Linked Life Data

7931551

Source:http://linkedlifedata.com/resource/pubmed/id/7931551

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
10
pubmed:dateCreated
1994-11-14
pubmed:abstractText
We simultaneously measured presynaptic free calcium ion concentration ([Ca2+]i) and synaptic strength at the crayfish claw opener neuromuscular junction (nmj) under a variety of experimental conditions. Our experiments were designed both to test the hypothesis that elevated [Ca2+]i is necessary and sufficient for the induction of a form of synaptic enhancement that persists for several seconds after tetanic stimulation--augmentation--and to determine the quantitative relationship between elevated [Ca2+]i and this enhancement. Action potential trains increased [Ca2+]i and enhanced transmission. During the decay phase of synaptic enhancement known as augmentation (time constant of decay approximately 7 sec at 20 degrees C with < 200 microM fura-2 in terminals), [Ca2+]i was elevated 700 nM or less above rest and an essentially linear relationship between [Ca2+]i and enhancement was observed. Introduction of exogenous Ca2+ buffers into the presynaptic terminal slowed the buildup and recovery kinetics of both [Ca2+]i and the component of synaptic enhancement corresponding to augmentation. The slope of the relationship relating delta [Ca2+]i to augmentation was not changed. The time course of augmentation and recovery of [Ca2+]i remained correlated as the temperature of the preparation was changed from about 10 degrees C to 20 degrees C, but the quantitative relationship of enhancement to [Ca2+]i was increased more than two- to threefold. During moderate frequency trains of action potentials, a slowly developing component of the total synaptic enhancement was approximately linearly related to residual [Ca2+]i measured with fura-2. The quantitative relationship between [Ca2+]i and this component of synaptic enhancement during trains was the same as that during synaptic augmentation after trains.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0270-6474
pubmed:author
pubmed:issnType
Print
pubmed:volume
14
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
5885-902
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
1994
pubmed:articleTitle
A quantitative measurement of the dependence of short-term synaptic enhancement on presynaptic residual calcium.
pubmed:affiliation
Biological Computation Research Department, AT&T Bell Laboratories, Murray Hill, New Jersey 07974.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't