Binocular visual experience and sleep promote visual cortex plasticity and restore binocular vision in a mouse model of amblyopia

Abstract

Amblyopia arises from an altered balance of input from the two eyes to the binocular zone of primary visual cortex (bV1) during childhood, causing long-lasting visual impairment. Amblyopia is commonly treated by patching the dominant eye, however, the relative impacts of monocular vs. binocular visual experiences on restoration of bV1 function remains unclear. Moreover, while sleep has been implicated in V1 plasticity in response to vision loss, its role in recovery from amblyopia is unknown. We used monocular deprivation (MD) in juvenile mice to model amblyopia in bV1. We compared recovery of visual responses for the two eyes among bV1 regular spiking (RS, putative principal) neurons and fast-spiking (FS, putative parvalbumin-expressing [PV+]) interneurons after identical-duration, identical-quality binocular recovery (BR) or monocular, reverse occlusion (RO) experiences. We find that BR is quantitatively superior to RO with respect to renormalizing both bV1 populations visual responses. However, this recovery was seen only in freely-sleeping mice; post-BR sleep deprivation prevented functional recovery. Thus, both binocular visual experience and subsequent sleep are required to optimally renormalize bV1 responses in a mouse model of amblyopia.