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...

ABSTRACT Projected future carbon dioxide (CO2) levels in the ocean can alter marine animal behaviours. Disrupted functioning of ?-aminobutyric acid type A (GABAA) receptors (ligand-gated chloride channels) is suggested to underlie CO2-induced behavioural changes fish. However, mechanisms underlying invertebrates are poorly understood. We pharmacologically tested role GABA-, glutamate-, acetylch...

Effect of injection in third ventricle of GABA, the GABA agonist muscimol, and the GABA antagonist picrotoxin on the activities of acetylcholinesterase (AChE), butyrylcholinesterase (BuChE) and monoamine oxidase (MAO) in serum and succinic dehydrogenase (SDH) in plasma has been studied. Surprisingly, the AChE, BuChE, MAO and SDH enzymes activity were inhibited by GABA and muscimol, while they w...

BACKGROUND Some data indicate that the dopaminergic and GABAergic systems interact in the vertebrate retina, but the type of interactions is not well understood. METHODS In this study we investigated the effect of dopamine D1 receptor blockade by 75 μM SCH 23390 on the electroretinographic ON (b-wave) and OFF (d-wave) responses in intact frog eyecup preparations and in eyecups where the ionot...

The present work was performed to show the possible interaction of GAB A, and GABAB receptors in catalepsy. The following results were obtained: 1- Muscimol (MUS), a GABAA agonist, induced catalepsy. This effect was dose-dependent. Baclofen (BAC), a GABAB agonist, had no effect in this respect. 2- Catalepsy induced by muscimol was potentiated by pretreatment of animals with bicuculline (BI...

The mu-opioid agonist, DAGO, and the indirect GABAA antagonist, picrotoxin, produced a dose-dependent increase in horizontal motor activity following injection into the nucleus accumbens that was independent of dopamine release. Injection of muscimol into the ventral pallidum antagonizes the motor stimulant effect of dopamine agonists. It was shown that muscimol abolished the locomotor stimulan...

Picrotoxin is extensively and specifically used to inhibit GABAA receptors and other members of the Cys-loop receptor superfamily. We find that picrotoxin acts independently of known Cys-loop receptors to shorten the period of the circadian clock markedly by specifically advancing the accumulation of PERIOD2 protein. We show that this mechanism is surprisingly tetrodotoxin-insensitive, and the ...