Modulation of gamma-aminobutyric acid-mediated inhibitory synaptic currents in dissociated cortical cell cultures.
AUTOR(ES)
Vicini, S
RESUMO
Inhibitory gamma-aminobutyric acid-mediated synaptic currents were studied in dissociated primary cultures of neonatal rat cortex with the whole-cell patch-clamp technique. Immunocytochemical staining of the cultures showed the presence of a large number of glutamic acid decarboxylase-containing neurons, and electrical stimulation of randomly selected neurons produced in many cases chloride-mediated and bicuculline-sensitive inhibitory synaptic currents in postsynaptic cells. The amplitude and decay time of the inhibitory synaptic currents were increased by flunitrazepam and decreased by the beta-carboline derivative methyl 6,7-dimethoxy-4-ethyl-beta-carboline-3-carboxylate, two high-affinity ligands for the allosteric regulatory sites of gamma-aminobutyric acid receptors. The imidazobenzodiazepine Ro 15-1788, another high-affinity ligand of the gamma-aminobutyric acid receptor regulatory sites that has negligible intrinsic activity, blocked the action of flunitrazepam and beta-carboline. However, Ro 15-1788 also increased the decay rate of the inhibitory synaptic currents. This might suggest that an endogenous ligand for the benzodiazepine-beta-carboline binding site is operative in gamma-aminobutyric acid-mediated synaptic transmission.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=387117Documentos Relacionados
- Inhibitory effect of cephalosporins on gamma-aminobutyric acid receptor binding in rat synaptic membranes.
- The modulation of rat hippocampal synaptic conductances by baclofen and gamma-aminobutyric acid.
- Gamma-aminobutyric acid uptake and the termination of inhibitory synaptic potentials in the rat hippocampal slice.
- Release of gamma-aminobutyric acid from inhibitory nerves of lobster.
- Variance analysis of gamma-aminobutyric acid (GABA)-ergic inhibitory postsynaptic currents from melanotropes of Xenopus laevis.