Temporal Sharpening of Sensory Responses by Layer V in the Mouse Primary Somatosensory Cortex

Curr Biol. 2020 May 4;30(9):1589-1599.e10. doi: 10.1016/j.cub.2020.02.004. Epub 2020 Mar 12.


The timing of stimulus-evoked spikes encodes information about sensory stimuli. Here we studied the neural circuits controlling this process in the mouse primary somatosensory cortex. We found that brief optogenetic activation of layer V pyramidal cells just after whisker deflection modulated the membrane potential of neurons and interrupted their long-latency whisker responses, increasing their accuracy in encoding whisker deflection time. In contrast, optogenetic inhibition of layer V during either passive whisker deflection or active whisking decreased accuracy in encoding stimulus or touch time, respectively. Suppression of layer V pyramidal cells increased reaction times in a texture discrimination task. Moreover, two-color optogenetic experiments revealed that cortical inhibition was efficiently recruited by layer V stimulation and that it mainly involved activation of parvalbumin-positive rather than somatostatin-positive interneurons. Layer V thus performs behaviorally relevant temporal sharpening of sensory responses through circuit-specific recruitment of cortical inhibition.

Keywords: GABAergic interneurons; cortical layers; parvalbumin; somatosensory cortex; somatostatin; whisking.

Publication types

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

MeSH terms

  • Action Potentials / physiology
  • Animals
  • Mice
  • Neurons / physiology
  • Somatosensory Cortex / anatomy & histology*
  • Somatosensory Cortex / physiology*
  • Time Factors
  • Touch / physiology*
  • Touch Perception / physiology*
  • Vibrissae / physiology*