[Glycine modulates the ERG b-waves and ON-type bipolar cells in carp retina]

In the present work we investigated the effects of glycine on the electroretinograms (ERG) and light responses of ON-type bipolar cells under dark- and light-adapted conditions in superfused, isolated crucian carp retinas. It was revealed that application of 4 mmol/L glycine significantly suppressed the b-waves and the responses of ON-type bipolar cells and the effects were blocked by co-application of 20 mumol/L strychnine. In addition, glycine had no apparent action on the PIII component (photoreceptor potential) isolated by application of 3 mmol/L glutamate. These results suggest that glycine may act on bipolar cells directly and thus modulate the activity of the ON pathway in the retina.