Head Movements Control the Activity of Primary Visual Cortex in a Luminance-Dependent Manner

The vestibular system broadcasts head-movement-related signals to sensory areas throughout the brain, including visual cortex. These signals are crucial for the brain’s ability to assess whether motion of the visual scene results from the animal’s head movements. However, how head movements affect visual cortical circuits remains poorly understood. Here, we discover that ambient luminance profoundly transforms how mouse primary visual cortex (V1) processes head movements. While in darkness, head movements result in overall suppression of neuronal activity; in ambient light, the same head movements trigger excitation across all cortical layers. This light-dependent switch in how V1 processes head movements is controlled by somatostatin-expressing (SOM) inhibitory neurons, which are excited by head movements in dark, but not in light. This study thus reveals a light-dependent switch in the response of V1 to head movements and identifies a circuit in which SOM cells are key integrators of vestibular and luminance signals. •Head movements in darkness suppress V1 activity•Head movements in light increase V1 activity•Specific inhibitory neurons mediate V1 suppression by head movements in darkness The vestibular system broadcasts head-movement-related signals throughout the brain. Bouvier et al. show that ambient light affects how primary visual cortex (V1) responds to head movements. V1 is suppressed by head movements in darkness and excited by head movements in light through the differential recruitment of somatostatin-expressing inhibitory neurons.