Figure 2.

D1 receptor activation weakens the spatial inhibitory input to OFF bipolar cells. A-B. Example L-IPSCs recorded in dark-adapted (black, A) and dark-adapted + SKF (+SKF, blue, B) conditions in response to a light stimulus (1 second, 25 μm bar) presented at −400, 0, and 400 μm from the cell. SKF application reduced L-IPSC strength at all stimulus distances. Light stimulus = light gray bar under example OFF type 1/2 traces. C. Spatial inhibition profiles of response charge transfer normalized to the center bar stimulus in dark-adapted and SKF conditions (n=7). The spatial profile became significantly narrower with SKF. D. Same as in C but for response peak amplitude. The peak amplitude profile was significantly narrower and smaller with light adaptation. E. Spatial inhibition profiles of response charge transfer normalized to the respective dark-adapted center bar stimulus in SKF and light-adapted (n=5, gray) conditions. Light-adapted spatial input was significantly narrower and smaller than with SKF application. F. Same as in E but for normalized response peak amplitude. The peak amplitude profile was significantly smaller in the periphery with light adaptation. Cells included in averages: SKF = 3 OFF type 1/2/4 and 4 OFF type 3; light-adapted = 1 OFF type 1/2/4 and 4 OFF type 3. Light-adapted data was adapted from Mazade and Eggers, 2016 Fig. 2C,F for comparison. Error bars are ±SEM and only show the outer bar for each data point. (*** p<0.001)