Visual experience instructs the organization of cortical feedback inputs to primary visual cortex

Cortical feedback (FB) projections are thought to modulate lower-order activity depending on learned expectations. However, whether FB inputs become bound to specific lower-order neurons depending on experience is unknown. We measured the effects of dark rearing and manipulations of experienced visual statistics on the retinotopic specificity of projections from the lateromedial (LM) visual area to layer 1 of the mouse primary visual cortex (V1). LM inputs were, on average, retinotopically matched with V1 neurons irrespective of visual experience. While the orientation tuning of LM axons determined the retinotopic position of the V1 neurons they innervated, this organization was absent in dark-reared mice. Restricting visual experience to a narrow range of orientations revealed that visual experience exerts an instructive role in the retinotopic organization of LM inputs in V1. Our observations support theories of hierarchical computation proposing that inputs from higher-order neurons to lower-order ones reflect learned hierarchical associations.