Test of visual performance, cortical activity maps and residual S-cone density of the same animal, a ChR2rd1/rd1 mouse, 223 d old. Test of visual performance, cortical activity maps and residual S-cone density of the same animal, a ChR2rd1/rd1 mouse, 223 d old. A, Learning curve of the discrimination of a bright field from a dark field in the VWT. After 4 d of training the mouse reached the criterion continuously (70% correct responses). B, Optical recording of the activity in the visual cortex of the same animal elicited by the up and down movement of a horizontal bar (see inset). The 4 positions of the stimulus screen and the stimulation conditions (binocular/monocular) are indicated on top and the evoked activities are shown underneath. Upper and middle row, Polar and phase map of the response (retinotopic map); bottom row, gray scale coded magnitude map of the visual cortical responses. The color code and the intensity code are indicated on the right. ant, anterior; med, medial. Scale bar, 1 mm. C, Immunostaining of the residual cones in the ventral retina of the same animal for S-opsin. Their peak density was 2431 cones/mm2. Scale bar, 50 μm. Senthil Thyagarajan et al. J. Neurosci. 2010;30:8745-8758 ©2010 by Society for Neuroscience