Cys-loop receptor binding sites characteristically possess an "aromatic box," where several aromatic amino acid residues surround the bound ligand. A cation-π interaction between one of these residues and the natural agonist is common, although the residue type and location are not conserved. Even in the closely related vertebrate GABA(A) and GABA(C) receptors, residues in distinct locations pe...

Macromolecular signalling complexes that link neurotransmitter receptors to functionally and structurally associated proteins play an important role in the regulation of neurotransmission. Thus the identification of proteins binding to neurotransmitter receptors describes molecular mechanisms of synaptic signal transduction. To identify interacting proteins of GABA(C) (where GABA is gamma-amino...

GABAergic inhibition in the central nervous system (CNS) can occur via rapid, transient postsynaptic currents and via a tonic increase in membrane conductance, mediated by synaptic and extrasynaptic GABA(A) receptors (GABA(A)Rs) respectively. Retinal bipolar cells (BCs) exhibit a tonic current mediated by GABA(C)Rs in their axon terminal, in addition to synaptic GABA(A)R and GABA(C)R currents, ...

The present paper describes the design, construction and testing of a temperature-sensitive N-isopropylacrylamide hydrogel device for studying the controlled presentation of gamma-aminobutyric acid (GABA) to GABA(C) membrane receptors expressed in Xenopus laevis oocytes. Upon temperature lowering, the GABA-loaded hydrogel positioned near the surface of the GABA(C)-expressing oocyte elicits a me...

Our understanding of the role GABA(C) receptors play in the central nervous system is limited due to a lack of specific ligands. Here we describe the pharmacological effects of (+/-)-cis-3- and (+/-)-trans-3-(aminocyclopentyl)methylphosphinic acids ((+/-)-cis- and (+/-)-trans-3-ACPMPA) as novel ligands for the GABA(C) receptor showing little activity at GABA(A) or GABA(B) receptors. (+/-)-cis-3...

Characteristics of ionotropic gamma-aminobutyric acid (GABA) receptors at bullfrog cone terminals were studied by patch clamp techniques in isolated cell and retinal slice preparations. GABA-induced inward currents from isolated cones reversed in polarity at a potential, very close to the chloride equilibrium potential, and they were completely suppressed by picrotoxin. Unexpectedly, the GABA c...

Introduction: According to the cumulative evidence, genes encoding GABA receptors inhibit neurotransmitters in CNS and are intricately involved in the pathogenesis of mood disorders. Based on this hypothesis, these genes may be expressed in bipolar patients. As a result, we evaluated the gene expressions of GABA-β3 and HT1D receptors to assess their associations with bipolar mood disorder....

Within the second synaptic layer of the retina, bipolar cell (BC) output to ganglion cells is regulated by inhibitory input to BC axon terminals. GABA(A) receptors (GABA(A)Rs) mediate rapid synaptic currents in BC terminals, whereas GABA(C) receptors (GABA(C)Rs) mediate slow evoked currents and a tonic current, which is strongly regulated by GAT-1 GABA transporters. We have used voltage-clamp r...

In the present study, we provide evidence for the expression of all three GABA(C) receptor rho subunits through development of the rat cerebellum. Injection of cerebellum mRNA into frog oocytes gave rise to the expression of both GABA(A) and GABA(C) receptors. qRT-PCR of RNA isolated from postnatal developing cerebella showed that the expression of each rho subunit is relatively low, with a rel...