Aspartate-induced dissociation of proximal from distal retinal activity in the mudpuppy.
The effects of aspartate (Asp) on the ERG and on neuronal, glial, and K+ responses were monitored continuously in the superfused mudpuppy eyecup. Asp induced a time-dependent sequence of events which may be divided into three stages: Stage 1, initially, light-evoked responses throughout the retina are depressed; Stage 2, distal responses (horizontal, bipolar, and K+ responses) return to near pre-drug amplitudes and there is a simultaneous ERG enhancement, but responses in the proximal retina remain suppressed; Stage 3, a second depression of retinal responses leads to a-wave isolation. The dissociation of distal from proximal responses observed during Stage 2 strongly supports the hypothesis that the ERG b-wave results from events arising in the distal retinal network.
D000818:Animals; D001224:Aspartic Acid / Q000494:pharmacology*; D002118:Calcium / Q000494:pharmacology; D004596:Electroretinography; D008274:Magnesium / Q000494:pharmacology; D009338:Necturus maculosus; D009457:Neuroglia / Q000187:drug effects / Q000502:physiology; D010775:Photic Stimulation; D011188:Potassium / Q000032:analysis; D012160:Retina / Q000166:cytology / Q000187:drug effects* / Q000502:physiology; D012165:Retinal Ganglion Cells / Q000187:drug effects / Q000502:physiology
D001224:Aspartic Acid; D008274:Magnesium; D011188:Potassium; D002118:Calcium