Linked Life Data

10479687

Source:http://linkedlifedata.com/resource/pubmed/id/10479687

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
18
pubmed:dateCreated
1999-10-4
pubmed:abstractText
Spatially localized Ca(2+) domains are thought to play a key role in action potential (AP)-evoked neurotransmitter release at fast synapses. We used a stage-scan confocal spot-detection method and the low-affinity Ca(2+) indicator Oregon Green 488 BAPTA-5N to study the spatiotemporal profile of presynaptic AP-induced Ca(2+) domains. Families of scanned AP-induced fluorescence transients were detected from spot locations separated by 200-300 nm, within the vicinity of Ca(2+) entry sites. Typically, the largest transient in a particular scan peaked within approximately 1 msec and decayed with rapid (tau(1) of 1.7 msec) and slow components (tau(2) of 16 msec, tau(3) of 78 msec). As the spot was incrementally displaced, transients progressively exhibited a slowing in their time-to-peak and a loss of the fast decay component. Three-dimensional graphs of fluorescence versus time and spot displacement revealed the presence of AP-induced fluorescence domains that dissipated within approximately 7 msec. The size of fluorescence domains were estimated from the full-width at half-maximum of gaussian fits to isochronal DeltaF/F plots and ranged from 0.6 to 3.0 micrometer, with a mean +/- SD of 1.6 +/- 0.6 micrometer. Model simulations of a localized Ca(2+) entry site predicted the major features of the fluorescence transients and suggested that, within approximately 1 msec of the initiation of the Ca(2+) current, both the fluorescence domain and the underlying Ca(2+) domain do not extend significantly beyond the site of entry. Consistent with this prediction, the intracellular addition of EGTA (up to 2 mM) accelerated the decay of the measured transients but did not affect the domain size.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
1529-2401
pubmed:author
pubmed:issnType
Electronic
pubmed:day
15
pubmed:volume
19
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
7846-59
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
Measurement of action potential-induced presynaptic calcium domains at a cultured neuromuscular junction.
pubmed:affiliation
Department of Physiology, University of California at Los Angeles School of Medicine, Los Angeles, California 90095, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.