Electrophysiological analysis of taurine and glycine action on neurons of the mudpuppy retina. II. ERG, PNR and Müller cell recordings.

Extracellular electrophysiological recordings of the electroretinogram (ERG) and proximal negative response (PNR) were carried out in the perfused retina-eyecup prepartation of the mudpuppy. Intracellular recordingws were obtained from Müller cells. Bath-applied taurine/glycine had identical effects on the ERG, PNR and Müller cell responses and the effects of both agents were blocked by strychnine. Taurine and glycine suppressed the d-wave of the ERG, the OFF response of Müller cells and ON and OFF responses of the PNR. These observations show that taurine/glycine sensitivity is predominantly found in the OFF channel of the ERG whose underlying neuronal basis appears to be dark evoked depolarization of OFF bipolars.