GABA-A RECEPTOR-MEDIATED FIELD POTENTIALS ARE ENHANCED IN AREA CA1 FOLLOWING PRENATAL COCAINE EXPOSURE

Prenatal cocaine exposure results in several documented changes in neu rotransmitter receptor number and structure. Increases have been repor ted for cortical catecholamine and indoleamine receptor number and bin ding affinity, in the subunit expression of glutamatergic NMDA and AMP A receptors in the striatum, and in GABA immunoreactivity in the anter ior cingulate cortex. We sought information on the functional conseque nces of cocaine-induced alterations in receptor structure/number. Sinc e hippocampal amino acid neurotransmitters are of critical importance and have been shown to be affected by cocaine, we studied field potent ials produced by synaptic activation of isolated glutamatergic NMDA an d AMPA receptors and GABAa and GABAb responsive receptors in area CA1 of rabbit hippocampal slices. We found the GABAa receptor population p roduced significantly larger field potentials in cocaine-exposed offsp ring compared to controls, while other receptors produced responses si milar to controls. (C) 1998 Elsevier Science B.V. All rights reserved.