Search results for "muscimol"
showing 10 items of 51 documents
Taurine potentiates the anticonvulsive effect of the GABAAagonist muscimol and pentobarbital in the immature mouse hippocampus
2019
Objective The high incidence of epileptic seizures in neonates and their frequent refractoriness to pharmacologic therapies require identification of new therapeutical options. Therefore, we investigated whether the modulatory effect of taurine on γ-aminobutyric acid (GABA)A receptors can enhance the anticonvulsive potential of the GABAA receptor agonist muscimol and of the barbiturate pentobarbital. Methods We performed field potential recordings in in toto hippocampus preparations of immature (postnatal days 4-7) C57Bl/6 mouse pups. Spontaneous epileptiform activity was induced by the continuous presence of the potassium channel blocker 4-aminopyridine and the glycinergic antagonist stryc…
GABAA receptors in the ventral tegmental area control the outcome of a social competition in rats
2018
Social dominance can be attained through social competitions. Recent work in both humans and rodents has identified trait anxiety as a crucial predictor of social competitiveness. In addition, the anxiolytic GABAA positive modulator, diazepam, injected either systemically or into the ventral tegmental area (VTA) was shown to increase social dominance. Here, we investigated the impact of pharmacologically targeting GABAA receptors in the VTA for the outcome of a social competition between two unfamiliar male rats, one of them infused with vehicle and the other one with the drug under study. We show that infusion of the GABAA receptor agonist, muscimol, reduced anxiety-like behaviors and enha…
Prevention of an increase in cortical ligand binding to AMPA receptors may represent a novel mechanism of endogenous brain protection by G-CSF after …
2016
PURPOSE Using G-CSF deficient mice we recently demonstrated neuroprotective properties of endogenous G-CSF after ischemic stroke. The present follow-up study was designed to check, whether specific alterations in ligand binding densities of excitatory glutamate or inhibitory GABAA receptors may participate in this effect. METHODS Three groups of female mice were subjected to 45 minutes of MCAO: wildtype, G-CSF deficient and G-CSF deficient mice substituted with G-CSF. Infarct volumes were determined after 24 hours and quantitative in vitro receptor autoradiography was performed using [3H]MK-801, [3H]AMPA and [3H]muscimol for labeling of NMDA, AMPA and GABAA receptors, respectively. Ligand b…
Very low doses of muscimol and baclofen ameliorate cognitive deficits and regulate protein expression in the brain of a rat model of streptozocin-ind…
2018
Recent studies devoted to neuroprotection have focused on the role of the gamma-aminobutyric acid (GABA) system in regulating neuroinflammatory processes which play a key role in the neurodegenerative processes observed in Alzheimer's disease (AD) by inducing glial cell overactivation and impairing neurotransmission. Data on the efficacy of classical GABA-A and GABA-B receptor agonists (muscimol and baclofen, respectively) in animal models of AD are not available. Moreover, no published studies have examined the ability of optimal doses of these compounds to prevent neuroinflammation, the alterations in neurotransmission and cognitive deficits. In the present study, we used a non-transgenic…
Coincident Activation of Glutamate Receptors Enhances GABAA Receptor-Induced Ionic Plasticity of the Intracellular Cl−-Concentration in Dissociated N…
2019
Massive activation of γ-amino butyric acid A (GABAA) receptors during pathophysiological activity induces an increase in the intracellular Cl−-concentration ([Cl−]i), which is sufficient to render GABAergic responses excitatory. However, to what extent physiological levels of GABAergic activity can influence [Cl−]i is not known. Aim of the present study is to reveal whether moderate activation of GABAA receptors mediates functionally relevant [Cl−]i changes and whether these changes can be augmented by coincident glutamatergic activity. To address these questions, we used whole-cell patch-clamp recordings from cultured cortical neurons [at days in vitro (DIV) 6–22] to determine changes in t…
Coupling between agonist and chloride ionophore sites of the GABA(A) receptor: agonist/antagonist efficacy of 4-PIOL.
2000
Eight gamma-aminobutyric acid (GABA) mimetics were tested on their ability to differentiate native GABA(A) receptor subtypes present in various rat brain regions. In rat brain cryostat sections, little regional variations by the agonistic actions of muscimol, thiomuscimol, 4,5,6,7-tetrahydroisoazolo(5,4-c)pyridin-3-ol, piperidine-4-sulphonic acid, taurine and beta-alanine on [35S]t-butylbicyclophosphorothionate ([35S]TBPS) binding to GABA(A) receptor channels were found. They were very similar to those found for GABA itself and indicated no direct correlation with single subunit distributions for any of these compounds. Only the low-efficacy GABA mimetic 5-(4-piperidyl)isoxazol-3-ol (4-PIOL…
GABA, receptor mediated fast synaptic inhibition in the rabbit brain-stem respiratory system
1991
The involvement of GABA mediated neurotransmission in the central control of respiration was investigated by administration of the specific GABAA receptor agonist muscimol and the specific GABAA receptor antagonist biculline into the fourth cerebral ventricle of the rabbit. Cycle-triggered averaging of the phrenic nerve activity (PNA) was used to quantify drug-induced changes of the central respiratory pattern. Muscimol reduced the peak amplitude of PNA and increased the duration of the respiratory phases. High amounts of muscimol led to a long-lasting but reversible central apnea. Bicuculline very effectively blocked the effects of externally applied muscimol. Blockade of intrinsically act…
GABAA agonist muscimol ameliorates learning/memory deficits in streptozocin-induced Alzheimer’s disease non-transgenic rat model
2015
Background: GABAergic inhibitory action regulates learning/memory processes and contributes to neurotransmission (Gong et al., 2009). Existing evidence suggests GABAergic system is involved in pathophysiology of Alzheimer’s disease (AD) via inhibitory interneuron deficits (Verret et al., 2012) and decrease in functional GABAA receptors (Limon et al., 2012). In vitro, GABA and muscimol (GABAA receptor agonist) blocked neuronal death induced by Aβ in rat hippocampal and cortical neurons (Paula-Lima et al., 2005). Our concept: low doses of muscimol may prevent learning/memory deficits in intracerebroventricular (icv) streptozocin (STZ)-induced AD non-transgenic rat model. Methods. Wistar male …
Determination of muscimol and ibotenic acid in mushrooms of Amanitaceae by capillary electrophoresis
2014
In this study, the CZE method for rapid quantitative and qualitative determination of ibotenic acid and muscimol in Amanita mushrooms naturally grown in Poland was developed. The investigations included the species of A. muscaria, A. pantherina, and A. citrina, collected in southern region of Poland. The studied hallucinogenic compounds were effectively extracted with a mixture of methanol and 1 mM sodium phosphate buffer at pH 3 (1:1 v/v) using ultrasound-assisted procedure. The obtained extracts were separated and determined by CZE utilizing a 25 mM sodium phosphate running buffer adjusted to pH 3 with 5% content of acetonitrile v/v. The calibration curves for both analytes were linear in…
Muscimol hydration and vibrational spectroscopy – The impact of explicit and implicit water
2022
The presented study focuses on the interaction of the well-known neurotoxin muscimol with water. Two approaches for the water solvent are applied – the explicit and the implicit. The muscimol-water clusters were obtained by the molecular dynamics simulations and the first solvation shell was kept for further studies. Implicit water was mimicked via the polarized continuum model (PCM). All three tautomeric forms of the free muscimol molecule are considered in the calculations. The combined theoretical and experimental vibrational IR and Raman studies determined the stability of the prevailing zwitterion form in water. We proved that water molecules in the first solvation shell are crucial fo…