Multimodal sensory control of motor performance by glycinergic interneurons of the mouse spinal cord deep dorsal horn
- PMID: 38452762
- DOI: 10.1016/j.neuron.2024.01.027
Multimodal sensory control of motor performance by glycinergic interneurons of the mouse spinal cord deep dorsal horn
Abstract
Sensory feedback is integral for contextually appropriate motor output, yet the neural circuits responsible remain elusive. Here, we pinpoint the medial deep dorsal horn of the mouse spinal cord as a convergence point for proprioceptive and cutaneous input. Within this region, we identify a population of tonically active glycinergic inhibitory neurons expressing parvalbumin. Using anatomy and electrophysiology, we demonstrate that deep dorsal horn parvalbumin-expressing interneuron (dPV) activity is shaped by convergent proprioceptive, cutaneous, and descending input. Selectively targeting spinal dPVs, we reveal their widespread ipsilateral inhibition onto pre-motor and motor networks and demonstrate their role in gating sensory-evoked muscle activity using electromyography (EMG) recordings. dPV ablation altered limb kinematics and step-cycle timing during treadmill locomotion and reduced the transitions between sub-movements during spontaneous behavior. These findings reveal a circuit basis by which sensory convergence onto dorsal horn inhibitory neurons modulates motor output to facilitate smooth movement and context-appropriate transitions.
Keywords: dorsal horn; glycinergic interneurons; inhibition; movement; proprioception; sensorimotor circuits; spinal cord; touch.
Copyright © 2024 Elsevier Inc. All rights reserved.
Conflict of interest statement
Declaration of interests The authors declare no competing interests.
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