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.
•Speech is a stereotyped rhythmic behavior predicted to be driven by a CPG•Similar to speech, mouse cries have rhythmic syllables and a stereotyped motor program•The iRO has the connectivity and intrinsic rhythmicity to produce timed cries•The iRO is necessary and sufficient for cries and the embedded syllable structure
Speech and innate vocalizations have stereotyped and rhythmic elements, similar to syllables, suggesting that a hardwired motor program underlies their production. Here, Wei et al. identify a vocalization central pattern generator, the first of its kind, that coordinates neonatal mouse cries with breathing and encodes the rhythmic syllable structure.
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.
Courtship displays have been traditionally considered stereotyped behaviours. Many elaborate courtships are displayed in specific locations or in courts prepared by the displaying individuals. Sudden ...environmental events may alter the spatial structure of the displaying site, and individuals should be able to cope with such disruptions. In some mating systems, courtship is the only or main trait used in mate choice. This is the case in lek mating systems where male mating success is highly skewed and intense sexual selection may drive the evolution of elaborate courtship. The golden-collared manakin is a lekking species of the Neotropical forests. Males have an elaborate courtship display that includes a series of acrobatic jumps within a court delimited by small saplings. The courtship ends with a jump on one of the saplings, called the mating sapling, which invites the female to copulate. The display of each male follows a consistent routine that males establish at the beginning of the reproductive season. We hypothesized that males possess behavioural flexibility to adapt their courtship behaviour to unpredictable environmental changes. We investigated the effects of a sudden disruption of the court configuration by placing a piece of bark on the mating sapling. Males gradually established a new display sequence with an alternative mating sapling, demonstrating a high level of behavioural flexibility that suggests the involvement of motor learning. When the bark was removed, some males reverted to the original sequence, showing retention of the original display sequence. Our study provides evidence for the involvement of motor learning in the establishment and adjustment of elaborate courtship displays.
•Male manakins modify their courtship after alteration of their court.•The gradual change of the courtship sequence indicates motor learning.•Some birds deploy the original sequence after court structure is restored.•Elaborate courtship appears to be established and adjusted through motor learning.
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.
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.
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.
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).
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
•Three motor patterns were identified: mild, proximal-distal and with trunk.•Pronation-supination and wrist extension were decisive for classification.•Clinical ratings of impairment and function differed for each motor pattern.•The largest pathological deviations were for supination and wrist extension.
•Women with Fibromyalgia suffer gait alteration when dividing their attention•Alterations in motor pattern may be caused by the search for greater safety gait.•Kinematic and Biomechanical parameters ...are needed to complement performance results
: 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.
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 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.
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.
Arousals are common, sudden and transient elevations of the vigilance level during normal sleep, but arousal-associated behaviors have not yet been studied.
We aimed to describe the duration as well ...as motor and autonomic patterns associated with arousals across sleep stages in normal subjects.
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.
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).
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.
•Most spontaneous arousals are associated with movements and behaviors.•Some movements resemble head orientation and comfort behaviors, as awake.•Other movements resemble sleep-associated automatisms (swallowing, chewing).•Arousal may be an intermediary state between wakefulness and sleep.
The cyclic motor patterns in the human colon Pervez, Maham; Ratcliffe, Elyanne; Parsons, Sean P. ...
Neurogastroenterology and motility,
20/May , Letnik:
32, Številka:
5
Journal Article
Recenzirano
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.
High‐resolution colonic manometry allows detailed assessment of human colon motor function and dysfunction. Here, a cyclic motor pattern at ~12 cycles/min follows a high‐amplitude propagating pressure wave at 160 mm Hg. It may restore the absorption and mixing condition after a mass movement of content.
Occupations characterized by a static low load and by repetitive actions show a high prevalence of work-related musculoskeletal disorders (WMSD) in the neck-shoulder region. Moreover, muscle fatigue ...and discomfort are reported to play a relevant initiating role in WMSD. Aims: To investigate relationships between altered sensory information, i.e. localized muscle fatigue, discomfort and pain and their associations to changes in motor control patterns. In total 101 subjects participated. Questionnaires, subjective assessments of perceived exertion and pain intensity as well as surface electromyography (SEMG), mechanomyography (MMG), force and kinematics recordings were performed. Multi-channel SEMG and MMG revealed that the degree of heterogeneity of the trapezius muscle activation increased with fatigue. Further, the spatial organization of trapezius muscle activity changed in a dynamic manner during sustained contraction with acute experimental pain. A graduation of the motor changes in relation to the pain stage (acute, subchronic and chronic) and work experience were also found. The duration of the work task was shorter in presence of acute and chronic pain. Acute pain resulted in decreased activity of the painful muscle while in subchronic and chronic pain, a more static muscle activation was found. Posture and movement changed in the presence of neck-shoulder pain. Larger and smaller sizes of arm and trunk movement variability were respectively found in acute pain and subchronic/chronic pain. The size and structure of kinematics variability decreased also in the region of discomfort. Motor variability was higher in workers with high experience. Moreover, the pattern of activation of the upper trapezius muscle changed when receiving SEMG/MMG biofeedback during computer work. SEMG and MMG changes underlie functional mechanisms for the maintenance of force during fatiguing contraction and acute pain that may lead to the widespread pain seen in WMSD. A lack of harmonious muscle recruitment/derecruitment may play a role in pain transition. Motor behavior changed in shoulder pain conditions underlining that motor variability may play a role in the WMSD development as corroborated by the changes in kinematics variability seen with discomfort. This prognostic hypothesis was further, supported by the increased motor variability among workers with high experience. Quantitative assessments of the functional motor adaptations can be a way to benchmark the pain status and help to indentify signs indicating WMSD development. Motor variability is an important characteristic in ergonomic situations. Future studies will investigate the potential benefit of inducing motor variability in occupational settings.
Rats sweep their facial whiskers back and forth to generate tactile sensory information through contact with environmental structure. The neural processes operating on the signals arising from these ...whisker contacts are widely studied as a model of sensing in general, even though detailed knowledge of the natural circumstances under which such signals are generated is lacking. We used digital video tracking and wireless recording of mystacial electromyogram signals to assess the effects of whisker-object contact on whisking in freely moving animals exploring simple environments. Our results show that contact leads to reduced protraction (forward whisker motion) on the side of the animal ipsilateral to an obstruction and increased protraction on the contralateral side. Reduced ipsilateral protraction occurs rapidly and in the same whisk cycle as the initial contact. We conclude that whisker movements are actively controlled so as to increase the likelihood of environmental contacts while constraining such interactions to involve a gentle touch. That whisking pattern generation is under strong feedback control has important implications for understanding the nature of the signals reaching upstream neural processes.
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