Linked Life Data

2430673

Source:http://linkedlifedata.com/resource/pubmed/id/2430673

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1-2
pubmed:dateCreated
1987-1-16
pubmed:abstractText
The effects of valproate (VPA) on neuronal excitability and on changes in extracellular potassium ([K+]o) and calcium ([Ca2+]o) were investigated with ion selective-reference electrode pairs in area CA1 of rat hippocampal slices. Field potential responses to single ortho- and antidromic stimuli were unaltered by VPA (1-5 mM). The afferent volley evoked in the Schaffer-commissural fibers was also unaffected. In contrast, VPA (1 mM) depressed frequency potentiation and paired pulse facilitation markedly. Decreases in [Ca2+]o induced either by repetitive stimulation or by application of the excitatory amino acids N-methyl-D-aspartate and quisqualate were reduced, and the latter results suggest that VPA interferes with postsynaptic Ca2+ entry. When synaptic transmission was blocked by lowering [Ca2+]o (0.2 mM) and elevating [Mg2+]o (7 mM), prolonged afterdischarges elicited by antidromic stimulation were blocked by VPA. VPA also suppressed the spontaneous epileptiform activity seen when [Ca2+]o was lowered to 0.2 mM, without elevating [Mg2+]o. The amplitudes of the rises in [K+]o induced by repetitive orthodromic stimulation were only slightly depressed and those elicited by antidromic stimulation were generally unaltered by VPA, as were laminar profiles of stimulus-evoked [K+]o signals. These results indicate that VPA has membrane actions in addition to known effects on excitatory and inhibitory transmitter pools.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0006-8993
pubmed:author
pubmed:issnType
Print
pubmed:day
29
pubmed:volume
386
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1-11
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1986
pubmed:articleTitle
The action of valproate on spontaneous epileptiform activity in the absence of synaptic transmission and on evoked changes in [Ca2+]o and [K+]o in the hippocampal slice.
pubmed:publicationType
Journal Article, In Vitro, Research Support, Non-U.S. Gov't