The neural mechanisms underlying excitatory and inhibitory eyeblink conditioning were compared using muscimol inactivation of the cerebellum. In experiment 1, rats were given saline or muscimol infusions into the anterior interpositus nucleus ipsilateral to the conditioned eye before each of four daily excitatory conditioning sessions. Postinfusion testing continued for four more excitatory con...

The substantia nigra pars reticulata (SNR) controls seizures in a sex-specific manner. At postnatal day 15 (P15), SNR infusion of GABA(A) receptor agonist muscimol have proconvulsant effects in males but not in females. In males, administration of an androgen receptor antagonist flutamide between P0-P2 led to the disappearance of the proconvulsant muscimol effects at P15. Thus, activation of an...

in the present study, the effect of gaba (γ-aminobutyric acid) receptor agonists and antagonists on morphine-induced antinociception was investigated in formalin test in rats. intraperitoneal (i.p.) injection of different doses of morphine (1, 3, 6 and 9 mg/kg) and intracerebroventricular (i.c.v.) injection of different doses of muscimol (0.5, 1 and 2 g/rat) or baclofen (0.25, 0.5 and 1 g/rat) ...

We explored how stimulation of GABA(A) receptors at different times during conditioned taste aversion (CTA) acquisition or extinction influenced extinction. In Experiment 1, rats acquired a CTA to 0.3% saccharin-flavored water (SAC) when it followed an injection of lithium chloride (LiCl; 81.0 mg/kg, i.p.). Following conditioning, rats received extinction training in which the GABA(A) agonist m...

The inhibitory neurotransmitter !-aminobutyric acid (GABA) has multiple receptors. In mammals, the GABAA receptor subtype is modulated by neurosteroids. However, whether steroid interaction with the GABAA receptor is unique to mammals or a conserved feature in vertebrates is unknown. Thus, neurosteroid modulation of the GABAA receptor was investigated in the brain of the bullfrog (Rana catesbei...

Assemblies of electrodes and a cannula were stereotaxically implanted in the ventromedial (VMH), lateral (LHA) and paraventricular (PVH) hypothalamic areas in male albino rats. Electrical activity of these regions was recorded electrographically before and following intracranial injection (ICI) of GABA, muscimol and picrotoxin. In another set of animals, food intake and water intake were also m...

Diverse γ-aminobutyric acid (GABAA) receptor modulators exhibited novel cytoprotective effects and mechanisms of action in rabbit renal proximal tubules subjected to mitochondrial inhibition (antimycin A) or hypoxia. Cytoprotective potencies (50% effective concentration, EC50) were 0.3 nM allopregnanolone (AP) > 0.4 nM 17α-OH-allopregnanolone (17α-OH-AP) > 30 nM dehydroepiandrosterone sulfate (...

The interaction of a gamma-aminobutyric acid-A (GABAA) receptor agonist and a benzodiazepine-type modulator of GABAA receptors on sleep was investigated. Low doses of muscimol (0.3 mg/kg) and the benzodiazepine midazolam (1.5 mg/kg) were administered alone and in combination, in random order, to eight rats. All injections were given intraperitoneally at light onset. Electroencephalogram (EEG) a...

Binding sites for [3H]muscimol, an analogue of gamma-aminobutyric acid (GABA) were localized in the synaptic layers of chicken retina by light microscopic and electron microscopic autoradiography. Light microscopic autoradiography of cryostat sections incubated in [3H]muscimol or [3H]GABA revealed identical binding patterns: a band over the inner plexiform layer (IPL) and a band over the outer ...