Linked Life Data

10812216

Source:http://linkedlifedata.com/resource/pubmed/id/10812216

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2-3
pubmed:dateCreated
2000-8-14
pubmed:abstractText
This in vivo study, aimed at detecting the N-methyl-D-aspartate (NMDA) evoked Ca(2+)-induced Ca(2+) release from intracellular stores in the neonatal rat brain, demonstrates that the application of 5 mM N-methyl-D-aspartate via a microdialysis probe for 20 min to the dentate gyrus (DG) of halotane-anesthetized 7 day-old (postnatal day 7, PND 7) rats induces a prolonged decrease in Ca(2+) concentration in an initially calcium-free dialysis medium, indicative of a drop in the extracellular concentration of Ca(2+) and Ca(2+) influx to neurons. In parallel experiments, a huge NMDA-evoked release of 45Ca from the pre-labeled endogenous Ca(2+) pool was observed and interpreted as the expression of intracellular Ca(2+) release. Dantrolene (100 microM) significantly inhibited the NMDA-induced 45Ca release, whereas 250 microM ryanodine exerted an unspecific biphasic effect. Autoradiographic and immunocytochemical detection of ryanodine receptors and calbindin D(28K), respectively, in the hippocampal region of PND 7 rats displayed a pronounced expression of [3H]ryanodine binding sites in the DG, but only a slight immunoreactivity of calbindin D(28K). Plastic changes in neurons or excitotoxic neuronal damage induced by the activation of NMDA receptors are mediated by Ca(2+) signals, resulting from an influx of extracellular Ca(2+), and also in some neurons, from the release of intracellular Ca(2+). Our previous in vivo microdialysis experiments visualized NMDA-evoked 45Ca release in the adult rat dentate gyrus, attributable to Ca(2+)-induced Ca(2+) release from the ryanodine-sensitive pool. An additional role of calbindin in the mechanism of this phenomenon has been suggested. This aspect has not been studied in vivo in newborn rats. Our present results indicate that the release of 45Ca from the prelabeled intracellular, dantrolene-sensitive Ca(2+) pool in the DG neurons of immature rats, most probably representing a phenomenon of Ca(2+)-induced Ca(2+) release, significantly participates in the generation of NMDA receptor-mediated intracellular Ca(2+) signals, whereas the role of calbindin D(28K) in the mechanism of 45Ca release is negligible.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0197-0186
pubmed:author
pubmed:issnType
Print
pubmed:volume
37
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
307-16
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:articleTitle
NMDA-induced 45Ca release in the dentate gyrus of newborn rats: in vivo microdialysis study.
pubmed:affiliation
Department of Neurochemistry, Medical Research Centre, Polish Academy of Sciences, Warsaw.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't