Figure 3.

Biased color representation of entire V1. (A,B) Averaged activation maps to S- and M-opsin isolating stimulations in V1 (n = 6 mice). Outline of V1 was determined for each animal according to the retinotopy and activation maps of grating patch, flashed bar and color stimulations. Extracted V1 images were aligned by the centroid of each V1 regions and averaged among animals. S-opsin isolating stimulation evoked strong activity in the posterior region (A), whereas M-opsin isolating stimulation activated mainly anterior part of V1 (B). (C) Averaged subtraction map (Panel B minus Panel A) demonstrates the S-opsin and M-opsin response-dominant region (positive and negative values represented by the color code indicate M-opsin- and S-opsin-response dominant areas, respectively). Scale bars = 1 mm. (D,E) Averaged response time courses from anterior and posterior regions shown in (C) by the white boxes indicated by black arrows. These two were minimal (S-opsin dominant) and maximal (M-opsin dominant) points, which were detected in the averaged subtraction map (C). Magenta and green lines represent responses to S- and M-opsin isolating stimulations, respectively. Stimulation was presented from 0 s to 4 s. Broken line represents stimulation onset. (F) Comparison of mean ΔF/F. Response to S-opsin isolating stimulation in posterior V1 was significantly higher than response to S-opsin isolating stimulation in anterior and response to M-opsin isolating stimulation in posterior. **p < 0.01 by two-way repeated measured ANOVA followed by simple effect analysis test (n = 6 mice). Scale bars in (A–C) = 1 mm.