Activation of metabotropic GABAB receptors (GABABRs) enhances tonic GABA current and substantially increases the frequency of spontaneous seizures. Despite the and pro-epileptic consequences of GABABR activation, mice lacking functional GABAB receptors (GABAB1R KO mice) exhibit clonic and rare absence seizures. To examine these mutant mice further, we recorded excitatory and inhibitory synaptic...

We have used double-label in situ hybridization techniques to examine the cellular localization of GABAB receptor mRNA in relation to serotonin transporter mRNA and glutamic acid decarboxylase mRNA in the rat dorsal raphe, median raphe and raphe magnus nuclei. The degree of cellular co-localization of these markers notably varied among the different nuclei. In the dorsal raphe, cell bodies show...

De Koninck, Yves and Istvan Mody. Endogenous GABA actition of these receptors to raise the intracellular concentration vates small-conductance K channels underlying slow IPSCs in of G proteins to the level required for activation of the K rat hippocampal neurons. J. Neurophysiol. 77: 2202–2208, 1997. channels (Destexhe and Sejnowski 1995), or 3) cause the The objective of this study was to dete...

Gamma-Aminobutyric acid-B (GABAB) receptor function and regulation in the nucleus of the solitary tract (NTS) was examined in Sprague-Dawley rats made chronically (4 to 5 weeks) hypertensive with the one-kidney, figure-8 renal wrap model of hypertension. NTS microinjection of the GABAB agonist baclofen produced a pressor response that was enhanced in hypertensive rats compared with the response...

GABA has been proposed to inhibit insulin secretion through GABAB receptors (GABABRs) in pancreatic beta-cells. We investigated whether GABABRs participated in the regulation of glucose homeostasis in vivo. The animals used in this study were adult male and female BALB/C mice, mice deficient in the GABAB1 subunit of the GABABR (GABAB(-/-)), and wild types (WT). Blood glucose was measured under ...

GABA acts as a presynaptic inhibitory transmitter in the spinal cord. In the lamprey, it has recently been shown that it acts in this way at both primary sensory and motor system synapses and is important in the generation of a locomotor rhythm. Both GABAA and GABAB receptors are activated at these sites by GABA released during physiological activity. In some systems, GABAB receptor activation ...

BACKGROUND AND PURPOSE Activation of GABAB receptors in the dentate gyrus (DG) enhances granule cell (GC) activity by reducing synaptic inhibition imposed by hilar interneurons. This disinhibitory action facilitates signal transfer from the perforant path to the hippocampus. However, as the two main molecular subtypes, GABA(B(1a,2)) and GABA(B(1b,2)) receptors, prefer axonal terminal and dendri...

bstract—Although multiple effects of GABAB receptor actiation on synaptic transmission in the striatum have been escribed, the precise locations of the receptors mediating hese effects have not been determined. To address this ssue, we carried out pre-embedding immunogold electron icroscopy in the rat using antibodies against the GABAB eceptor subunits, GABAB1 and GABAB2. In addition, to inesti...

GABA receptor regulation of NMDA-receptor-mediated synaptic responses was studied in area CA1 of the rat hippocampus using extracellular and intracellular recording techniques. Picrotoxin (PTX) was used to suppress GABAA inhibition and 6,7-dinitroquinoxaline-2,3-dione (DNQX) was used to suppress non-NMDA receptor-mediated responses. In this manner, we were able to avoid the complicating factors...

GABA (γ-aminobutyric acid), the predominant inhibitory neurotransmitter in the mature mammalian brain, is excitatory for neurons during early development upon GABAA receptor activation. In astrocytes, GABA induces intracellular Ca2+ transients by activation of both, GABAA and GABAB receptors. GABAB receptor-mediated [Ca]i increases are involved in neuron-glia interaction by potentiating inhibit...