Physiological movements during sleep in healthy adults across all ages: a video-polysomnographic analysis of non-codified movements reveals sex differences and distinct motor patterns.

STUDY OBJECTIVES: to define sleep-related movements in healthy adults according to sex and age. METHODS: sleep-related movements from 50 video-polysomnography (vPSG) recordings of 27 men and 23 women, from 20 to 70 years old, were classified according to ICDS-3-TR and AASM criteria (codified movements); the remaining movements (non-codified movements) were described according to type (elementary movements-EMs or complex movements-CMs), topography (focal, segmental, multifocal or generalized) and, if present, were assigned to motor patterns (MPs). RESULTS: of 4057 movements analyzed, 54.6% (2216/4057) were non-codified (1861 CMs, 355 EMs) and 1841 were codified. CMs were mainly generalized (70%) while EMs were multifocal (40%) or focal (30%). The median movement index (MI; movement/hour) was 11 and the median duration was 4 s. MI decreased from stages N1/REM>N2>N3; men showed a higher MI. An MP was assigned to 2204 codified and non-codified movements, mainly stretching (50%) and scratching (30%). Stretching increased in REM sleep while food-carrying behaviors increased in N2. Men showed more food-carrying behaviors, changes of body positions and comfort movements while stretching was more common in women. Younger subjects exhibited more food-carrying behaviors, while scratching and stretching were more prevalent in the middle-aged group. Older subjects showed more changes in body positions and comfort movements. CONCLUSIONS: 54.6% of sleep-related movements in healthy subjects were non-codified and characterized by motor sequences that can configure MPs. Our comprehensive classification method allows a detailed description of the physiological movements underlying differential motor control during sleep stages influenced by age and sex.

Motor patterns of the impaired upper limb in children with unilateral cerebral palsy performing bimanual tasks.

BACKGROUND: Upper limb movement patterns have not yet been identified in bimanual conditions despite the difficulties children with unilateral cerebral palsy have performing bimanual activities. The aim was to identify specific motor patterns from kinematic deviations during bimanual tasks in this population. METHODS: Twenty children with unilateral cerebral palsy and 20 age-matched, typically developing children performed the five tasks of a 3D bimanual protocol. To evaluate upper limb kinematic deviations, 10 Arm Variable Scores were calculated for the affected /non-dominant upper limb of each participant for each task. Sparse K-means cluster analysis was applied to the 50 Arm Variable Scores of all the children to identify motor patterns and determining variables. Clinical tests of impairment (muscle strength, selectivity, spasticity) and function (Assisting hand assessment, Abilhand-Kids) were compared between the clusters obtained. FINDINGS: Three different motor patterns were identified using the data from all the children: mild, proximal-distal and proximal-distal with trunk. The most important cluster determinants were the Arm Variable Scores for pronation-supination and wrist extension. In the cerebral palsy group, scores of impairments (p < .01) and function (Assisting Hand Assessment [p < .001] and Abilhand-Kids [p = .004]) differed for each motor pattern. Supination and wrist extension deviations differed significantly between the groups (p < .001). INTERPRETATION: During performance of bimanual tasks, children with unilateral cerebral palsy used distinct motor patterns that each corresponded to a specific clinical profile. Elbow-wrist deviations were the largest and most decisive and were specific to the cerebral palsy group: they should be the target of interventions to enhance bimanual function. CLINICALTRIALS: gov identifier: NCT03888443.

Intersegmental Interactions Give Rise to a Global Network.

Animal motor behaviors require the coordination of different body segments. Thus the activity of the networks that control each segment, which are distributed along the nerve cord, should be adequately matched in time. This temporal organization may depend on signals originated in the brain, the periphery or other segments. Here we evaluate the role of intersegmental interactions. Because of the relatively regular anatomy of leeches, the study of intersegmental coordination in these animals restricts the analysis to interactions among iterated units. We focused on crawling, a rhythmic locomotive behavior through which leeches move on solid ground. The motor pattern was studied ex vivo, in isolated ganglia and chains of three ganglia, and in vivo. Fictive crawling ex vivo (crawling) displayed rhythmic characteristics similar to those observed in vivo. Within the three-ganglion chains the motor output presented an anterior-posterior order, revealing the existence of a coordination mechanism that occurred in the absence of brain or peripheral signals. An experimental perturbation that reversibly abolished the motor pattern in isolated ganglia produced only a marginal effect on the motor activity recorded in three-ganglion chains. Therefore, the segmental central pattern generators present in each ganglion of the chain lost the autonomy observed in isolated ganglia, and constituted a global network that reduced the degrees of freedom of the system. However, the intersegmental phase lag in the three-ganglion chains was markedly longer than in vivo. This work suggests that intersegmental interactions operate as a backbone of correlated motor activity, but additional signals are required to enhance and speed coordination in the animal.

A novel reticular node in the brainstem synchronizes neonatal mouse crying with breathing.

Human speech can be divided into short, rhythmically timed elements, similar to syllables within words. Even our cries and laughs, as well as the vocalizations of other species, are periodic. However, the cellular and molecular mechanisms underlying the tempo of mammalian vocalizations remain unknown. Furthermore, even the core cells that produce vocalizations remain ill-defined. Here, we describe rhythmically timed neonatal mouse vocalizations that occur within single breaths and identify a brainstem node that is necessary for and sufficient to structure these cries, which we name the intermediate reticular oscillator (iRO). We show that the iRO acts autonomously and sends direct inputs to key muscles and the respiratory rhythm generator in order to coordinate neonatal vocalizations with breathing, as well as paces and patterns these cries. These results reveal that a novel mammalian brainstem oscillator embedded within the conserved breathing circuitry plays a central role in the production of neonatal vocalizations.

Movements and behaviors during spontaneous arousals in healthy young adults: an intermediary stage between wakefulness and sleep?

BACKGROUND: Arousals are common, sudden and transient elevations of the vigilance level during normal sleep, but arousal-associated behaviors have not yet been studied. OBJECTIVE: We aimed to describe the duration as well as motor and autonomic patterns associated with arousals across sleep stages in normal subjects. METHODS: The spontaneous arousals of 25 healthy young adults were randomly analyzed on polysomnography with body- and face-oriented video cameras. The duration of the heart rate response as well as the frequency, amplitude, speed, body segment and semiology of associated movements were measured. RESULTS: Among 624 arousals (258 in N2, 140 in N3 and 226 in REM sleep), REM sleep arousals had the shortest duration, and N3 arousals were associated with greater heart rate acceleration. Movements and behaviors (mostly involving the head and neck, then the upper limbs, with rare eyes opening and no turning in bed) were frequent during arousals (69.4% during N2 sleep, 89.3% during N3 and 93.8% during REM sleep). Arousals more frequently included ample, prolonged and whole-body movements during N3 sleep and fast movements and facial expressions during REM sleep. During N2 arousals, chewing was the most prevalent behavior. Some movements resembled orientation and comfort behaviors (flexing/rotating the neck and trunk, scratching, pulling the sheets, rubbing the nose, yawning, smiling, frowning and speaking), whereas others resembled sleep-associated automatisms (swallowing, chewing). CONCLUSION: In contrast with previous assumptions, most arousals are associated with movements. The type of movements suggests that arousal is an intermediary state between wakefulness and sleep.

Locomotion Control With Frequency and Motor Pattern Adaptations.

Existing adaptive locomotion control mechanisms for legged robots are usually aimed at one specific type of adaptation and rarely combined with others. Adaptive mechanisms thus stay at a conceptual level without their coupling effect with other mechanisms being investigated. However, we hypothesize that the combination of adaptation mechanisms can be exploited for enhanced and more efficient locomotion control as in biological systems. Therefore, in this work, we present a central pattern generator (CPG) based locomotion controller integrating both a frequency and motor pattern adaptation mechanisms. We use the state-of-the-art Dual Integral Learner for frequency adaptation, which can automatically and quickly adapt the CPG frequency, enabling the entire motor pattern or output signal of the CPG to be followed at a proper high frequency with low tracking error. Consequently, the legged robot can move with high energy efficiency and perform the generated locomotion with high precision. The versatile state-of-the-art CPG-RBF network is used as a motor pattern adaptation mechanism. Using this network, the motor patterns or joint trajectories can be adapted to fit the robot's morphology and perform sensorimotor integration enabling online motor pattern adaptation based on sensory feedback. The results show that the two adaptation mechanisms can be combined for adaptive locomotion control of a hexapod robot in a complex environment. Using the CPG-RBF network for motor pattern adaptation, the hexapod learned basic straight forward walking, steering, and step climbing. In general, the frequency and motor pattern mechanisms complement each other well and their combination can be seen as an essential step toward further studies on adaptive locomotion control.

Real-time measurement of adenosine and ATP release in the central nervous system.

This brief review recounts how, stimulated by the work of Geoff Burnstock, I developed biosensors that allowed direct real-time measurement of ATP and adenosine during neural function. The initial impetus to create an adenosine biosensor came from trying to understand how ATP and adenosine-modulated motor pattern generation in the frog embryo spinal cord. Early biosensor measurements demonstrated slow accumulation of adenosine during motor activity. Subsequent application of these biosensors characterized real-time release of adenosine in in vitro models of brain ischaemia, and this line of work has recently led to clinical measurements of whole blood purine levels in patients undergoing carotid artery surgery or stroke. In parallel, the wish to understand the role of ATP signalling in the chemosensory regulation of breathing stimulated the development of ATP biosensors. This revealed that release of ATP from the chemosensory areas of the medulla oblongata preceded adaptive changes in breathing, triggered adaptive changes in breathing via activation of P2 receptors, and ultimately led to the discovery of connexin26 as a channel that mediates CO2-gated release of ATP from cells.

Biologically Plausible Class Discrimination Based Recurrent Neural Network Training for Motor Pattern Generation.

Biological brain stores massive amount of information. Inspired by features of the biological memory, we propose an algorithm to efficiently store different classes of spatio-temporal information in a Recurrent Neural Network (RNN). A given spatio-temporal input triggers a neuron firing pattern, known as an attractor, and it conveys information about the class to which the input belongs. These attractors are the basic elements of the memory in our RNN. Preparing a set of good attractors is the key to efficiently storing temporal information in an RNN. We achieve this by means of enhancing the "separation" and "approximation" properties associated with the attractors, during the RNN training. We furthermore elaborate how these attractors can trigger an action via the readout in the RNN, similar to the sensory motor action processing in the cerebellum cortex. We show how different voice commands by different speakers trigger hand drawn impressions of the spoken words, by means of our separation and approximation based learning. The method further recognizes the gender of the speaker. The method is evaluated on the TI-46 speech data corpus, and we have achieved 98.6% classification accuracy on the TI-46 digit corpus.

Impact of cognitive tasks on biomechanical and kinematic parameters of gait in women with fibromyalgia: A cross-sectional study.

BACKGROUND: Fibromyalgia (FM) is a chronic disease whose symptoms may cause altered walking pattern, which is important given the relevance of walking in daily life activities. These activities use to require the ability to perform both a motor and a cognitive task simultaneously. The main aim of the current study was to evaluate the impact of performing a simultaneous cognitive task in the gait pattern of women with FM. METHODS: A total of 36 women recruited from a local association took part in this cross-sectional study. The time required to complete the 10-meters-walking-test and kinematic outcomes including number of steps, cadence, trunk tilt and ranges of motion were analyzed under single (motor task only) and dual task (motor and cognitive tasks simultaneously) conditions. The secondary task consisted in counting aloud backward in rows of two. RESULTS: Results showed a significant increment in the time required to complete the test (p < 0.01) when participants performed the motor and cognitive tasks at the same time. Moreover, relevant changes in kinematic parameters such as increment of number of steps (p < 0.01), cadence (p < 0.01), trunk tilt (p < 0.01) and both hip (p < 0.01) and knee (p = 0.03) ranges of motion were also observed. CONCLUSION: Adding a cognitive task to a primary motor task affects the walking motor pattern in women with FM, making it more stable and safer walking pattern when the attention is focused on two simultaneous tasks.

A visual lamina in the medulla oblongata of the frog, Rana pipiens.

We have discovered a lamina of visually responsive units in the medulla oblongata of the frog. It spans the entire medial aspect of the rostrocaudal length of the medulla and extends dorsoventrally from the cell-dense dorsal zone into the cell-sparse ventral zone. Most visual units within this lamina have large receptive fields, with the majority extending bilaterally in the frontal visual field. Most of these neurons are binocular, have no apparent directional preference, respond equally well to stimuli of a variety of shapes and sizes, and exhibit strong habituation. More medial locations in the visual lamina represent ipsilateral visual space while more lateral locations within the lamina represent contralateral visual space. Many units in the caudal aspect of the visual lamina are bimodal, responding to both visual and somatosensory stimuli. HRP tracing reveals inputs to the lamina from many primary and secondary visual areas in the midbrain and diencephalon. There is no area-by-area segregation of the projections to the visual lamina. For example, most parts of the tectum project across the visual lamina. The only spatial order in the visual lamina is that at more medial sites there tends to be more input from contralateral tectum; and at more lateral sites there tends to be more input from ipsilateral tectum. There is bilateral input to the visual lamina from tectum, tegmentum, posterior nucleus of the thalamus, posterior tuberculum, and ventromedial thalamic nucleus. There is ipsilateral input to the visual lamina from torus semicircularis, pretectum, nucleus of Bellonci, and ventrolateral thalamic nucleus. There is contralateral input to the visual lamina from basal optic complex. Collectively, these results show the presence of visual influences in regions of the medulla that likely represent an important step in sensorimotor transformation.

Validity and Reliability of the New Basic Functional Assessment Protocol (BFA).

The global evaluation of motion patterns can examine the synchrony of neuromuscular control, range of motion, strength, resistance, balance and coordination needed to complete the movement. Visual assessments are commonly used to detect risk factors. However, it is essential to define standardized field-based tests that can evaluate with accuracy. The aims of the study were to design a protocol to evaluate fundamental motor patterns (FMP), and to analyze the validity and reliability of an instrument created to provide information about the quality of movement in FMP. Five tasks were selected: Overhead Squat (OHS); Hurdle Step (HS); Forward Step Down (FSD); Shoulder Mobility (SM); Active Stretching Leg Raise (ASLR). A list of variables was created for the evaluation of each task. Ten qualified judges assessed the validity of the instrument, while six external observers performed inter-intra reliability. The results show that the instrument is valid according to the experts' opinion; however, the reliability shows values below those established. Thus, the instrument was considered unreliable, so it is recommended to repeat the reliability process by performing more training sessions for the external observers. The present study creates the basic functional assessment (BFA), a new protocol which comprises five tasks and an instrument to evaluate FMP.

The cyclic motor patterns in the human colon.

BACKGROUND: High-resolution colonic manometry gives an unprecedented window into motor patterns of the human colon. Our objective was to characterize motor activities throughout the entire colon that possessed persistent rhythmicity and spanning at least 5 cm. METHODS: High-resolution colonic manometry using an 84-channel water-perfused catheter was performed in 19 healthy volunteers. Rhythmic activity was assessed during baseline, proximal balloon distention, meal, and bisacodyl administration. KEY RESULTS: Throughout the entire colon, a cyclic motor pattern occurred either in isolation or following a high-amplitude propagating pressure wave (HAPW), consisting of clusters of pressure waves at a frequency centered on 11-13 cycles/min, unrelated to breathing. The cluster duration was 1-6 minutes; the pressure waves traveled for 8-27 cm, lasting 5-8 seconds. The clusters itself could be rhythmic at 0.5-2 cpm. The propagation direction of the individual pressure waves was mixed with >50% occurring simultaneous. This high-frequency cyclic motor pattern co-existed with the well-known low-frequency cyclic motor pattern centered on 3-4 cpm. In the rectum, the low-frequency cyclic motor pattern dominated, propagating predominantly in retrograde direction. Proximal balloon distention, a meal and bisacodyl administration induced HAPWs followed by cyclic motor patterns. CONCLUSIONS AND INFERENCES: Within cyclic motor patterns, retrograde propagating, low-frequency pressure waves dominate in the rectum, likely keeping the rectum empty; and mixed propagation, high-frequency pressure waves dominate in the colon, likely promoting absorption and storage, hence contributing to continence. Propagation and frequency characteristics are likely determined by network properties of the interstitial cells of Cajal.

Visual-perceptual training with motor practice of the observed movement pattern improves anticipation in emerging expert cricket batsmen.

This study addressed the paucity of evidence of whether visual anticipation can be improved in emerging experts in striking sports. Twelve emerging expert batsmen from a state cricket squad were equally randomised into intervention and control groups. They were pre-and-post tested on a video temporal occlusion test of a fast bowler, as well as transfer tests of different fast and slow bowlers. The intervention group received two sessions per week of point-light display temporal occlusion training with motor practice of the observed bowler's action over a 4-week period. The control group completed only the testing phases. Batting averages before, during, and after the study were recorded for both groups. The intervention group, but not the control group, improved anticipation to significantly above chance level across pre-to-post-tests based upon pre-ball flight information. The intervention, but not the control, transferred their learning to anticipate significantly above chance level based upon pre-ball flight information across different fast and slow (spin) bowlers. Batting average of the intervention group was higher than the control group during the study. Findings indicate that the intervention can improve anticipation in emerging expert batsmen, beyond sport-specific practice. This improvement may benefit competition performance, but further evidence is required.

Motor strategy for rapid gait initiation under conditions of limited center of pressure control.

[Purpose] The general motor strategy for gait initiation is achieved by the difference between the center of gravity and center of pressure; it be as bigger under speed optimization. This study aimed to investigate the motor pattern in rapid gait initiation under conditions of limited backward displacement of center of pressure. [Participants and Methods] The participants were 30 healthy young males (mean age, 19.7 ± 1.0 years). They performed a gait initiation task at three center of pressure start positions (anterior, middle, and posterior) and two speed conditions (normal and rapid). The gait initiation motion was measured using a video camera and motor pattern in the images was classified. The center of pressure position was continuously monitored using a pressure distribution measurement system. [Results] Forward tilt pattern was the most common under no limited center of pressure control and normal speed. The backward tilt pattern was the most preferred in the posterior position under limited center of pressure control and rapid speed. Displacement of the center of pressure showed a significant decline when the center of pressure start position was displaced backward. [Conclusion] The backward tilt pattern is the most effective motor strategy to increase the forward speed of the center of gravity.

A descriptive analysis of shoulder muscle activities during individual stages of the Turkish Get-Up exercise.

The Turkish Get-Up (TGU) is a complex and multi-planar exercise; the performer begins in a supine lying position, progresses toward upright standing through a series of 7 stages while holding a mass overhead in one hand, and returns to the original supine lying position through a reversal of the same 7 stages. A descriptive analysis of shoulder muscle activity during the TGU may provide insight toward its use in training and rehabilitation contexts. Our objectives were to: (1) describe the activity patterns from a subset of muscles that span the glenohumeral joint during individual stages of the TGU, and (2) interpret these patterns through comparisons between left- and right-side muscles, and between the up and down phases of the TGU. Twelve individuals with at least one-year experience performing the TGU were included in this study. Surface electromyographic (EMG) recordings were bilaterally obtained from 8 glenohumeral muscle groups while participants performed ten trials of the TGU with a kettlebell in their right hand. Instants representing the start and end of each TGU stage were identified from a synchronized video for each trial, and EMG activities for each muscle were integrated over the duration of each stage. Average integrated EMG and within-participant coefficients of variation were calculated. Overall, the greatest muscular demand occurred during the second (press to elbow support) and fifth (leg sweep) stages. Activities from muscles on the ipsilateral side to the kettlebell (right-side) were greater during stages when the contralateral upper limb did not contribute to supporting the body; however, contralateral (left-side) muscles were invoked during stages when the non-kettlebell-bearing forearm or hand contributed to supporting the body. The results suggest the importance of training both phases of the TGU to gain the most benefit from the exercise and highlights the asymmetric nature of the exercise, which may be particularly relevant for athletes engaged in activities with rotational demands.

Morphology and Physiology of the Ascidian Nervous Systems and the Effectors.

Neurobiology in ascidians has made many advances. Ascidians have offered natural advantages to researchers, including fecundity, structural simplicity, invariant morphology, and fast and stereotyped developmental processes. The researchers have also accumulated on this animal a great deal of knowledge, genomic resources, and modern genetic techniques. A recent connectomic analysis has shown an ultimately resolved image of the larval nervous system, whereas recent applications of live imaging and optogenetics have clarified the functional organization of the juvenile nervous system. Progress in resources and techniques have provided convincing ways to deepen what we have wanted to know about the nervous systems of ascidians. Here, the research history and the current views regarding ascidian nervous systems are summarized.

Oviposition-like central pattern generators in pregenital segments of male and female grasshoppers.

Grasshoppers produce an extraordinary oviposition behavior that is associated with multiple specializations of the skeletal and neuromuscular systems in the posterior abdomen, including a central pattern generator (CPG) in the female's terminal abdominal ganglion. Two pairs of shovel-shaped appendages, the ovipositor valves on the abdomen tip, excavate the soil for deposition of eggs. By contrast, the sexually monomorphic pregenital region of the abdomen is without appendages. Morphological homologues of ovipositor muscles and efferent neurons in the eighth abdominal segment are nevertheless present in pregenital segments of males and females. In both sexes, a robust rhythmic motor program was induced in pregenital segments by the same experimental methods used to elicit oviposition digging. The activity, recorded extracellularly, was oviposition-like in burst period (5-6 s) and homologous muscle phase relationships, and it persisted after sensory inputs were removed, indicating the presence of pregenital CPGs. The abdomen exhibited posterior-going waves of activity with an intersegmental phase delay of approximately 1 s. These results indicate that serially homologous motor systems, including functional CPGs, provided the foundation for the evolution of oviposition behavior.

Output variability across animals and levels in a motor system.

Rhythmic behaviors vary across individuals. We investigated the sources of this output variability across a motor system, from the central pattern generator (CPG) to the motor plant. In the bilaterally symmetric leech heartbeat system, the CPG orchestrates two coordinations in the bilateral hearts with different intersegmental phase relations (Δϕ) and periodic side-to-side switches. Population variability is large. We show that the system is precise within a coordination, that differences in repetitions of a coordination contribute little to population output variability, but that differences between bilaterally homologous cells may contribute to some of this variability. Nevertheless, much output variability is likely associated with genetic and life history differences among individuals. Variability of Δϕ were coordination-specific: similar at all levels in one, but significantly lower for the motor pattern than the CPG pattern in the other. Mechanisms that transform CPG output to motor neurons may limit output variability in the motor pattern.

Serotonergic network in the subesophageal zone modulates the motor pattern for food intake in Drosophila.

The functional organization of central motor circuits underlying feeding behaviors is not well understood. We have combined electrophysiological and genetic approaches to investigate the regulatory networks upstream of the motor program underlying food intake in the Drosophila larval central nervous system. We discovered that the serotonergic network of the CNS is able to set the motor rhythm frequency of pharyngeal pumping. Pharmacological experiments verified that modulation of the feeding motor pattern is based on the release of serotonin. Classical lesion and laser based cell ablation indicated that the serotonergic neurons in the subesophageal zone represent a redundant network for motor control of larval food intake.

Evaluating the triplet hypothesis during rhythmic mastication in primates.

Mammalian mastication involves precise jaw movements including transverse movement of the mandible during the power stroke. Jaw elevation and transverse movement are driven by asymmetrical jaw elevator muscle activity, which is thought to include a phylogenetically primitive and conserved triplet motor pattern consisting of: triplet I (balancing side: superficial masseter and medial pterygoid; working side: posterior temporalis), which reaches onset, peak and offset first; and triplet II (working side: superficial masseter and medial pterygoid; balancing side: posterior temporalis), which is active second. Although the presence of a triplet motor pattern has been confirmed in several primate species, the prevalence of this motor pattern - i.e. the proportion of masticatory cycles that display it - has not been evaluated in primates. The present study quantifies the presence and prevalence of the triplet motor pattern in five different primate species, Eulemur fulvus, Propithecus verreauxi, Papio anubis, Macacafuscata and Pan troglodytes, using mean onset, peak and offset time relative to working superficial masseter. In all five of the species studied, the mean triplet motor pattern was observed at peak muscle activation, and in four out of the five species the triplet motor pattern occurred more frequently than expected at random at peak muscle activation and offset. Non-triplet motor patterns were observed in varying proportions at different time points in the masticatory cycle, suggesting that the presence or absence of the triplet motor pattern is not a binomial trait. Instead, the primate masticatory motor pattern is malleable within individual cycles, within individual animals and therefore within species.