Article

Motor cortex gates vibrissal responses in a thalamocortical projection pathway.

Centre de Recherche Université Laval Robert-Giffard, Québec City, Canada G1J 2G3.
Neuron (impact factor: 14.74). 12/2007; 56(4):714-25. DOI:10.1016/j.neuron.2007.10.023 pp.714-25
Source: PubMed

ABSTRACT Higher-order thalamic nuclei receive input from both the cerebral cortex and prethalamic sensory pathways. However, at rest these nuclei appear silent due to inhibitory input from extrathalamic regions, and it has therefore remained unclear how sensory gating of these nuclei takes place. In the rodent, the ventral division of the zona incerta (ZIv) serves as a relay station within the paralemniscal thalamocortical projection pathway for whisker-driven motor activity. Most, perhaps all, ZIv neurons are GABAergic, and recent studies have shown that these cells participate in a feedforward inhibitory circuit that blocks sensory transmission in the thalamus. The present study provides evidence that the stimulation of the vibrissa motor cortex suppresses vibrissal responses in ZIv via an intra-incertal GABAergic circuit. These results provide support for the proposal that sensory transmission operates via a top-down disinhibitory mechanism that is contingent on motor activity.

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Keywords

blocks sensory transmission
 
cerebral cortex
 
extrathalamic regions
 
feedforward inhibitory circuit
 
Higher-order thalamic nuclei
 
intra-incertal GABAergic circuit
 
motor activity
 
paralemniscal thalamocortical projection pathway
 
prethalamic sensory pathways
 
recent studies
 
relay station
 
sensory transmission
 
silent
 
stimulation
 
thalamus
 
top-down disinhibitory mechanism
 
ventral division
 
vibrissa motor cortex suppresses vibrissal responses
 
whisker-driven motor activity
 

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