V3 Spinal Neurons Establish a Robust and Balanced Locomotor Rhythm During Walking

Neuron. 2008 Oct 9;60(1):84-96. doi: 10.1016/j.neuron.2008.09.027.

Abstract

A robust and well-organized rhythm is a key feature of many neuronal networks, including those that regulate essential behaviors such as circadian rhythmogenesis, breathing, and locomotion. Here we show that excitatory V3-derived neurons are necessary for a robust and organized locomotor rhythm during walking. When V3-mediated neurotransmission is selectively blocked by the expression of the tetanus toxin light chain subunit (TeNT), the regularity and robustness of the locomotor rhythm is severely perturbed. A similar degeneration in the locomotor rhythm occurs when the excitability of V3-derived neurons is reduced acutely by ligand-induced activation of the allatostatin receptor. The V3-derived neurons additionally function to balance the locomotor output between both halves of the spinal cord, thereby ensuring a symmetrical pattern of locomotor activity during walking. We propose that the V3 neurons establish a regular and balanced motor rhythm by distributing excitatory drive between both halves of the spinal cord.

Publication types

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

MeSH terms

  • Action Potentials / genetics
  • Action Potentials / physiology
  • Animals
  • Basic Helix-Loop-Helix Transcription Factors / genetics
  • Basic Helix-Loop-Helix Transcription Factors / physiology
  • Interneurons / physiology*
  • Mice
  • Mice, Transgenic
  • Motor Activity / genetics
  • Motor Activity / physiology*
  • Motor Neurons / physiology*
  • Nerve Net / physiology
  • Postural Balance / physiology*
  • Repressor Proteins / genetics
  • Repressor Proteins / physiology
  • Spinal Cord / physiology*
  • Walking / physiology*

Substances

  • Basic Helix-Loop-Helix Transcription Factors
  • Repressor Proteins
  • SIM1 protein, human