Adaptation-induced sharpening of orientation tuning curves in the mouse visual cortex

Abstract

Orientation selectivity is an emergent property of visual neurons across species with columnar and non-columnar organization of the visual cortex. To compute the orientation selectivity of a neuron, a tuning function is fit on the raw responses of a neuron and then a measure, termed orientation selectivity index (OSI), is derived from this fitted curve to determine the tuning of the neuron. Previously, it has been shown that adaptation (a protocol where a neuron under observation is presented a non-optimal stimulus for a specific time) has varying effects on the tuning properties of neurons, such as, orientation, spatial frequency, motion etc. The emergence of OSI is more established in columnar cortices than the non-columnar ones. However, how adaptation impinges upon the OSI of the latter has not been systematically investigated. Here, in the mouse primary visual cortex (V1), we show that a 12-min adaptation protocol sharpens the OSI (tuning) of the visual neurons, underlying a specific dendritic neural mechanism, potentially facilitating the learning of novel features.