Cell Reports
Volume 14, Issue 2, 12 January 2016, Pages 208-215
Journal home page for Cell Reports

Report
Cortical Sensory Responses Are Enhanced by the Higher-Order Thalamus

https://doi.org/10.1016/j.celrep.2015.12.026Get rights and content
Under a Creative Commons license
open access

Highlights

  • Effect of the higher-order thalamus on cortical sensory processing is investigated

  • Cortical neurons in layer 5 integrate inputs from two parallel thalamic pathways

  • Higher-order thalamus enhances cortical responses on fast and slow timescales

Summary

In the mammalian brain, thalamic signals reach the cortex via two major routes: primary and higher-order thalamocortical pathways. While primary thalamocortical nuclei transmit sensory signals from the periphery, the function of higher-order thalamocortical projections remains enigmatic, in particular their role in sensory processing in the cortex. Here, by optogenetically controlling the thalamocortical pathway from the higher-order posteromedial thalamic nucleus (POm) during whisker stimulation, we demonstrate the integration of the two thalamocortical streams by single pyramidal neurons in layer 5 (L5) of the mouse barrel cortex under anesthesia. We report that POm input mainly enhances sub- and suprathreshold activity via net depolarization. Sensory enhancement is accompanied by prolongation of cortical responses over long (800-ms) periods after whisker stimulation. Thus, POm amplifies and temporally sustains cortical sensory signals, possibly serving to accentuate highly relevant sensory information.

Cited by (0)

This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).