Initiation Of Swimming Research Articles

Sensorimotor integration enhances temperature stimulus processing.

Animals optimize behavior by integrating sensory input with motor actions. We hypothesized that coupling thermosensory information with motor output enhances the brain's capacity to process temperature changes, leading to more precise and adaptive behaviors. To test this, we developed a virtual "thermal plaid" environment where zebrafish either actively controlled temperature changes (sensorimotor feedback) or passively experienced the same thermal fluctuations. Our findings demonstrate that sensorimotor feedback amplifies the influence of thermal stimuli on swim initiation, resulting in more structured and organized motor output. We show that previously identified mixed-selectivity neurons that simultaneously encode thermal cues and motor activity enable the integration of sensory and motor feedback to optimize behavior. These results highlight the role of sensorimotor integration in refining thermosensory processing, revealing critical neural mechanisms underlying flexible thermoregulatory behavior. Our study offers new insights into how animals adaptively process environmental stimuli and adjust their actions, contributing to a deeper understanding of the neural circuits driving goal-directed behavior in dynamic environments.

Effect of swimming initiation period and continuation frequency on motor competence development in children aged up to 3 years: the Japan environment and children’s study

BackgroundAlthough involvement of toddlers in swimming activities has increased recently, information regarding the impact of swimming during toddlerhood on subsequent child motor competence development is scarce. This study aimed to determine how swimming experience, particularly the timing of initiation and the continuity of swimming activities up to the age of 3 years, affects motor competence development.MethodsThis prospective cohort study included data on children aged 1.5 and 3 years (100,286 mother–child pairs) from the Japan Environment and Children’s Study. The outcomes measured were gross and fine motor function, using the Japanese version of the Ages and Stages Questionnaire (Third edition). We assessed how these functions correlated with the continuous pattern of swimming pool use frequency from age 1 up to 3 years.ResultsThe group that used a swimming pool once a month or more from age 1–1.5 years but stopped from age 2–3 years showed consistently significant negative associations with gross motor development delay (minimum adjusted odds ratio [aOR]: 0.66, 95% confidence interval [CI]: 0.60–0.73) and fine motor development delay (minimum aOR: 0.66, 95% CI: 0.58–0.76). The group that continued swimming once a month or more from age 1–3 years showed consistently significant negative associations with gross motor development delay (minimum aOR: 0.64, 95% CI: 0.54–0.75) and fine motor development delay (minimum aOR: 0.42, 95% CI: 0.31–0.55).ConclusionsThese results suggest that swimming experience starting around age 1 year is positively associated with gross and fine motor function development. The beneficial impact on gross motor function persisted from age 1–3 years. In contrast, the effects on fine motor function were not evident until age ≥ 2.5 years after starting swimming at approximately age 1 year. These findings underscore the potential benefits of early swimming experiences in enhancing overall motor skills development during early childhood.

An early midbrain sensorimotor pathway is involved in the timely initiation and direction of swimming in the hatchling Xenopus laevis tadpole.

Vertebrate locomotion is heavily dependent on descending control originating in the midbrain and subsequently influencing central pattern generators in the spinal cord. However, the midbrain neuronal circuitry and its connections with other brainstem and spinal motor circuits has not been fully elucidated. Vertebrates with very simple nervous system, like the hatchling Xenopus laevis tadpole, have been instrumental in unravelling fundamental principles of locomotion and its suspraspinal control. Here, we use behavioral and electrophysiological approaches in combination with lesions of the midbrain to investigate its contribution to the initiation and control of the tadpole swimming in response to trunk skin stimulation. None of the midbrain lesions studied here blocked the tadpole's sustained swim behavior following trunk skin stimulation. However, we identified that distinct midbrain lesions led to significant changes in the latency and trajectory of swimming. These changes could partly be explained by the increase in synchronous muscle contractions on the opposite sides of the tadpole's body and permanent deflection of the tail from its normal position, respectively. We conclude that the tadpole's embryonic trunk skin sensorimotor pathway involves the midbrain, which harbors essential neuronal circuitry to significantly contribute to the appropriate, timely and coordinated selection and execution of locomotion, imperative to the animal's survival.

Dopamine receptor DOP-1 engages a sleep pathway to modulate swimming in C. elegans

SummaryAnimals require robust yet flexible programs to support locomotion. Here we report a pathway that connects the D1-like dopamine receptor DOP-1 with a sleep mechanism to modulate swimming in C. elegans. We show that DOP-1 plays a negative role in sustaining swimming behavior. By contrast, a pathway through the D2-like dopamine receptor DOP-3 negatively regulates the initiation of swimming, but its impact fades quickly over a few minutes. We find that DOP-1 and the GPCR kinase (G-protein-coupled receptor kinase-2) function in the sleep interneuron RIS, where DOP-1 modulates the secretion of a sleep neuropeptide FLP-11. We further show that DOP-1 and FLP-11 act in the same pathway to modulate swimming. Together, these results delineate a functional connection between a dopamine receptor and a sleep program to regulate swimming in C. elegans. The temporal transition between DOP-3 and DOP-1 pathways highlights the dynamic nature of neuromodulation for rhythmic movements that persist over time.

Ultrasonographic Evaluation of the Shoulders and Its Associations with Shoulder Pain, Age, and Swim Training in Masters Swimmers.

Background and objectives: The long head of the biceps (LHB) and rotator cuff tendinopathy is the major cause of shoulder pain in competitive swimmers. The risk of tendinopathy increases with aging; however, the structural changes of LHB and rotator cuff in populations of masters swimmers have not been well examined. The purpose of this study was to investigate the prevalence of ultrasonographic abnormalities of the shoulders in masters swimmers, and the association of pain, age, and swim training with structural changes in this population. Materials and Methods: A total of 60 subjects participated in this study, with 20 masters swimmers with shoulder pain, 20 asymptomatic masters swimmers, and 20 sex- and age-matched controls. All swimmers completed a self-reported questionnaire for shoulder pain, their history of competition, and training volume. Each subject underwent ultrasonographic examination of both shoulders for pathologic findings in the LHB tendon, rotator cuff (supraspinatus (SSP) and subscapularis (SSC)) tendons, and subacromial bursa (SAB) of both shoulders and had thickness measured. Results: The prevalence of tendinosis (LHB, 48.8%; SSP, 17.5%; SSC, 15.9%), partial tear (SSP, 35.0%), and calcification (SSC, 10.0%) were higher in swimmers than in controls. LHB and SSP tendinosis were associated with shoulder pain. Older age and later start of competition were associated with an increased risk of LHB tendinosis and SSC calcification. Earlier initiation of swimming and longer history of competition were associated with an increased risk of SSP and SSC tendinosis. The thicker SSP tendon significantly increased the risk of tendinosis and partial tear. Conclusions: A high prevalence of structural changes in the rotator cuff and biceps tendons in masters swimmers reflects the effect of shoulder symptoms, aging, and swim training.

Water Specific Therapy Halliwick (WSTH) : intérêt de la thérapie dans l’eau pour enfants paralysés cérébraux

The Halliwick method, created in England in 1949 by J. McMillan, engineer, who offered his services at the Halliwick swimming school for young girls cp, is based on the physical properties of water and consists of a program in ten points (TPP) for swimming initiation; WSTH is a learning engine in water which facilitates the management of the movements and activities of daily life on earth. It's in agreement with the normal motor development of the child, the levels of motor evolution (NEM), International Classification of Functioning, disability and health (ICF) proposed by the WHO in 2001 as well as with Huber's positive health (2011). Several scientific studies attest to the efficientness of the Halliwick method and of the WSTH on motor skills. Four field studies, published, compared WSTH to conventional aquatic therapy (CAT), randomized, in children with cp: (1) on spasticity (elbow/wrist/knee/ankle measurement), WSTH shows a decrease HS specifically on the wrist and ankle after WSTH; S results for CAT; (2) on the range of motion, the measurements show a S increase proximally, especially on the UE after WSTH; (3) on the active trunk recovery, the WSTH shows an action THS in th12, S in th8 and c7; NS in CAT; (4) on the head control, the results are, after WSTH, HS in flexion/extension/inclinations and S in rotations; they are NS for CAT. ConclusionThe Halliwick method and the WSTH have been proven to be efficient on motor skills; our 4 field studies show significantly better effects with WSTH – probably thanks to “its rotation points” – than with CAT.

Neuromodulatory Selection of Motor Neuron Recruitment Patterns in a Visuomotor Behavior Increases Speed.

Animals generate locomotion at different speeds to suit their behavioral needs. Spinal circuits generate locomotion at these varying speeds by sequential activation of different spinal interneurons and motor neurons. Larval zebrafish can generate slow swims for prey capture and exploration by activation of secondary motor neurons and much faster and vigorous swims during escape and struggle via additional activation of primary motor neurons. Neuromodulators are known to alter the motor output of spinal circuits, but their precise role in speed regulation is not wellunderstood. Here, in the context of optomotor response (OMR), an innate evoked locomotor behavior, we show that dopamine (DA) provides an additional layer to regulation of swim speed in larval zebrafish. Activation of D1-like receptors increases swim speed during OMR in free-swimming larvae. By analyzing tail bend kinematics in head-restrained larvae, we show that the increase in speed is actuated by larger tail bends. Whole-cell patch-clamp recordings from motor neurons reveal that, during OMR, typically only secondary motor neurons are active, whereas primary motor neurons are quiescent. Activation of D1-like receptors increases intrinsic excitability and excitatory synaptic drive in primary and secondary motor neurons. These actions result in greater recruitment of motor neurons during OMR. Our findings provide an example of neuromodulatory reconfiguration of spinal motor neuron speed modules where members are selectively recruited and motor drive is increased to effect changes in locomotor speed. VIDEO ABSTRACT.

Decoding the essential interplay between central and peripheral control in adaptive locomotion of amphibious centipedes

Amphibious animals adapt their body coordination to compensate for changing substrate properties as they transition between terrestrial and aquatic environments. Using behavioural experiments and mathematical modelling of the amphibious centipede Scolopendra subspinipes mutilans, we reveal an interplay between descending command (brain), local pattern generation, and sensory feedback that controls the leg and body motion during swimming and walking. The elongated and segmented centipede body exhibits a gradual transition in the locomotor patterns as the animal crosses between land and water. Changing environmental conditions elicit a mechano-sensory feedback mechanism, inducing a gait change at the local segment level. The body segments operating downstream of a severed nerve cord (no descending control) can generate walking with mechano-sensory inputs alone while swimming behaviour is not recovered. Integrating the descending control for swimming initiation with the sensory feedback control for walking in a mathematical model successfully generates the adaptive behaviour of centipede locomotion, capturing the possible mechanism for flexible motor control in animals.

An interhemispheric neural circuit allowing binocular integration in the optic tectum

Binocular stereopsis requires the convergence of visual information from corresponding points in visual space seen by two different lines of sight. This may be achieved by superposition of retinal input from each eye onto the same downstream neurons via ipsi- and contralaterally projecting optic nerve fibers. Zebrafish larvae can perceive binocular cues during prey hunting but have exclusively contralateral retinotectal projections. Here we report brain activity in the tectal neuropil ipsilateral to the visually stimulated eye, despite the absence of ipsilateral retinotectal projections. This activity colocalizes with arbors of commissural neurons, termed intertectal neurons (ITNs), that connect the tectal hemispheres. ITNs are GABAergic, establish tectal synapses bilaterally and respond to small moving stimuli. ITN-ablation impairs capture swim initiation when prey is positioned in the binocular strike zone. We propose an intertectal circuit that controls execution of the prey-capture motor program following binocular localization of prey, without requiring ipsilateral retinotectal projections.

Impact of swimming initiation on the physical fitness and mental health of elderly women

This quasi-experimental study aimed to analyze the impact of swimming initiation on the physical fitness and mental health of 10 elderly women. It used the Senior Fitness Test, the Rosenberg Self-esteem Scale, the Geriatric Anxiety Inventory, the Perceived Stress Scale, the WHOQOL-BREF and the WHOQOL-OLD. The program involved 12 weeks of swimming initiation lessons, twice a week. There was significant difference between pre- and post-test in ‘sit-to-stand’ (p = 0.005), ‘elbow flexion’ (p = 0.007), ‘walk 2.44 m and sit’ (p = .005), ‘walk 6 min.’ (p = 0.005), as well as in anxiety (p = 0.005), stress (p = 0.005), self-esteem (p = 0.007) and quality of life (p < 0.05). Swimming was effective in improving the physical fitness and mental health of the elderly women.

Stimulation of Single, Possible CHX10 Hindbrain Neurons Turns Swimming On and Off in Young Xenopus Tadpoles

Vertebrate central pattern generators (CPGs) controlling locomotion contain neurons which provide the excitation that drives and maintains network rhythms. In a simple vertebrate, the developing Xenopus tadpole, we study the role of excitatory descending neurons with ipsilateral projecting axons (descending interneurons, dINs) in the control of swimming rhythms. In tadpoles with both intact central nervous system (CNS) and transections in the hindbrain, exciting some individual dINs in the caudal hindbrain region could start swimming repeatedly. Analyses indicated the recruitment of additional dINs immediately after such evoked dIN spiking and prior to swimming. Excitation of dINs can therefore be sufficient for the initiation of swimming. These “powerful” dINs all possessed both ascending and descending axons. However, their axon projection lengths were not different from those of other excitatory dINs at similar locations. The dorsoventral position of dINs, as a population, significantly better matched that of cells marked by immunocytochemistry for the transcription factor CHX10 than other known neuron types in the ventral hindbrain and spinal cord. The comparison suggests that the excitatory interneurons including dINs are CHX10-positive, in agreement with CHX10 as a marker for excitatory neurons with ipsilateral projections in the spinal cord and brainstem of other vertebrates. Overall, our results further demonstrate the key importance of dINs in driving tadpole swimming rhythms.

Swimming for dementia: An exploratory qualitative study: Innovative practice.

Swimming is a non-weight bearing form of exercise that can be enjoyable and promote physical fitness. This qualitative study investigated a local group established as part of a national dementia swimming initiative. Semi-structured interviews with people with dementia (N = 4), carers or companions (N = 4) and the organisers and facilitators of the group (N = 6) were analysed using thematic analysis. This revealed four main themes: (1) the pleasure of swimming and its benefits as a form of exercise and for building confidence and empowering participants, (2) the importance of insight and empathy in creating a safe and secure experience, (3) the impact of dementia and (4) how participants valued being part of a group 'all in the same boat'. 'Dementia friendly swimming' appears to be a valuable form of exercise, but it requires considerable preparation and support to make it happen.

Muscarinic modulation of the Xenopus laevis tadpole spinal mechanosensory pathway

Muscarinic acetylcholine receptors (mAChRs) mediate effects of acetylcholine (ACh) in many systems, including those involved in spinal functions like locomotion. In Xenopus laevis tadpoles at two days old, a model vertebrate for motor control research, we investigated the role of mAChRs in the skin mechanosensory pathway. We found that mAChR activation by carbachol did not affect the sensory Rohon-Beard neuron properties. However, carbachol could hyperpolarise sensory interneurons and decrease their voltage responses to outward currents. Carbachol could increase the threshold for the mechanosensory pathway to start swimming, preventing the initiation of swimming at higher concentrations altogether. Recording from the sensory interneurons in carbachol showed that their spiking after skin stimulation was depressed. However, the general muscarinic antagonist atropine did not have a clear effect on the swimming threshold or the modulation of sensory interneuron membrane conductance. Our results suggest the skin mechanosensory pathway may be subject to muscarinic modulation in this simple vertebrate system.

Mechanosensory Stimulation Evokes Acute Concussion-Like Behavior by Activating GIRKs Coupled to Muscarinic Receptors in a Simple Vertebrate.

Most vertebrates show concussion responses when their heads are hit suddenly by heavy objects. Previous studies have focused on the direct physical injuries to the neural tissue caused by the concussive blow. We study a similar behavior in a simple vertebrate, the Xenopus laevis tadpole. We find that concussion-like behavior can be reliably induced by the mechanosensory stimulation of the head skin without direct physical impacts on the brain. Head skin stimulation activates a cholinergic pathway which then opens G protein-coupled inward-rectifying potassium channels (GIRKs) via postsynaptic M2 muscarinic receptors to inhibit brainstem neurons critical for the initiation and maintenance of swimming for up to minutes and can explain many features commonly observed immediately after concussion. We propose that some acute symptoms of concussion in vertebrates can be explained by the opening of GIRKs following mechanosensory stimulation to the head.

Abstract 19425: A Small Molecule Enforcing MEF2 Deacetylation Prevents and Reverses Hypertrophy and Normalizes Cardiac Function in Multiple Stress Models

Background: Cardiac hypertrophy leads to progressive cardiac dysfunction, and is an independent risk factor for death. Myocyte enhancer factor 2 (MEF2) is silenced by interaction with class IIa histone deacetylases and activated by p300 acetyltransferase during hypertrophy. Hypothesis: Targeting the co-regulatory site on MEF2 will prevent and reverse hypertrophy and associated cardiac dysfunction. Methods: Transverse aortic coarctation (TAC) and swimming stress models were used to initiate cardiac hypertrophy in male C57Bl/6 mice. Mice swam for 3 hours twice daily; control mice were immersed briefly. 8MI was administered by daily IP injection at a dose of 40 mg/kg beginning either at the time of intervention (TAC, swimming stress) or 4 weeks afterward (TAC) and continued for 4 weeks. N ≥ 5 per group. RT-PCR, immunohistochemistry, and echocardiography were used to assess cardiac structure and function. Neonatal rat ventricular myocytes (NRVM) were treated with 8MI, the histone deacetylase inhibitors MC1568 (class IIa-selective) or trichostatin A (nonselective, TSA). Results: Both TAC and forced swimming induced pathological hypertrophy with deterioration in systolic function in mice receiving DMSO (p<0.001 for both). 4 weeks after TAC or the initiation of swimming, 8MI-treated animals had myocardial mass and function similar to those of sham-operated or immersed-control mice. After 8MI treatment was stopped at 4 weeks, hypertrophy developed in mice that continued to swim, similar to DMSO-treated animals. In mice with established hypertrophy 4 weeks after TAC, treatment with 8MI, but not DMSO, reversed systolic dysfunction (n=5 per group, p=0.0018) and reduced myocardial wall thickness to near that of sham-operated animals. No evidence of systemic toxicity was seen. Mechanistically, 8MI, but not MC1568, promoted HDAC4 nuclear retention and maintained MEF2 in a deacetylated state, and unlike TSA, prevented EP300 accumulation. Conclusions: Pharmacological targeting of MEF acetylation in vivo prevents and reverses stress-associated hypertrophy in multiple models. Reversal of hypertrophy by this means improves systolic function and does not prevent successful adaptation to increased cardiac work.

Research Analysis of Selection Criteria at the Initial Stage of Swimming Training of Primary School Junior Students

This article serves as a review of literature dedicated to the issue of selection criteria at the initial stage of swimming training of children in junior grades of primary school. Research methods used by the reviewed authors were varied. Only in some cases the overall anthropometric examination was used. This paper presents research results of multiple authors concerned with the swimming initiation age, basic somatic features (height and body mass), physical (motor) fitness, and physical function as major criteria for selection. The literature presented in this article lacks, however, information about potential correlations between the sports skills and measurements of motor skills and somatic features of children who are at an initial stage of competitive swimming. Therefore, this issue has not been discussed in the article.

Enhanced sensory sampling precedes self-initiated locomotion in an electric fish.

Cortical activity precedes self-initiated movements by several seconds in mammals; this observation has led into inquiries on the nature of volition. Preparatory neural activity is known to be associated with decision making and movement planning. Self-initiated locomotion has been linked to increased active sensory sampling; however, the precise temporal relationship between sensory acquisition and voluntary movement initiation has not been established. Based on long-term monitoring of sensory sampling activity that is readily observable in freely behaving pulse-type electric fish, we show that heightened sensory acquisition precedes spontaneous initiation of swimming. Gymnotus sp. revealed a bimodal distribution of electric organ discharge rate (EODR) demonstrating down- and up-states of sensory sampling and neural activity; movements only occurred during up-states and up-states were initiated before movement onset. EODR during voluntary swimming initiation exhibited greater trial-to-trial variability than the sound-evoked increases in EODR. The sampling variability declined after voluntary movement onset as previously observed for the neural variability associated with decision making in primates. Spontaneous movements occurred randomly without a characteristic timescale, and no significant temporal correlation was found between successive movement intervals. Using statistical analyses of spontaneous exploratory behaviours and associated preparatory sensory sampling increase, we conclude that electric fish exhibit key attributes of volitional movements, and that voluntary behaviours in vertebrates may generally be preceded by increased sensory sampling. Our results suggest that comparative studies of the neural basis of volition may therefore be possible in pulse-type electric fish, given the substantial homologies between the telencephali of teleost fish and mammals.

The impact of a community free swimming programme for young people (under 19) in England

A national free swimming programme for under 16s in England was a central government initiative to increase participation in 2008/09, although not all local authorities adopted it. One implemented a bespoke free swimming initiative (FSI) for under 19s in the community instead, aiming to improve the health of young people through the programme and provide value for money for managers. The FSI saw 33% of the eligible population participating at least once. However, the programme evaluation demonstrated that, despite cost being removed, participation decreased over the programme. Furthermore, the FSI had a large market penetration effect, where the majority of participants were already swimming regularly prior to the intervention. Overall, the programme provided some health benefits to the more engaged participants, but in terms of wider social benefit there was little evidence to suggest the intervention had any additional impact. The cost per swim of the community investment was almost six times more per head than the central government funded scheme, suggesting that widespread programming did not provide value for money when compared to a more targeted programme.

Enhanced attention precedes self-initiated locomotion in an electric fish

Volition is generally considered as a defining human faculty; but the outcome of a voluntary decision can be predicted by brain activity even before subject’s conscious awareness [1], and similar phenomena are observed in many species. Preparatory neural activities for voluntary movements involve movement planning and decision making [2], and active movements accompany heightened attention [3]. We show that enhanced attention precedes self-initiated movements in an animal model that exhibits a readily observable and quantifiable sensory acquisition rate. In addition to demonstrating preparatory increases in sensory sampling, our results reveal close similarities between the sensory sampling and the neural activity suggest associated with voluntary decision making [4]. Cortical activity precedes self-initiated movements by several seconds in mammals; this observation has led into inquiries on the nature of volition [1]. Preparatory neural activity is known to be associated with decision making and movement planning [2]. Self-initiated locomotion has been linked to active sensing indicative of enhanced attention [3]; however, the precise temporal relationship between sensory acquisition and voluntary movement initiation has not been established. Based on long-term monitoring of sensory sampling activity that is readily observable in freely behaving pulse-type electric fish, we show that heightened sensory acquisition precedes spontaneous initiation of swimming. Gymnotus sp. revealed a bimodal distribution of electric organ discharge rate (EODR) demonstrating Down- and Up-states of sensory sampling and neural activity; movements only occurred during Up-states and Up-states were initiated before movement-onset. EODR during voluntary swimming initiation exhibited greater trial-to-trial variability than the sound-evoked increases in EODR. The sensory sampling variability increased before, and declined after voluntary movement onset as previously observed for the neural variability associated with decision-making in primates [4]. In contrast, stimulus onset quenched the sampling variability similar to that previously reported in neural variability [5]. Spontaneous movements occurred randomly without a characteristic timescale, and no significant temporal correlation was found between successive movement intervals.

Local implementation of national policy: a case-study critique of the Free Swimming Initiative for the 60 plus population

There is a well-established link between ageing and declining health, and this is exacerbated in areas of socio-economic deprivation. Being physically active can alleviate many of the major health problems for older people, yet participation in this demographic category remains low. This study is part of a larger programme of research concerned with a major national public health intervention, the Free Swimming Initiative. Semi-structured interviews were conducted to address local implementation of the national policy imperative in Wales and explored the views of non-users (n = 20) and community leisure providers (n = 7). The research was based in Abertillery – a traditional mining town in the South Wales Valleys with higher than average levels of social deprivation. Findings revealed a series of weaknesses in the delivery of this public policy intervention. They are (i) a lack of partnership infrastructure, (ii) insufficient participant involvement, (iii) an evidence gap and (iv) disjointed multiple aims.