Figure 2.

Sinusoidal L-EPSPs were changed by dopamine receptor 1 (D₁R) signaling in bipolar cells. (A) A representative L-EPSP recorded from an XBC cell in response to a sum-of-sines light stimulus (bottom). (B) L-EPSPs in the presence of 10 μM SKF38393. (C) Bipolar cell temporal responses were fit to the exponential curves. Each curve exhibits a frequency-response relation for each bipolar cell (black) and the average population response (thick black) in the control solution. (D) The temporal responses for each bipolar cell (red) and the average response (thick red) in the presence of 10 μM SKF38393. The peak frequency response shifted to the right in some bipolar cells, indicating that D₁R signaling increased the sensitivity to higher frequencies.