Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Experiment Videos

A clockwork hypothesis: synaptic release by rod photoreceptors must be regular.

Stan Schein1, Kareem M Ahmad

  • 1Department of Psychology, and Brain Research Institute, University of California, Los Angeles, Los Angeles, California 90095-1563, USA. schein@ucla.edu

Biophysical Journal
|September 20, 2005
PubMed
Summary

Rods can detect single photons, but a single activated rhodopsin (Rh*) causes minimal hyperpolarization. Regular neurotransmitter release, modeled as an Erlang process, explains efficient single-photon detection in rods.

Related Concept Videos

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Keplerate Ag<sub>192</sub> Cluster with 6 Silver and 14 Chalcogenide Octahedral and Tetrahedral Shells.

Journal of the American Chemical Society·2021
Same author

Precise Implantation of an Archimedean Ag@Cu<sub>12</sub> Cuboctahedron into a Platonic Cu<sub>4</sub>Bis(diphenylphosphino)hexane<sub>6</sub> Tetrahedron.

ACS nano·2021
Same author

A Keplerian Ag<sub>90</sub> nest of Platonic and Archimedean polyhedra in different symmetry groups.

Nature communications·2020
Same author

Three Silver Nests Capped by Thiolate/Phenylphosphonate.

Chemistry (Weinheim an der Bergstrasse, Germany)·2018
Same author

Assembly of silver Trigons into a buckyball-like Ag<sub>180</sub> nanocage.

Proceedings of the National Academy of Sciences of the United States of America·2017
Same author

Transformation of personal computers and mobile phones into genetic diagnostic systems.

Analytical chemistry·2014

Area of Science:

  • Neuroscience
  • Photoreceptor Physiology
  • Vision Science

Background:

  • Rods are highly sensitive photoreceptors capable of detecting single photons.
  • Single rhodopsin activation (Rh*) causes a small hyperpolarization (1 mV) in mammalian rods.
  • This hyperpolarization is insufficient to explain the observed sensitivity if neurotransmitter release were random (Poisson).

Purpose of the Study:

  • To investigate the mechanism of neurotransmitter release in rod photoreceptors.
  • To reconcile the low impact of single rhodopsin activation with high sensitivity.
  • To model the quantal release process in rods.

Main Methods:

  • Analysis of voltage-dependent Ca2+ channels and synaptic terminal Ca2+ concentrations.
  • Modeling of neurotransmitter release using Poisson and Erlang processes.

Related Experiment Videos

  • Simulation of quantal release distributions and detection thresholds.

    • Main Results:

    • A 1 mV hyperpolarization reduces neurotransmitter release by only ~20% if release is Poisson.
    • Poisson release leads to significant overlap between dark and single-photon response distributions, causing false positives/negatives.
    • Modeling release as a regular Erlang process yields narrower distributions, reducing overlap.

    Conclusions:

    • Quantal neurotransmitter release in rods must be regular, not Poisson.
    • Regular release, modeled as an Erlang process, allows for low false positives and efficient single-photon detection (~35%).
    • This mechanism explains how rods achieve high sensitivity to single photons.