{Reference Type}: Journal Article
{Title}: Multimodal sensory control of motor performance by glycinergic interneurons of the mouse spinal cord deep dorsal horn.
{Author}: Gradwell MA;Ozeri-Engelhard N;Eisdorfer JT;Laflamme OD;Gonzalez M;Upadhyay A;Medlock L;Shrier T;Patel KR;Aoki A;Gandhi M;Abbas-Zadeh G;Oputa O;Thackray JK;Ricci M;George A;Yusuf N;Keating J;Imtiaz Z;Alomary SA;Bohic M;Haas M;Hernandez Y;Prescott SA;Akay T;Abraira VE;
{Journal}: Neuron
{Volume}: 112
{Issue}: 8
{Year}: 2024 Apr 17
{Factor}: 18.688
{DOI}: 10.1016/j.neuron.2024.01.027
{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.