Somatosensory integration controlled by dynamic thalamocortical feed-forward inhibition

Neuron. 2005 Oct 20;48(2):315-27. doi: 10.1016/j.neuron.2005.09.022.


The temporal features of tactile stimuli are faithfully represented by the activity of neurons in the somatosensory cortex. However, the cellular mechanisms that enable cortical neurons to report accurate temporal information are not known. Here, we show that in the rodent barrel cortex, the temporal window for integration of thalamic inputs is under the control of thalamocortical feed-forward inhibition and can vary from 1 to 10 ms. A single thalamic fiber can trigger feed-forward inhibition and contacts both excitatory and inhibitory cortical neurons. The dynamics of feed-forward inhibition exceed those of each individual synapse in the circuit and are captured by a simple disynaptic model of the thalamocortical projection. The variations in the integration window produce changes in the temporal precision of cortical responses to whisker stimulation. Hence, feed-forward inhibitory circuits, classically known to sharpen spatial contrast of tactile inputs, also increase the temporal resolution in the somatosensory cortex.

Publication types

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

MeSH terms

  • Animals
  • Dose-Response Relationship, Radiation
  • Electric Stimulation / methods
  • Feedback / physiology*
  • In Vitro Techniques
  • Membrane Potentials / physiology
  • Membrane Potentials / radiation effects
  • Mice
  • Mice, Inbred ICR
  • Models, Neurological
  • Neural Inhibition / physiology*
  • Neural Pathways / physiology*
  • Neurons / physiology*
  • Neurons / radiation effects
  • Nonlinear Dynamics
  • Patch-Clamp Techniques / methods
  • Reaction Time / physiology
  • Reaction Time / radiation effects
  • Somatosensory Cortex / cytology*
  • Synaptic Transmission / physiology
  • Synaptic Transmission / radiation effects
  • Thalamus / cytology*
  • Thalamus / radiation effects
  • Time Factors