Spinal Inhibitory Interneuron Diversity Delineates Variant Motor Microcircuits

Cell. 2016 Mar 24;165(1):207-219. doi: 10.1016/j.cell.2016.01.027. Epub 2016 Mar 3.

Abstract

Animals generate movement by engaging spinal circuits that direct precise sequences of muscle contraction, but the identity and organizational logic of local interneurons that lie at the core of these circuits remain unresolved. Here, we show that V1 interneurons, a major inhibitory population that controls motor output, fractionate into highly diverse subsets on the basis of the expression of 19 transcription factors. Transcriptionally defined V1 subsets exhibit distinct physiological signatures and highly structured spatial distributions with mediolateral and dorsoventral positional biases. These positional distinctions constrain patterns of input from sensory and motor neurons and, as such, suggest that interneuron position is a determinant of microcircuit organization. Moreover, V1 diversity indicates that different inhibitory microcircuits exist for motor pools controlling hip, ankle, and foot muscles, revealing a variable circuit architecture for interneurons that control limb movement.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Extremities / physiology*
  • Mice
  • Movement*
  • Proprioception
  • Renshaw Cells / chemistry*
  • Renshaw Cells / classification
  • Renshaw Cells / cytology*
  • Renshaw Cells / physiology
  • Spinal Cord / cytology*
  • Transcription Factors / analysis*
  • Transcriptome

Substances

  • Transcription Factors