Functional Specialization of Mouse Higher Visual Cortical Areas

SummaryThe mouse is emerging as an important model for understanding how sensory neocortex extracts cues to guide behavior, yet little is known about how these cues are processed beyond primary cortical areas. Here, we used two-photon calcium imaging in awake mice to compare visual responses in primary visual cortex (V1) and in two downstream target areas, AL and PM. Neighboring V1 neurons had diverse stimulus preferences spanning five octaves in spatial and temporal frequency. By contrast, AL and PM neurons responded best to distinct ranges of stimulus parameters. Most strikingly, AL neurons preferred fast-moving stimuli while PM neurons preferred slow-moving stimuli. By contrast, neurons in V1, AL, and PM demonstrated similar selectivity for stimulus orientation but not for stimulus direction. Based on these findings, we predict that area AL helps guide behaviors involving fast-moving stimuli (e.g., optic flow), while area PM helps guide behaviors involving slow-moving objects.

► 3D cellular imaging of visual cortical areas V1, AL and PM in awake mice
► Areas AL and PM prefer high and low subranges of the speeds encoded in V1
► Areal differences in speed preferences were largely independent of locomotion
► Similar orientation selectivity but not direction selectivity in areas V1, PM, and AL