Fig. 4. Intracellular recordings obtained in a spectrally opponent cell (G51L31C1), stained with Neurobiotin and identified as a G15 ganglion cell. Upper trace: the response to a large spot stimulus at the receptive field centre (radius, =1250µm) depolarises from 300 to 500nm and hyperpolarizes from 520 to 700nm. Lower trace: responses to equal quanta flashes at four wavelengths. (Modified from Fig.10 in Ventura et al., 1999 with permission of Visual Neuroscience.)