In the vertebrate brain, inhibition is largely mediated by γ-aminobutyric acid (GABA). This neurotransmitter comprises a signaling machinery of GABAA, GABAB receptors, transporters, glutamate decarboxylases (gads) and 4-aminobutyrate aminotransferase (abat), and associated proteins. Chloride is intimately related to GABAA receptor conductance, GABA uptake, and GADs activity. The response of tar...

This study was performed to investigate the sedative-hypnotic activity of γ-aminobutyric acid (GABA)-enriched fermented marine organisms (FMO), including sea tangle (FST) and oyster (FO) by Lactobacillus brevis BJ20 (L. brevis BJ20). FST and FO were tested for their binding activity of the GABAA-benzodiazepine and 5-HT2C receptors, which are well-known molecular targets for sleep aids. We also ...

Propofol is a widely used intravenous general anesthetic. Propofol-induced unconsciousness in humans is associated with inhibition of thalamic activity evoked by somatosensory stimuli. However, the cellular mechanisms underlying the effects of propofol in thalamic circuits are largely unknown. We investigated the influence of propofol on synaptic responsiveness of thalamocortical relay neurons ...

Dehydroepiandrosterone sulfate (DHEAS) is a neuroactive steroid with antagonist action at gamma-aminobutyric acid type A (GABAA) receptors. Patch-clamp techniques were used to investigate DHEAS actions at GABAA receptors of the rat pituitary gland at two distinct loci: posterior pituitary nerve terminals and intermediate pituitary endocrine cells. The GABA responses in these two regions were qu...

GABAA receptor-mediated Cl- currents in rat thalamic reticular and relay neurons. J. Neurophysiol. 78: 2280-2286, 1997. Spontaneous and evoked inhibitory postsynaptic currents (sIPSCs and eIPSCs) and responses to exogenously applied gamma-aminobutyric acid (GABA), mediated by GABA type A (GABAA) receptors, were recorded in inhibitory neurons of nucleus reticularis thalami (nRt) and their target...

4'-Ethynyl-4-n-[2,3-3H2]propylbicycloorthobenzoate ([3H]EBOB) binding to the GABAA receptor complex was characterized autoradiographically in rat brain and then its binding in human brain was investigated. [3H]EBOB binding was saturable, specific and identified a single population of binding sites. The Kd obtained from saturation studies was 4.59 nM. Picrotoxin produced dose-dependent inhibitio...

Benzodiazepines are the current first-line standard-of-care treatment for status epilepticus but fail to terminate seizures in about one third of cases. Synaptic GABAA receptors, which mediate phasic inhibition in central circuits, are the molecular target of benzodiazepines. As status epilepticus progresses, these receptors are internalized and become functionally inactivated, conferring benzo...

Dopamine is a critical neuromodulator that activates GPCRs in mammals or ligand-gated ion channels in invertebrates. The present study demonstrates that dopamine (0.1-10 mm) exerts novel, opposing effects on different populations of mammalian (rat) GABAA receptors. Using whole-cell patch-clamp electrophysiology, we observed direct dopamine-mediated inhibition of tonic-level (1 μm) GABA-evoked c...