In this study, the influence of dopamine receptor agonists and antagonists on antinociception induced by bac10fen has been examined in the formalin test. The GABA-B agonist bac10fen induced antinociception in both phases of the formalin test in mice. The dopamine receptor agonists SKF 38393 and quinpirole also induced antinociception in both phases of the test. SKF 38393 but not quinpirole ...

The purpose of this study was to examine our hypothesis that gamma-aminobutyric acid (GABA) in the nucleus tractus solitarii (NTS) may be related to the hypoxic ventilatory decline (HVD) and that chemoreceptor stimulation was essential to activate this mechanism. We used unanesthetized, freely moving rats in this study. An in vivo microdialysis technique was used to measure the extracellular GA...

gamma-Aminobutyric acid (GABA), trans-4-aminocrotonic acid (TACA), muscimol, imidazole-4-acetic acid (I4AA), cis-4-aminocrotonic acid (CACA), and isoguvacine are all GABA(C) receptor agonists. These compounds have different apparent sensitivities (EC(50)) and efficacies (I(max)) on exogenously expressed human rho1 homomeric GABA(C) receptors. It is not clear if these differences are due to dist...

GABA(B) receptors are heterodimers of two subunits, GABA(B1) (GB1) and GABA(B2) (GB2). Agonists such as GABA and baclofen bind to the GB1 subunit only, whereas GB2 is essential for G protein activation. Positive allosteric modulators enhance the potency and efficacy of agonists at GABA(B) receptors and are of particular interest because they lack the sedative and muscle relaxant properties of a...

The electrical activity of the brain arises from single neurons communicating with each other. However, how single neurons interact during early development to give rise to neural network activity remains poorly understood. We studied the emergence of synchronous neural activity in human pluripotent stem cell (hPSC)-derived neural networks simultaneously on a single-neuron level and network lev...

The zolpidem discriminative cue is mediated by GABA(A)-alpha1 receptors, whereas the chlordiazepoxide cue may be mediated via non-alpha1 GABA(A) receptors because compounds with selective affinity for GABA(A)-alpha1 receptors fully generalize to the former cue. We predicted that L-838,417 [7-tert-butyl-3-(2,5-difluorophenyl)-6-(2-methyl-2H-1,2,4-triazol-3-ylmethoxy)-1,2,4-triazolo[4,3-b]pyridaz...

Fast inhibition in the nervous system is commonly mediated by GABA(A) receptors comprised of 2alpha/2beta/1gamma subunits. In contrast, GABA(C) receptors containing only rho subunits (rho1-rho3) have been predominantly detected in the retina. However, here using reverse transcription-PCR and in situ hybridization we show that mRNA encoding the rho1 subunit is highly expressed in brainstem neuro...

Ambient GABA modulates firing patterns in adult neural circuits by tonically activating extrasynaptic GABA(A) receptors. Here, we demonstrate that during a developmental period when activation of GABA(A) receptors causes membrane depolarization, tonic activation of GABA(A) receptors blocks all spontaneous activity recorded in retinal ganglion cells (RGCs) and starburst amacrine cells (SACs). Ba...

gamma-aminobutyric acid (GABA) plays important roles in the central nervous system, acting as a neurotransmitter on both ionotropic ligand-gated Cl(-)-channels, and metabotropic G-protein coupled receptors (GPCRs). These two types of receptors called GABA(A) (and C) and GABA(B) are the targets of major therapeutic drugs such as the anxiolytic benzodiazepines, and antispastic drug baclofen (lior...

Hypothalamic proopiomelanocortin (POMC) neurons and their peptide products mediate important aspects of energy balance, analgesia, and reward. In addition to peptide products, there is evidence that POMC neurons can also express the amino acid transmitters GABA and glutamate, suggesting these neurons may acutely inhibit or activate downstream neurons. However, the release of amino acid transmit...