Synaptic Mechanisms of Feature Coding in the Visual Cortex of Awake Mice.

ABSTRACT: The synaptic mechanisms of feature coding in the visual cortex are poorly understood, particularly in awake animals. The ratio between excitation (E) and inhibition (I) might be constant across stimulus space, controlling only the gain and timing of neuronal responses, or it might change, directly contributing to feature coding. Whole-cell recordings in L2/3 of awake mice revealed that the E/I ratio systematically declines with increasing stimulus contrast or size. Suppressing somatostatin (SOM) neurons enhanced the E and I underlying size tuning, explaining SOM neurons' role in surround suppression. These data imply that contrast and size tuning result from a combination of a changing E/I ratio and the tuning of total synaptic input. Furthermore, they provide experimental support in awake

SUBMITTER: Adesnik H 

PROVIDER: S-EPMC5580349 | biostudies-literature | 2017 Aug

REPOSITORIES: biostudies-literature