Linked Life Data

9414163

Source:http://linkedlifedata.com/resource/pubmed/id/9414163

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6661
pubmed:dateCreated
1998-1-8
pubmed:abstractText
Cyclic-nucleotide-gated (CNG) channels in outer segments of vertebrate photoreceptors generate electrical signals in response to changes in cyclic GMP concentration during phototransduction. CNG channels also allow the influx of Ca2+, which is essential for photoreceptor adaptation. In cone photoreceptors, cGMP triggers an increase in membrane capacitance indicative of exocytosis, suggesting that CNG channels are also involved in synaptic function. Here we examine whether CNG channels reside in cone terminals and whether they regulate neurotransmitter release, specifically in response to nitric oxide (NO), a retrograde transmitter that increases cGMP synthesis and potentiates synaptic transmission in the brain. Using intact retina, we show that endogenous NO modulates synapses between cones and horizontal cells. In experiments on isolated cones, we show directly that CNG channels occur in clusters and are indirectly activated by S-nitrosocysteine (SNC), an NO donor. Furthermore, both SNC and pCPT-cGMP, a membrane-permeant analogue of cGMP, trigger the release of transmitter from the cone terminals. The NO-induced transmitter release is suppressed by guanylate cyclase inhibitors and prevented by direct activation of CNG channels, indicating that their activation is required for NO to elicit release. These results expand our view of CNG channel function to include the regulation of synaptic transmission and mediation of the presynaptic effects of NO.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0028-0836
pubmed:author
pubmed:issnType
Print
pubmed:volume
390
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
694-8
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:articleTitle
Cyclic-nucleotide-gated channels mediate synaptic feedback by nitric oxide.
pubmed:affiliation
Department of Molecular and Cellular Pharmacology, University of Miami School of Medicine, Florida 33101, USA.
pubmed:publicationType
Journal Article, In Vitro, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't