Temporal Sharpening of Sensory Responses by Layer V in the Mouse Primary Somatosensory Cortex
Dania Vecchia, Riccardo Beltramo, Fabio Vallone, Ronan Chéreau, Angelo Forli, Manuel Molano‐Mazón, Tanika Bawa, Noemi Binini, Claudio Moretti, Anthony Holtmaat, Stefano Panzeri, Tommaso Fellin
Abstract
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.