24 25 Gamma-aminobutyric acid (GABA) – gated chloride channel receptors are abundant in the 26 central nervous system where their physiological role is to mediate fast inhibitory 27 neurotransmission. In insects, this inhibitory transmission plays a crucial role in olfactory 28 information processing. In an effort to understand the nature and properties of the ionotropic 29 receptors involved i...

This chapter forms an introduction to the subsequent chapters in this volume which highlight the significance and potential therapeutic application of GABA(B) receptors. It is now 30 years since the GABA(B) site was first described in mammalian tissue. Since then much has emerged about its physiological role in the mammalian nervous system and its relationship to other neurotransmitter receptor...

Clinical studies showed that GABA(B) receptor agonists improve symptoms in patients with gastroesophageal reflux disease. One proposed mechanism of this effect is direct inhibition of the gastroesophageal vagal tension mechanosensors by GABA(B) agonists leading to reduction of reflux. In addition to tension mechanosensors, the vagal nodose ganglion supplies the esophagus with nociceptive C-fibe...

Increased activity of dopamine-containing neurons in the ventral tegmental area is necessary for the reinforcing effects of opioids and other abused drugs. Intracellular recordings from these cells in slices of rat brain in vitro showed that opioids do not affect the principal (dopamine-containing) neurons but hyperpolarize secondary (GABA-containing) interneurons. Experiments with agonists and...

Mice lacking the gene encoding fragile X mental retardation protein (FMR1) are susceptible to audiogenic seizures, and antagonists of the group I metabotropic glutamate receptors (mGluRs) have been shown to block seizures in FMR1 knockout mice. We investigated whether the G-protein-inhibitory activity of the regulator of G-protein signaling protein, RGS4, could also alter the susceptibility to ...

g -aminobutiric acid (gaba), the major inhibitory neurotransmitter in the central nervous system has two major receptor subtypes (gabaa and gabab). gabab receptors are activated by the antispastic and muscle relaxant agent, baclofen, which is a lipophilic derivative of gaba. since 1962 several strategies have been reported for the synthesis of baclofen.in this study an approach has been made to...

Despite the profound effect of cannabinoids on motor function, and their therapeutic potential in Parkinson's and Huntington's diseases, the cellular and subcellular distributions of striatal CB1 receptors are not well defined. Here, we show that CB1 receptors are primarily located on GABAergic (vesicular GABA transporter-positive) and glutamatergic [vesicular glutamate transporter-1 (VGLUT-1)-...

Light-induced phase shifts of the circadian locomotor rhythm of hamsters can be blocked by agents that alter GABA neurotransmission. The GABA antagonist bicuculline blocks phase delays induced by light and the benzodiazepine diazepam, which can potentiate GABA activity, blocks light-induced phase advances. In the experiments reported here, we found that the bicuculline blockade of phase delays ...

Blackshaw, L. Ashley, Esther Staunton, Anders Lehmann, and John Dent. Inhibition of transient LES relaxations and reflux in ferrets by GABA receptor agonists. Am. J. Physiol. 277 (Gastrointest. Liver Physiol. 40): G867– G874, 1999.—Transient lower esophageal sphincter (LES) relaxation is the major mechanism of gastroesophageal reflux. This study uses an established ferret model to evaluate GABA...

Transmitter-mediated homosynaptic potentiation is generally implemented by the same transmitter that mediates the excitatory postsynaptic potentials (EPSPs), e.g., glutamate. When a presynaptic neuron contains more than one transmitter, however, potentiation can in principle be implemented by a transmitter different from that which elicits the EPSPs. Neuron B20 in Aplysia contains both dopamine...