An essential role for the latero-medial secondary visual cortex in the acquisition and retention of visual perceptual learning in mice

Perceptual learning refers to any change in discrimination abilities as a result of practice, a fundamental process that improves the organism’s response to the external environment. Visual perceptual learning (vPL) is supposed to rely on functional rearrangements in brain circuity occurring at early stages of sensory processing, with a pivotal role for the primary visual cortex (V1). However, top-down inputs from higher-order visual areas (HVAs) have been suggested to play a key part in vPL, conveying information on attention, expectation and the precise nature of the perceptual task. A direct assessment of the possibility to modulate vPL by manipulating top-down activity in awake subjects is still missing. Here, we used a combination of chemogenetics, behavioral analysis and multichannel electrophysiological assessments to show a critical role in vPL acquisition and retention for neuronal activity in the latero-medial secondary visual cortex (LM), the prime source for top-down feedback projections reentering V1. While information conveyed to the primary visual cortex (V1) by top-down signals is thought to be required for visual perceptual learning, it remains unknown whether it is possible to modulate visual perceptual learning by manipulating top-down neuronal activity. Here the authors employ a mouse model of visual perceptual learning in a forced-choice visual discrimination task to demonstrate an essential role of the latero-medial secondary visual cortex, the prime source for top-down feedback projections reentering V1.