Figure 6. Effects of melatonin on ERG PIII responses.

A, PIII responses were induced by a dim (log I =−3.0), 500 nm flash of 500 ms, presented at intervals of 20 s. When 100 nm melatonin was bath-applied, the PIII responses were hardly changed. Light signals are shown below the continuous response trace. B, bar chart, summarizing the effects of 100 nm melatonin on PIII responses induced by flashes of two different light intensities. P = 0.269 for log I =−3.0 (n = 4) and P = 0.143 for log I =−4.0 (n = 5).