Linked Life Data

3017511

Source:http://linkedlifedata.com/resource/pubmed/id/3017511

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1986-10-6
pubmed:abstractText
Evidence has accumulated suggesting that the presence of calcium is critical for development of hippocampal long-term potentiation (LTP). However, there is a paucity of information about whether calcium's role in LTP is pre- or postsynaptic. In the present study, we examined the effectiveness of nitrendipine, verapamil, flunarizine and the benzodiazepine diazepam in: blocking voltage-dependent calcium channels; blocking synaptic transmission; and preventing development of LTP. Using the in vitro slice preparation, we obtained intracellular and extracellular recordings from guinea pig hippocampal CA1 pyramidal cells. At the cellular level, all 4 drugs were ineffective in blocking voltage-dependent calcium spikes (TTX resistant) and the calcium-dependent afterhyperpolarization. Verapamil and diazepam appeared to antagonize synaptic transmission, as reflected in smaller population spike amplitudes. Development of long-term potentiation was not affected by the presence of verapamil, flunarizine and diazepam. Nitrendipine appeared to reduce the percentage of slices exhibiting LTP; however, ethanol, the vehicle used to dissolve nitrendipine, was shown in separate experiments to reduce the percentage of slices exhibiting LTP. These results suggest that neither the organic calcium channel blockers--nitrendipine, verapamil, and flunarizine--nor micromolar concentrations of diazepam are potent blockers of extrasynaptic voltage-sensitive calcium channels in hippocampus. They thus cannot be used to demonstrate a specific pre- or postsynaptic calcium role in LTP.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0006-8993
pubmed:author
pubmed:issnType
Print
pubmed:day
6
pubmed:volume
379
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
275-85
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1986
pubmed:articleTitle
Ineffectiveness of organic calcium channel blockers in antagonizing long-term potentiation.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S.