Review articleFunctional dissection of inhibitory microcircuits in the visual cortex

•We review cell-type-specific function of cortical GABAergic inhibitory neurons in the visual cortex.•GABAergic inhibition is critical for shaping receptive-field properties of V1 neurons.•Cortico-cortical and subcortico-cortical projections to specific types of GABAergic interneurons modulate visual processing and cortical states.

Cerebral cortex contains various types of GABAergic neurons exerting local inhibition. Although the number of GABAergic inhibitory neurons is much smaller than glutamatergic excitatory neurons, they show greater diversity in their morphological and physiological properties. Genetic markers for distinct sub-classes of GABAergic neurons have been identified, and technical advances achieved in the past few decades have brought about a demonstration of a unique function of each sub-class of GABAergic neurons in the cortex. In particular, visual processing in the cortex requires inhibitory function of various GABAergic neurons. Here, we summarize current understandings on the function of inhibitory neurons in the cortex, especially focusing on their roles in visual processing.