• Bicuculline is a phthalide-isoquinoline compound that is a light-sensitive competitive antagonist of GABAA receptors. (wikipedia.org)
  • The action of bicuculline is primarily on the ionotropic GABAA receptors, which are ligand-gated ion channels concerned chiefly with the passing of chloride ions across the cell membrane, thus promoting an inhibitory influence on the target neuron. (wikipedia.org)
  • The half-maximal inhibitory concentration (IC50) of bicuculline on GABAA receptors is 3 μM. (wikipedia.org)
  • Sensitivity to bicuculline is defined by IUPHAR as a major criterion in the definition of GABAA receptors Picrotoxin Hydrastine (very similar in structure) Johnston, Graham AR (2013). (wikipedia.org)
  • The excitatory synaptic currents mediated by AMPA and NMDA receptors and the inhibitory current mediated by GABA A receptors were pharmacologically isolated and recorded by whole-cell patch-clamp techniques. (jneurosci.org)
  • GABA A inhibition suppressed activation of NMDA receptors and reduced both the degree of AMPA EPSC depression and the extent of temporal summation of NMDA EPSCs. (jneurosci.org)
  • The inhibitory response is mediated mainly by GABA A receptors (Ma et al. (jneurosci.org)
  • The decrease in the frequency of mIPSCs of SCN neurons produced by the selective 5-HT 1B receptor agonist CP-93,129 is consistent with the interpretation that 5-HT 1B receptors are located on GABA terminals in the SCN and that 5-HT inhibits GABA release via a 5-HT 1B presynaptic receptor-mediated mechanism. (unl.edu)
  • To investigate the relationship between intraocular pressure (IOP) and GABA receptors within the arcuate nucleus (ARC). (molvis.org)
  • To assess the expression of GABA-A/B receptors within the ARC under persistent high IOP, we performed immunofluorescence (IF) and immunohistochemical (IHC) staining at 2 weeks and 4 weeks. (molvis.org)
  • In the following induced high IOP animal model, the expression of GABA-A/B receptors within the ARC was evaluated in DBA/2J mice which developed progressive eye abnormalities spontaneously that closely mimic human hereditary glaucoma. (molvis.org)
  • GABA-A/B receptors in the ARC may be involved in regulation of IOP, and pathologically high IOP affects the expression of GABA-A/B receptors in the ARC. (molvis.org)
  • There are two types of GABA receptors. (molvis.org)
  • The third was an investigation of the excitatory amino acid receptors responsible for epileptiform bursting activity in 2 animal models of epilepsy: a chronic model of temporal lobe epilepsy, involved prior lesioning of the hippocampus with kainic acid, and an acute model which involved application of the GABA-A receptor antagonist, bicuculline. (soton.ac.uk)
  • Volatile anesthetics act primarily through upregulating the activity of γ-aminobutyric acid type A (GABA A ) receptors. (asahq.org)
  • γ-Aminobutyric acid (GABA) is the major inhibitory neurotransmitter in the vertebrate brain, and fast inhibitory postsynaptic potentials are mediated by GABA A receptors (GABARs). (aspetjournals.org)
  • However, spontaneous channel activity has been reported in recombinant α4β1 receptors as well as β1 or β3 homomeric receptors, although these isoforms are insensitive to activation by GABA. (aspetjournals.org)
  • 4 General anesthetic agents primarily target γ-aminobutyric acid type A (GABA A ) receptors and enhance inhibitory neurotransmission. (silverchair.com)
  • The subunit composition of GABA A receptors is heteromeric, and these receptors are nonuniformly expressed across the brain and change developmentally. (silverchair.com)
  • To test this hypothesis, we injected adult animals with saline alone (controls), or 100â mgâ kg-1 aminophylline or 1â mgâ kg-1 bicuculline, to block adenosine or GABAA receptors, respectively. (bvsalud.org)
  • The neurotransmitter γ-aminobutyric acid (GABA) drives critical inhibitory processes in and beyond the nervous system, partly via ionotropic type-A receptors (GABAARs). (bvsalud.org)
  • 3 Synaptic terminals from local and distant γ-aminobutyric acid (GABA)-containing neurons 4,5 as well as GABA type A (GABA A ) receptors 6-8 are present in the pontine reticular formation and modulate behavioral arousal. (silverchair.com)
  • The influence of γ-aminobutyric type-A (GABA A ) receptors agonist (muscimol hydrobromide, 0.1 µg/0.5 µl) injections into the right or left basolateral amygdala (BLA) on the behavior of high-an- xiety (HA) and low-anxiety (LA) rats subjected to the elevated plus-maze (EPM) test was investigated. (scirp.org)
  • Preparations were superfused at 20-22 °C with Cl - -free artificial cerebrospinal fluid (aCSF) or with aCSF containing agonists/antagonists ofγ-aminobutyric acid (GABA) or glycine receptors. (silverchair.com)
  • Fast inhibition in the nervous system is commonly mediated by GABA(A) receptors comprised of 2alpha/2beta/1gamma subunits. (ox.ac.uk)
  • In contrast, GABA(C) receptors containing only rho subunits (rho1-rho3) have been predominantly detected in the retina. (ox.ac.uk)
  • γ-Aminobutyric acid A (GABA A ) receptors (GABARs) are responsible for most fast inhibitory neurotransmission in the mammalian brain. (aspetjournals.org)
  • The GABA receptors are a class of receptors that respond to the neurotransmitter gamma-aminobutyric acid (GABA), the chief inhibitory compound in the mature vertebrate central nervous system. (targetmol.com)
  • There are two classes of GABA receptors: GABAA and GABAB. (targetmol.com)
  • citation needed] In addition to being a potent GABAA receptor antagonist, bicuculline can be used to block Ca2+-activated potassium channels. (wikipedia.org)
  • The GABAA receptor antagonist Picrotoxin is commonly used to reduce the levels inhibition by blocking the actions of the neurotransmitter GABA. (hellobio.com)
  • 6,2'-Dihydroxyflavone is a novel antagonist of GABAA receptor. (targetmol.com)
  • Local application of the GABAA antagonist bicuculline partially restored cortical changes, particularly in the rostral forelimb area. (unife.it)
  • The results indicate that GABA A receptor-mediated inhibition plays a crucial role in maintaining the balance of excitation and inhibition and in allowing ICC neurons to process temporal information more precisely. (jneurosci.org)
  • Functional and pharmacological properties of GABA-mediated inhibition in the human neocortex. (timtec.net)
  • 5-HT 1B Receptor-Mediated Presynaptic Inhibition of GABA Rel" by Jayne R. Bramley, Patricia J. Sollars et al. (unl.edu)
  • Most anesthetic drugs potentiate GABA A receptor-mediated inhibition, and this potentiation is thought to comprise part of the mechanism by which general anesthetics produce hypnosis. (silverchair.com)
  • These findings suggest that dopamine-, Asp-, Glu- and Gly-containing retinal neurons are subject to tonic inhibition by GABA in darkness. (tci-thaijo.org)
  • It was not abolished but enhanced by the GABA(A) antagonist bicuculline (5 muM), suggesting that DHPG's action was not due to facilitated inhibition or changes in neuronal network activity. (elsevierpure.com)
  • Low concentrations of GABA (0.5 mmol l -1 ) produced a significant increase in lung burst frequency followed by almost complete inhibition at 5.0 mmol l -1 ,accompanied by the abolition of gill ventilation at 2.5-5.0 mmol l -1 . (silverchair.com)
  • By contrast, fictive lung ventilation in adults was inhibited in a dose-dependent manner by glycine and GABA, and inhibition occurred at approximately 10-fold lower concentrations compared with tadpoles. (silverchair.com)
  • Guvacine can enhance the inhibition of spinal neurones by GABA. (targetmol.com)
  • This study provides evidence for motor cortex remodeling after unilateral dopamine denervation, suggesting that cortical changes were associated with dopamine denervation, pathogenic intracortical GABA inhibition, and altered interhemispheric activity. (unife.it)
  • The glycine receptor antagonist strychnine (2.5-25.0 μmol l -1 ) and the GABA A receptor antagonist bicuculline (1-10 μmol l -1 )inhibited fictive gill ventilation and increased fictive lung ventilation in tadpoles. (silverchair.com)
  • 75, 526, (1997) Johnson, S.W., Seutin, V., Bicuculline methiodide potentiates NMDA-dependent burst firing in rat dopamine neurons by blocking apamin-sensitive Ca2+-activated K+ currents. (timtec.net)
  • Bicuculline methiodide is a methiodide form of classical GABA A receptor antagonist (+)-bicuculline . (tocris.com)
  • If you know of a relevant reference for (-)-Bicuculline methiodide, please let us know . (tocris.com)
  • Bicuculline methiodide, a GABA(A)-receptor antagonist, completely arrested GABA influences on the electromotility response. (northwestern.edu)
  • Taken together these separate lines of evidence suggest that the effects of GABA in central neurons can be mediated by heteromeric complexes of GABA(A) and GABA(C) receptor subunits. (ox.ac.uk)
  • There was a dose- and calcium-dependent release of dopamine from turtle retinas incubated in $\sp3$H-dopamine after perfusion of the GABA antagonist bicuculline. (tmc.edu)
  • This indicated that dopamine release was tonically inhibited by GABA. (tmc.edu)
  • Glutamate antagonists selective for hyperpolarizing bipolar cells, such as 2,3-piperidine dicarboxylic acid (PDA), caused dose- and calcium-dependent release of dopamine from the retina. (tmc.edu)
  • The present study was conducted to determine whether the GABA antagonist, bicuculline, could modulate the release of dopamine and amino acid neurotransmitters upon exposure to light or darkness. (tci-thaijo.org)
  • Bicuculline (10-4M) increased the release of dopamine but decreased the release of Asp, Glu and Gly. (tci-thaijo.org)
  • The effects of bicuculline on the release of dopamine and amino acid neurotransmitters were in the same direction of exposure to light. (tci-thaijo.org)
  • Excitatory synaptic transmission in the brain is predominantly mediated by the neurotransmitter glutamate, while inhibitory transmission is mediated mainly by the neurotransmitter gamma-amino butyric acid (GABA). (frontiersin.org)
  • Amiloride acted primarily as a competitive antagonist, reducing the sensitivity of the receptor to GABA without affecting the maximal current amplitude. (aspetjournals.org)
  • Furthermore, all ACh-induced cellular and network changes were blocked by muscarinic, but not nicotinic receptor antagonists. (springer.com)
  • However, D-tubocurarine, a nicotinic receptor antagonist, while not blocking the ACh effect, altered the cell's apparent operating point. (northwestern.edu)
  • Of particular interest are contributions from γ-aminobutyric acid (GABA), which is the primary inhibitory neurotransmitter in the nervous system of most adult mammals, and adenosine, the accumulation of which increases during hypoxia as a breakdown product of ATP. (bvsalud.org)
  • The main groups include sodium channel blockers, calcium current inhibitors, gamma-aminobutyric acid (GABA) enhancers, glutamate blockers, carbonic anhydrase inhibitors, hormones, and drugs with unknown mechanisms of action (see the image below). (medscape.com)
  • These data extend the pharmacological characterization of ε-containing GABARs and demonstrate that incorporation of the ε subunit permits spontaneous channel gating while preserving the structural information necessary for GABA sensitivity. (aspetjournals.org)
  • These findings highlight a key role for PFC GABA transmission in reducing sensitivity to distractors during attentional performance. (researcher-app.com)
  • 1999). SP antagonists Many potent and selective non-peptide, low molecular tachykinin antagonists have been developed and proven effective in preclinical studies (Carvalho et al. (niepokorny.org)
  • Each rat received microinjections of Ringer's (vehicle control), the GABA uptake inhibitor nipecotic acid, and the GABA synthesis inhibitor 3-mercaptopropionic acid. (silverchair.com)
  • 12 Furthermore, administering drugs that selectively increase or decrease GABA levels into rat pontine reticular formation causes an increase or decrease, respectively, in wakefulness. (silverchair.com)
  • Both doses of bicuculline impaired vigilance, selectively increasing errors during nonsignal trials. (researcher-app.com)
  • 2018). Early experiments showed that antagonists selectively block nociceptive responses such as the slow, prolonged, excitatory postsynaptic potential that follows intense electrical stimuli to small high-threshold multimodal nociceptors (De Koninck and Henry 1991). (niepokorny.org)
  • An apparent resting state, determined first in the absence of modulators, was recapitulated with the specific inhibitor (1,2,5,6-tetrahydropyridin-4-yl)methylphosphinic acid and blocker picrotoxin and provided a rationale for bicuculline insensitivity. (bvsalud.org)
  • Combining GABA with picrotoxin also captured an apparent uncoupled intermediate state. (bvsalud.org)
  • Thus, we have decided to evaluate potential contributions of picrotoxin, a GABA, channel blocker, on pilocarpine-induced SE. (unifesp.br)
  • Alterations in the transient and steady-state electromotility transfer curves were examined by application of acetylcholine (ACh) and γ-aminobutyric acid (GABA) to the synaptic pole. (northwestern.edu)
  • The response kinetics of AMPA receptor-mediated EPSCs and GABA A receptor-mediated IPSCs were similar and much faster than those of NMDA receptor-mediated EPSCs. (jneurosci.org)
  • With a single pulse of current stimulation, the AMPA, NMDA, and GABA A receptor-mediated responses overlap each other temporally. (jneurosci.org)
  • In this study, we recorded the postsynaptic responses to repetitive stimulation of the lateral lemniscus and examined the effects of AMPA, NMDA, and GABA A receptor antagonists. (jneurosci.org)
  • Both prefrontal cortex (PFC) GABA A and NMDA transmission regulate attentional processes, yet how they may differentially regulate signal detection or other aspects of attention is unclear. (researcher-app.com)
  • We examined PFC GABA A and NMDA receptor regulation of attention using a sustained attention task (SAT) permitting identification of distinct forms of impairments. (researcher-app.com)
  • They then received intra-PFC infusions of the GABA A antagonist bicuculline (12.5-50 ng), the NMDA antagonist MK-801 (6 μg), and i.p. injections of MK-801 (0.1-0.3 mg/kg) prior to testing. (researcher-app.com)
  • Furthermore, we treated the ARC with GABA-A/B receptor antagonists separately, and IOP was evaluated, as well as retinal ganglion cell apoptosis in the chronic high IOP rat model. (molvis.org)
  • Responses to GABA(C) agonists were also enhanced by the GABA(A) receptor modulator pentobarbitone (300 microM). (ox.ac.uk)
  • Electrophysiology revealed that responses to GABA(C) receptor agonists were enhanced by the GABA(A) receptor modulator zolpidem (500 nm), which acts on the alpha1 subunit when the gamma2 subunit is also present. (ox.ac.uk)
  • In contrast, release was not observed after perfusion with 4-aminophosphonobutyric acid, a specific antagonist of depolarizing bipolar cells. (tmc.edu)
  • On the other hand local administration of the non-N-methyl-d-aspartate antagonist 2,3-dihydroxy-6-nitro-7-sulfamoil-benzo(F)quinoxaline was followed by an increase in acetylcholine output which reached a maximum of about +55% at 12.8 μM 2,3-dihydroxy-6-nitro-7-sulfamoil-benzo(F)quinoxaline and was readily reversed when the drug was withdrawn from the perfusion solution. (unifi.it)
  • Local administration of the non-N-methyl-d-aspartate receptor agonist (S)-alfa-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (50 and 200 μM) decreased acetylcholine output and this effect was reversed by simultaneous perfusion with the GABA antagonist bicuculline (50 μM). (unifi.it)
  • Atropin, a muscarinic receptor antagonist, completely blocked the increase in electromotility response due to ACh. (northwestern.edu)
  • Previous studies in which simultaneous injections of other GABA(A) antagonists (i.e. bicuculline) and pirocarpine were performed, did not show clear evidences of a synergistic action between these two systems. (unifesp.br)
  • 10,11 Dialysis delivery of bicuculline to cat pontine reticular formation increases local acetylcholine release and also triggers REM sleep. (silverchair.com)
  • A transversal microdialysis membrane was inserted in the striatum and acetylcholine or GABA levels in the dialysate were measured. (unifi.it)
  • Acetylcholine levels in the dialysate were quantified by a high-performance liquid chromatography method with an electrochemical detector, while GABA levels were measured by a high-performance liquid chromatography method with a fluorescence detector. (unifi.it)
  • Local administration of the N-methyl-d-aspartate antagonist 3-[(RS)-2-carboxypiperazin-4-yl]-propyl-1-phosphonic acid (25-100 μM) brought about a decrease in striatal acetylcholine output which was dose-dependent, reversible and partially antagonized by 100 μM N-methyl-d-aspartate. (unifi.it)
  • In one set of experiments the effect of the non-N-methyl-d-aspartate antagonist quisqualate was investigated both on acetylcholine and GABA output from the striatum of the same animal. (unifi.it)
  • Quisqualate perfused through the striatum resulted in a decrease in acetylcholine output and a concomitant increase in GABA output. (unifi.it)
  • Bottom: Representative traces of light-evoked GABAergic currents before and after bath application of the GABA-A receptor antagonist bicuculline. (uni-koeln.de)
  • Layer-specific effects of focal application of bicuculline indicate that the GABAergic depolarization is concentrated on tetanized dendrites. (ox.ac.uk)
  • A new γ-aminobutyric acid (GABA) A receptor (GABAR) subunit class, ε, has recently been cloned and shown to form functional channels when coexpressed with both α and β subunits. (aspetjournals.org)
  • Most GABAR isoforms require binding of GABA to initiate entry into open states. (aspetjournals.org)
  • The γ-aminobutyric acid A (GABA A ) receptor (GABAR) is a target for many clinically and experimentally important drugs. (aspetjournals.org)
  • Spontaneous and evoked IPSPs were reduced in amplitude but never abolished by TPMPA, but were completely blocked by bicuculline. (ox.ac.uk)
  • Aminooxyacetic acid hemihydrochloride is a malate-aspartate shuttle (MAS) inhibitor which also inhibits the GABA degradating enzyme GABA-T. (targetmol.com)
  • We report that the combination of α1β3ε subunit subtypes expressed in L929 cells produced functional chloride ion channels that were both spontaneously active and gated by the application of extracellular GABA. (aspetjournals.org)
  • We therefore tested the hypothesis that GABA(A) and GABA(C) subunits formed a heteromeric receptor. (ox.ac.uk)
  • GABA(A)-mediated postsynaptic currents were subject to paired-pulse depression that was inhibited by the GABA(B) antagonist CGP 55845A (5 microM). (nih.gov)
  • ACh challenge evokes greater magnitude responses in basal turn OHCs, whereas GABA induces greater motility response decrease in apical turn OHCs. (northwestern.edu)
  • This was strongly reduced by the broad-spectrum antagonist (+)alpha-methyl-4-carboxyphenylglycine (MCPG, 1 mM, similar to95% reduction), by the mGluR1 antagonist LY367385 (100 muM, similar to 80% reduction) but not by the mGluR5 antagonist 6-methyl-2-(phenylethynyl)pyridine (MPEP, 1 - 100 muM). (elsevierpure.com)
  • GABA A IPSCs could also follow stimulus pulses over this frequency range but showed depression at low rates and facilitation at higher rates. (jneurosci.org)
  • All recordings for IPSCs were made in the presence of AMPAR antagonists. (hellobio.com)
  • Many general anesthetics are thought to produce a loss of wakefulness, in part, by enhancing gamma-aminobutyric acid (GABA) neurotransmission. (silverchair.com)
  • Homocarnosine acetate is a dipeptide unique to brain consisting of γ-aminobutyric acid (GABA) and histidine. (targetmol.com)
  • Bilateral microinjections of 1 mM bicuculline in the rNTS significantly reduced the number of coughs (CN), amplitudes of DIA and ABD EMG, inspiratory and expiratory EP, and prolonged the duration of the cough expiratory phase (CTE) as well as the total cough cycle duration (CTtot). (bvsalud.org)
  • Bicuculline and saclofen were microinjected into the rostral (rNTS) and caudal nucleus of the solitary tract (cNTS) in 17 anesthetized cats. (bvsalud.org)
  • Comparative structures, mutant recordings, and molecular simulations with and without GABA further explained the sensitized but slower activation of ρ1 relative to canonical subtypes. (bvsalud.org)
  • Bilateral microinjection of bicuculline in the cNTS significantly reduced CN and amplitudes of ABD EMG and elongated CTE and CTtot. (bvsalud.org)
  • Relative to wakefulness, GABA levels were significantly decreased by isoflurane. (silverchair.com)
  • Non-GABA receptor-mediated actions reported, including actions on calcium-dependent potassium channels. (tocris.com)
  • and (2) pontine reticular formation administration of drugs that increase or decrease GABA levels increases or decreases, respectively, isoflurane induction time. (silverchair.com)
  • We found that bicuculline had relatively minor effects on metabolism and thermoregulation but sensitized ventilation such that the HVR became manifest at 7% instead of 5% O2 and was greater in magnitude. (bvsalud.org)
  • Shows GABA antagonist activity. (timtec.net)
  • These results suggest that both ACh and GABA can change the electromotile activity of OHCs, in a tonotopically biased manner. (northwestern.edu)
  • Increased power in the electroencephalogram and decreased activity in the electromyogram caused by isoflurane covaried with pontine reticular formation GABA levels. (silverchair.com)
  • For example, microinjecting the GABA A receptor agonist muscimol into the pontine reticular formation increases wakefulness. (silverchair.com)
  • 9,10 Conversely, microinjecting the GABA A receptor antagonist bicuculline into the pontine reticular formation increases REM sleep and decreases wakefulness. (silverchair.com)
  • These findings suggest an important role in anxiety regulation of the amygdalar GABA levels, and the assumed GABA hemispheric lateralization. (scirp.org)
  • Based on the analysis of literature data, as well as our previous findings, we hypothesize that the level of GABA and, probably, its difference between the right and the left amygdala, may determine the differences in the anxiety levels in animals. (scirp.org)
  • Biological ActivityClassical GABA A antagonist. (timtec.net)