Home

About

Advanced Search

Browse by Discipline

Scientific Societies

E-print Alerts

Add E-prints

E-print Network
FAQHELPSITE MAPCONTACT US


  Advanced Search  

 
A Positive Feedback Synapse from Retinal Horizontal Cells to Cone Photoreceptors
 

Summary: A Positive Feedback Synapse from Retinal Horizontal
Cells to Cone Photoreceptors
Skyler L. Jackman1
, Norbert Babai2
, James J. Chambers3
, Wallace B. Thoreson2
, Richard H. Kramer4
*
1 Department of Physics, University of California, Berkeley, Berkeley, California, United States of America, 2 Department of Ophthalmology, University of Nebraska Medical
Center, Omaha, Nebraska, United States of America, 3 Department of Chemistry, University of Massachusetts, Amherst, Amherst, Massachusetts, United States of America,
4 Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California, United States of America
Abstract
Cone photoreceptors and horizontal cells (HCs) have a reciprocal synapse that underlies lateral inhibition and establishes
the antagonistic center-surround organization of the visual system. Cones transmit to HCs through an excitatory synapse
and HCs feed back to cones through an inhibitory synapse. Here we report that HCs also transmit to cone terminals a
positive feedback signal that elevates intracellular Ca2+
and accelerates neurotransmitter release. Positive and negative
feedback are both initiated by AMPA receptors on HCs, but positive feedback appears to be mediated by a change in HC
Ca2+
, whereas negative feedback is mediated by a change in HC membrane potential. Local uncaging of AMPA receptor

  

Source: Alford, Simon - Department of Biological Sciences, University of Illinois at Chicago

 

Collections: Biology and Medicine