Linked Life Data

7901400

Source:http://linkedlifedata.com/resource/pubmed/id/7901400

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:dateCreated
1993-11-29
pubmed:abstractText
1. Pharmacological evidence suggests L-glutamate is a strong candidate as a transmitter at the giant synapse of the squid. Postsynaptic activation at the giant synapse cannot be effected by conventional application of putative neurotransmitters by iontophoresis or perfusion, apparently because the complex structure of the synapse prevents a sufficiently rapid change in concentration at the postsynaptic membrane. Flash photolytic release of L-glutamate from a pharmacologically inert 'caged' L-glutamate pre-equilibrated in the stellate ganglion of Alloteuthis or Loligo was used to determine whether L-glutamate can produce postsynaptic activation when released rapidly in the synaptic clefts. 2. The preparation, reaction mechanism and properties of the caged L-glutamate, N-1-(2-nitrophenyl)ethoxycarbonyl-L-glutamate, are described. The product quantum yield on photolysis was 0.65 (+/- 0.05). On flash photolysis glutamate release followed a single exponential time-course in the pH range 5.5-7.8. The rate constant was proportional to [H+] and was 93 s-1 at pH 5.5 and 16 degrees C in artificial sea water (ionic strength, I = 0.68 M). 3. At pH 7.8 flash photolysis of caged glutamate pre-equilibrated in the synapse caused only a slow depolarization. A second photolytic release of L-glutamate or transsynaptic activation produced no further depolarization, suggesting desensitization and inactivation of postsynaptic mechanisms by the initial pulse of L-glutamate. 4. Synaptic transmission in the giant synapse was normal at pH 5.5. Flash photolysis at pH 5.5 caused rapid production of L-glutamate within the synaptic cleft and a fast postsynaptic depolarization which generated postsynaptic action potentials.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:commentsCorrections
http://linkedlifedata.com/resource/pubmed/commentcorrection/7901400-14085408, http://linkedlifedata.com/resource/pubmed/commentcorrection/7901400-2161925, http://linkedlifedata.com/resource/pubmed/commentcorrection/7901400-2504882, http://linkedlifedata.com/resource/pubmed/commentcorrection/7901400-2567041, http://linkedlifedata.com/resource/pubmed/commentcorrection/7901400-2660825, http://linkedlifedata.com/resource/pubmed/commentcorrection/7901400-2747531, http://linkedlifedata.com/resource/pubmed/commentcorrection/7901400-2904933, http://linkedlifedata.com/resource/pubmed/commentcorrection/7901400-30092, http://linkedlifedata.com/resource/pubmed/commentcorrection/7901400-4374500, http://linkedlifedata.com/resource/pubmed/commentcorrection/7901400-4383088, http://linkedlifedata.com/resource/pubmed/commentcorrection/7901400-4625481, http://linkedlifedata.com/resource/pubmed/commentcorrection/7901400-4722064, http://linkedlifedata.com/resource/pubmed/commentcorrection/7901400-5807007
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0022-3751
pubmed:author
pubmed:issnType
Print
pubmed:volume
465
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1-8
pubmed:dateRevised
2009-11-18
pubmed:meshHeading
pubmed:year
1993
pubmed:articleTitle
Postsynaptic activation at the squid giant synapse by photolytic release of L-glutamate from a 'caged' L-glutamate.
pubmed:affiliation
National Institute for Medical Research, Mill Hill, London.
pubmed:publicationType
Journal Article, In Vitro, Research Support, Non-U.S. Gov't