Presynaptic inhibition selectively suppresses leg proprioception in behavingDrosophila

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2023, Volume and Issue: unknown

Published: Oct. 23, 2023

Controlling arms and legs requires feedback from proprioceptive sensory neurons that detect joint position movement. Proprioceptive must be tuned for different behavioral contexts, but the underlying circuit mechanisms remain poorly understood. Using calcium imaging in behaving

Language: Английский

---

Operation regimes of spinal circuits controlling locomotion and the role of supraspinal drives and sensory feedback

eLife, Journal Year: 2024, Volume and Issue: 13

Published: Oct. 14, 2024

Locomotion in mammals is directly controlled by the spinal neuronal network, operating under control of supraspinal signals and somatosensory feedback that interact with each other. However, functional architecture locomotor its operation regimes, role sensory different behaviors, including at speeds, remain unclear. We developed a computational model circuits receiving drives limb could reproduce multiple experimental data obtained intact spinal-transected cats during tied-belt split-belt treadmill locomotion. provide evidence network operates regimes depending on speed. In an system, slow speeds (<0.4 m/s), non-oscillating state-machine regime requires or external inputs for phase transitions. Removing related to extension prevents oscillations speeds. With increasing speed drives, switches flexor-driven oscillatory then classical half-center regime. Following transection, predicts can only operate Our results suggest exploratory fast escape making use mechanisms.

Language: Английский

---

A Synchronized Event-Cue Feedback Loop Integrating a 3D Printed Wearable Flexible Sensor-Tactor Platform

Biosensors and Bioelectronics, Journal Year: 2025, Volume and Issue: 273, P. 117161 - 117161

Published: Jan. 14, 2025

Language: Английский

---

Generation and modification of human locomotor EMG activity when walking faster and carrying additional weight

Experimental Physiology, Journal Year: 2025, Volume and Issue: unknown

Published: March 6, 2025

In activities of daily living, people walk at different speeds with or without carrying additional loads. this study, we sought to examine how human adults manage these commonly encountered demands during walking. We measured electromyography (EMG), triceps surae H-reflexes, joint motion and ground reaction forces (GRF) while participants walked 1.0 m/s 1.5 an 20.4 kg weight (the equivalent 23-36% bodyweight). Faster walking was accompanied by a universal increase in burst EMG amplitude across flexors extensors upper lower leg muscles (with most notable increases found the plantarflexors) patterns activity were maintained. addition, range increased ankle, knee hip joints, step cycle duration shortened. bearing weight, extensor activity, especially early stance quadriceps minimally affected ankle (but not hip). When faster changes locomotor (except for displayed combined features those two demands; plantarflexor more complex. Locomotor H-reflexes larger than only when weight. generating controlling propulsive force generation multiple mechanisms both spinal supraspinal origin may be involved.

Language: Английский

---

The brain integrates proprioceptive information to ensure robust locomotion

The Journal of Physiology, Journal Year: 2022, Volume and Issue: 600(24), P. 5267 - 5294

Published: Oct. 22, 2022

Robust locomotion relies on information from proprioceptors: sensory organs that communicate the position of body parts to spinal cord and brain. Proprioceptive circuits in are known coarsely regulate presence perturbations. Yet, regulatory importance brain maintaining robust remains less clear. Here, through mouse genetic studies vivo electrophysiology, we examined role integrating proprioceptive during perturbed locomotion. The systemic removal proprioceptors left mice a constantly state, similar observed mechanically wild-type characterised by longer accurate synergistic activation patterns. By contrast, after surgically interrupting ascending projection dorsal column cord, showed normal walking behaviour, yet lost ability respond external Our findings provide direct evidence pivotal for achieving robust, safe KEY POINTS: Whether integration feedback is crucial coping with not We responding perturbations ensure used genetics remove lesion model interrupt flow animals. Using custom-built treadmill, administered sudden random mechanical walking. External affected absence genetically modified mice. muscle spindles Golgi tendon contributed locomotor robustness. Wild-type interruption brainstem.

Language: Английский

---

Changes in intra‐ and interlimb reflexes from forelimb cutaneous afferents after staggered thoracic lateral hemisections during locomotion in cats

The Journal of Physiology, Journal Year: 2024, Volume and Issue: 602(22), P. 6225 - 6258

Published: Sept. 27, 2024

Abstract In quadrupeds, such as cats, cutaneous afferents from the forepaw dorsum signal external perturbations and send inputs to spinal circuits co‐ordinate activity in muscles of all four limbs. How these reflex pathways forelimb are reorganized after an incomplete cord injury is not clear. Using a staggered thoracic lateral hemisections paradigm, we investigated changes intralimb interlimb by electrically stimulating left right superficial radial nerves seven adult cats recording responses five ten hindlimb muscles. After first (right T5–T6) second (left T10–T11) hemisections, forelimb–hindlimb co‐ordination was altered weakened. hemisection, required balance assistance perform quadrupedal locomotion. Short‐, mid‐ long‐latency homonymous crossed their phase modulation remained largely unaffected hemisections. The occurrence homolateral diagonal evoked with nerve stimulation significantly reduced at time point but partially recovered stimulation. These were lost or hemisection. When present, responses, including diagonal, maintained phase‐dependent modulation. Therefore, our results show considerable loss transmission cervical lumbar levels injury, albeit preservation modulation, probably affecting functional perturbations. image Key points Cutaneous afferent muscle limbs during locomotion when contacts obstacle. Thoracic disrupts communication between locomotor centres located levels, impairing limb co‐ordination. We reflexes bilaterally, before cats. showed loss/reduction early hemisection that stimulation, being Targeting projecting could help develop therapeutic approaches aimed restoring ascending descending pathways.

Language: Английский

---

Operation of spinal sensorimotor circuits controlling phase durations during tied-belt and split-belt locomotion after a lateral thoracic hemisection

Published: Jan. 14, 2025

Locomotion is controlled by spinal circuits that interact with supraspinal drives and sensory feedback from the limbs. These sensorimotor interactions are disrupted following cord injury. The thoracic lateral hemisection represents an experimental model of incomplete injury, where connections between brain abolished on one side cord. To investigate effects such injury operation locomotor network, we used our computational cat locomotion recently published in eLife (Rybak et al., 2024) to predict changes cycle phase durations a during treadmill tied-belt (equal left-right speeds) split-belt (unequal conditions. In simulations, “hemisection” was always applied right side. Based model, hypothesized hemisection, contralesional (“intact”, left) network mostly drives, whereas ipsilesional (“hemisected”, right) somatosensory feedback. We then compared simulated results those obtained experiments adult cats before after mid-thoracic same Our confirmed many predicted simulations. show having hindlimb step slow belt, but not fast substantially reduces hemisection. provides explanations for temporal characteristics based altered circuits,

Language: Английский

---

Operation of spinal sensorimotor circuits controlling phase durations during tied-belt and split-belt locomotion after a lateral thoracic hemisection

eLife, Journal Year: 2025, Volume and Issue: 13

Published: Jan. 27, 2025

Locomotion is controlled by spinal circuits that interact with supraspinal drives and sensory feedback from the limbs. These sensorimotor interactions are disrupted following cord injury. The thoracic lateral hemisection represents an experimental model of incomplete injury, where connections between brain abolished on one side cord. To investigate effects such injury operation locomotor network, we used our computational cat locomotion recently published in eLife (Rybak et al., 2024) to predict changes cycle phase durations a during treadmill tied-belt (equal left-right speeds) split-belt (unequal conditions. In simulations, ‘hemisection’ was always applied right side. Based model, hypothesized contralesional (‘intact’, left) network mostly drives, whereas ipsilesional (‘hemisected’, right) somatosensory feedback. We then compared simulated results those obtained experiments adult cats before after mid-thoracic same Our confirmed many predicted simulations. show having hindlimb step slow belt, but not fast substantially reduces hemisection. provides explanations for temporal characteristics based altered circuits,

Language: Английский

---

Relationship of strength, joint kinesthesia, and plantar tactile sensation to dynamic and static postural stability among patients with anterior cruciate ligament reconstruction

Frontiers in Physiology, Journal Year: 2023, Volume and Issue: 14

Published: Jan. 18, 2023

Objective: Postural stability is essential for high-level physical activities after anterior cruciate ligament reconstruction (ACLR). This study was conducted to investigate the relationship of muscle strength, joint kinesthesia, and plantar tactile sensation dynamic static postural among patients with reconstruction. Methods: Forty-four over 6 months post (age: 27.9 ± 6.8 years, height: 181.7 8.7 cm, weight: 80.6 9.4 kg, postoperative duration: 10.3 3.6 months) participated in this study. Their stability, hamstring/quadriceps ratio, were measured. Partial correlations used determine correlation above-mentioned variables time stabilization (TTS) root mean square center pressure (COP-RMS) anterior-posterior (AP) mediolateral (ML) directions. Results: Both TTSAP TTSML related strength kinesthesia knee flexion extension; COP-RMSAP correlated sensations at great toe arch, while COP-RMSML flexion, heel. Dynamic sequentially kinesthesia. Conclusion: Among reconstruction, stability. Strength has a higher level than

Language: Английский

---

Balancing sensory inputs: somatosensory reweighting from proprioception to tactile sensation in maintaining postural stability among older adults with sensory deficits

Frontiers in Public Health, Journal Year: 2023, Volume and Issue: 11

Published: May 4, 2023

Background Sensory deficits increase the risk of falls among older adults. The purpose this study was to investigate correlations lower extremity muscle strength, proprioception, and tactile sensation postural stability adults with without sensory deficits, understand contribution each factor stability, explore reweighting two populations. Methods A total 103 participants were recruited divided into adult groups (female = 24, male 26, age 69.1 ± 3.15 years, height 162.72 6.94 cm, body mass 64.05 9.82 kg) 27, 70.02 4.9 163.76 7.60 65.83 10.31 kg), based on whether a 5.07 Semmes–Weinstein monofilament could be detected at foot soles. Their Berg Balance Scale (BBS), tested compared between groups. Pearson's or Spearman's used relationships BBS variable. Factor analysis multivariate linear regression verify degrees correlation generated factors stability. Results Low ( p 0.003, η 2 0.088) scores higher proprioception thresholds (knee flexion: 0.015, 0.059; knee extension: 0.011, 0.065; ankle plantarflexion: 0.006, 0.075; dorsiflexion: 0.001, 0.106) those deficits. Lower strength (ankle r 0.342, 0.002; hip abduction: 0.303, 0.041) −0.419, 0.004; −0.292, 0.049; −0.450, −0.441, 0.002) correlated while 0.501, p&lt;0.001; 0.302, (great toe: −0.388, 0.008; 5th metatarsal: −0.301, 0.042) Conclusion Older have poorer Somatosensory occurs from in maintaining

Language: Английский

---