The antagonists of gamma-aminobutyric acid, bicuculline and picrotoxin, were found to narrow the receptive field profile of the large field horizontal cell (L1HC) in the turtle retina when added to the perfusion medium in micromolar concentrations. The coupling resistance between neighboring L1HCs was increased by bicuculline or picrotoxin. Under control conditions, the dye Lucifer yellow injec...

The aim of this study was to evaluate effects of strychnine, as well as bicuculline and picrotoxin on the anticonvulsant action of felbamate against maximal electroshock (MES)-induced seizures in mice. Strychnine (up to 0.5 mg/kg), bicuculline (up to 2 mg/kg) and picrotoxin (3 mg/kg) did not affect the seizure threshold. However, strychnine (0.25-0.5 mg/kg) and picrotoxin (3 mg/kg) impaired the...

In order to evaluate the site of action of picrotoxin (antagonist of ionotropic GABA receptors) on the electroretinographic (ERG) b- and d-waves, in this study we compared its effects on the intensity-response function of the ERG waves in intact light adapted frog eyecup preparations with its effects in eyecups, where the activity of proximal neurons was blocked by 1 mMN-methyl-d-aspartate (MND...

We studied the role of GABA in adaptive changes in a lateral inhibitory system in the tiger salamander retina. In dark-adapted retinal slice preparations picrotoxin caused a slow enhancement of glycine-mediated IPSCs in ganglion cells. The enhancement of glycinergic IPSCs developed slowly over the course of 5-20 min, even though picrotoxin blocked both GABA(A) and GABA(C) receptors within a few...

The effect of L-arginine (840 mg/kg) pre- (30 min before challenge) and post-treatment (5 min after challenge) period was tested on picrotoxin-induced increase in ammonia concentrations in brain regions (cerebral cortex, brain stem and cerebellum) and the accompanying convulsive responses in adult male rats. The combined effect of L-arginine and diazepam was also tested against picrotoxin-induc...

background: estradiol and progesterone as well as hippocampal gabaa receptors are believed to play a role in the modulation of pain. the aim of present study was to investigate the effect of intrahippocampal injections of gabaa receptor agonist (muscimol) and gabaa receptor antagonist (picrotoxin) on pain sensitivity during estrous cycle. methods: pain sensitivity was evaluated in rats by forma...

OBJECTIVE To study the effect of simvastatin on picrotoxin-induce seizures in mice in order to understand the impact of gabaergic system on neuronal cell death. METHODS The study was held between July and September 2011, at the Karadeniz Technical University in Trabzon, Turkey. Balb/c mice weighting 20-40g were randomly selected and divided into five groups of six each. The first group was de...

The role of gamma amino butyric acid A receptors/neurons of the hypothalamic, endocrine and alimentary systems in the food intake seen in hunger was studied in 20 h food-deprived rats. Food deprivation decreased blood glucose, serum insulin and produced hyperphagia. The hyperphagia was inhibited by subcutaneous or ventromedial hypothalamic administration of gamma amino butyric acid A antagonist...

Picrotoxin, an antagonist for γ-aminobutyric acid receptor subtype A (GABAA), was used to investigate the role of GABAA receptors in nociceptive and nonnociceptive reflex bladder activities and pudendal inhibition of these activities in cats under α-chloralose anesthesia. Acetic acid (AA; 0.25%) was used to irritate the bladder and induce nociceptive bladder overactivity, while saline was used ...