Motor modulation of afferent somatosensory circuits

Nat Neurosci. 2008 Dec;11(12):1430-8. doi: 10.1038/nn.2227. Epub 2008 Nov 16.

Abstract

A prominent feature of thalamocortical circuitry in sensory systems is the extensive and highly organized feedback projection from the cortex to the thalamic neurons that provide stimulus-specific input to the cortex. In lightly sedated rats, we found that focal enhancement of motor cortex activity facilitated sensory-evoked responses of topographically aligned neurons in primary somatosensory cortex, including antidromically identified corticothalamic cells; similar effects were observed in ventral posterior medial thalamus (VPm). In behaving rats, thalamic responses were normally smaller during whisking but larger when signal transmission in brainstem trigeminal nuclei was bypassed or altered. During voluntary movement, sensory activity may be globally suppressed in the brainstem, whereas signaling by cortically facilitated VPm neurons is simultaneously enhanced relative to other VPm neurons receiving no such facilitation.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Action Potentials / drug effects
  • Action Potentials / physiology
  • Afferent Pathways / drug effects
  • Afferent Pathways / physiology
  • Afferent Pathways / radiation effects
  • Anesthetics, Local / pharmacology
  • Animals
  • Behavior, Animal
  • Bicuculline / analogs & derivatives
  • Bicuculline / pharmacology
  • Brain Mapping*
  • Bupivacaine / pharmacology
  • Electric Stimulation / methods
  • Evoked Potentials, Somatosensory / physiology
  • Female
  • GABA Antagonists / pharmacology
  • Motor Cortex / anatomy & histology
  • Motor Cortex / physiology*
  • Neurons / drug effects
  • Neurons / physiology*
  • Neurons / radiation effects
  • Psychomotor Performance
  • Rats
  • Rats, Sprague-Dawley
  • Somatosensory Cortex / physiology*
  • Thalamus / cytology
  • Thalamus / physiology
  • Time Factors
  • Vibrissae*

Substances

  • Anesthetics, Local
  • GABA Antagonists
  • bicuculline methiodide
  • Bicuculline
  • Bupivacaine