Vision and locomotion shape the interactions between neuron types in mouse visual cortex
Locomotion profoundly changes sensory responses in mouse primary visual cortex. These changes are thought to arise from a disinhibitory circuit, whereby interneurons expressing vasoactive intestinal peptide (Vip) inhibit those expressing somatostatin (Sst) thus disinhibiting pyramidal cells (Pyr) We studied the effect of locomotion on these cell types and on interneurons expressing parvalbumin (Pvalb) in layer 2/3 of mouse V1, and found inconsistencies with the disinhibitory model. Locomotion increased Sst cell responses to large stimuli and to full field gray screen, without decreasing them in Vip cells. Moreover, it increased Vip cell responses to small stimuli, without decreasing them in Sst cells. Signal and noise correlations between cell types provided further evidence against the disinhibitory model. Our data resolve apparent contradictions in the literature and suggest an alternative to the disinhibitory model, where Vip and Sst cells inhibit each other in a circuit whose effect depends on stimulus and behavioral state.