ISSN:
1471-4159
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Medicine
Notes:
Abstract : We have examined the effects of transient global ischemiaon both the gene expression levels and the functionality of GABABreceptors in rat brain, using antisense in situ hybridization andelectrophysiological evaluations. At the level of gene expression, nosignificant change in GABAB receptor expression was observed in anyhippocampal subfield at either 6 or 12 h after challenge. At 24 hpostchallenge, however, a significant decrease in GABAB receptorexpression was observed in both the CA1 and CA3 subfields, whereas no changewas observed in the dentate granule cell layer. Although expression in boththe vulnerable CA1 and less vulnerable CA3 subfields was diminished at thistime postchallenge, there was no significant difference in the degree of thediminished expression between these subfields. At the functional level, thedose-dependent ability of baclofen (1-100 μM) to inhibit an evokedexcitatory postsynaptic potential (f-EPSP) in the CA1 subfield was evaluatedat 24 h postischemia, in comparison with the dose-response observed insham-operated subjects. No significant differences were observed in theefficacy of GABAB receptor-mediated inhibition of the elicitedf-EPSP at any of the baclofen concentrations examined. These data demonstratethat although the mRNA expression levels for the GABAB receptor arediminished in both vulnerable and less vulnerable neurons of Ammon's horn at24 h following transient global ischemia, the functionality of theGABAB receptor system is maintained at this time postchallenge.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1046/j.1471-4159.1999.0720087.x
