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

The Journal of Physiology, Journal Year: 2024, Volume and Issue: 602(9), P. 1987 - 2017

Published: April 9, 2024

Abstract When the foot dorsum contacts an obstacle during locomotion, cutaneous afferents signal central circuits to coordinate muscle activity in four limbs. Spinal cord injury disrupts these interactions, impairing balance and interlimb coordination. We evoked reflexes by electrically stimulating left right superficial peroneal nerves before after two thoracic lateral hemisections placed on opposite sides of at 9‐ 13‐week interval seven adult cats (4 males 3 females). recorded reflex responses ten hindlimb five forelimb muscles bilaterally. After first (right T5–T6) second (left T10–T11) hemisections, coordination fore‐ hindlimbs was altered and/or became less consistent. hemisection, required assistance perform quadrupedal locomotion. Short‐latency homonymous crossed largely remained unaffected staggered hemisections. However, mid‐ long‐latency both occurred frequently In muscles, homolateral diagonal response occurrence significantly decreased all limbs, however, when present, short‐, maintained their phase‐dependent modulation. also observed reduced durations short‐latency inhibitory extensors early hemisection delayed ipsilesional hemisection. Therefore, changes correlated with impaired balance/stability locomotion spinal injury. Restoring transmission could be used as a biomarker facilitate locomotor recovery. image Key points Cutaneous afferent inputs limbs obstacle. Thoracic communication between centres located cervical lumbar levels, limb investigated nerve bilaterally, cats. showed loss/reduction which balance. Targeting pathways projecting help develop therapeutic approaches aimed restoring ascending descending pathways.

Language: Английский

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Multimodal sensory control of motor performance by glycinergic interneurons of the mouse spinal cord deep dorsal horn

Neuron, Journal Year: 2024, Volume and Issue: 112(8), P. 1302 - 1327.e13

Published: March 6, 2024

Language: Английский

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Forelimb movements contribute to hindlimb cutaneous reflexes during locomotion in cats

Journal of Neurophysiology, Journal Year: 2024, Volume and Issue: 131(6), P. 997 - 1013

Published: May 1, 2024

During quadrupedal locomotion, interactions between spinal and supraspinal circuits somatosensory feedback coordinate forelimb hindlimb movements. How this is achieved not clear. To determine whether movements modulate cutaneous reflexes involved in responding to an external perturbation, we stimulated the superficial peroneal nerve six intact cats during locomotion hindlimb-only (with forelimbs standing on stationary platform) two with a low transection (T12-T13) locomotion. We compared evoked ipsilateral four contralateral muscles. Results showed similar occurrence phase-dependent modulation of short-latency inhibitory excitatory responses cats. However, depth was reduced semitendinosus Additionally, longer-latency occurred less frequently extensor muscles bilaterally whereas more sartorius anterior, respectively. After transection, were both conditions, mid- or abolished. Our results comparison spinal-transected suggest that absence suppresses inputs from structures and/or cervical cord normally contribute reflex

Language: Английский

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Neuromechanical Strategies for Obstacle Negotiation during Overground Locomotion following Incomplete Spinal Cord Injury in Adult Cats

Journal of Neuroscience, Journal Year: 2023, Volume and Issue: 43(31), P. 5623 - 5641

Published: July 20, 2023

Following incomplete spinal cord injury in animals, including humans, substantial locomotor recovery can occur. However, functional aspects of locomotion, such as negotiating obstacles, remains challenging. We collected kinematic and electromyography data 10 adult cats (5 males, 5 females) before at weeks 1-2 7-8 after a lateral mid-thoracic hemisection on the right side while they negotiated obstacles three different heights. Intact always cleared without contact. At hemisection, ipsilesional hindlimb contacted ∼50% trials, triggering stumbling corrective reaction or absent responses, which we termed Other. When complete clearance occurred, observed exaggerated flexion when crossing obstacle with contralesional Left limbs leading. proportion increased, Other responses decreased, reactions remained relatively unchanged. found redistribution weight support reduced diagonal supports increased homolateral supports, particularly left side. The main neural strategy for intact consisted knee flexor activation. After activation remained, but it was insufficient more variable limb approached obstacle. also their speed stepping over an obstacle, increase that disappeared hemisection. time paralleled muscle patterns new strategies. Our results suggest partial anticipatory control through neuroplastic changes system.

Language: Английский

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Subsets of leg proprioceptors influence leg kinematics but not interleg coordination in Drosophila melanogaster walking

Journal of Experimental Biology, Journal Year: 2022, Volume and Issue: 225(20)

Published: Oct. 15, 2022

Legged locomotion in terrestrial animals is often essential for mating and survival, locomotor behavior must be robust adaptable to successful. This adaptability largely provided by proprioceptors monitoring positions movements of body parts providing feedback other components networks. In insects, proprioceptive chordotonal organs span joints encode parameters relative movement between segments. Previous studies have used whole-organ ablation, reduced preparations or broad physiological manipulations impair the function femoral organ (fCO), which monitors femur-tibia joint, demonstrated its contribution interleg coordination walking behavior. The fCO Drosophila melanogaster comprises groups neurons that differ their morphology encoding properties (club, hook, claw); sub-population-level not been methodologically accessible. Here, we took advantage genetic toolkit available D. identify sub-populations transient optogenetic inhibition investigate roles coordination. Our findings demonstrate a subset club hook replicates effects inhibiting whole fCO; when inhibited alone, however, individual types did strongly affect spatial aspects single-leg kinematics. Moreover, subsets seem play only minor role temporal Thus, contains functionally distinct subgroups, this functional classification may from those based on anatomy properties; should investigated future involvement

Language: Английский

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Modulation of the gait pattern during split-belt locomotion after lateral spinal cord hemisection in adult cats

Journal of Neurophysiology, Journal Year: 2022, Volume and Issue: 128(6), P. 1593 - 1616

Published: Nov. 16, 2022

Most previous studies investigated the recovery of locomotion in animals and people with incomplete spinal cord injury (SCI) during relatively simple tasks (e.g., walking a straight line on horizontal surface or treadmill). We know less about after SCI left-right asymmetric conditions, such as turning stepping along circular trajectories. To investigate this, we collected kinematic electromyography data split-belt at different speed differences before right thoracic lateral hemisection nine adult cats. After hemisection, although cats still performed locomotion, observed several changes gait pattern compared intact state early (1-2 wk) late (7-8 time points. Cats larger lesions showed new coordination patterns between fore- hindlimbs, forelimbs taking more steps. Despite this change fore-hind coordination, maintained consistent phasing hindlimbs. Adjustments cycle phase (stance swing) durations slow fast sides allowed to maintain 1:1 coordination. Periods triple support involving (ipsilesional) hindlimb decreased favor quad other limbs. Step stride lengths concurrent possibly avoid interference. The above adjustments retain ability locomote conditions SCI. discuss potential plastic neuromechanical mechanisms involved locomotor these conditions.NEW & NOTEWORTHY Everyday often involves asymmetries, when turning, paths, uneven terrains, etc. show how affects control treadmill one side faster than other. that kinematics muscle activity perform hemisection.

Language: Английский

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Complexity of modular neuromuscular control increases and variability decreases during human locomotor development

Communications Biology, Journal Year: 2022, Volume and Issue: 5(1)

Published: Nov. 16, 2022

Abstract When does modular control of locomotion emerge during human development? One view is that modularity not innate, being learnt over several months experience. Alternatively, the basic motor modules are present at birth, but subsequently reconfigured due to changing brain-body-environment interactions. problem in identifying structures stepping infants presence noise. Here, using both simulated and experimental muscle activity data from neonates, infants, preschoolers, adults, we dissect influence noise, identify all individuals, including neonates. Complexity increases neonatal stage adulthood multiple levels infrastructure, intrinsic rhythmicity measured level individual muscles activities, synergies bilateral intermuscular network connectivity. Low complexity high variability neuromuscular signals attest immaturity, they also involve potential benefits for learning locomotor tasks.

Language: Английский

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A sensory signal related to left-right symmetry modulates intra- and interlimb cutaneous reflexes during locomotion in intact cats

Frontiers in Systems Neuroscience, Journal Year: 2023, Volume and Issue: 17

Published: June 9, 2023

During locomotion, cutaneous reflexes play an essential role in rapidly responding to external perturbation, for example, prevent a fall when the foot contacts obstacle. In cats and humans, involve all four limbs are task- phase modulated generate functionally appropriate whole-body responses.

Language: Английский

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Spinal Sensorimotor Circuits Play a Prominent Role in Hindlimb Locomotor Recovery after Staggered Thoracic Lateral Hemisections but Cannot Restore Posture and Interlimb Coordination during Quadrupedal Locomotion in Adult Cats

eNeuro, Journal Year: 2023, Volume and Issue: 10(6), P. ENEURO.0191 - 23.2023

Published: June 1, 2023

Spinal sensorimotor circuits interact with supraspinal and peripheral inputs to generate quadrupedal locomotion. Ascending descending spinal pathways ensure coordination between the forelimbs hindlimbs. cord injury (SCI) disrupts these pathways. To investigate control of interlimb hindlimb locomotor recovery, we performed two lateral thoracic hemisections on opposite sides (right T5-T6 left T10-T11) at an interval approximately months in eight adult cats. In three cats, was transected T12-T13. We collected electromyography (EMG) kinematic data during hindlimb-only locomotion before after lesions. show that (1) cats spontaneously recover following staggered but require balance assistance second one, (2) hindlimbs displays 2:1 patterns (two cycles one forelimb within cycle) becomes weaker more variable both hemisections, (3) left-right asymmetries stance swing durations appear first hemisection reverse second, (4) support periods reorganize favor involving diagonal limbs. Cats expressed day transection, indicating lumbar play a prominent role recovery hemisections. These results reflect series changes allow maintain some level functionality diminished motor commands from brain cervical cord, although posture remains impaired.

Language: Английский

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Sensory Perturbations from Hindlimb Cutaneous Afferents Generate Coordinated Functional Responses in All Four Limbs during Locomotion in Intact Cats

eNeuro, Journal Year: 2022, Volume and Issue: 9(6), P. ENEURO.0178 - 22.2022

Published: Nov. 1, 2022

Coordinating the four limbs is an important feature of terrestrial mammalian locomotion. When foot dorsum contacts obstacle, cutaneous mechanoreceptors send afferent signals to spinal cord elicit coordinated reflex responses in ensure dynamic balance and forward progression. To determine how locomotor pattern all changes response a sensory perturbation evoked by activating afferents from one hindlimb, we electrically stimulated superficial peroneal (SP) nerve with relatively long train at different phases (mid-stance, stance-to-swing transition, mid-swing, swing-to-stance transition) hindlimb cycle seven adult cats. The largest functional effects stimulation were found mid-swing transition several ipsilateral such as increased activity muscles that flex knee hip joints, joint flexion toe height, stride/step lengths swing duration. We also observed support periods shift other three limbs. same applied mid-stance produced more subtle pattern. no stride step these phases. did observe some slightly greater flexions ankle joints reduction double increase triple support. Our results show correcting or preventing stumbling involves contributions

Language: Английский

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