Mechanisms regulating variability of the single photon responses of mammalian rod photoreceptors.

Journal Article (Journal Article)

Variability in the single photon responses of rod photoreceptors limits the accuracy with which the number and timing of photon absorptions are encoded. We investigated how much single photon responses of mammalian rods fluctuate and what mechanisms control these fluctuations. Mammalian rods, like those of toads, generated responses to single photons with trial-to-trial fluctuations 3-4 times smaller than other familiar signals produced by single molecules. We used the properties of the measured fluctuations to constrain models for how the single photon responses are regulated. Neither feedback control of rhodopsin's activity nor saturation within the transduction cascade were consistent with experiment. The measured responses, however, could be explained by multistep shutoff of rhodopsin or a combination of multistep shutoff and saturation.

Full Text

Duke Authors

Cited Authors

  • Field, GD; Rieke, F

Published Date

  • August 15, 2002

Published In

Volume / Issue

  • 35 / 4

Start / End Page

  • 733 - 747

PubMed ID

  • 12194872

International Standard Serial Number (ISSN)

  • 0896-6273

Digital Object Identifier (DOI)

  • 10.1016/s0896-6273(02)00822-x


  • eng

Conference Location

  • United States