What is barrel cortex for?


April 4, 2018 - 1:00pm
Northwest Building Room 243
About the Speaker
Y. Kate Hong
Speaker Title: 
Postdoctoral Researcher
Speaker Affiliation: 
Bruno Lab, Columbia University

Sensory detection tasks have become a staple for probing cortical circuitry during behavior, but the role of cortex in this fundamental ability remains controversial. A common strategy to establish the role of a brain structure in behavior is to inactivate or ablate it. However, recent studies have underscored how off-target effects during transient inactivation can lead to false conclusions of necessity. We directly compare acute vs. chronic inactivation of primary somatosensory cortex (S1) in mice trained to actively move their large facial whiskers to detect an object via touch and respond with a lever to obtain a water reward. Transient inactivation, as well as permanent lesions of S1, produced both movement and sensory deficits that impair detection behavior, demonstrating the inextricable link between sensory and motor systems during active sensation. Surprisingly, lesioned mice rapidly recovered full behavioral capabilities by the subsequent session. Recovery was experience-dependent, and early re-exposure to the task after lesion facilitated recovery. Furthermore, primary sensory cortex ablation prior to learning did not affect task acquisition. This combined optogenetic and lesion approach suggests that manipulations of sensory cortex may be only temporarily disruptive to other brain structures, which are themselves capable of coordinating multiple, arbitrary movements with sensation. The somatosensory cortex itself is entirely dispensable for detecting events in our environment.