The glutamate-isolated mass receptor potential of the frog's retina. I. General properties and intensity dependence.
The glutamate-isolated mass receptor potential of the superfused frog's retina was investigated in order to find a method for discrimination of both rod and cone contribution to the sum response. After mesopic white light stimuli the potential showed a biphasic decay with a rapid and a slow part, respectively. Regarding threshold, saturation, light adaptation, and time course, the rapid decay is shown to correspond to the cone response. The remaining part of mass receptor potential, on the other hand, resembled the rod response in all these properties. This analysis provides the basis for studying the cation dependence of rod and cone receptor potentials with the stable mass receptor potentials. Moreover, the time course of the rod's light response is discussed to draw some conclusions regarding the internal transmission in rod photoreceptors.
D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D003624:Darkness; D005971:Glutamates / Q000494:pharmacology*; D018698:Glutamic Acid; D008027:Light; D010775:Photic Stimulation; D011893:Rana esculenta; D012160:Retina / Q000502:physiology*
D005971:Glutamates; D018698:Glutamic Acid