Extracellular electrophysiological recordings of the electroretinogram (ERG) and proximal negative response (PNR) were carried out in the perfused retina-eyecup preparation of the mudpuppy. Intracellular recordings 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.
- Müller cell
- ON and OFF response