Spreading depression in isolated carp retina.
(1) Spreading depression (SD) could be elicited in isolated carp retina by KCI application, the concomitants of which were similar to those described in other vertebrates. (2) The threshold for generating SD was greatly reduced by brief immersion of the retina in low ci-ringer's solutions. The properties of SD waves were almost the same with treated and untreated retinas, except for intervals. (3) Extracellular negative potential shifts during SD, averaging 4.6 mV in amplitude and 27 sec in duration, were recorded in whole retinal layers with the maximum amplitude about at the inner plexiform layer. (4) The PIII potential of the local electroretinogram was virtually unaffected by SD. (5) Both L-and C-type S-potentials could be evoked with increase of 20-40% in amplitude around the peak of slow membrane depolarizations (mean value of maximal amplitude 5.8 mV) during SD in horizontal cells. (6) Increase in spike number was observed in both on-and off-center ganglion cells before and after the spike cessation during SD in the untreated retina. However, the off-discharges, which were a unique response to light in the immersed retina, only decreased during SD.
D000818:Animals; D002347:Carps; D002712:Chlorides / Q000494:pharmacology; D013181:Cortical Spreading Depression / Q000187:drug effects*; D005724:Ganglia / Q000502:physiology; D008564:Membrane Potentials; D010775:Photic Stimulation; D011189:Potassium Chloride / Q000494:pharmacology; D012160:Retina / Q000187:drug effects / Q000502:physiology*
D002712:Chlorides; D011189:Potassium Chloride