GABAB receptor activation modulates neuronal activity mediated by multiple CNS transmitters and can occur at pre- and postsynaptic sites. In low concentrations, baclofen acts presynaptically to diminish transmitter release via both hetero- and autoreceptors, whereas at increasing concentrations, the same compound alters postsynaptic membrane excitability by inducing a membrane hyperpolarization...

The postnatal development of GABAB binding sites in rat brain was studied by quantitative receptor autoradiography using [3H]GABA under selective conditions. Binding levels peak at regionally specific times during the first three weeks of life and then decline to adult levels. GABAB binding peaked in the globus pallidus, vestibular and spinal trigeminal nuclei, and the CA3 region of the hippoca...

Fragile X mental retardation protein (FMRP) is an RNA-binding protein important for the control of translation and synaptic function. The mutation or silencing of FMRP causes Fragile X syndrome (FXS), which leads to intellectual disability and social impairment. γ-Aminobutyric acid (GABA) is the major inhibitory neurotransmitter of the mammalian central nervous system, and its metabotropic GABA...

We compared the distribution of GABAA and GABAB binding sites in the cochlear nucleus using quantitative receptor autoradiography with [3H]GABA. To visualize GABAA binding sites, GABAB binding sites were blocked with +/- baclofen. To visualize GABAB binding sites, isoguvacine was used to block GABAA binding sites. GABAA binding sites predominated over GABAB, although there were marked regional ...

GABAB receptors modulate swimming behavior in Paramecium by inhibiting dihydropyridine-sensitive Ca2+ channels via G-proteins. Prolonged occupancy of GABAB receptors by baclofen results in a decrease in GABAB receptor functions. Since changes in the number of cell-surface GABAA receptors have been postulated to be of importance in modulating inhibitory synaptic transmission in neurons, we have ...

Adult neurogenesis is tightly regulated through the interaction of neural stem/progenitor cells (NSCs) with their niche. Neurotransmitters, including GABA activation of GABAA receptor ion channels, are important niche signals. We show that adult mouse hippocampal NSCs and their progeny express metabotropic GABAB receptors. Pharmacological inhibition of GABAB receptors stimulated NSC proliferati...

We have developed a model of gamma-aminobutyric acid (GABA)ergic synaptic transmission mediated by GABAA and GABAB receptors, including cooperativity in the guanine nucleotide binding protein (G protein) cascade mediating the activation of K+ channels by GABAB receptors. If the binding of several G proteins is needed to activate the K+ channels, then only a prolonged activation of GABAB recepto...

In vertebrates, γ-aminobutyric acid (GABA) is the main inhibitory transmitter in the central nervous system (CNS) acting through ionotropic (GABAA) and metabotropic (GABAB) receptors. The GABAB receptor produces a slow inhibition since it activates second messenger systems through the binding and activation of guanine nucleotide-binding proteins [G-protein-coupled receptors (GPCRs)]. Lampreys a...

GABAB receptors regulate the intracellular Ca2+ concentration ([Ca2+]i) in a number of cells (e.g., retina, airway epithelium and smooth muscle), but whether they are expressed in vascular endothelial cells and similarly regulate the [Ca2+]i is not known. The purpose of this study was to investigate the expression of GABAB receptors, a subclass of receptors to the inhibitory neurotransmitter γ-...

background: hypertension is considered an independent risk factor for cardiovascular mortality in diabetic patients. the present study was designed to determine the role of gamma amino butyric acid b (gabab) receptor and l-arginine (l-arg) in gaba-induced vasorelaxation in normal and streptozotocin-induced diabetic rat vessels. methods: diabetes was induced by a single i.p. injection of strepto...