Single-cell transcriptomic analysis of the adult mouse spinal cord reveals molecular diversity of autonomic and skeletal motor neurons

The spinal cord is a fascinating structure that is responsible for coordinating movement in vertebrates. Spinal motor neurons control muscle activity by transmitting signals from the spinal cord to diverse peripheral targets. In this study, we profiled 43,890 single-nucleus transcriptomes from the adult mouse spinal cord using fluorescence-activated nuclei sorting to enrich for motor neuron nuclei. We identified 16 sympathetic motor neuron clusters, which are distinguishable by spatial localization and expression of neuromodulatory signaling genes. We found surprising skeletal motor neuron heterogeneity in the adult spinal cord, including transcriptional differences that correlate with electrophysiologically and spatially distinct motor pools. We also provide evidence for a novel transcriptional subpopulation of skeletal motor neuron (gamma*). Collectively, these data provide a single-cell transcriptional atlas (http://spinalcordatlas.org) for investigating the organizing molecular logic of adult motor neuron diversity, as well as the cellular and molecular basis of motor neuron function in health and disease.

Automated summary

This study analyzed single-nucleus transcriptomes from the adult mouse spinal cord, revealing heterogeneity in skeletal motor neurons and identifying a novel transcriptional subpopulation. The data provide important insights into investigating the molecular logic of adult motor neuron diversity and the cellular and molecular basis of motor neuron function in health and disease.