Bicarbonate boosts flash response amplitude to augment absolute sensitivity and extend dynamic range in murine retinal rods.

ABSTRACT: Rod photoreceptors in the retina adjust their responsiveness and sensitivity so that they can continue to provide meaningful information over a wide range of light intensities. By stimulating membrane guanylate cyclases in the outer segment to synthesize cGMP at a faster rate in a Ca²⁺-dependent fashion, bicarbonate increases the circulating "dark" current and accelerates flash response kinetics in amphibian rods. Compared to amphibian rods, mammalian rods are smaller in size, operate at a higher temperature, and express visual cascade proteins with somewhat different biochemical properties. Here, we evaluated the role of bicarbonate in rods of cpfl3 mice. These mice are deficient in their expression of functional cone transducin, Gnat2, making cones very insensitive to l

SUBMITTER: Adhikari RD 

PROVIDER: S-EPMC10140344 | biostudies-literature | 2023

REPOSITORIES: biostudies-literature