate that rhythm-based predictions are mediated by synchronizing low-frequency neural oscillations to the rhythm, as indicated by increased phase concentration (PC) of low-frequency neural activity for rhythmic compared to random streams. However, we show here that PC enhancement in scalp recordings is not specific to rhythms but is observed to the same extent in less periodic streams if they enable memory-based prediction. This is inconsistent with the predictions of a computational entrainment model of stronger PC for rhythmic streams. Anticipatory change in alpha activity and facilitation of electroencephalogram (EEG) manifestations of response selection are also comparable between rhythm- and memory-based predictions. However, rhythmic sequences uniquely result in obligatory depression of preparation-related premotor brain activity when an on-beat event is omitted, even when it is strategically beneficial to maintain preparation, leading to larger behavioral costs for violation of prediction. Thus, while our findings undermine the validity of PC as a sign of rhythmic entrainment, they constitute the first electrophysiological dissociation, to our knowledge, between mechanisms of rhythmic predictions and of memory-based predictions: the former obligatorily lead to resonance-like preparation patterns (that are in line with entrainment), while the latter allow flexible resource allocation in time regardless of periodicity in the input. Taken together, they delineate the neural mechanisms of three distinct modes of preparation: continuous vigilance, interval-timing-based prediction and rhythm-based prediction.

Goal orientations and sport motivation, differences between the athletes of competitive and non-competitive rhythmic gymnastics.

PubMed

Koumpoula, M; Tsopani, D; Flessas, K; Chairopoulou, C

2011-09-01

The present study examines the sport motivation and the goal orientations in the competitive and non-competitive structure of rhythmic gymnastics. Participation of individuals in one or the other structure of the sport differs in line with the goals they want to achieve and possibly also with respect to the factors that impulse them to take part in one or the other. The purpose of this study is to examine how individuals who participate in different structures of the sport of rhythmic gymnastics differentiate with regard to the type of motivation (intrinsic, extrinsic, amotivation) and goal orientations. The study involved 98 young female rhythmic gymnastics athletes (aged 14 years and up), out of which 40 were athletes of competitive clubs or members of national teams, and 58 were athletes of non-competitive clubs. For the evaluation of motivation and goal orientations the following tools were used: the Sport Motivation Scale (SMS) and the Task and Ego Orientation in Sport Questionnaire (TEOSQ). Descriptive and inductive statistical data analysis was conducted. The results showed that the athletes of the non-competitive structure presented higher levels of introjected regulation (extrinsic motivation), amotivation and lower levels of ego orientation (P<0.05). Rhythmic gymnastics athletes' (regardless of the structure of the sport) presented high level in task orientation while the high levels of task orientation is positively associated with high levels of intrinsic motivation regardless of the levels of ego orientation. The intrinsic motivation of athletes participating in rhythmic gymnastics runs at high levels. The amotivation of rhythmic gymnastics athletes' is a phenomenon which is also presented in the the non-competitive sport structure. It is important that the two different structures of sports be determined with accurate criteria.

Neural mechanisms of rhythm-based temporal prediction: Delta phase-locking reflects temporal predictability but not rhythmic entrainment

PubMed Central

Deouell, Leon Y.

2017-01-01

Predicting the timing of upcoming events enables efficient resource allocation and action preparation. Rhythmic streams, such as music, speech, and biological motion, constitute a pervasive source for temporal predictions. Widely accepted entrainment theories postulate that rhythm-based predictions are mediated by synchronizing low-frequency neural oscillations to the rhythm, as indicated by increased phase concentration (PC) of low-frequency neural activity for rhythmic compared to random streams. However, we show here that PC enhancement in scalp recordings is not specific to rhythms but is observed to the same extent in less periodic streams if they enable memory-based prediction. This is inconsistent with the predictions of a computational entrainment model of stronger PC for rhythmic streams. Anticipatory change in alpha activity and facilitation of electroencephalogram (EEG) manifestations of response selection are also comparable between rhythm- and memory-based predictions. However, rhythmic sequences uniquely result in obligatory depression of preparation-related premotor brain activity when an on-beat event is omitted, even when it is strategically beneficial to maintain preparation, leading to larger behavioral costs for violation of prediction. Thus, while our findings undermine the validity of PC as a sign of rhythmic entrainment, they constitute the first electrophysiological dissociation, to our knowledge, between mechanisms of rhythmic predictions and of memory-based predictions: the former obligatorily lead to resonance-like preparation patterns (that are in line with entrainment), while the latter allow flexible resource allocation in time regardless of periodicity in the input. Taken together, they delineate the neural mechanisms of three distinct modes of preparation: continuous vigilance, interval-timing-based prediction and rhythm-based prediction. PMID:28187128

Awareness of Rhythm Patterns in Speech and Music in Children with Specific Language Impairments

PubMed Central

Cumming, Ruth; Wilson, Angela; Leong, Victoria; Colling, Lincoln J.; Goswami, Usha

2015-01-01

Children with specific language impairments (SLIs) show impaired perception and production of language, and also show impairments in perceiving auditory cues to rhythm [amplitude rise time (ART) and sound duration] and in tapping to a rhythmic beat. Here we explore potential links between language development and rhythm perception in 45 children with SLI and 50 age-matched controls. We administered three rhythmic tasks, a musical beat detection task, a tapping-to-music task, and a novel music/speech task, which varied rhythm and pitch cues independently or together in both speech and music. Via low-pass filtering, the music sounded as though it was played from a low-quality radio and the speech sounded as though it was muffled (heard “behind the door”). We report data for all of the SLI children (N = 45, IQ varying), as well as for two independent subgroupings with intact IQ. One subgroup, “Pure SLI,” had intact phonology and reading (N = 16), the other, “SLI PPR” (N = 15), had impaired phonology and reading. When IQ varied (all SLI children), we found significant group differences in all the rhythmic tasks. For the Pure SLI group, there were rhythmic impairments in the tapping task only. For children with SLI and poor phonology (SLI PPR), group differences were found in all of the filtered speech/music AXB tasks. We conclude that difficulties with rhythmic cues in both speech and music are present in children with SLIs, but that some rhythmic measures are more sensitive than others. The data are interpreted within a “prosodic phrasing” hypothesis, and we discuss the potential utility of rhythmic and musical interventions in remediating speech and language difficulties in children. PMID:26733848

Awareness of Rhythm Patterns in Speech and Music in Children with Specific Language Impairments.

PubMed

Cumming, Ruth; Wilson, Angela; Leong, Victoria; Colling, Lincoln J; Goswami, Usha

2015-01-01

Children with specific language impairments (SLIs) show impaired perception and production of language, and also show impairments in perceiving auditory cues to rhythm [amplitude rise time (ART) and sound duration] and in tapping to a rhythmic beat. Here we explore potential links between language development and rhythm perception in 45 children with SLI and 50 age-matched controls. We administered three rhythmic tasks, a musical beat detection task, a tapping-to-music task, and a novel music/speech task, which varied rhythm and pitch cues independently or together in both speech and music. Via low-pass filtering, the music sounded as though it was played from a low-quality radio and the speech sounded as though it was muffled (heard "behind the door"). We report data for all of the SLI children (N = 45, IQ varying), as well as for two independent subgroupings with intact IQ. One subgroup, "Pure SLI," had intact phonology and reading (N = 16), the other, "SLI PPR" (N = 15), had impaired phonology and reading. When IQ varied (all SLI children), we found significant group differences in all the rhythmic tasks. For the Pure SLI group, there were rhythmic impairments in the tapping task only. For children with SLI and poor phonology (SLI PPR), group differences were found in all of the filtered speech/music AXB tasks. We conclude that difficulties with rhythmic cues in both speech and music are present in children with SLIs, but that some rhythmic measures are more sensitive than others. The data are interpreted within a "prosodic phrasing" hypothesis, and we discuss the potential utility of rhythmic and musical interventions in remediating speech and language difficulties in children.

Impact of Auditory Context on Executed Motor Actions

PubMed Central

Yoles-Frenkel, Michal; Avron, Maayan; Prut, Yifat

2016-01-01

The auditory and motor systems are strongly coupled, as is evident in the specifically tight motor synchronization that occurs in response to regularly occurring auditory cues compared with cues of other modalities. Timing of rhythmic action is known to rely on multiple neural centers including the cerebellum and the basal-ganglia which have access to both motor cortical and spinal circuitries. To date, however, there is little information on the motor mechanisms that operate during preparation and execution of rhythmic vs. non-rhythmic movements. We measured acceleration profile and muscle activity while subjects performed tapping movements in response to auditory cues. We found that when tapping at random intervals there was a higher variability of both acceleration profile and muscle activity during motor preparation compared to rhythmic tapping. However, the specific rhythmic context (cued, self-paced, or syncopation) did not affect the motor parameters of the executed taps. Finally, during entrainment we found a gradual as opposed to episodic change in low-level motor parameters (i.e., preparatory muscle activity) that was strongly correlated with changes in high-level parameters (i.e., shift in the reaction time to negative asynchrony). These findings suggest that motor entrainment involves not only adjusting the timing of movement but also modifying parameters that are related to its production. These changes in motor output were insensitive to the specifics of the rhythmic cue: although it took subjects different times to become entrained to different types of rhythmic cues, the motor actions produced once entrainment was obtained were indistinguishable. These findings suggest that motor entrainment involves not only adjusting the timing of movement but also modifying parameters related to its production. The reduced variability of muscle activity during the preparatory period could be one mechanism used by the motor system to enhance the accuracy of motor timing. PMID:26834584

Getting through to circadian oscillators: why use constant routines?

NASA Technical Reports Server (NTRS)

Duffy, Jeanne F.; Dijk, Derk-Jan

2002-01-01

Overt 24-h rhythmicity is composed of both exogenous and endogenous components, reflecting the product of multiple (periodic) feedback loops with a core pacemaker at their center. Researchers attempting to reveal the endogenous circadian (near 24-h) component of rhythms commonly conduct their experiments under constant environmental conditions. However, even under constant environmental conditions, rhythmic changes in behavior, such as food intake or the sleep-wake cycle, can contribute to observed rhythmicity in many physiological and endocrine variables. Assessment of characteristics of the core circadian pacemaker and its direct contribution to rhythmicity in different variables, including rhythmicity in gene expression, may be more reliable when such periodic behaviors are eliminated or kept constant across all circadian phases. This is relevant for the assessment of the status of the circadian pacemaker in situations in which the sleep-wake cycle or food intake regimes are altered because of external conditions, such as in shift work or jet lag. It is also relevant for situations in which differences in overt rhythmicity could be due to changes in either sleep oscillatory processes or circadian rhythmicity, such as advanced or delayed sleep phase syndromes, in aging, or in particular clinical conditions. Researchers studying human circadian rhythms have developed constant routine protocols to assess the status of the circadian pacemaker in constant behavioral and environmental conditions, whereas this technique is often thought to be unnecessary in the study of animal rhythms. In this short review, the authors summarize constant routine methodology and what has been learned from constant routines and argue that animal and human circadian rhythm researchers should (continue to) use constant routines as a step on the road to getting through to central and peripheral circadian oscillators in the intact organism.

Frequency modulation entrains slow neural oscillations and optimizes human listening behavior

PubMed Central

Henry, Molly J.; Obleser, Jonas

2012-01-01

The human ability to continuously track dynamic environmental stimuli, in particular speech, is proposed to profit from “entrainment” of endogenous neural oscillations, which involves phase reorganization such that “optimal” phase comes into line with temporally expected critical events, resulting in improved processing. The current experiment goes beyond previous work in this domain by addressing two thus far unanswered questions. First, how general is neural entrainment to environmental rhythms: Can neural oscillations be entrained by temporal dynamics of ongoing rhythmic stimuli without abrupt onsets? Second, does neural entrainment optimize performance of the perceptual system: Does human auditory perception benefit from neural phase reorganization? In a human electroencephalography study, listeners detected short gaps distributed uniformly with respect to the phase angle of a 3-Hz frequency-modulated stimulus. Listeners’ ability to detect gaps in the frequency-modulated sound was not uniformly distributed in time, but clustered in certain preferred phases of the modulation. Moreover, the optimal stimulus phase was individually determined by the neural delta oscillation entrained by the stimulus. Finally, delta phase predicted behavior better than stimulus phase or the event-related potential after the gap. This study demonstrates behavioral benefits of phase realignment in response to frequency-modulated auditory stimuli, overall suggesting that frequency fluctuations in natural environmental input provide a pacing signal for endogenous neural oscillations, thereby influencing perceptual processing. PMID:23151506

Modeling discrete and rhythmic movements through motor primitives: a review.

PubMed

Degallier, Sarah; Ijspeert, Auke

2010-10-01

Rhythmic and discrete movements are frequently considered separately in motor control, probably because different techniques are commonly used to study and model them. Yet the increasing interest in finding a comprehensive model for movement generation requires bridging the different perspectives arising from the study of those two types of movements. In this article, we consider discrete and rhythmic movements within the framework of motor primitives, i.e., of modular generation of movements. In this way we hope to gain an insight into the functional relationships between discrete and rhythmic movements and thus into a suitable representation for both of them. Within this framework we can define four possible categories of modeling for discrete and rhythmic movements depending on the required command signals and on the spinal processes involved in the generation of the movements. These categories are first discussed in terms of biological concepts such as force fields and central pattern generators and then illustrated by several mathematical models based on dynamical system theory. A discussion on the plausibility of theses models concludes the work.

Rhythmic entrainment source separation: Optimizing analyses of neural responses to rhythmic sensory stimulation.

PubMed

Cohen, Michael X; Gulbinaite, Rasa

2017-02-15

Steady-state evoked potentials (SSEPs) are rhythmic brain responses to rhythmic sensory stimulation, and are often used to study perceptual and attentional processes. We present a data analysis method for maximizing the signal-to-noise ratio of the narrow-band steady-state response in the frequency and time-frequency domains. The method, termed rhythmic entrainment source separation (RESS), is based on denoising source separation approaches that take advantage of the simultaneous but differential projection of neural activity to multiple electrodes or sensors. Our approach is a combination and extension of existing multivariate source separation methods. We demonstrate that RESS performs well on both simulated and empirical data, and outperforms conventional SSEP analysis methods based on selecting electrodes with the strongest SSEP response, as well as several other linear spatial filters. We also discuss the potential confound of overfitting, whereby the filter captures noise in absence of a signal. Matlab scripts are available to replicate and extend our simulations and methods. We conclude with some practical advice for optimizing SSEP data analyses and interpreting the results. Copyright © 2016 Elsevier Inc. All rights reserved.

Bridging music and speech rhythm: rhythmic priming and audio-motor training affect speech perception.

PubMed

Cason, Nia; Astésano, Corine; Schön, Daniele

2015-02-01

Following findings that musical rhythmic priming enhances subsequent speech perception, we investigated whether rhythmic priming for spoken sentences can enhance phonological processing - the building blocks of speech - and whether audio-motor training enhances this effect. Participants heard a metrical prime followed by a sentence (with a matching/mismatching prosodic structure), for which they performed a phoneme detection task. Behavioural (RT) data was collected from two groups: one who received audio-motor training, and one who did not. We hypothesised that 1) phonological processing would be enhanced in matching conditions, and 2) audio-motor training with the musical rhythms would enhance this effect. Indeed, providing a matching rhythmic prime context resulted in faster phoneme detection, thus revealing a cross-domain effect of musical rhythm on phonological processing. In addition, our results indicate that rhythmic audio-motor training enhances this priming effect. These results have important implications for rhythm-based speech therapies, and suggest that metrical rhythm in music and speech may rely on shared temporal processing brain resources. Copyright © 2015 Elsevier B.V. All rights reserved.

Prenatal complex rhythmic music sound stimulation facilitates postnatal spatial learning but transiently impairs memory in the domestic chick.

PubMed

Kauser, H; Roy, S; Pal, A; Sreenivas, V; Mathur, R; Wadhwa, S; Jain, S

2011-01-01

Early experience has a profound influence on brain development, and the modulation of prenatal perceptual learning by external environmental stimuli has been shown in birds, rodents and mammals. In the present study, the effect of prenatal complex rhythmic music sound stimulation on postnatal spatial learning, memory and isolation stress was observed. Auditory stimulation with either music or species-specific sounds or no stimulation (control) was provided to separate sets of fertilized eggs from day 10 of incubation. Following hatching, the chicks at age 24, 72 and 120 h were tested on a T-maze for spatial learning and the memory of the learnt task was assessed 24 h after training. In the posthatch chicks at all ages, the plasma corticosterone levels were estimated following 10 min of isolation. The chicks of all ages in the three groups took less (p < 0.001) time to navigate the maze over the three trials thereby showing an improvement with training. In both sound-stimulated groups, the total time taken to reach the target decreased significantly (p < 0.01) in comparison to the unstimulated control group, indicating the facilitation of spatial learning. However, this decline was more at 24 h than at later posthatch ages. When tested for memory after 24 h of training, only the music-stimulated chicks at posthatch age 24 h took a significantly longer (p < 0.001) time to traverse the maze, suggesting a temporary impairment in their retention of the learnt task. In both sound-stimulated groups at 24 h, the plasma corticosterone levels were significantly decreased (p < 0.001) and increased thereafter at 72 h (p < 0.001) and 120 h which may contribute to the differential response in spatial learning. Thus, prenatal auditory stimulation with either species-specific or complex rhythmic music sounds facilitates spatial learning, though the music stimulation transiently impairs postnatal memory. 2011 S. Karger AG, Basel.

Mechanisms of circadian rhythmicity of carbon tetrachloride hepatotoxicity.

PubMed

Bruckner, James V; Ramanathan, Raghupathy; Lee, K Monica; Muralidhara, Srinivasa

2002-01-01

The toxicity of carbon tetrachloride (CCl(4)) and certain other chemicals varies over a 24-h period. Because the metabolism of some drugs follows a diurnal rhythm, it was decided to investigate whether the hepatic metabolic activation of CCl(4) was rhythmic and coincided in time with maximum susceptibility to CCl(4) hepatotoxicity. A related objective was to test the hypothesis that abstinence from food during the sleep cycle results in lipolysis and formation of acetone, which participates in induction of liver microsomal cytochrome P450IIE1 (CYP2E1), resulting in a diurnal increase in CCl(4) metabolic activation and acute liver injury. Groups of fed and fasted male Sprague-Dawley rats were given a single oral dose of 800 mg of CCl(4)/kg at 2- to 4-h intervals over a 24-h period. Serum enzyme activities, measured 24 h post dosing as indices of acute liver injury, exhibited distinct maxima in both fed and fasted animals dosed with CCl(4) near the beginning of their dark/active cycle. Blood acetone, hepatic CYP2E1 activity, and covalent binding of (14)CCl(4)/metabolites to hepatic microsomal proteins in untreated rats fed ad libitum followed circadian rhythms similar to that of susceptibility to CCl(4). Parallel fluctuations of greater amplitude were seen in rats fasted for 24 h. Hepatic glutathione levels were lowest at the time of greatest susceptibility to CCl(4). Acetone dose-response experiments showed high correlations between blood acetone levels, CYP2E1 induction, and CCl(4)-induced liver injury. Pretreatment with diallyl sulfide suppressed CYP2E1 and abolished the circadian rhythmicity of susceptibility to CCl(4). These findings provide additional support for acetone's physiological role in CYP2E1 induction and for CYP2E1's role in modulating CCl(4) chronotoxicity in rats.

Association of disrupted circadian rhythmicity with mood disorders, subjective wellbeing, and cognitive function: a cross-sectional study of 91 105 participants from the UK Biobank.

PubMed

Lyall, Laura M; Wyse, Cathy A; Graham, Nicholas; Ferguson, Amy; Lyall, Donald M; Cullen, Breda; Celis Morales, Carlos A; Biello, Stephany M; Mackay, Daniel; Ward, Joey; Strawbridge, Rona J; Gill, Jason M R; Bailey, Mark E S; Pell, Jill P; Smith, Daniel J

2018-06-01

Disruption of sleep and circadian rhythmicity is a core feature of mood disorders and might be associated with increased susceptibility to such disorders. Previous studies in this area have used subjective reports of activity and sleep patterns, but the availability of accelerometer-based data from UK Biobank participants permits the derivation and analysis of new, objectively ascertained circadian rhythmicity parameters. We examined associations between objectively assessed circadian rhythmicity and mental health and wellbeing phenotypes, including lifetime history of mood disorder. UK residents aged 37-73 years were recruited into the UK Biobank general population cohort from 2006 to 2010. We used data from a subset of participants whose activity levels were recorded by wearing a wrist-worn accelerometer for 7 days. From these data, we derived a circadian relative amplitude variable, which is a measure of the extent to which circadian rhythmicity of rest-activity cycles is disrupted. In the same sample, we examined cross-sectional associations between low relative amplitude and mood disorder, wellbeing, and cognitive variables using a series of regression models. Our final model adjusted for age and season at the time that accelerometry started, sex, ethnic origin, Townsend deprivation score, smoking status, alcohol intake, educational attainment, overall mean acceleration recorded by accelerometry, body-mass index, and a binary measure of childhood trauma. We included 91 105 participants with accelerometery data collected between 2013 and 2015 in our analyses. A one-quintile reduction in relative amplitude was associated with increased risk of lifetime major depressive disorder (odds ratio [OR] 1·06, 95% CI 1·04-1·08) and lifetime bipolar disorder (1·11, 1·03-1·20), as well as with greater mood instability (1·02, 1·01-1·04), higher neuroticism scores (incident rate ratio 1·01, 1·01-1·02), more subjective loneliness (OR 1·09, 1·07-1·11), lower happiness (0·91, 0·90-0·93), lower health satisfaction (0·90, 0·89-0·91), and slower reaction times (linear regression coefficient 1·75, 1·05-2·45). These associations were independent of demographic, lifestyle, education, and overall activity confounders. Circadian disruption is reliably associated with various adverse mental health and wellbeing outcomes, including major depressive disorder and bipolar disorder. Lower relative amplitude might be linked to increased susceptibility to mood disorders. Lister Institute of Preventive Medicine. Copyright © 2018 Elsevier Ltd. All rights reserved.

Allatostatin A Signalling in Drosophila Regulates Feeding and Sleep and Is Modulated by PDF.

PubMed

Chen, Jiangtian; Reiher, Wencke; Hermann-Luibl, Christiane; Sellami, Azza; Cognigni, Paola; Kondo, Shu; Helfrich-Förster, Charlotte; Veenstra, Jan A; Wegener, Christian

2016-09-01

Feeding and sleep are fundamental behaviours with significant interconnections and cross-modulations. The circadian system and peptidergic signals are important components of this modulation, but still little is known about the mechanisms and networks by which they interact to regulate feeding and sleep. We show that specific thermogenetic activation of peptidergic Allatostatin A (AstA)-expressing PLP neurons and enteroendocrine cells reduces feeding and promotes sleep in the fruit fly Drosophila. The effects of AstA cell activation are mediated by AstA peptides with receptors homolog to galanin receptors subserving similar and apparently conserved functions in vertebrates. We further identify the PLP neurons as a downstream target of the neuropeptide pigment-dispersing factor (PDF), an output factor of the circadian clock. PLP neurons are contacted by PDF-expressing clock neurons, and express a functional PDF receptor demonstrated by cAMP imaging. Silencing of AstA signalling and continuous input to AstA cells by tethered PDF changes the sleep/activity ratio in opposite directions but does not affect rhythmicity. Taken together, our results suggest that pleiotropic AstA signalling by a distinct neuronal and enteroendocrine AstA cell subset adapts the fly to a digestive energy-saving state which can be modulated by PDF.

Allatostatin A Signalling in Drosophila Regulates Feeding and Sleep and Is Modulated by PDF

PubMed Central

Reiher, Wencke; Hermann-Luibl, Christiane; Sellami, Azza; Cognigni, Paola; Helfrich-Förster, Charlotte; Veenstra, Jan A.

2016-01-01

Feeding and sleep are fundamental behaviours with significant interconnections and cross-modulations. The circadian system and peptidergic signals are important components of this modulation, but still little is known about the mechanisms and networks by which they interact to regulate feeding and sleep. We show that specific thermogenetic activation of peptidergic Allatostatin A (AstA)-expressing PLP neurons and enteroendocrine cells reduces feeding and promotes sleep in the fruit fly Drosophila. The effects of AstA cell activation are mediated by AstA peptides with receptors homolog to galanin receptors subserving similar and apparently conserved functions in vertebrates. We further identify the PLP neurons as a downstream target of the neuropeptide pigment-dispersing factor (PDF), an output factor of the circadian clock. PLP neurons are contacted by PDF-expressing clock neurons, and express a functional PDF receptor demonstrated by cAMP imaging. Silencing of AstA signalling and continuous input to AstA cells by tethered PDF changes the sleep/activity ratio in opposite directions but does not affect rhythmicity. Taken together, our results suggest that pleiotropic AstA signalling by a distinct neuronal and enteroendocrine AstA cell subset adapts the fly to a digestive energy-saving state which can be modulated by PDF. PMID:27689358

Shifts of Gamma Phase across Primary Visual Cortical Sites Reflect Dynamic Stimulus-Modulated Information Transfer.

PubMed

Besserve, Michel; Lowe, Scott C; Logothetis, Nikos K; Schölkopf, Bernhard; Panzeri, Stefano

2015-01-01

Distributed neural processing likely entails the capability of networks to reconfigure dynamically the directionality and strength of their functional connections. Yet, the neural mechanisms that may allow such dynamic routing of the information flow are not yet fully understood. We investigated the role of gamma band (50-80 Hz) oscillations in transient modulations of communication among neural populations by using measures of direction-specific causal information transfer. We found that the local phase of gamma-band rhythmic activity exerted a stimulus-modulated and spatially-asymmetric directed effect on the firing rate of spatially separated populations within the primary visual cortex. The relationships between gamma phases at different sites (phase shifts) could be described as a stimulus-modulated gamma-band wave propagating along the spatial directions with the largest information transfer. We observed transient stimulus-related changes in the spatial configuration of phases (compatible with changes in direction of gamma wave propagation) accompanied by a relative increase of the amount of information flowing along the instantaneous direction of the gamma wave. These effects were specific to the gamma-band and suggest that the time-varying relationships between gamma phases at different locations mark, and possibly causally mediate, the dynamic reconfiguration of functional connections.

Shifts of Gamma Phase across Primary Visual Cortical Sites Reflect Dynamic Stimulus-Modulated Information Transfer

PubMed Central

Besserve, Michel; Lowe, Scott C.; Logothetis, Nikos K.; Schölkopf, Bernhard; Panzeri, Stefano

2015-01-01

Distributed neural processing likely entails the capability of networks to reconfigure dynamically the directionality and strength of their functional connections. Yet, the neural mechanisms that may allow such dynamic routing of the information flow are not yet fully understood. We investigated the role of gamma band (50–80 Hz) oscillations in transient modulations of communication among neural populations by using measures of direction-specific causal information transfer. We found that the local phase of gamma-band rhythmic activity exerted a stimulus-modulated and spatially-asymmetric directed effect on the firing rate of spatially separated populations within the primary visual cortex. The relationships between gamma phases at different sites (phase shifts) could be described as a stimulus-modulated gamma-band wave propagating along the spatial directions with the largest information transfer. We observed transient stimulus-related changes in the spatial configuration of phases (compatible with changes in direction of gamma wave propagation) accompanied by a relative increase of the amount of information flowing along the instantaneous direction of the gamma wave. These effects were specific to the gamma-band and suggest that the time-varying relationships between gamma phases at different locations mark, and possibly causally mediate, the dynamic reconfiguration of functional connections. PMID:26394205

Frequency modulation of neural oscillations according to visual task demands.

PubMed

Wutz, Andreas; Melcher, David; Samaha, Jason

2018-02-06

Temporal integration in visual perception is thought to occur within cycles of occipital alpha-band (8-12 Hz) oscillations. Successive stimuli may be integrated when they fall within the same alpha cycle and segregated for different alpha cycles. Consequently, the speed of alpha oscillations correlates with the temporal resolution of perception, such that lower alpha frequencies provide longer time windows for perceptual integration and higher alpha frequencies correspond to faster sampling and segregation. Can the brain's rhythmic activity be dynamically controlled to adjust its processing speed according to different visual task demands? We recorded magnetoencephalography (MEG) while participants switched between task instructions for temporal integration and segregation, holding stimuli and task difficulty constant. We found that the peak frequency of alpha oscillations decreased when visual task demands required temporal integration compared with segregation. Alpha frequency was strategically modulated immediately before and during stimulus processing, suggesting a preparatory top-down source of modulation. Its neural generators were located in occipital and inferotemporal cortex. The frequency modulation was specific to alpha oscillations and did not occur in the delta (1-3 Hz), theta (3-7 Hz), beta (15-30 Hz), or gamma (30-50 Hz) frequency range. These results show that alpha frequency is under top-down control to increase or decrease the temporal resolution of visual perception.

Simple neural substrate predicts complex rhythmic structure in duetting birds

NASA Astrophysics Data System (ADS)

Amador, Ana; Trevisan, M. A.; Mindlin, G. B.

2005-09-01

Horneros (Furnarius Rufus) are South American birds well known for their oven-looking nests and their ability to sing in couples. Previous work has analyzed the rhythmic organization of the duets, unveiling a mathematical structure behind the songs. In this work we analyze in detail an extended database of duets. The rhythms of the songs are compatible with the dynamics presented by a wide class of dynamical systems: forced excitable systems. Compatible with this nonlinear rule, we build a biologically inspired model for how the neural and the anatomical elements may interact to produce the observed rhythmic patterns. This model allows us to synthesize songs presenting the acoustic and rhythmic features observed in real songs. We also make testable predictions in order to support our hypothesis.

Seasonal rhythms of body temperature in the free-ranging raccoon dog (Nyctereutes procyonoides) with special emphasis on winter sleep.

PubMed

Mustonen, Anne-Mari; Asikainen, Juha; Kauhala, Kaarina; Paakkonen, Tommi; Nieminen, Petteri

2007-01-01

The raccoon dog (Nyctereutes procyonoides) is the only canid with passive overwintering in areas with cold winters, but the depth and rhythmicity of wintertime hypothermia in the wild raccoon dog are unknown. To study the seasonal rhythms of body temperature (T(b)), seven free-ranging animals were captured and implanted with intra-abdominal T(b) loggers and radio-tracked during years 2004-2006. The average size of the home ranges was 306+/-26 ha, and the average 24 h T(b) was 38.0+/-<0.01 degrees C during the snow-free period (May-November). The highest and lowest T(b) were usually recorded around midnight (21:00-02:00 h) and between 05:00-11:00 h, respectively, and the range of the 24 h oscillations was 1.2+/-0.01 degrees C. The animals lost approximately 43+/-6% of body mass in winter (December-April), when the average size of the home ranges was 372+/-108 ha. During the 2-9-wk periods of passivity in January-March, the average 24 h T(b) decreased by 1.4-2.1 degrees C compared to the snow-free period. The raccoon dogs were hypothermic for 5 h in the morning (06:00-11:00 h), whereas the highest T(b) values were recorded between 16:00-23:00 h. The range of the 24 h oscillations increased by approximately 0.6 degrees C, and the rhythmicity was more pronounced than in the snow-free period. The ambient temperature and depth of snow cover were important determinants of the seasonal T(b) rhythms. The overwintering strategy of the raccoon dog resembled the patterns of winter sleep in bears and badgers, but the wintertime passivity of the species was more intermittent and the decrease in the T(b) less pronounced.

Center for the Study of Rhythmic Processes

DTIC Science & Technology

1990-12-01

NO. ;hington, D.C. 20332-6448 161103F 13484 1A4 iE (incude Security Ca--sficarion) iter for the Study of Rhythmic Processes ER$ONAL A~~S Kopell TYPE 9F...Djock number) The Center for the Study of Rhythmic Processes began operation in the academic year 1986-1989 and was supported as a Center of Excellence... Processes Personnel, 1986-1990 1. Nancy Kopell, Department of Mathematics, Boston University, P.I. Steven Strogatz, Postdoctoral Fellow Stephane Laederich

[Role of rhythmicity in infant development].

PubMed

Ciccone, A

2015-09-01

This article deals with rhythm in the experiences of infants, focusing in particular on the function of rhythmicity in the baby's sense of being and its continuity. Infants are inevitably subjected to experiences of discontinuity. These experiences are necessary to development, but they expose the child to chaotic experiences when a basic rhythmicity is not ensured. The rhythmicity of childcare experiences gives the illusion of permanence and enables anticipation. This nourishes the basic feeling of security and supports the development of thought. Interactive and intersubjective exchanges must be rhythmic and must be in keeping with the rhythm of the baby, who needs to withdraw regularly from the interaction to internalize the experience of the exchange. Without this retreat, the interaction is over-stimulating and prevents internalization. Object presence/ absence must also be rhythmic, to enable the infant to keep the object alive inside him/ herself. Observation of babies has demonstrated their ability to manage experiences of discontinuity: they are able to sustain a continuous link via their gaze, look for clues indicating the presence of a lost object, search for support in sensations, and fabricate rhythmicity to remain open to the self and the world. The author gives some examples of infant observations that provide evidence of these capacities. One observation shows how a baby defends itself against a discontinuity by actively maintaining a link via his/her gaze. Another example shows an infant holding on to "hard sensations" in order to stay away from "soft" ones, which represent the fragility of the separation experience. This example pertains to a seven-month-old's prelanguage and "prosodic tonicity". The author takes this opportunity to propose the notion of "psychic bisensuality" to describe these two sensation poles, which must be harmoniously articulated to guarantee an inner sense of security. Such repairs of discontinuity are only possible if the experience of discontinuity is not overly disorganizing. For instance, if an object is absent for more than a certain amount of time, it is no longer alive in the infant's mind and despair is inevitable. This prompts us to think carefully about the separation experiences we impose upon babies and their duration. Rhythms of security set in right from the beginning of early childhood, or even in utero. The author gives an example of recourse to inner rhythmicity in an 8 - or 9-month-old baby, which serves to ground the baby's sense of security. In infants, as in each one of us, rhythmicity organizes a foundation of permanence and bridges the gap created by separation. If leaning on sensations and creating neo-rhythms fails to repair the discontinuities, the baby will plunge into experiences of chaos and confusion, as seen, for example, in inconsolability. Even in this latter case, one can find a rhythmicity in the infant's crying, for example, as if the baby didn't want to be separated from the sorrow, a sort of paradoxical companion. Traces of all these primitive defenses can be found in the older child and in adult psychopathology. The importance of rhythmicity is stressed in relation to learning, which involves the experience of otherness and reality, and the rhythmic patterns of engagement and withdrawal support the integration process. The same holds true for the caretaking relationship: rhythmic involvement supports coming together, sharing, and understanding. In all of these situations, the parent, the teacher, the caregiver, must adapt to the child, the pupil, the patient; the external rhythms must fit the internal rhythm of the subject. Copyright © 2015 L’Encéphale. Published by Elsevier Masson SAS.. All rights reserved.

Circadian rhythm asynchrony in man during hypokinesis.

NASA Technical Reports Server (NTRS)

Winget, C. M.; Vernikos-Danellis, J.; Cronin, S. E.; Leach, C. S.; Rambaut, P. C.; Mack, P. B.

1972-01-01

Posture and exercise were investigated as synchronizers of certain physiologic rhythms in eight healthy male subjects in a defined environment. Four subjects exercised during bed rest. Body temperature (BT), heart rate, plasma thyroid hormone, and plasma steroid data were obtained from the subjects for a 6-day ambulatory equilibration period before bed rest, 56 days of bed rest, and a 10-day recovery period after bed rest. The results indicate that the mechanism regulating the circadian rhythmicity of the cardiovascular system is rigorously controlled and independent of the endocrine system, while the BT rhythm is more closely aligned to the endocrine system.

Medical and surgical treatment of tremors.

PubMed

Schneider, Susanne A; Deuschl, Günther

2015-02-01

Tremor is a hyperkinetic movement disorder characterized by rhythmic oscillations of one or more body parts. Disease severity ranges from mild to severe with various degrees of impact on quality of life. Essential tremor and parkinsonian tremor are the most common etiologic subtypes. Treatment may be challenging; although several drugs are available, response may be unsatisfactory. For some tremor forms, controlled data are scarce or completely missing and treatment is often based on anecdotal evidence. In this article, we review the current literature on tremor treatment, with a focus on common forms. Copyright © 2015 Elsevier Inc. All rights reserved.

Design, implementation and stabilization of a Bipedal robot

NASA Astrophysics Data System (ADS)

Nath, Alok; Das, Goutam; Mallick, Anik; Chowdhury, Shovan

2017-12-01

In this paper, we have presented the mechanical design and fabrication of a Bipedal walking robot as well as control strategies to be implemented for walking and balance recovery. For this robot, we considered Six Degree of Freedom (D.O.P) in the lower body one at each hip, one at each knee and one at each ankle. Each degree of freedom is powered by a RC servo motor and this robot is controlled by Arduino Mega 2560 micro controller. By balancing center of mass (C.O.M) it walks in rhythmic way as like as human one.

Principles of complementary medicine in terms of a suggested scientific basis.

PubMed

Popp, Fritz-Albert

2008-05-01

In order to create a scientific basis of complementary medicine it is certainly necessary to add a more non-local approach to the molecular substance of orthodox "life-sciences". It should be able to explain strange phenomena like healing by homeopathy or acupuncture. A possible frame concerns oscillatory electromagnetic interactions as regulatory and - in case of disease--deregulatory impulses of the organisms. These couplings are found, for instance, in biological rhythms, external rhythmical influences (sun exposure, atmospheric disturbances), and vibrations of the body over a huge range of frequencies. One basic example is biophotons and "delayed luminescence".

Rhythmic Layering in Danielson Crater on Mars

NASA Image and Video Library

2011-11-21

Rhythmic patterns of sedimentary layering in Danielson Crater on Mars result from periodic changes in climate related to changes in tilt of the planet in this image was taken by NASA Mars Reconnaissance Orbiter.

Music and Motion: The Rhythmic Language of Children

ERIC Educational Resources Information Center

Andrews, Palmyra

1976-01-01

Gives examples of how music can be incorporated into activities throughout the school day, showing how musical and rhythmic expression enables children to grow in their capacity to experience, respond, and relate. (MS)

The Involvement of Endogenous Neural Oscillations in the Processing of Rhythmic Input: More Than a Regular Repetition of Evoked Neural Responses

PubMed Central

Zoefel, Benedikt; ten Oever, Sanne; Sack, Alexander T.

2018-01-01

It is undisputed that presenting a rhythmic stimulus leads to a measurable brain response that follows the rhythmic structure of this stimulus. What is still debated, however, is the question whether this brain response exclusively reflects a regular repetition of evoked responses, or whether it also includes entrained oscillatory activity. Here we systematically present evidence in favor of an involvement of entrained neural oscillations in the processing of rhythmic input while critically pointing out which questions still need to be addressed before this evidence could be considered conclusive. In this context, we also explicitly discuss the potential functional role of such entrained oscillations, suggesting that these stimulus-aligned oscillations reflect, and serve as, predictive processes, an idea often only implicitly assumed in the literature. PMID:29563860

Effects of rhythmical and extra-rhythmical qualities of music on heart rate during stationary bike activities.

PubMed

DI Cagno, Alessandra; Iuliano, Enzo; Fiorilli, Giovanni; Aquino, Giovanna; Giombini, Arrigo; Menotti, Federica; Tsopani, Despina; Calcagno, Giuseppe

2016-10-01

The aim of this study was to evaluate the effects of rhythmical and extra-rhythmical qualities of music on the heart rate (HR) and rates of perceived exertion (RPE), during sub-maximal stationary bike activity. HR of 28 female adult participants was monitored during 3 session of physical activity, performed under 3 different conditions: Hi-BPM (music with 150-170 BPM), RHYTHM (rhythmical qualities only of Hi-BPM condition) and control condition without music (CONTROL). Four parameters were analyzed: the highest HR value (High-HR), High-HR minus starting HR (∆HR), time to reach the 75% of Maximal HR (MHR) (TimeTo75%) and time over 75% MHR (TimeOver75%). HR trend analysis was performed to evaluate differences among the three conditions. OMNI-Cycle Scale was administered to evaluate RPE. MANOVA showed significant differences between the three conditions in TimeTo75%, ∆HR (P<0.01) and TimeOver75% (P<0.05). In RHYTHM and CONTROL conditions after reaching 75% MHR, the HR increase were significantly lower than Hi-BPM (P<0.01). No significant differences were found in OMNI-Cycle Scale scores of Hi-BPM and RHYTHM whereas RPE was significantly higher in CONTROL condition (P<0.05). Hi-BPM and RHYTHM music allowed a faster reaching of the aerobic training zone compared to CONTROL conditions. Nevertheless, after 75% MHR, extra-rhythmical qualities are necessary to maintain or to increase the working HR levels.

Serotonin targets inhibitory synapses to induce modulation of network functions

PubMed Central

Manzke, Till; Dutschmann, Mathias; Schlaf, Gerald; Mörschel, Michael; Koch, Uwe R.; Ponimaskin, Evgeni; Bidon, Olivier; Lalley, Peter M.; Richter, Diethelm W.

2009-01-01

The cellular effects of serotonin (5-HT), a neuromodulator with widespread influences in the central nervous system, have been investigated. Despite detailed knowledge about the molecular biology of cellular signalling, it is not possible to anticipate the responses of neuronal networks to a global action of 5-HT. Heterogeneous expression of various subtypes of serotonin receptors (5-HTR) in a variety of neurons differently equipped with cell-specific transmitter receptors and ion channel assemblies can provoke diverse cellular reactions resulting in various forms of network adjustment and, hence, motor behaviour. Using the respiratory network as a model for reciprocal synaptic inhibition, we demonstrate that 5-HT1AR modulation primarily affects inhibition through glycinergic synapses. Potentiation of glycinergic inhibition of both excitatory and inhibitory neurons induces a functional reorganization of the network leading to a characteristic change of motor output. The changes in network operation are robust and help to overcome opiate-induced respiratory depression. Hence, 5-HT1AR activation stabilizes the rhythmicity of breathing during opiate medication of pain. PMID:19651659

Top-Down Beta Rhythms Support Selective Attention via Interlaminar Interaction: A Model

PubMed Central

Lee, Jung H.; Whittington, Miles A.; Kopell, Nancy J.

2013-01-01

Cortical rhythms have been thought to play crucial roles in our cognitive abilities. Rhythmic activity in the beta frequency band, around 20 Hz, has been reported in recent studies that focused on neural correlates of attention, indicating that top-down beta rhythms, generated in higher cognitive areas and delivered to earlier sensory areas, can support attentional gain modulation. To elucidate functional roles of beta rhythms and underlying mechanisms, we built a computational model of sensory cortical areas. Our simulation results show that top-down beta rhythms can activate ascending synaptic projections from L5 to L4 and L2/3, responsible for biased competition in superficial layers. In the simulation, slow-inhibitory interneurons are shown to resonate to the 20 Hz input and modulate the activity in superficial layers in an attention-related manner. The predicted critical roles of these cells in attentional gain provide a potential mechanism by which cholinergic drive can support selective attention. PMID:23950699

New modules are added to vibrissal premotor circuitry with the emergence of exploratory whisking

PubMed Central

Takatoh, Jun; Nelson, Anders; Zhou, Xiang; Bolton, M. McLean; Ehlers, Michael D.; Arenkiel, Benjamin R.; Mooney, Richard; Wang, Fan

2012-01-01

SUMMARY Rodents begin to use bilaterally coordinated, rhythmic sweeping of their vibrissae (“whisking”) for environmental exploration around two weeks after birth. Whether and how vibrissal control circuitry changes after birth is unknown, and relevant premotor circuitry remains poorly characterized. Using a modified rabies virus transsynaptic tracing strategy, we labeled neurons synapsing directly onto vibrissa facial motor neurons (vFMNs). Sources of potential excitatory, inhibitory, and modulatory vFMN premotor neurons, and differences between the premotor circuitry for vFMNs innervating intrinsic versus extrinsic vibrissal muscles, were systematically characterized. The emergence of whisking is accompanied by the addition of “new” sets of bilateral excitatory inputs to vFMNs from neurons in the lateral paragigantocellularis (LPGi). Furthermore, descending axons from the motor cortex directly innervate LPGi premotor neurons. Thus, neural modules well suited to facilitate the bilateral coordination and cortical control of whisking are added to premotor circuitry in parallel with the emergence of this exploratory behavior. PMID:23352170

Faster embryonic segmentation through elevated Delta-Notch signalling

PubMed Central

Liao, Bo-Kai; Jörg, David J.; Oates, Andrew C.

2016-01-01

An important step in understanding biological rhythms is the control of period. A multicellular, rhythmic patterning system termed the segmentation clock is thought to govern the sequential production of the vertebrate embryo's body segments, the somites. Several genetic loss-of-function conditions, including the Delta-Notch intercellular signalling mutants, result in slower segmentation. Here, we generate DeltaD transgenic zebrafish lines with a range of copy numbers and correspondingly increased signalling levels, and observe faster segmentation. The highest-expressing line shows an altered oscillating gene expression wave pattern and shortened segmentation period, producing embryos with more, shorter body segments. Our results reveal surprising differences in how Notch signalling strength is quantitatively interpreted in different organ systems, and suggest a role for intercellular communication in regulating the output period of the segmentation clock by altering its spatial pattern. PMID:27302627

Thalamocortical interactions underlying visual fear conditioning in humans.

PubMed

Lithari, Chrysa; Moratti, Stephan; Weisz, Nathan

2015-11-01

Despite a strong focus on the role of the amygdala in fear conditioning, recent works point to a more distributed network supporting fear conditioning. We aimed to elucidate interactions between subcortical and cortical regions in fear conditioning in humans. To do this, we used two fearful faces as conditioned stimuli (CS) and an electrical stimulation at the left hand, paired with one of the CS, as unconditioned stimulus (US). The luminance of the CS was rhythmically modulated leading to "entrainment" of brain oscillations at a predefined modulation frequency. Steady-state responses (SSR) were recorded by MEG. In addition to occipital regions, spectral analysis of SSR revealed increased power during fear conditioning particularly for thalamus and cerebellum contralateral to the upcoming US. Using thalamus and amygdala as seed-regions, directed functional connectivity was calculated to capture the modulation of interactions that underlie fear conditioning. Importantly, this analysis showed that the thalamus drives the fusiform area during fear conditioning, while amygdala captures the more general effect of fearful faces perception. This study confirms ideas from the animal literature, and demonstrates for the first time the central role of the thalamus in fear conditioning in humans. © 2015 Wiley Periodicals, Inc.

Rhythmic syllable-related activity in a songbird motor thalamic nucleus necessary for learned vocalizations

PubMed Central

Danish, Husain H.; Aronov, Dmitriy; Fee, Michale S.

2017-01-01

Birdsong is a complex behavior that exhibits hierarchical organization. While the representation of singing behavior and its hierarchical organization has been studied in some detail in avian cortical premotor circuits, our understanding of the role of the thalamus in adult birdsong is incomplete. Using a combination of behavioral and electrophysiological studies, we seek to expand on earlier work showing that the thalamic nucleus Uvaeformis (Uva) is necessary for the production of stereotyped, adult song in zebra finch (Taeniopygia guttata). We confirm that complete bilateral lesions of Uva abolish singing in the ‘directed’ social context, but find that in the ‘undirected’ social context, such lesions result in highly variable vocalizations similar to early babbling song in juvenile birds. Recordings of neural activity in Uva reveal strong syllable-related modulation, maximally active prior to syllable onsets and minimally active prior to syllable offsets. Furthermore, both song and Uva activity exhibit a pronounced coherent modulation at 10Hz—a pattern observed in downstream premotor areas in adult and, even more prominently, in juvenile birds. These findings are broadly consistent with the idea that Uva is critical in the sequential activation of behavioral modules in HVC. PMID:28617829

Evidence for Multiple Rhythmic Skills

PubMed Central

Tierney, Adam; Kraus, Nina

2015-01-01

Rhythms, or patterns in time, play a vital role in both speech and music. Proficiency in a number of rhythm skills has been linked to language ability, suggesting that certain rhythmic processes in music and language rely on overlapping resources. However, a lack of understanding about how rhythm skills relate to each other has impeded progress in understanding how language relies on rhythm processing. In particular, it is unknown whether all rhythm skills are linked together, forming a single broad rhythmic competence, or whether there are multiple dissociable rhythm skills. We hypothesized that beat tapping and rhythm memory/sequencing form two separate clusters of rhythm skills. This hypothesis was tested with a battery of two beat tapping and two rhythm memory tests. Here we show that tapping to a metronome and the ability to adjust to a changing tempo while tapping to a metronome are related skills. The ability to remember rhythms and to drum along to repeating rhythmic sequences are also related. However, we found no relationship between beat tapping skills and rhythm memory skills. Thus, beat tapping and rhythm memory are dissociable rhythmic aptitudes. This discovery may inform future research disambiguating how distinct rhythm competencies track with specific language functions. PMID:26376489

Circadian clock-dependent and -independent rhythmic proteomes implement distinct diurnal functions in mouse liver.

PubMed

Mauvoisin, Daniel; Wang, Jingkui; Jouffe, Céline; Martin, Eva; Atger, Florian; Waridel, Patrice; Quadroni, Manfredo; Gachon, Frédéric; Naef, Felix

2014-01-07

Diurnal oscillations of gene expression controlled by the circadian clock underlie rhythmic physiology across most living organisms. Although such rhythms have been extensively studied at the level of transcription and mRNA accumulation, little is known about the accumulation patterns of proteins. Here, we quantified temporal profiles in the murine hepatic proteome under physiological light-dark conditions using stable isotope labeling by amino acids quantitative MS. Our analysis identified over 5,000 proteins, of which several hundred showed robust diurnal oscillations with peak phases enriched in the morning and during the night and related to core hepatic physiological functions. Combined mathematical modeling of temporal protein and mRNA profiles indicated that proteins accumulate with reduced amplitudes and significant delays, consistent with protein half-life data. Moreover, a group comprising about one-half of the rhythmic proteins showed no corresponding rhythmic mRNAs, indicating significant translational or posttranslational diurnal control. Such rhythms were highly enriched in secreted proteins accumulating tightly during the night. Also, these rhythms persisted in clock-deficient animals subjected to rhythmic feeding, suggesting that food-related entrainment signals influence rhythms in circulating plasma factors.

Circadian clock-dependent and -independent rhythmic proteomes implement distinct diurnal functions in mouse liver

PubMed Central

Mauvoisin, Daniel; Wang, Jingkui; Jouffe, Céline; Martin, Eva; Atger, Florian; Waridel, Patrice; Quadroni, Manfredo; Gachon, Frédéric; Naef, Felix

2014-01-01

Diurnal oscillations of gene expression controlled by the circadian clock underlie rhythmic physiology across most living organisms. Although such rhythms have been extensively studied at the level of transcription and mRNA accumulation, little is known about the accumulation patterns of proteins. Here, we quantified temporal profiles in the murine hepatic proteome under physiological light–dark conditions using stable isotope labeling by amino acids quantitative MS. Our analysis identified over 5,000 proteins, of which several hundred showed robust diurnal oscillations with peak phases enriched in the morning and during the night and related to core hepatic physiological functions. Combined mathematical modeling of temporal protein and mRNA profiles indicated that proteins accumulate with reduced amplitudes and significant delays, consistent with protein half-life data. Moreover, a group comprising about one-half of the rhythmic proteins showed no corresponding rhythmic mRNAs, indicating significant translational or posttranslational diurnal control. Such rhythms were highly enriched in secreted proteins accumulating tightly during the night. Also, these rhythms persisted in clock-deficient animals subjected to rhythmic feeding, suggesting that food-related entrainment signals influence rhythms in circulating plasma factors. PMID:24344304

Spatiotemporal dynamics of rhythmic spinal interneurons measured with two-photon calcium imaging and coherence analysis.

PubMed

Kwan, Alex C; Dietz, Shelby B; Zhong, Guisheng; Harris-Warrick, Ronald M; Webb, Watt W

2010-12-01

In rhythmic neural circuits, a neuron often fires action potentials with a constant phase to the rhythm, a timing relationship that can be functionally significant. To characterize these phase preferences in a large-scale, cell type-specific manner, we adapted multitaper coherence analysis for two-photon calcium imaging. Analysis of simulated data showed that coherence is a simple and robust measure of rhythmicity for calcium imaging data. When applied to the neonatal mouse hindlimb spinal locomotor network, the phase relationships between peak activity of >1,000 ventral spinal interneurons and motor output were characterized. Most interneurons showed rhythmic activity that was coherent and in phase with the ipsilateral motor output during fictive locomotion. The phase distributions of two genetically identified classes of interneurons were distinct from the ensemble population and from each other. There was no obvious spatial clustering of interneurons with similar phase preferences. Together, these results suggest that cell type, not neighboring neuron activity, is a better indicator of an interneuron's response during fictive locomotion. The ability to measure the phase preferences of many neurons with cell type and spatial information should be widely applicable for studying other rhythmic neural circuits.

Speak on time! Effects of a musical rhythmic training on children with hearing loss.

PubMed

Hidalgo, Céline; Falk, Simone; Schön, Daniele

2017-08-01

This study investigates temporal adaptation in speech interaction in children with normal hearing and in children with cochlear implants (CIs) and/or hearing aids (HAs). We also address the question of whether musical rhythmic training can improve these skills in children with hearing loss (HL). Children named pictures presented on the screen in alternation with a virtual partner. Alternation rate (fast or slow) and the temporal predictability (match vs mismatch of stress occurrences) were manipulated. One group of children with normal hearing (NH) and one with HL were tested. The latter group was tested twice: once after 30 min of speech therapy and once after 30 min of musical rhythmic training. Both groups of children (NH and with HL) can adjust their speech production to the rate of alternation of the virtual partner. Moreover, while children with normal hearing benefit from the temporal regularity of stress occurrences, children with HL become sensitive to this manipulation only after rhythmic training. Rhythmic training may help children with HL to structure the temporal flow of their verbal interactions. Copyright © 2017 Elsevier B.V. All rights reserved.

Evolution of central pattern generators and rhythmic behaviours

PubMed Central

Katz, Paul S.

2016-01-01

Comparisons of rhythmic movements and the central pattern generators (CPGs) that control them uncover principles about the evolution of behaviour and neural circuits. Over the course of evolutionary history, gradual evolution of behaviours and their neural circuitry within any lineage of animals has been a predominant occurrence. Small changes in gene regulation can lead to divergence of circuit organization and corresponding changes in behaviour. However, some behavioural divergence has resulted from large-scale rewiring of the neural network. Divergence of CPG circuits has also occurred without a corresponding change in behaviour. When analogous rhythmic behaviours have evolved independently, it has generally been with different neural mechanisms. Repeated evolution of particular rhythmic behaviours has occurred within some lineages due to parallel evolution or latent CPGs. Particular motor pattern generating mechanisms have also evolved independently in separate lineages. The evolution of CPGs and rhythmic behaviours shows that although most behaviours and neural circuits are highly conserved, the nature of the behaviour does not dictate the neural mechanism and that the presence of homologous neural components does not determine the behaviour. This suggests that although behaviour is generated by neural circuits, natural selection can act separately on these two levels of biological organization. PMID:26598733

Evolution of central pattern generators and rhythmic behaviours.

PubMed

Katz, Paul S

2016-01-05

Comparisons of rhythmic movements and the central pattern generators (CPGs) that control them uncover principles about the evolution of behaviour and neural circuits. Over the course of evolutionary history, gradual evolution of behaviours and their neural circuitry within any lineage of animals has been a predominant occurrence. Small changes in gene regulation can lead to divergence of circuit organization and corresponding changes in behaviour. However, some behavioural divergence has resulted from large-scale rewiring of the neural network. Divergence of CPG circuits has also occurred without a corresponding change in behaviour. When analogous rhythmic behaviours have evolved independently, it has generally been with different neural mechanisms. Repeated evolution of particular rhythmic behaviours has occurred within some lineages due to parallel evolution or latent CPGs. Particular motor pattern generating mechanisms have also evolved independently in separate lineages. The evolution of CPGs and rhythmic behaviours shows that although most behaviours and neural circuits are highly conserved, the nature of the behaviour does not dictate the neural mechanism and that the presence of homologous neural components does not determine the behaviour. This suggests that although behaviour is generated by neural circuits, natural selection can act separately on these two levels of biological organization. © 2015 The Author(s).

Nascent body ego: metapsychological and neurophysiological aspects.

PubMed

Lehtonen, Johannes; Partanen, Juhani; Purhonen, Maija; Valkonen-Korhonen, Minna; Kononen, Mervi; Saarikoski, Seppo; Launiala, Kari

2006-10-01

For Freud, body ego was the organizing basis of the structural theory. He defined it as a psychic projection of the body surface. Isakower's and Lewin's classical findings suggest that the body surface experiences of nursing provide the infant with sensory-affective stimulation that initiates a projection of sensory processes towards the psychic realm. During nursing, somato-sensory, gustatory and olfactory modalities merge with a primitive somatic affect of satiation, whereas auditory modality is involved more indirectly and visual contact more gradually. Repeated regularly, such nascent experiences are likely to play a part in the organization of the primitive protosymbolic mental experience. In support of this hypothesis, the authors review findings from a neurophysiological study of infants before, during and after nursing. Nursing is associated with a significant amplitude change in the newborn electroencephalogram (EEG), which wanes before the age of 3 months, and is transformed at the age of 6 months into rhythmic 3-5 Hz hedonic theta-activity. Sucking requires active physiological work, which is shown in a regular rise in heart rate. The hypothesis of a sensory-affective organization of the nascent body ego, enhanced by nursing and active sucking, seems concordant with neurophysiological phenomena related to nursing.

Effect of Divided Attention on Children's Rhythmic Response

ERIC Educational Resources Information Center

Thomas, Jerry R.; Stratton, Richard K.

1977-01-01

Audio and visual interference did not significantly impair rhythmic response levels of second- and fourth-grade boys as measured by space error scores, though audio input resulted in significantly less consistent temporal performance. (MB)

Properties of human motoneurones and their synaptic noise deduced from motor unit recordings with the aid of computer modelling.

PubMed

Matthews, P B

1999-01-01

This paper reviews two new facets of the behaviour of human motoneurones; these were demonstrated by modelling combined with analysis of long periods of low-frequency tonic motor unit firing (sub-primary range). 1) A novel transformation of the interval histogram has shown that the effective part of the membrane's post-spike voltage trajectory is a segment of an exponential (rather than linear), with most spikes being triggered by synaptic noise before the mean potential reaches threshold. The curvature of the motoneurone's trajectory affects virtually all measures of its behaviour and response to stimulation. The 'trajectory' is measured from threshold, and so includes any changes in threshold during the interspike interval. 2) A novel rhythmic stimulus (amplitude-modulated pulsed vibration) has been used to show that the motoneurone produces appreciable phase-advance during sinusoidal excitation. At low frequencies, the advance increases with rising stimulus frequency but then, slightly below the motoneurones mean firing rate, it suddenly becomes smaller. The gain has a maximum for stimuli at the mean firing rate (the 'carrier'). Such behaviour is functionally important since it affects the motoneurone's response to any rhythmic input, whether generated peripherally by the receptors (as in tremor) or by the CNS (as with cortical oscillations). Low mean firing rates favour tremor, since the high gain and reduced phase advance at the 'carrier' reduce the stability of the stretch reflex.

Perceived empty duration between sounds of different lengths: Possible relation with repetition and rhythmic grouping.

PubMed

Kuroda, Tsuyoshi; Tomimatsu, Erika; Grondin, Simon; Miyazaki, Makoto

2016-11-01

We investigated how perceived duration of empty time intervals would be modulated by the length of sounds marking those intervals. Three sounds were successively presented in Experiment 1. Each sound was short (S) or long (L), and the temporal position of the middle sound's onset was varied. The lengthening of each sound resulted in delayed perception of the onset; thus, the middle sound's onset had to be presented earlier in the SLS than in the LSL sequence so that participants perceived the three sounds as presented at equal interonset intervals. In Experiment 2, a short sound and a long sound were alternated repeatedly, and the relative duration of the SL interval to the LS interval was varied. This repeated sequence was perceived as consisting of equal interonset intervals when the onsets of all sounds were aligned at physically equal intervals. If the same onset delay as in the preceding experiment had occurred, participants should have perceived equality between the interonset intervals in the repeated sequence when the SL interval was physically shortened relative to the LS interval. The effects of sound length seemed to be canceled out when the presentation of intervals was repeated. Finally, the perceived duration of the interonset intervals in the repeated sequence was not influenced by whether the participant's native language was French or Japanese, or by how the repeated sequence was perceptually segmented into rhythmic groups.

The effects of visual stimulation and selective visual attention on rhythmic neuronal synchronization in macaque area V4.

PubMed

Fries, Pascal; Womelsdorf, Thilo; Oostenveld, Robert; Desimone, Robert

2008-04-30

Selective attention lends relevant sensory input priority access to higher-level brain areas and ultimately to behavior. Recent studies have suggested that those neurons in visual areas that are activated by an attended stimulus engage in enhanced gamma-band (30-70 Hz) synchronization compared with neurons activated by a distracter. Such precise synchronization could enhance the postsynaptic impact of cells carrying behaviorally relevant information. Previous studies have used the local field potential (LFP) power spectrum or spike-LFP coherence (SFC) to indirectly estimate spike synchronization. Here, we directly demonstrate zero-phase gamma-band coherence among spike trains of V4 neurons. This synchronization was particularly evident during visual stimulation and enhanced by selective attention, thus confirming the pattern inferred from LFP power and SFC. We therefore investigated the time course of LFP gamma-band power and found rapid dynamics consistent with interactions of top-down spatial and feature attention with bottom-up saliency. In addition to the modulation of synchronization during visual stimulation, selective attention significantly changed the prestimulus pattern of synchronization. Attention inside the receptive field of the recorded neuronal population enhanced gamma-band synchronization and strongly reduced alpha-band (9-11 Hz) synchronization in the prestimulus period. These results lend further support for a functional role of rhythmic neuronal synchronization in attentional stimulus selection.

Reciprocal links between metabolic and ionic events in islet cells. Their relevance to the rhythmics of insulin release.

PubMed

Malaisse, W J

1998-02-01

The notion of reciprocal links between metabolic and ionic events in islet cells and the rhythmics of insulin release is based on (i) the rhythmic pattern of hormonal release from isolated perfused rat pancreas, which supports the concept of an intrapancreatic pacemaker; (ii) the assumption that this phasic pattern is due to the integration of secretory activity in distinct functional units, e.g. distinct islets; and (iii) the fact that reciprocal coupling between metabolic and ionic events is operative in the secretory sequence.

Rhythmic Ganglion Cell Activity in Bleached and Blind Adult Mouse Retinas

PubMed Central

Menzler, Jacob; Channappa, Lakshmi; Zeck, Guenther

2014-01-01

In retinitis pigmentosa – a degenerative disease which often leads to incurable blindness- the loss of photoreceptors deprives the retina from a continuous excitatory input, the so-called dark current. In rodent models of this disease this deprivation leads to oscillatory electrical activity in the remaining circuitry, which is reflected in the rhythmic spiking of retinal ganglion cells (RGCs). It remained unclear, however, if the rhythmic RGC activity is attributed to circuit alterations occurring during photoreceptor degeneration or if rhythmic activity is an intrinsic property of healthy retinal circuitry which is masked by the photoreceptor’s dark current. Here we tested these hypotheses by inducing and analysing oscillatory activity in adult healthy (C57/Bl6) and blind mouse retinas (rd10 and rd1). Rhythmic RGC activity in healthy retinas was detected upon partial photoreceptor bleaching using an extracellular high-density multi-transistor-array. The mean fundamental spiking frequency in bleached retinas was 4.3 Hz; close to the RGC rhythm detected in blind rd10 mouse retinas (6.5 Hz). Crosscorrelation analysis of neighbouring wild-type and rd10 RGCs (separation distance <200 µm) reveals synchrony among homologous RGC types and a constant phase shift (∼70 msec) among heterologous cell types (ON versus OFF). The rhythmic RGC spiking in these retinas is driven by a network of presynaptic neurons. The inhibition of glutamatergic ganglion cell input or the inhibition of gap junctional coupling abolished the rhythmic pattern. In rd10 and rd1 retinas the presynaptic network leads to local field potentials, whereas in bleached retinas additional pharmacological disinhibition is required to achieve detectable field potentials. Our results demonstrate that photoreceptor bleaching unmasks oscillatory activity in healthy retinas which shares many features with the functional phenotype detected in rd10 retinas. The quantitative physiological differences advance the understanding of the degeneration process and may guide future rescue strategies. PMID:25153888

Rhythmic ganglion cell activity in bleached and blind adult mouse retinas.

PubMed

Menzler, Jacob; Channappa, Lakshmi; Zeck, Guenther

2014-01-01

In retinitis pigmentosa--a degenerative disease which often leads to incurable blindness--the loss of photoreceptors deprives the retina from a continuous excitatory input, the so-called dark current. In rodent models of this disease this deprivation leads to oscillatory electrical activity in the remaining circuitry, which is reflected in the rhythmic spiking of retinal ganglion cells (RGCs). It remained unclear, however, if the rhythmic RGC activity is attributed to circuit alterations occurring during photoreceptor degeneration or if rhythmic activity is an intrinsic property of healthy retinal circuitry which is masked by the photoreceptor's dark current. Here we tested these hypotheses by inducing and analysing oscillatory activity in adult healthy (C57/Bl6) and blind mouse retinas (rd10 and rd1). Rhythmic RGC activity in healthy retinas was detected upon partial photoreceptor bleaching using an extracellular high-density multi-transistor-array. The mean fundamental spiking frequency in bleached retinas was 4.3 Hz; close to the RGC rhythm detected in blind rd10 mouse retinas (6.5 Hz). Crosscorrelation analysis of neighbouring wild-type and rd10 RGCs (separation distance <200 µm) reveals synchrony among homologous RGC types and a constant phase shift (∼70 msec) among heterologous cell types (ON versus OFF). The rhythmic RGC spiking in these retinas is driven by a network of presynaptic neurons. The inhibition of glutamatergic ganglion cell input or the inhibition of gap junctional coupling abolished the rhythmic pattern. In rd10 and rd1 retinas the presynaptic network leads to local field potentials, whereas in bleached retinas additional pharmacological disinhibition is required to achieve detectable field potentials. Our results demonstrate that photoreceptor bleaching unmasks oscillatory activity in healthy retinas which shares many features with the functional phenotype detected in rd10 retinas. The quantitative physiological differences advance the understanding of the degeneration process and may guide future rescue strategies.

Effects of a free-choice high-fat high-sugar diet on brain PER2 and BMAL1 protein expression in mice.

PubMed

Blancas-Velazquez, Aurea; la Fleur, Susanne E; Mendoza, Jorge

2017-10-01

The suprachiasmatic nucleus (SCN) times the daily rhythms of behavioral processes including feeding. Beyond the SCN, the hypothalamic arcuate nucleus (ARC), involved in feeding regulation and metabolism, and the epithalamic lateral habenula (LHb), implicated in reward processing, show circadian rhythmic activity. These brain oscillators are functionally coupled to coordinate the daily rhythm of food intake. In rats, a free choice high-fat high-sugar (fcHFHS) diet leads to a rapid increase of calorie intake and body weight gain. Interestingly, under a fcHFHS condition, rats ingest a similar amount of sugar during day time (rest phase) as during night time (active phase), but keep the rhythmic intake of regular chow-food. The out of phase between feeding patterns of regular (chow) and highly rewarding food (sugar) may involve alterations of brain circadian oscillators regulating feeding. Here, we report that the fcHFHS diet is a successful model to induce calorie intake, body weight gain and fat tissue accumulation in mice, extending its effectiveness as previously reported in rats. Moreover, we observed that whereas in the SCN the day-night difference in the PER2 clock protein expression was similar between chow-fed and fcHFHS-fed animals, in the LHb, this day-night difference was altered in fcHFHS-exposed animals compared to control chow mice. These findings confirm previous observations in rats showing disrupted daily patterns of feeding behavior under a fcHFHS diet exposure, and extend our insights on the effects of the diet on circadian gene expression in brain clocks. Copyright © 2017 Elsevier Ltd. All rights reserved.

The central pattern generator underlying swimming in Dendronotus iris: a simple half-center network oscillator with a twist.

PubMed

Sakurai, Akira; Katz, Paul S

2016-10-01

The nudibranch mollusc, Dendronotus iris, swims by rhythmically flexing its body from left to right. We identified a bilaterally represented interneuron, Si3, that provides strong excitatory drive to the previously identified Si2, forming a half-center oscillator, which functions as the central pattern generator (CPG) underlying swimming. As with Si2, Si3 inhibited its contralateral counterpart and exhibited rhythmic bursts in left-right alternation during the swim motor pattern. Si3 burst almost synchronously with the contralateral Si2 and was coactive with the efferent impulse activity in the contralateral body wall nerve. Perturbation of bursting in either Si3 or Si2 by current injection halted or phase-shifted the swim motor pattern, suggesting that they are both critical CPG members. Neither Si2 nor Si3 exhibited endogenous bursting properties when activated alone; activation of all four neurons was necessary to initiate and maintain the swim motor pattern. Si3 made a strong excitatory synapse onto the contralateral Si2 to which it is also electrically coupled. When Si3 was firing tonically but not exhibiting bursting, artificial enhancement of the Si3-to-Si2 synapse using dynamic clamp caused all four neurons to burst. In contrast, negation of the Si3-to-Si2 synapse by dynamic clamp blocked ongoing swim motor patterns. Together, these results suggest that the Dendronotus swim CPG is organized as a "twisted" half-center oscillator in which each "half" is composed of two excitatory-coupled neurons from both sides of the brain, each of which inhibits its contralateral counterpart. Consisting of only four neurons, this is perhaps the simplest known network oscillator for locomotion. Copyright © 2016 the American Physiological Society.

Automatic reference selection for quantitative EEG interpretation: identification of diffuse/localised activity and the active earlobe reference, iterative detection of the distribution of EEG rhythms.

PubMed

Wang, Bei; Wang, Xingyu; Ikeda, Akio; Nagamine, Takashi; Shibasaki, Hiroshi; Nakamura, Masatoshi

2014-01-01

EEG (Electroencephalograph) interpretation is important for the diagnosis of neurological disorders. The proper adjustment of the montage can highlight the EEG rhythm of interest and avoid false interpretation. The aim of this study was to develop an automatic reference selection method to identify a suitable reference. The results may contribute to the accurate inspection of the distribution of EEG rhythms for quantitative EEG interpretation. The method includes two pre-judgements and one iterative detection module. The diffuse case is initially identified by pre-judgement 1 when intermittent rhythmic waveforms occur over large areas along the scalp. The earlobe reference or averaged reference is adopted for the diffuse case due to the effect of the earlobe reference depending on pre-judgement 2. An iterative detection algorithm is developed for the localised case when the signal is distributed in a small area of the brain. The suitable averaged reference is finally determined based on the detected focal and distributed electrodes. The presented technique was applied to the pathological EEG recordings of nine patients. One example of the diffuse case is introduced by illustrating the results of the pre-judgements. The diffusely intermittent rhythmic slow wave is identified. The effect of active earlobe reference is analysed. Two examples of the localised case are presented, indicating the results of the iterative detection module. The focal and distributed electrodes are detected automatically during the repeating algorithm. The identification of diffuse and localised activity was satisfactory compared with the visual inspection. The EEG rhythm of interest can be highlighted using a suitable selected reference. The implementation of an automatic reference selection method is helpful to detect the distribution of an EEG rhythm, which can improve the accuracy of EEG interpretation during both visual inspection and automatic interpretation. Copyright © 2013 IPEM. Published by Elsevier Ltd. All rights reserved.

[Music and health--what kind of music is helpful for whom? What music not?].

PubMed

Trappe, H-J

2009-12-01

It is well known that music not only may improve quality of life (QoL) but also have different effects on heart rate (HR) and its variability (HRV). Music emphasis and rhythmic phrases are tracked consistently by physiological variables. Autonomic responses are synchronized with music, which might therefore convey emotions through autonomic arousal during crescendos or rhythmic phrases. A greater modulation of HR, HRV and modulations in cardiac autonomic nerve activity was revealed with a greater effect for music performance than music perception. Reactions to music are considered subjective, but studies suggested that cardiorespiratory variables are influenced under different circumstances. It has been shown that relaxing music decreases significantly the level of anxiety in a preoperative setting to a greater extent than orally administered midazolam (p < 0,001). Higher effectiveness and absence of apparent adverse effects make preoperative relaxing music a useful alternative to midazolam for premedication. In addition, there is sufficient practical evidence of stress reduction to suggest that a proposed regimen of listening to music while resting in bed after open heart surgery. Music intervention should be offered as an integral part of the multimodal regime administered to the patients that have undergone cardiovascular surgery. It is a supportive source that increases relaxation. Music is also effective in under conditions and music can be utilized as an effective intervention for patients with depressive symptoms, geriatrics and in pain, intensive care or palliative medicine. However, careful selected music that incorporates a patient's own preferences may offer an effective method to reduce anxiety and to improve quality of life. The most benefit on health is visible in classic music, meditation music whereas heavy metal music or technosounds are even ineffective or dangerous and will lead to stress and/or life threatening arrhythmias. There are many composers most effectively to improve QoL, particularly Bach, Mozart and Italian composers are "ideal". Georg Thieme Verlag KG Stuttgart, New York.

Daily rhythmicity of glycemia in four species of domestic animals under various feeding regimes.

PubMed

Piccione, Giuseppe; Fazio, Francesco; Caola, Giovanni; Refinetti, Roberto

2008-08-01

Daily rhythmicity of physiological processes has been described for numerous variables in numerous species. A major source of this rhythmicity is a circadian pacemaker located in the mammalian hypothalamus, but very little is known about how the pacemaker generates the multiplicity of bodily rhythms. Research on rats has shown that the rhythm of blood glucose concentration is not a mere consequence of the rhythm of food ingestion, but is rather generated directly by the pacemaker. In this study, we investigated the rhythm of blood glucose concentration in four different species of domestic animals under four different feeding regimes. Our results suggest that, as in rats, the rhythm of blood glucose concentration is not a mere consequence of the rhythm of food ingestion in sheep and cattle. In dogs and horses, however, the rhythmicity of blood glucose concentration seems to be contingent on the presence of a feeding regime.

Rhythmic patterning in Malaysian and Singapore English.

PubMed

Tan, Rachel Siew Kuang; Low, Ee-Ling

2014-06-01

Previous work on the rhythm of Malaysian English has been based on impressionistic observations. This paper utilizes acoustic analysis to measure the rhythmic patterns of Malaysian English. Recordings of the read speech and spontaneous speech of 10 Malaysian English speakers were analyzed and compared with recordings of an equivalent sample of Singaporean English speakers. Analysis was done using two rhythmic indexes, the PVI and VarcoV. It was found that although the rhythm of read speech of the Singaporean speakers was syllable-based as described by previous studies, the rhythm of the Malaysian speakers was even more syllable-based. Analysis of the syllables in specific utterances showed that Malaysian speakers did not reduce vowels as much as Singaporean speakers in cases of syllables in utterances. Results of the spontaneous speech confirmed the findings for the read speech; that is, the same rhythmic patterning was found which normally triggers vowel reductions.

Body Movement Synchrony in Psychotherapeutic Counseling: A Study Using the Video-Based Quantification Method

NASA Astrophysics Data System (ADS)

Nagaoka, Chika; Komori, Masashi

Body movement synchrony (i. e. rhythmic synchronization between the body movements of interacting partners) has been described by subjective impressions of skilled counselors and has been considered to reflect the depth of the client-counselor relationship. This study analyzed temporal changes in body movement synchrony through a video analysis of client-counselor dialogues in counseling sessions. Four 50-minute psychotherapeutic counseling sessions were analyzed, including two negatively evaluated sessions (low evaluation groups) and two positively evaluated sessions (high evaluation groups). In addition, two 50-minute ordinary advice sessions between two high school teachers and the clients in the high rating group were analyzed. All sessions represent role-playing. The intensity of the participants' body movement was measured using a video-based system. Temporal change of body movement synchrony was analyzed using moving correlations of the intensity between the two time series. The results revealed (1) A consistent temporal pattern among the four counseling cases, though the moving correlation coefficients were higher for the high evaluation group than the low evaluation group and (2) Different temporal patterns for the counseling and advice sessions even when the clients were the same. These results were discussed from the perspective of the quality of client-counselor relationship.

Circadian rhythmicity as a predictor of weight-loss effectiveness

USDA-ARS?s Scientific Manuscript database

Some of the major challenges associated with successful dietary weight management include the identification of individuals not responsive to specific interventions. The aim was to investigate the potential relationship between weight loss and circadian rhythmicity, using wrist temperature and actim...

The effect of lysergic acid diethylamide, 5-hydroxytryptamine, and related compounds on the liver fluke, fasciola hepatica

PubMed Central

Mansour, T. E.

1957-01-01

The rhythmical activity of the liver fluke, Fasciola hepatica, was stimulated by 5-hydroxytryptamine and by lysergic acid diethylamide at very low concentrations. The effect was peripheral and was not mediated through the central ganglion. Other amines also stimulated rhythmical activity, the most potent being the indolamines. Bromolysergic acid diethylamide, and other analogues such as yohimbine, harmine, and dopamine depressed rhythmical movement and antagonized the stimulant action of 5-hydroxytryptamine and lysergic acid diethylamide. Evidence which suggests the presence of tryptamine receptors in the trematode is discussed. PMID:13489165

Rhythmic chewing with oral jaws in teleost fishes: a comparison with amniotes.

PubMed

Gintof, Chris; Konow, Nicolai; Ross, Callum F; Sanford, Christopher P J

2010-06-01

Intra-oral prey processing (chewing) using the mandibular jaws occurs more extensively among teleost fishes than previously documented. The lack of muscle spindles, gamma-motoneurons and periodontal afferents in fishes makes them useful for testing hypotheses regarding the relationship between these sensorimotor components and rhythmic chewing in vertebrates. Electromyography (EMG) data from the adductor mandibulae (AM) were used to quantify variation in chew cycle duration in the bowfin Amia, three osteoglossomorphs (bony-tongues), four salmonids and one esocid (pike). All species chewed prey using their oral jaw in repetitive trains of between 3 and 30 consecutive chews, a pattern that resembles cyclic chewing in amniote vertebrates. Variance in rhythmicity was compared within and between lineages using coefficients of variation and Levene's test for homogeneity of variance. These comparisons revealed that some teleosts exhibit degrees of rhythmicity that are comparable to mammalian mastication and higher than in lepidosaurs. Moreover, chew cycle durations in fishes, as in mammals, scale positively with mandible length. Chewing among basal teleosts may be rhythmic because it is stereotyped and inflexible, the result of patterned interactions between sensory feedback and a central pattern generator, because the lack of a fleshy tongue renders jaw-tongue coordination unnecessary and/or because stereotyped opening and closing movements are important for controlling fluid flow in the oral cavity.

Differential processing of melodic, rhythmic and simple tone deviations in musicians--an MEG study.

PubMed

Lappe, Claudia; Lappe, Markus; Pantev, Christo

2016-01-01

Rhythm and melody are two basic characteristics of music. Performing musicians have to pay attention to both, and avoid errors in either aspect of their performance. To investigate the neural processes involved in detecting melodic and rhythmic errors from auditory input we tested musicians on both kinds of deviations in a mismatch negativity (MMN) design. We found that MMN responses to a rhythmic deviation occurred at shorter latencies than MMN responses to a melodic deviation. Beamformer source analysis showed that the melodic deviation activated superior temporal, inferior frontal and superior frontal areas whereas the activation pattern of the rhythmic deviation focused more strongly on inferior and superior parietal areas, in addition to superior temporal cortex. Activation in the supplementary motor area occurred for both types of deviations. We also recorded responses to similar pitch and tempo deviations in a simple, non-musical repetitive tone pattern. In this case, there was no latency difference between the MMNs and cortical activation was smaller and mostly limited to auditory cortex. The results suggest that prediction and error detection of musical stimuli in trained musicians involve a broad cortical network and that rhythmic and melodic errors are processed in partially different cortical streams. Copyright © 2015 Elsevier Inc. All rights reserved.

Superior short-term learning effect of visual and sensory organisation ability when sensory information is unreliable in adolescent rhythmic gymnasts.

PubMed

Chen, Hui-Ya; Chang, Hsiao-Yun; Ju, Yan-Ying; Tsao, Hung-Ting

2017-06-01

Rhythmic gymnasts specialise in dynamic balance under sensory conditions of numerous somatosensory, visual, and vestibular stimulations. This study investigated whether adolescent rhythmic gymnasts are superior to peers in Sensory Organisation test (SOT) performance, which quantifies the ability to maintain standing balance in six sensory conditions, and explored whether they plateaued faster during familiarisation with the SOT. Three and six sessions of SOTs were administered to 15 female rhythmic gymnasts (15.0 ± 1.8 years) and matched peers (15.1 ± 2.1 years), respectively. The gymnasts were superior to their peers in terms of fitness measures, and their performance was better in the SOT equilibrium score when visual information was unreliable. The SOT learning effects were shown in more challenging sensory conditions between Sessions 1 and 2 and were equivalent in both groups; however, over time, the gymnasts gained marginally significant better visual ability and relied less on visual sense when unreliable. In conclusion, adolescent rhythmic gymnasts have generally the same sensory organisation ability and learning rates as their peers. However, when visual information is unreliable, they have superior sensory organisation ability and learn faster to rely less on visual sense.

Reducing language to rhythm: Amazonian Bora drummed language exploits speech rhythm for long-distance communication

NASA Astrophysics Data System (ADS)

Seifart, Frank; Meyer, Julien; Grawunder, Sven; Dentel, Laure

2018-04-01

Many drum communication systems around the world transmit information by emulating tonal and rhythmic patterns of spoken languages in sequences of drumbeats. Their rhythmic characteristics, in particular, have not been systematically studied so far, although understanding them represents a rare occasion for providing an original insight into the basic units of speech rhythm as selected by natural speech practices directly based on beats. Here, we analyse a corpus of Bora drum communication from the northwest Amazon, which is nowadays endangered with extinction. We show that four rhythmic units are encoded in the length of pauses between beats. We argue that these units correspond to vowel-to-vowel intervals with different numbers of consonants and vowel lengths. By contrast, aligning beats with syllables, mora or only vowel length yields inconsistent results. Moreover, we also show that Bora drummed messages conventionally select rhythmically distinct markers to further distinguish words. The two phonological tones represented in drummed speech encode only few lexical contrasts. Rhythm thus appears to crucially contribute to the intelligibility of drummed Bora. Our study provides novel evidence for the role of rhythmic structures composed of vowel-to-vowel intervals in the complex puzzle concerning the redundancy and distinctiveness of acoustic features embedded in speech.

Reducing language to rhythm: Amazonian Bora drummed language exploits speech rhythm for long-distance communication

PubMed Central

Grawunder, Sven; Dentel, Laure

2018-01-01

Many drum communication systems around the world transmit information by emulating tonal and rhythmic patterns of spoken languages in sequences of drumbeats. Their rhythmic characteristics, in particular, have not been systematically studied so far, although understanding them represents a rare occasion for providing an original insight into the basic units of speech rhythm as selected by natural speech practices directly based on beats. Here, we analyse a corpus of Bora drum communication from the northwest Amazon, which is nowadays endangered with extinction. We show that four rhythmic units are encoded in the length of pauses between beats. We argue that these units correspond to vowel-to-vowel intervals with different numbers of consonants and vowel lengths. By contrast, aligning beats with syllables, mora or only vowel length yields inconsistent results. Moreover, we also show that Bora drummed messages conventionally select rhythmically distinct markers to further distinguish words. The two phonological tones represented in drummed speech encode only few lexical contrasts. Rhythm thus appears to crucially contribute to the intelligibility of drummed Bora. Our study provides novel evidence for the role of rhythmic structures composed of vowel-to-vowel intervals in the complex puzzle concerning the redundancy and distinctiveness of acoustic features embedded in speech. PMID:29765620

Impaired Thermogenesis and a Molecular Signature for Brown Adipose Tissue in Id2 Null Mice

PubMed Central

Zhou, Peng; Robles-Murguia, Maricela; Mathew, Deepa; Duffield, Giles E.

2016-01-01

Inhibitor of DNA binding 2 (ID2) is a helix-loop-helix transcriptional repressor rhythmically expressed in many adult tissues. Our previous studies have demonstrated that Id2 null mice have sex-specific elevated glucose uptake in brown adipose tissue (BAT). Here we further explored the role of Id2 in the regulation of core body temperature over the circadian cycle and the impact of Id2 deficiency on genes involved in insulin signaling and adipogenesis in BAT. We discovered a reduced core body temperature in Id2−/− mice. Moreover, in Id2−/− BAT, 30 genes including Irs1, PPARs, and PGC-1s were identified as differentially expressed in a sex-specific pattern. These data provide valuable insights into the impact of Id2 deficiency on energy homeostasis of mice in a sex-specific manner. PMID:27144179

Clinical identification of the simple sleep-related movement disorders.

PubMed

Walters, Arthur S

2007-04-01

Simple sleep-related movement disorders must be distinguished from daytime movement disorders that persist during sleep, sleep-related epilepsy, and parasomnias, which are generally characterized by activity that appears to be simultaneously complex, goal-directed, and purposeful but is outside the conscious awareness of the patient and, therefore, inappropriate. Once it is determined that the patient has a simple sleep-related movement disorder, the part of the body affected by the movement and the age of the patient give clues as to which sleep-related movement disorder is present. In some cases, all-night polysomnography with accompanying video may be necessary to make the diagnosis. Hypnic jerks (ie, sleep starts), bruxism, rhythmic movement disorder (ie, head banging/body rocking), and nocturnal leg cramps are discussed in addition to less well-appreciated disorders such as benign sleep myoclonus of infancy, excessive fragmentary myoclonus, and hypnagogic foot tremor/alternating leg muscle activation.

Melatonin effects on hard tissues: bone and tooth.

PubMed

Liu, Jie; Huang, Fang; He, Hong-Wen

2013-05-10

Melatonin is an endogenous hormone rhythmically produced in the pineal gland under the control of the suprachiasmatic nucleus (SCN) and the light/dark cycle. This indole plays an important role in many physiological processes including circadian entrainment, blood pressure regulation, seasonal reproduction, ovarian physiology, immune function, etc. Recently, the investigation and applications of melatonin in the hard tissues bone and tooth have received great attention. Melatonin has been investigated relative to bone remolding, osteoporosis, osseointegration of dental implants and dentine formation. In the present review, we discuss the large body of published evidence and review data of melatonin effects on hard tissues, specifically, bone and tooth.

Continuum theory of gene expression waves during vertebrate segmentation.

PubMed

Jörg, David J; Morelli, Luis G; Soroldoni, Daniele; Oates, Andrew C; Jülicher, Frank

2015-09-01

The segmentation of the vertebrate body plan during embryonic development is a rhythmic and sequential process governed by genetic oscillations. These genetic oscillations give rise to traveling waves of gene expression in the segmenting tissue. Here we present a minimal continuum theory of vertebrate segmentation that captures the key principles governing the dynamic patterns of gene expression including the effects of shortening of the oscillating tissue. We show that our theory can quantitatively account for the key features of segmentation observed in zebrafish, in particular the shape of the wave patterns, the period of segmentation and the segment length as a function of time.

Continuum theory of gene expression waves during vertebrate segmentation

PubMed Central

Jörg, David J; Morelli, Luis G; Soroldoni, Daniele; Oates, Andrew C; Jülicher, Frank

2015-01-01

Abstract The segmentation of the vertebrate body plan during embryonic development is a rhythmic and sequential process governed by genetic oscillations. These genetic oscillations give rise to traveling waves of gene expression in the segmenting tissue. Here we present a minimal continuum theory of vertebrate segmentation that captures the key principles governing the dynamic patterns of gene expression including the effects of shortening of the oscillating tissue. We show that our theory can quantitatively account for the key features of segmentation observed in zebrafish, in particular the shape of the wave patterns, the period of segmentation and the segment length as a function of time. PMID:28725158

Development of Poincare Software to Predict Arrythmias

NASA Technical Reports Server (NTRS)

Maaliki, Samer

2003-01-01

The most distressing types of heart malfunction occur because of an abnormal rhythm of the heart. Cardiac arrythmias can be caused by abnormal rhythmicity of the pacemaker, electrolyte disturbances, blockage of the transmission of the electric impulse through the heart, and other abnormalities. There is strong evidence that space flight is associated with decreased cardiac electrical stability that may pose a life threatening risk to astronauts. For example, during the Skylab missions, a crewmember had a five beat run of ventricular tachycardia during lower body negative pressure. Also, analysis of nine 24-hour Holter monitor recordings obtained during long term spaceflight on Mir revealed one 14-beat run of ventricular tachycardia. A Mir cosmonaut was replaced in 1986 because of cardiac dysrhythmias. Most recently, in July of 1997, a Mir commander was unable to participate in the Spektr module repair due to complaints of an irregular heart rhythm. Despite these examples, possible mechanisms of arrhythmias and countermeasure strategies have barely been addressed. The Poincare method has been proposed as a technique that might potentially predict life-threatening arrhythmias before they occur. According to this method, each RR interval obtained from an EKG recording is plotted sequentially vs. the previous RR interval. Several studies using the method have demonstrated a strong correlation between the shape of the Poincare plot and ventricular arrhythmia. Our purpose was to develop an automated software program that detects the R peaks from an EKG recording while simultaneously displaying the Poincare plot and other related parameters.

Nesfatin-1-Like Peptide Encoded in Nucleobindin-1 in Goldfish is a Novel Anorexigen Modulated by Sex Steroids, Macronutrients and Daily Rhythm

PubMed Central

Sundarrajan, Lakshminarasimhan; Blanco, Ayelén Melisa; Bertucci, Juan Ignacio; Ramesh, Naresh; Canosa, Luis Fabián; Unniappan, Suraj

2016-01-01

Nesfatin-1 is an 82 amino acid anorexigen encoded in a secreted precursor nucleobindin-2 (NUCB2). NUCB2 was named so due to its high sequence similarity with nucleobindin-1 (NUCB1). It was recently reported that NUCB1 encodes an insulinotropic nesfatin-1-like peptide (NLP) in mice. Here, we aimed to characterize NLP in fish. RT- qPCR showed NUCB1 expression in both central and peripheral tissues. Western blot analysis and/or fluorescence immunohistochemistry determined NUCB1/NLP in the brain, pituitary, testis, ovary and gut of goldfish. NUCB1 mRNA expression in goldfish pituitary and gut displayed a daily rhythmic pattern of expression. Pituitary NUCB1 mRNA expression was downregulated by estradiol, while testosterone upregulated its expression in female goldfish brain. High carbohydrate and fat suppressed NUCB1 mRNA expression in the brain and gut. Intraperitoneal injection of synthetic rat NLP and goldfish NLP at 10 and 100 ng/g body weight doses caused potent inhibition of food intake in goldfish. NLP injection also downregulated the expression of mRNAs encoding orexigens, preproghrelin and orexin-A, and upregulated anorexigen cocaine and amphetamine regulated transcript mRNA in goldfish brain. Collectively, these results provide the first set of results supporting the anorectic action of NLP, and the regulation of tissue specific expression of goldfish NUCB1. PMID:27329836

Is Vasomotion in Cerebral Arteries Impaired in Alzheimer's Disease?

PubMed

Di Marco, Luigi Yuri; Farkas, Eszter; Martin, Chris; Venneri, Annalena; Frangi, Alejandro F

2015-01-01

A substantial body of evidence supports the hypothesis of a vascular component in the pathogenesis of Alzheimer's disease (AD). Cerebral hypoperfusion and blood-brain barrier dysfunction have been indicated as key elements of this pathway. Cerebral amyloid angiopathy (CAA) is a cerebrovascular disorder, frequent in AD, characterized by the accumulation of amyloid-β (Aβ) peptide in cerebral blood vessel walls. CAA is associated with loss of vascular integrity, resulting in impaired regulation of cerebral circulation, and increased susceptibility to cerebral ischemia, microhemorrhages, and white matter damage. Vasomotion- the spontaneous rhythmic modulation of arterial diameter, typically observed in arteries/arterioles in various vascular beds including the brain- is thought to participate in tissue perfusion and oxygen delivery regulation. Vasomotion is impaired in adverse conditions such as hypoperfusion and hypoxia. The perivascular and glymphatic pathways of Aβ clearance are thought to be driven by the systolic pulse. Vasomotion produces diameter changes of comparable amplitude, however at lower rates, and could contribute to these mechanisms of Aβ clearance. In spite of potential clinical interest, studies addressing cerebral vasomotion in the context of AD/CAA are limited. This study reviews the current literature on vasomotion, and hypothesizes potential paths implicating impaired cerebral vasomotion in AD/CAA. Aβ and oxidative stress cause vascular tone dysregulation through direct effects on vascular cells, and indirect effects mediated by impaired neurovascular coupling. Vascular tone dysregulation is further aggravated by cholinergic deficit and results in depressed cerebrovascular reactivity and (possibly) impaired vasomotion, aggravating regional hypoperfusion and promoting further Aβ and oxidative stress accumulation.

A hypothesis on the biological origins and social evolution of music and dance.

PubMed

Wang, Tianyan

2015-01-01

The origins of music and musical emotions is still an enigma, here I propose a comprehensive hypothesis on the origins and evolution of music, dance, and speech from a biological and sociological perspective. I suggest that every pitch interval between neighboring notes in music represents corresponding movement pattern through interpreting the Doppler effect of sound, which not only provides a possible explanation for the transposition invariance of music, but also integrates music and dance into a common form-rhythmic movements. Accordingly, investigating the origins of music poses the question: why do humans appreciate rhythmic movements? I suggest that human appreciation of rhythmic movements and rhythmic events developed from the natural selection of organisms adapting to the internal and external rhythmic environments. The perception and production of, as well as synchronization with external and internal rhythms are so vital for an organism's survival and reproduction, that animals have a rhythm-related reward and emotion (RRRE) system. The RRRE system enables the appreciation of rhythmic movements and events, and is integral to the origination of music, dance and speech. The first type of rewards and emotions (rhythm-related rewards and emotions, RRREs) are evoked by music and dance, and have biological and social functions, which in turn, promote the evolution of music, dance and speech. These functions also evoke a second type of rewards and emotions, which I name society-related rewards and emotions (SRREs). The neural circuits of RRREs and SRREs develop in species formation and personal growth, with congenital and acquired characteristics, respectively, namely music is the combination of nature and culture. This hypothesis provides probable selection pressures and outlines the evolution of music, dance, and speech. The links between the Doppler effect and the RRREs and SRREs can be empirically tested, making the current hypothesis scientifically concrete.

Effect of rhythmic auditory cueing on gait in cerebral palsy: a systematic review and meta-analysis.

PubMed

Ghai, Shashank; Ghai, Ishan; Effenberg, Alfred O

2018-01-01

Auditory entrainment can influence gait performance in movement disorders. The entrainment can incite neurophysiological and musculoskeletal changes to enhance motor execution. However, a consensus as to its effects based on gait in people with cerebral palsy is still warranted. A systematic review and meta-analysis were carried out to analyze the effects of rhythmic auditory cueing on spatiotemporal and kinematic parameters of gait in people with cerebral palsy. Systematic identification of published literature was performed adhering to Preferred Reporting Items for Systematic Reviews and Meta-Analyses and American Academy for Cerebral Palsy and Developmental Medicine guidelines, from inception until July 2017, on online databases: Web of Science, PEDro, EBSCO, Medline, Cochrane, Embase and ProQuest. Kinematic and spatiotemporal gait parameters were evaluated in a meta-analysis across studies. Of 547 records, nine studies involving 227 participants (108 children/119 adults) met our inclusion criteria. The qualitative review suggested beneficial effects of rhythmic auditory cueing on gait performance among all included studies. The meta-analysis revealed beneficial effects of rhythmic auditory cueing on gait dynamic index (Hedge's g =0.9), gait velocity (1.1), cadence (0.3), and stride length (0.5). This review for the first time suggests a converging evidence toward application of rhythmic auditory cueing to enhance gait performance and stability in people with cerebral palsy. This article details underlying neurophysiological mechanisms and use of cueing as an efficient home-based intervention. It bridges gaps in the literature, and suggests translational approaches on how rhythmic auditory cueing can be incorporated in rehabilitation approaches to enhance gait performance in people with cerebral palsy.

Transitions between discrete and rhythmic primitives in a unimanual task

PubMed Central

Sternad, Dagmar; Marino, Hamal; Charles, Steven K.; Duarte, Marcos; Dipietro, Laura; Hogan, Neville

2013-01-01

Given the vast complexity of human actions and interactions with objects, we proposed that control of sensorimotor behavior may utilize dynamic primitives. However, greater computational simplicity may come at the cost of reduced versatility. Evidence for primitives may be garnered by revealing such limitations. This study tested subjects performing a sequence of progressively faster discrete movements in order to “stress” the system. We hypothesized that the increasing pace would elicit a transition to rhythmic movements, assumed to be computationally and neurally more efficient. Abrupt transitions between the two types of movements would support the hypothesis that rhythmic and discrete movements are distinct primitives. Ten subjects performed planar point-to-point arm movements paced by a metronome: starting at 2 s, the metronome intervals decreased by 36 ms per cycle to 200 ms, stayed at 200 ms for several cycles, then increased by similar increments. Instructions emphasized to insert explicit stops between each movement with a duration that equaled the movement time. The experiment was performed with eyes open and closed, and with short and long metronome sounds, the latter explicitly specifying the dwell duration. Results showed that subjects matched instructed movement times but did not preserve the dwell times. Rather, they progressively reduced dwell time to zero, transitioning to continuous rhythmic movements before movement times reached their minimum. The acceleration profiles showed an abrupt change between discrete and rhythmic profiles. The loss of dwell time occurred earlier with long auditory specification, when subjects also showed evidence of predictive control. While evidence for hysteresis was weak, taken together, the results clearly indicated a transition between discrete and rhythmic movements, supporting the proposal that representation is based on primitives rather than on veridical internal models. PMID:23888139

Rhythmic autocrine activity in cultured insect epidermal cells.

PubMed

Mesnier, M; Partiaoglou, N; Oberlander, H; Porcheron, P

2000-05-01

It is now well established that ecdysteroids can be produced in insects in the absence of prothoracic glands. In this respect, it has been shown that cells in culture can produce ecdysteroids. Our aims were: (1) to determine whether ecdysteroid target cells of epidermal origin could also be the source of ecdysteroids; (2) to monitor more accurately the kinetics of ecdysteroid production; and (3) to check for possible relationships between this synthetic activity and dynamics of cell division. An insect cell line (IAL-PID2) established from imaginal discs of the Indian meal moth, Plodia interpunctella, with wild-type sensitivity to ecdysteroids was used in our study. Our results showed that the Plodia cell line exhibited autocrine activity. When division of IAL-PID2 cells was synchronized, a rhythmic production of ecdysteroids was observed. However, further experiments indicated that this rhythmicity could be cell autonomous. This led us to anticipate the existence of two cell subpopulations that would be able to produce ecdysteroids rhythmically, a minor one that would be cell cycle serum-independent population, and a major population that would need serum growth factors to proliferate and produce ecdysteroids. Qualitative study of the ecdysteroid content of the media clearly showed that ecdysone was the major immunoreactive product. Taken together, our findings clearly show that an insect cell line of epidermal origin is capable of rhythmic autocrine production of ecdysteroids. These results support the hypothesis that alternate sites for ecdysteroid production in vivo may exist and could play a role in local regulation of development. We now plan to determine the cellular basis of this rhythmic autocrine activity and to confirm the existence of growth factor-autonomous cells in the culture as well as the potent role played by ecdysteroids in the cross-talk between various cell subpopulations. Copyright 2000 Wiley-Liss, Inc.

Nascent-Seq reveals novel features of mouse circadian transcriptional regulation

PubMed Central

Menet, Jerome S; Rodriguez, Joseph; Abruzzi, Katharine C; Rosbash, Michael

2012-01-01

A substantial fraction of the metazoan transcriptome undergoes circadian oscillations in many cells and tissues. Based on the transcription feedback loops important for circadian timekeeping, it is commonly assumed that this mRNA cycling reflects widespread transcriptional regulation. To address this issue, we directly measured the circadian dynamics of mouse liver transcription using Nascent-Seq (genome-wide sequencing of nascent RNA). Although many genes are rhythmically transcribed, many rhythmic mRNAs manifest poor transcriptional rhythms, indicating a prominent contribution of post-transcriptional regulation to circadian mRNA expression. This analysis of rhythmic transcription also showed that the rhythmic DNA binding profile of the transcription factors CLOCK and BMAL1 does not determine the transcriptional phase of most target genes. This likely reflects gene-specific collaborations of CLK:BMAL1 with other transcription factors. These insights from Nascent-Seq indicate that it should have broad applicability to many other gene expression regulatory issues. DOI: http://dx.doi.org/10.7554/eLife.00011.001 PMID:23150795

Modular neuron-based body estimation: maintaining consistency over different limbs, modalities, and frames of reference

PubMed Central

Ehrenfeld, Stephan; Herbort, Oliver; Butz, Martin V.

2013-01-01

This paper addresses the question of how the brain maintains a probabilistic body state estimate over time from a modeling perspective. The neural Modular Modality Frame (nMMF) model simulates such a body state estimation process by continuously integrating redundant, multimodal body state information sources. The body state estimate itself is distributed over separate, but bidirectionally interacting modules. nMMF compares the incoming sensory and present body state information across the interacting modules and fuses the information sources accordingly. At the same time, nMMF enforces body state estimation consistency across the modules. nMMF is able to detect conflicting sensory information and to consequently decrease the influence of implausible sensor sources on the fly. In contrast to the previously published Modular Modality Frame (MMF) model, nMMF offers a biologically plausible neural implementation based on distributed, probabilistic population codes. Besides its neural plausibility, the neural encoding has the advantage of enabling (a) additional probabilistic information flow across the separate body state estimation modules and (b) the representation of arbitrary probability distributions of a body state. The results show that the neural estimates can detect and decrease the impact of false sensory information, can propagate conflicting information across modules, and can improve overall estimation accuracy due to additional module interactions. Even bodily illusions, such as the rubber hand illusion, can be simulated with nMMF. We conclude with an outlook on the potential of modeling human data and of invoking goal-directed behavioral control. PMID:24191151

Rhythmicity, Sequence and Syncrony of English and Japanese Face-to-Face Conversation.

ERIC Educational Resources Information Center

Hayashi, Reiko

1990-01-01

Investigates the interactional rhythmicity among a group of four people and presents a new analytic model involving two parameters, floor and time. The model is used to further investigate the emic meaning of interactional rhythm and cross-cultural differences. (47 references) (GLR)

Rhythmic Isometric Fatigue Patterns of the Elbow Flexors and Knee Extensors

ERIC Educational Resources Information Center

Ordway, George A.; And Others

1977-01-01

During a rhythmic, all-out task, the rates of fatigue experienced by elbow flexor and knee extendor muscle groups tend to differ, with the elbow flexors fatiguing more rapidly initially, but reaching a plateau at a relatively higher level than the knee extensors. (Author)

Association of Periodic and Rhythmic Electroencephalographic Patterns With Seizures in Critically Ill Patients.

PubMed

Rodriguez Ruiz, Andres; Vlachy, Jan; Lee, Jong Woo; Gilmore, Emily J; Ayer, Turgay; Haider, Hiba Arif; Gaspard, Nicolas; Ehrenberg, J Andrew; Tolchin, Benjamin; Fantaneanu, Tadeu A; Fernandez, Andres; Hirsch, Lawrence J; LaRoche, Suzette

2017-02-01

Periodic and rhythmic electroencephalographic patterns have been associated with risk of seizures in critically ill patients. However, specific features that confer higher seizure risk remain unclear. To analyze the association of distinct characteristics of periodic and rhythmic patterns with seizures. We reviewed electroencephalographic recordings from 4772 critically ill adults in 3 academic medical centers from February 2013 to September 2015 and performed a multivariate analysis to determine features associated with seizures. Continuous electroencephalography. Association of periodic and rhythmic patterns and specific characteristics, such as pattern frequency (hertz), Plus modifier, prevalence, and stimulation-induced patterns, and the risk for seizures. Of the 4772 patients included in our study, 2868 were men and 1904 were women. Lateralized periodic discharges (LPDs) had the highest association with seizures regardless of frequency and the association was greater when the Plus modifier was present (58%; odds ratio [OR], 2.00, P < .001). Generalized periodic discharges (GPDs) and lateralized rhythmic delta activity (LRDA) were associated with seizures in a frequency-dependent manner (1.5-2 Hz: GPDs, 24%,OR, 2.31, P = .02; LRDA, 24%, OR, 1.79, P = .05; ≥ 2 Hz: GPDs, 32%, OR, 3.30, P < .001; LRDA, 40%, OR, 3.98, P < .001) as was the association with Plus (GPDs, 28%, OR, 3.57, P < .001; LRDA, 40%, P < .001). There was no difference in seizure incidence in patients with generalized rhythmic delta activity compared with no periodic or rhythmic pattern (13%, OR, 1.18, P = .26). Higher prevalence of LPDs and GPDs also conferred increased seizure risk (37% frequent vs 45% abundant/continuous, OR, 1.64, P = .03 for difference; 8% rare/occasional vs 15% frequent, OR, 2.71, P = .03, vs 23% abundant/continuous, OR, 1.95, P = .04). Patterns associated with stimulation did not show an additional risk for seizures from the underlying pattern risk (P > .10). In this study, LPDs, LRDA, and GPDs were associated with seizures while generalized rhythmic delta activity was not. Lateralized periodic discharges were associated with seizures at all frequencies with and without Plus modifier, but LRDA and GPDs were associated with seizures when the frequency was 1.5 Hz or faster or when associated with a Plus modifier. Increased pattern prevalence was associated with increased risk for seizures in LPDs and GPDs. Stimulus-induced patterns were not associated with such risk. These findings highlight the importance of detailed electroencephalographic interpretation using standardized nomenclature for seizure risk stratification and clinical decision making.

Neurobiological foundations of neurologic music therapy: rhythmic entrainment and the motor system

PubMed Central

Thaut, Michael H.; McIntosh, Gerald C.; Hoemberg, Volker

2015-01-01

Entrainment is defined by a temporal locking process in which one system’s motion or signal frequency entrains the frequency of another system. This process is a universal phenomenon that can be observed in physical (e.g., pendulum clocks) and biological systems (e.g., fire flies). However, entrainment can also be observed between human sensory and motor systems. The function of rhythmic entrainment in rehabilitative training and learning was established for the first time by Thaut and colleagues in several research studies in the early 1990s. It was shown that the inherent periodicity of auditory rhythmic patterns could entrain movement patterns in patients with movement disorders (see for a review: Thaut et al., 1999). Physiological, kinematic, and behavioral movement analysis showed very quickly that entrainment cues not only changed the timing of movement but also improved spatial and force parameters. Mathematical models have shown that anticipatory rhythmic templates as critical time constraints can result in the complete specification of the dynamics of a movement over the entire movement cycle, thereby optimizing motor planning and execution. Furthermore, temporal rhythmic entrainment has been successfully extended into applications in cognitive rehabilitation and speech and language rehabilitation, and thus become one of the major neurological mechanisms linking music and rhythm to brain rehabilitation. These findings provided a scientific basis for the development of neurologic music therapy. PMID:25774137

Effects of 60-Hz electric fields on serotonin metabolism in the rat pineal gland

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

Anderson, L.E.; Hilton, D.I.; Phillips, R.D.

Serotonin and two of its metabolites, melatonin and 5-methoxytryptophol, exhibit circadian rhythmicity in the pineal gland. We recently reported a marked reduction in the normal night-time increase in melatonin concentration in the pineal glands of rats exposed to 60-Hz electric fields. Concomitant with the apparent abolition of melatonin rhythmicity, serotonin-N-acetyl transferase (SNAT) activity was suppressed. We have now conducted studies to determine if abolition of the rhythm in melatonin production in electric-field-exposed rats arises solely from interference in SNAT activity, or if the availability of pineal serotonin is a factor that is affected by exposure. Pineal serotonin concentrations were comparedmore » in rats that were either exposed or sham exposed to 65 kV/m for 30 days. Sham-exposed animals exhibited normal diurnal rhythmicity for pineal concentrations of both melatonin and serotonin; melatonin levels increased markedly during the dark phase with a concurrent decrease in serotonin levels. In the exposed animals, however, normal serotonin rhythmicity was abolished; serotonin levels in these animals did not increase during the light period. The conclusion that electric field exposure results in a biochemical alteration in SNAT enzyme activity can be inferred from the loss of both serotonin and melatonin rhythmicity, as well as by direct measurement of SNAT activity itself. 35 references, 3 figures, 1 table.« less

VRILLE Controls PDF Neuropeptide Accumulation and Arborization Rhythms in Small Ventrolateral Neurons to Drive Rhythmic Behavior in Drosophila.

PubMed

Gunawardhana, Kushan L; Hardin, Paul E

2017-11-20

In Drosophila, the circadian clock is comprised of transcriptional feedback loops that control rhythmic gene expression responsible for daily rhythms in physiology, metabolism, and behavior. The core feedback loop, which employs CLOCK-CYCLE (CLK-CYC) activators and PERIOD-TIMELESS (PER-TIM) repressors to drive rhythmic transcription peaking at dusk, is required for circadian timekeeping and overt behavioral rhythms. CLK-CYC also activates an interlocked feedback loop, which uses the PAR DOMAIN PROTEIN 1ε (PDP1ε) activator and the VRILLE (VRI) repressor to drive rhythmic transcription peaking at dawn. Although Pdp1ε mutants disrupt activity rhythms without eliminating clock function, whether vri is required for clock function and/or output is not known. Using a conditionally inactivatable transgene to rescue vri developmental lethality, we show that clock function persists after vri inactivation but that activity rhythms are abolished. The inactivation of vri disrupts multiple output pathways thought to be important for activity rhythms, including PDF accumulation and arborization rhythms in the small ventrolateral neuron (sLN v ) dorsal projection. These results demonstrate that vri acts as a key regulator of clock output and suggest that the primary function of the interlocked feedback loop in Drosophila is to drive rhythmic transcription required for overt rhythms. Copyright © 2017 Elsevier Ltd. All rights reserved.

Neurobiological foundations of neurologic music therapy: rhythmic entrainment and the motor system.

PubMed

Thaut, Michael H; McIntosh, Gerald C; Hoemberg, Volker

2014-01-01

Entrainment is defined by a temporal locking process in which one system's motion or signal frequency entrains the frequency of another system. This process is a universal phenomenon that can be observed in physical (e.g., pendulum clocks) and biological systems (e.g., fire flies). However, entrainment can also be observed between human sensory and motor systems. The function of rhythmic entrainment in rehabilitative training and learning was established for the first time by Thaut and colleagues in several research studies in the early 1990s. It was shown that the inherent periodicity of auditory rhythmic patterns could entrain movement patterns in patients with movement disorders (see for a review: Thaut et al., 1999). Physiological, kinematic, and behavioral movement analysis showed very quickly that entrainment cues not only changed the timing of movement but also improved spatial and force parameters. Mathematical models have shown that anticipatory rhythmic templates as critical time constraints can result in the complete specification of the dynamics of a movement over the entire movement cycle, thereby optimizing motor planning and execution. Furthermore, temporal rhythmic entrainment has been successfully extended into applications in cognitive rehabilitation and speech and language rehabilitation, and thus become one of the major neurological mechanisms linking music and rhythm to brain rehabilitation. These findings provided a scientific basis for the development of neurologic music therapy.

Differential maturation of rhythmic clock gene expression during early development in medaka (Oryzias latipes).

PubMed

Cuesta, Ines H; Lahiri, Kajori; Lopez-Olmeda, Jose Fernando; Loosli, Felix; Foulkes, Nicholas S; Vallone, Daniela

2014-05-01

One key challenge for the field of chronobiology is to identify how circadian clock function emerges during early embryonic development. Teleosts such as the zebrafish are ideal models for studying circadian clock ontogeny since the entire process of development occurs ex utero in an optically transparent chorion. Medaka (Oryzias latipes) represents another powerful fish model for exploring early clock function with, like the zebrafish, many tools available for detailed genetic analysis. However, to date there have been no reports documenting circadian clock gene expression during medaka development. Here we have characterized the expression of key clock genes in various developmental stages and in adult tissues of medaka. As previously reported for other fish, light dark cycles are required for the emergence of clock gene expression rhythms in this species. While rhythmic expression of per and cry genes is detected very early during development and seems to be light driven, rhythmic clock and bmal expression appears much later around hatching time. Furthermore, the maturation of clock function seems to correlate with the appearance of rhythmic expression of these positive elements of the clock feedback loop. By accelerating development through elevated temperatures or by artificially removing the chorion, we show an earlier onset of rhythmicity in clock and bmal expression. Thus, differential maturation of key elements of the medaka clock mechanism depends on the developmental stage and the presence of the chorion.

Rhythmic EEG patterns in extremely preterm infants: Classification and association with brain injury and outcome.

PubMed

Weeke, Lauren C; van Ooijen, Inge M; Groenendaal, Floris; van Huffelen, Alexander C; van Haastert, Ingrid C; van Stam, Carolien; Benders, Manon J; Toet, Mona C; Hellström-Westas, Lena; de Vries, Linda S

2017-12-01

Classify rhythmic EEG patterns in extremely preterm infants and relate these to brain injury and outcome. Retrospective analysis of 77 infants born <28 weeks gestational age (GA) who had a 2-channel EEG during the first 72 h after birth. Patterns detected by the BrainZ seizure detection algorithm were categorized: ictal discharges, periodic epileptiform discharges (PEDs) and other waveforms. Brain injury was assessed with sequential cranial ultrasound (cUS) and MRI at term-equivalent age. Neurodevelopmental outcome was assessed with the BSITD-III (2 years) and WPPSI-III-NL (5 years). Rhythmic patterns were observed in 62.3% (ictal 1.3%, PEDs 44%, other waveforms 86.3%) with multiple patterns in 36.4%. Ictal discharges were only observed in one and excluded from further analyses. The EEG location of the other waveforms (p<0.05), but not PEDs (p=0.238), was significantly associated with head position. No relation was found between the median total duration of each pattern and injury on cUS and MRI or cognition at 2 and 5 years. Clear ictal discharges are rare in extremely preterm infants. PEDs are common but their significance is unclear. Rhythmic waveforms related to head position are likely artefacts. Rhythmic EEG patterns may have a different significance in extremely preterm infants. Copyright © 2017 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.

Language identification from visual-only speech signals

PubMed Central

Ronquest, Rebecca E.; Levi, Susannah V.; Pisoni, David B.

2010-01-01

Our goal in the present study was to examine how observers identify English and Spanish from visual-only displays of speech. First, we replicated the recent findings of Soto-Faraco et al. (2007) with Spanish and English bilingual and monolingual observers using different languages and a different experimental paradigm (identification). We found that prior linguistic experience affected response bias but not sensitivity (Experiment 1). In two additional experiments, we investigated the visual cues that observers use to complete the language-identification task. The results of Experiment 2 indicate that some lexical information is available in the visual signal but that it is limited. Acoustic analyses confirmed that our Spanish and English stimuli differed acoustically with respect to linguistic rhythmic categories. In Experiment 3, we tested whether this rhythmic difference could be used by observers to identify the language when the visual stimuli is temporally reversed, thereby eliminating lexical information but retaining rhythmic differences. The participants performed above chance even in the backward condition, suggesting that the rhythmic differences between the two languages may aid language identification in visual-only speech signals. The results of Experiments 3A and 3B also confirm previous findings that increased stimulus length facilitates language identification. Taken together, the results of these three experiments replicate earlier findings and also show that prior linguistic experience, lexical information, rhythmic structure, and utterance length influence visual-only language identification. PMID:20675804

Precompetition warm-up in elite and subelite rhythmic gymnastics.

PubMed

Guidetti, Laura; Di Cagno, Alessandra; Gallotta, Maria Chiara; Battaglia, Claudia; Piazza, Marina; Baldari, Carlo

2009-09-01

The aim of this study was to investigate which precompetition warm-up methodologies resulted in the best overall performance in rhythmic gymnastics. The coaches of national and international clubs (60 elite and 90 subelite) were interviewed. The relationship between sport performance and precompetition warm-up routines was examined. A total of 49% of the coaches interviewed spent more than 1 hour to prepare their athletes for the competition, including 45 minutes dedicated to warm-up exercises. In spite of previous studies' suggestions, the time between the end of warm-up and the beginning of competition was more than 5 minutes for 68% of those interviewed. A slow run was the activity of choice used to begin the warm-up (96%). Significant differences between elite and subelite gymnasts were found concerning the total duration of warm-up, duration of slow running, utilization of rhythmic steps and leaps during the warm-up, the use of dynamic flexibility exercises, competition performances repetition (p < 0.01), and utilization of imagery (p < 0.05). A precompetition warm-up in rhythmic gymnastics would include static stretching exercises at least 60 minutes prior to the competition starting time and the active stretching exercises alternated with analytic muscle strengthening aimed at increasing muscle temperature. Rhythmic gymnastics coaches at all levels can use this data as a review of precompetition warm-up practices and a possible source of new ideas.

The effect of a rhythmic gymnastics program on the dynamic balance ability of individuals with intellectual disability.

PubMed

Fotiadou, Eleni G; Neofotistou, Konstantina H; Sidiropoulou, Maria P; Tsimaras, Vasilios K; Mandroukas, Athanasios K; Angelopoulou, Nickoletta A

2009-10-01

The purpose of this study was to examine the effect of a rhythmic gymnastics program on the dynamic balance ability of a group of adults with intellectual disability (ID). The sample consisted of 18 adults with ID. The control group consisted of 8 adults and an intervention group of 10. The subjects were assigned to each group according to their desire to participate or not in the intervention program. Both groups were comparable in terms of age, weight, height, IQ, and socioeconomic background. The intervention group received a 12-week rhythmic gymnastics program at a frequency of 3 lessons per week, of 45 minutes. The methods of data collection included pre/post-test measurements of the dynamic balance for all subjects of both groups. The dynamic balance ability was measured by means of a balance deck (Lafayette) and was determined by the number of seconds the subject could remain standing on the platform of the stabilometer in durations of 30-, 45-, and 60-second intervals. As the results indicated, the intervention group showed a statistically significant improvement (p < 0.05) in terms of dynamic balance ability in each interval after the application of the rhythmic gymnastics program when compared with the control group. It is concluded that adults with ID can improve their balance ability with the application of a well-designed rhythmic gymnastics program.

Neuromodulation to the Rescue: Compensation of Temperature-Induced Breakdown of Rhythmic Motor Patterns via Extrinsic Neuromodulatory Input

PubMed Central

Städele, Carola; Heigele, Stefanie; Stein, Wolfgang

2015-01-01

Stable rhythmic neural activity depends on the well-coordinated interplay of synaptic and cell-intrinsic conductances. Since all biophysical processes are temperature dependent, this interplay is challenged during temperature fluctuations. How the nervous system remains functional during temperature perturbations remains mostly unknown. We present a hitherto unknown mechanism of how temperature-induced changes in neural networks are compensated by changing their neuromodulatory state: activation of neuromodulatory pathways establishes a dynamic coregulation of synaptic and intrinsic conductances with opposing effects on neuronal activity when temperature changes, hence rescuing neuronal activity. Using the well-studied gastric mill pattern generator of the crab, we show that modest temperature increase can abolish rhythmic activity in isolated neural circuits due to increased leak currents in rhythm-generating neurons. Dynamic clamp-mediated addition of leak currents was sufficient to stop neuronal oscillations at low temperatures, and subtraction of additional leak currents at elevated temperatures was sufficient to rescue the rhythm. Despite the apparent sensitivity of the isolated nervous system to temperature fluctuations, the rhythm could be stabilized by activating extrinsic neuromodulatory inputs from descending projection neurons, a strategy that we indeed found to be implemented in intact animals. In the isolated nervous system, temperature compensation was achieved by stronger extrinsic neuromodulatory input from projection neurons or by augmenting projection neuron influence via bath application of the peptide cotransmitter Cancer borealis tachykinin-related peptide Ia (CabTRP Ia). CabTRP Ia activates the modulator-induced current IMI (a nonlinear voltage-gated inward current) that effectively acted as a negative leak current and counterbalanced the temperature-induced leak to rescue neuronal oscillations. Computational modelling revealed the ability of IMI to reduce detrimental leak-current influences on neuronal networks over a broad conductance range and indicated that leak and IMI are closely coregulated in the biological system to enable stable motor patterns. In conclusion, these results show that temperature compensation does not need to be implemented within the network itself but can be conditionally provided by extrinsic neuromodulatory input that counterbalances temperature-induced modifications of circuit-intrinsic properties. PMID:26417944

Effects from fine muscle and cutaneous afferents on spinal locomotion in cats

PubMed Central

Kniffki, K.-D.; Schomburg, E. D.; Steffens, H.

1981-01-01

1. The effects of chemically activated fine muscle afferents (groups III and IV) and electrically activated cutaneous afferents on motoneuronal discharges were studied before and during fictive locomotion induced pharmacologically by i.v. administration of nialamide and l-DOPA in high spinal cats. Efferent activity was recorded simultaneously from nerve filaments to ipsi- and contralateral extensor and flexor muscles. In addition, intracellular recordings were made from lumbar α-motoneurones. 2. After nialamide but before treatment with l-DOPA, in some cases, transient locomotor-like discharges were induced by an increased activity in fine muscle afferents. The response pattern in nerves to both hind limbs could be different showing e.g. only transient alternating activity between knee flexor and extensor of one limb but not of the other one. 3. Treatment with l-DOPA did not always cause fictive locomotion. Often not all motoneurone pools showed rhythmic activity. In these cases stimulation of group III and IV muscle afferents usually caused transient periodic activity. In cases with apparent rhythmic activity, algesic stimulation of the gastrocnemius—soleus muscle caused an accentuation of the rhythm by a more abrupt transition from the active phase to the non-active interval. Again, the response patterns on both sides were not uniform in all cases. 4. A second type of response to activation of fine muscle afferents had a quite different character: the rhythmic activity was more or less completely overridden by a strong transient tonic hyperactivity or the rhythm was transiently blocked. These phenomena did not occur in the same way in all nerves. 5. Electrical stimulation of cutaneous nerves of the hind limb generally induced the same response pattern as chemical stimulation of the group III and IV muscle afferents. The effects varied depending on the stimulus strength and the nerve. 6. The results revealed that cutaneous and fine muscle afferents not only have similar functions in the reflex control of a limb but also in evocation and modulation of locomotion. Therefore, it is assumed that both types of afferents may serve together as a peripheral feed-back to the spinal locomotor centre. PMID:7320927

MIT-Skywalker: considerations on the Design of a Body Weight Support System.

PubMed

Gonçalves, Rogério Sales; Krebs, Hermano Igo

2017-09-06

To provide body weight support during walking and balance training, one can employ two distinct embodiments: support through a harness hanging from an overhead system or support through a saddle/seat type. This paper presents a comparison of these two approaches. Ultimately, this comparison determined our selection of the body weight support system employed in the MIT-Skywalker, a robotic device developed for the rehabilitation/habilitation of gait and balance after a neurological injury. Here we will summarize our results with eight healthy subjects walking on the treadmill without any support, with 30% unloading supported by a harness hanging from an overhead system, and with a saddle/seat-like support system. We compared the center of mass as well as vertical and mediolateral trunk displacements across different walking speeds and support. The bicycle/saddle system had the highest values for the mediolateral inclination, while the overhead harness body weight support showed the lowest values at all speeds. The differences were statistically significant. We selected the bicycle/saddle system for the MIT-Skywalker. It allows faster don-and-doff, better centers the patient to the split treadmill, and allows all forms of training. The overhead harness body weight support might be adequate for rhythmic walking training but limits any potential for balance training.

Seeing the Body Distorts Tactile Size Perception

ERIC Educational Resources Information Center

Longo, Matthew R.; Sadibolova, Renata

2013-01-01

Vision of the body modulates somatosensation, even when entirely non-informative about stimulation. For example, seeing the body increases tactile spatial acuity, but reduces acute pain. While previous results demonstrate that vision of the body modulates somatosensory sensitivity, it is unknown whether vision also affects metric properties of…

Friends, not foes: Magnetoencephalography as a tool to uncover brain dynamics during transcranial alternating current stimulation.

PubMed

Neuling, Toralf; Ruhnau, Philipp; Fuscà, Marco; Demarchi, Gianpaolo; Herrmann, Christoph S; Weisz, Nathan

2015-09-01

Brain oscillations are supposedly crucial for normal cognitive functioning and alterations are associated with cognitive dysfunctions. To demonstrate their causal role on behavior, entrainment approaches in particular aim at driving endogenous oscillations via rhythmic stimulation. Within this context, transcranial electrical stimulation, especially transcranial alternating current stimulation (tACS), has received renewed attention. This is likely due to the possibility of defining oscillatory stimulation properties precisely. Also, measurements comparing pre-tACS with post-tACS electroencephalography (EEG) have shown impressive modulations. However, the period during tACS has remained a blackbox until now, due to the enormous stimulation artifact. By means of application of beamforming to magnetoencephalography (MEG) data, we successfully recovered modulations of the amplitude of brain oscillations during weak and strong tACS. Additionally, we demonstrate that also evoked responses to visual and auditory stimuli can be recovered during tACS. The main contribution of the present study is to provide critical evidence that during ongoing tACS, subtle modulations of oscillatory brain activity can be reconstructed even at the stimulation frequency. Future tACS experiments will be able to deliver direct physiological insights in order to further the understanding of the contribution of brain oscillations to cognition and behavior. Copyright © 2015. Published by Elsevier Inc.

Structural Basis of Tonic Inhibition by Dimers of Dimers in Hyperpolarization-Activated Cyclic-Nucleotide-Modulated (HCN) Ion Channels.

PubMed

VanSchouwen, Bryan; Melacini, Giuseppe

2016-10-03

The hyperpolarization-activated cyclic-nucleotide-modulated (HCN) ion channels control rhythmicity in neurons and cardiomyocytes. Cyclic AMP (cAMP) modulates HCN activity through cAMP-dependent formation of a tetrameric gating ring spanning the intracellular region (IR) of HCN. In the absence of cAMP, the IR cAMP-binding domain (CBD) mainly samples its inactive conformation, resulting in steric clashes that destabilize the IR tetramer. Although these clashes with the inactive CBD are released through tetramer dissociation into monomers, functional mutagenesis suggests that the apo IR is not fully monomeric. To investigate the inhibitory non-monomeric IR species, we performed molecular dynamics simulations starting from "hybrid" structures that are tetrameric, but contain inactive apo-state CBD conformations. The ensemble of simulated trajectories reveals that full dissociation of the tetramer into monomers is not necessary to release the steric hindrance with the inactive CBD. Specifically, we found that partial dissociation of the tetramer into dimers is sufficient to accommodate four inactive CBDs, while reduction of the quaternary symmetry of the non-dissociated tetramer from four- to two-fold permits accommodation of two inactive CBDs. Our findings not only rationalize available electrophysiological, fluorometry and sedimentation equilibrium data, but they also provide unprecedented structural insight into previously elusive non-monomeric auto-inhibitory HCN species.

Firing-rate resonances in the peripheral auditory system of the cricket, Gryllus bimaculatus.

PubMed

Rau, Florian; Clemens, Jan; Naumov, Victor; Hennig, R Matthias; Schreiber, Susanne

2015-11-01

In many communication systems, information is encoded in the temporal pattern of signals. For rhythmic signals that carry information in specific frequency bands, a neuronal system may profit from tuning its inherent filtering properties towards a peak sensitivity in the respective frequency range. The cricket Gryllus bimaculatus evaluates acoustic communication signals of both conspecifics and predators. The song signals of conspecifics exhibit a characteristic pulse pattern that contains only a narrow range of modulation frequencies. We examined individual neurons (AN1, AN2, ON1) in the peripheral auditory system of the cricket for tuning towards specific modulation frequencies by assessing their firing-rate resonance. Acoustic stimuli with a swept-frequency envelope allowed an efficient characterization of the cells' modulation transfer functions. Some of the examined cells exhibited tuned band-pass properties. Using simple computational models, we demonstrate how different, cell-intrinsic or network-based mechanisms such as subthreshold resonances, spike-triggered adaptation, as well as an interplay of excitation and inhibition can account for the experimentally observed firing-rate resonances. Therefore, basic neuronal mechanisms that share negative feedback as a common theme may contribute to selectivity in the peripheral auditory pathway of crickets that is designed towards mate recognition and predator avoidance.

Friends, not foes: Magnetoencephalography as a tool to uncover brain dynamics during transcranial alternating current stimulation

PubMed Central

Neuling, Toralf; Ruhnau, Philipp; Fuscà, Marco; Demarchi, Gianpaolo; Herrmann, Christoph S.; Weisz, Nathan

2015-01-01

Brain oscillations are supposedly crucial for normal cognitive functioning and alterations are associated with cognitive dysfunctions. To demonstrate their causal role on behavior, entrainment approaches in particular aim at driving endogenous oscillations via rhythmic stimulation. Within this context, transcranial electrical stimulation, especially transcranial alternating current stimulation (tACS), has received renewed attention. This is likely due to the possibility of defining oscillatory stimulation properties precisely. Also, measurements comparing pre-tACS with post-tACS electroencephalography (EEG) have shown impressive modulations. However, the period during tACS has remained a blackbox until now, due to the enormous stimulation artifact. By means of application of beamforming to magnetoencephalography (MEG) data, we successfully recovered modulations of the amplitude of brain oscillations during weak and strong tACS. Additionally, we demonstrate that also evoked responses to visual and auditory stimuli can be recovered during tACS. The main contribution of the present study is to provide critical evidence that during ongoing tACS, subtle modulations of oscillatory brain activity can be reconstructed even at the stimulation frequency. Future tACS experiments will be able to deliver direct physiological insights in order to further the understanding of the contribution of brain oscillations to cognition and behavior. PMID:26080310

Interspecific studies of circadian genes period and timeless in Drosophila.

PubMed

Noreen, Shumaila; Pegoraro, Mirko; Nouroz, Faisal; Tauber, Eran; Kyriacou, Charalambos P

2018-03-30

The level of rescue of clock function in genetically arrhythmic Drosophila melanogaster hosts using interspecific clock gene transformation was used to study the putative intermolecular coevolution between interacting clock proteins. Among them PER and TIM are the two important negative regulators of the circadian clock feedback loop. We transformed either the D. pseudoobscura per or tim transgenes into the corresponding arrhythmic D. melanogaster mutant (per01 or tim01) and observed >50% rhythmicity but the period of activity rhythm was either longer (D. pseudoobscura-per) or shorter than 24 h (D. pseudoobscura-tim) compared to controls. By introducing both transgenes simultaneously into double mutants, we observed that the period of the activity rhythm was rescued by the pair of hemizygous transgenes (~24 h). These flies also showed a more optimal level of temperature compensation for the period. Under LD 12:12 these flies have a D. pseudoobscura like activity profile with the absence of morning anticipation as well as a very prominent earlier evening peak of activity rhythm. These observation are consistent with the view that TIM and PER form a heterospecific coevolved module at least for the circadian period of activity rhythms. However the strength of rhythmicity was reduced by having both transgenes present, so while evidence for a coevolution between PER and TIM is observed for some characters it is not for others. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

Synthesizing genetic sequential logic circuit with clock pulse generator.

PubMed

Chuang, Chia-Hua; Lin, Chun-Liang

2014-05-28

Rhythmic clock widely occurs in biological systems which controls several aspects of cell physiology. For the different cell types, it is supplied with various rhythmic frequencies. How to synthesize a specific clock signal is a preliminary but a necessary step to further development of a biological computer in the future. This paper presents a genetic sequential logic circuit with a clock pulse generator based on a synthesized genetic oscillator, which generates a consecutive clock signal whose frequency is an inverse integer multiple to that of the genetic oscillator. An analogous electronic waveform-shaping circuit is constructed by a series of genetic buffers to shape logic high/low levels of an oscillation input in a basic sinusoidal cycle and generate a pulse-width-modulated (PWM) output with various duty cycles. By controlling the threshold level of the genetic buffer, a genetic clock pulse signal with its frequency consistent to the genetic oscillator is synthesized. A synchronous genetic counter circuit based on the topology of the digital sequential logic circuit is triggered by the clock pulse to synthesize the clock signal with an inverse multiple frequency to the genetic oscillator. The function acts like a frequency divider in electronic circuits which plays a key role in the sequential logic circuit with specific operational frequency. A cascaded genetic logic circuit generating clock pulse signals is proposed. Based on analogous implement of digital sequential logic circuits, genetic sequential logic circuits can be constructed by the proposed approach to generate various clock signals from an oscillation signal.

How annual course of photoperiod shapes seasonal behavior of diploid and triploid oysters, Crassostrea gigas

PubMed Central

Payton, Laura; Sow, Mohamedou; Massabuau, Jean-Charles; Ciret, Pierre

2017-01-01

In this work, we study if ploidy (i.e. number of copies of chromosomes) in the oyster Crassostrea gigas may introduce differences in behavior and in its synchronization by the annual photoperiod. To answer to the question about the effect of the seasonal course of the photoperiod on the behavior of C. gigas according to its ploidy, we quantified valve activity by HFNI valvometry in situ for 1 year in both diploid and triploid oysters. Chronobiological analyses of daily, tidal and lunar rhythms were performed according the annual change of the photoperiod. In parallel, growth and gametogenesis status were measured and spawning events were detected by valvometry. The results showed that triploids had reduced gametogenesis, without spawning events, and approximately three times more growth than diploids. These differences in physiological efforts could explain the result that photoperiod (daylength and/or direction of daylength) differentially drives and modulates seasonal behavior of diploid and triploid oysters. Most differences were observed during long days (spring and summer), where triploids showed longer valve opening duration but lower opening amplitude, stronger daily rhythm and weaker tidal rhythm. During this period, diploids did major gametogenesis and spawning whereas triploids did maximal growth. Differences were also observed in terms of moonlight rhythmicity and neap-spring tidal cycle rhythmicity. We suggest that the seasonal change of photoperiod differentially synchronizes oyster behavior and biological rhythms according to physiological needs based on ploidy. PMID:29020114

How annual course of photoperiod shapes seasonal behavior of diploid and triploid oysters, Crassostrea gigas.

PubMed

Payton, Laura; Sow, Mohamedou; Massabuau, Jean-Charles; Ciret, Pierre; Tran, Damien

2017-01-01

In this work, we study if ploidy (i.e. number of copies of chromosomes) in the oyster Crassostrea gigas may introduce differences in behavior and in its synchronization by the annual photoperiod. To answer to the question about the effect of the seasonal course of the photoperiod on the behavior of C. gigas according to its ploidy, we quantified valve activity by HFNI valvometry in situ for 1 year in both diploid and triploid oysters. Chronobiological analyses of daily, tidal and lunar rhythms were performed according the annual change of the photoperiod. In parallel, growth and gametogenesis status were measured and spawning events were detected by valvometry. The results showed that triploids had reduced gametogenesis, without spawning events, and approximately three times more growth than diploids. These differences in physiological efforts could explain the result that photoperiod (daylength and/or direction of daylength) differentially drives and modulates seasonal behavior of diploid and triploid oysters. Most differences were observed during long days (spring and summer), where triploids showed longer valve opening duration but lower opening amplitude, stronger daily rhythm and weaker tidal rhythm. During this period, diploids did major gametogenesis and spawning whereas triploids did maximal growth. Differences were also observed in terms of moonlight rhythmicity and neap-spring tidal cycle rhythmicity. We suggest that the seasonal change of photoperiod differentially synchronizes oyster behavior and biological rhythms according to physiological needs based on ploidy.

Morphologic variations in the pineal gland of the albino rat after a chronic alcoholisation process.

PubMed

Martínez-Salvador, J; Ruiz-Torner, A; Blasco-Serra, A; Martínez-Soriano, F; Valverde-Navarro, A A

2018-04-01

We studied the effect of alcohol on the pineal gland of 48 male Wistar rats. Animals were divided into control and experimental groups. The experimental group underwent a previous progressive alcoholisation period with ethanol diluted in water at a concentration of 40%. Animals were sacrificed at 3, 6, 9 and 12 months, and the ultrastructure, karyometric indices, and number of synaptic bodies in the pineal gland were analysed. The results showed progressive morphologic alterations in the ethanol-treated animals, which culminated in fatty degeneration of the pineal parenchyma after 6 months. The karyometric indices decreased in both the central and peripheral areas compared with the control group. Moreover, the seasonal rhythmicity observed in the controls disappeared in the experimental groups, whose number of different populations of synaptic bodies (synaptic ribbons and synaptic spherules) considerably lowered with inversion of their normal seasonal rhythm. These results support that chronic alcoholisation leads to fatty degeneration of the pineal parenchyma, and a considerable alteration in nuclear functional rhythms and synaptic bodies. Copyright © 2018 Elsevier Ltd. All rights reserved.