Rod transduction parameters from the a wave of local receptor populations.
The analysis of electroretinogram a waves from locally stimulated populations of rods is complicated by the presence of scattered light within the eye. Scattered-light and cone contributions can be assessed after brief flashes of light designed to saturate only rods in the locally stimulated area. Subtracting the scattered-light and the cone responses from the local electroretinogram gives a pure rod a wave that can be fitted with models of photoreceptor activity. We demonstrate the feasibility of this technique by recording local rod a waves from a group of five normal subjects and by fitting the a waves with the rod model to derive transduction parameters. The local rod a waves are compared with expected responses derived from simulations in which the response of the entire retina to heterogeneous illumination is mimicked.
D000328:Adult; D004596:Electroretinography; D006801:Humans; D008027:Light; D010775:Photic Stimulation; D010786:Photoreceptor Cells / Q000502:physiology*; D017949:Retinal Cone Photoreceptor Cells / Q000502:physiology; D017948:Retinal Rod Photoreceptor Cells / Q000502:physiology*; D012542:Scattering, Radiation; D015398:Signal Transduction / Q000502:physiology*