Light-induced calcium release by intact retinal rods.
Year: 1980
Type: article
Abstract: Brief illumination of the isolated toad retina produces a transient increase in the extracellular free Ca concentration in the photoreceptor layer. This change in concentration arises from the release of Ca2+ by the rod outer segments. The release begins within 200 msec after the stimulus flash. The peak amplitude of the concentration change increases linearly with light intensity up to approximately 100 absorbed photons per rod and saturates at about 10(7) absorbed photons per rod. In the linear range, the amount of Ca released corresponds to about 2 x 10(4) Ca2+ per absorbed photon per rod. The high stoichiometry of this release, in relation to the low free intracellular Ca concentration, suggests that the release reflects a light-dependent increase in the intracellular free Ca concentration. This light-activated Ca release occurs in the absence of a detectable receptor potential (in low-Na Ringer's solution) and, therefore, must reflect one of the initial stages in the transduction process.
Authors: G H Gold, J I Korenbrot
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: green
Funder: National Institutes of Health
OpenAlex ID: W2020007950