Figure 1.
Whole-cell recordings of inhibitory feedback in RBCs in retinal slices. A, Micrographs of an RBC in a retinal slice. i, High-magnification DIC image of the INL, showing bipolar cell somata. ii, iii, The selected cell (*) was patched (ii), filled with Alexa-488, and imaged under epifluorescence (iii). The scale bar in iii also applies to ii. B, As in A, but recording from a cone bipolar cell (CBC). C, Feedback IPSCs elicited in an RBC (Vhold = 0 mV) were blocked partially by GABAR antagonists TPMPA and SR95531 (SR); the remaining IPSC was blocked by the glycine receptor antagonist strychnine (Strych). D, Time course of drug effects on IPSC amplitude (filled circles; n = 4). IPSC amplitude (IPSC Amp.) remained stable in the absence of applied drugs (open circles; n = 4). GCL, Ganglion cell layer.