Current-clamp recordings from an Off ganglion cell under scotopic and photopic conditions. The light onset and offset are indicated on the top of each panel. A: Under scotopic conditions, bath application of APB did not abolish the Off response, indicating this Off response was mediated by the APB insensitive rod Off-pathways. B: Under scotopic condition, this cell followed a flashing light at a frequency up to 4 Hz. The stimulus light intensity was 19 Rh*/rod/s and the contrast was 1 in A&B. C: After switching to photopic condition, this cell was able to follow flashing light frequencies up to 6 Hz. The recordings in B&C were obtained without the presence of APB. The stimulus light intensity was 6000 Rh*/rod/s, the background light intensity was 1500 Rh*/rod/s, and the contrast was 0.6 in C.