Parvalbumin-Expressing Interneurons Linearly Transform Cortical Responses to Visual Stimuli

SummaryThe response of cortical neurons to a sensory stimulus is shaped by the network in which they are embedded. Here we establish a role of parvalbumin (PV)-expressing cells, a large class of inhibitory neurons that target the soma and perisomatic compartments of pyramidal cells, in controlling cortical responses. By bidirectionally manipulating PV cell activity in visual cortex we show that these neurons strongly modulate layer 2/3 pyramidal cell spiking responses to visual stimuli while only modestly affecting their tuning properties. PV cells' impact on pyramidal cells is captured by a linear transformation, both additive and multiplicative, with a threshold. These results indicate that PV cells are ideally suited to modulate cortical gain and establish a causal relationship between a select neuron type and specific computations performed by the cortex during sensory processing.

► We perturb the activity in cortical PV cells during visual processing
► PV cells tightly control the spiking response of pyramidal cells to visual stimuli
► PV cells only modestly affect pyramidal cell tuning properties
► PV cells modulate the gain of cortical responses to visual stimuli