Ontogenesis of GABAergic signaling may play an important role in developmental changes in seizure susceptibility in the high-potassium model of ictogenesis in vitro. The age-dependent effects of [K(+)](o) on the reversal potential of the GABA(A)-mediated responses and membrane potential in hippocampal slices in vitro were compared with the effect of GABA(A)-receptors antagonists and GABA(A) mod...

Activation of the metabotropic g-aminobutyric acidB (GABAB) receptor increases K conductance and decreases Ca channel activity in neuronal membranes. Studies with a number of new GABAB receptor agonists and antagonists reveal that in addition to their muscle relaxant effects, agonists display analgesic activity and reduce the craving for cocaine. With regard to GABAB receptor antagonists, precl...

Fear can be considered as a functional defense behavior to protect living beings against dangerous situation. In our studies we have investigated the fear behavior in rats in elevated plus maze .The increase in two parameters percent of open arm entries (%OAE) and percent of time spent in the open arms (% OAT) and decrease in the percent of time spent in closed arm (%CAT) was considered as fear...

Fear can be considered as a functional defense behavior to protect living beings against dangerous situation. In our studies we have investigated the fear behavior in rats in elevated plus maze .The increase in two parameters percent of open arm entries (%OAE) and percent of time spent in the open arms (% OAT) and decrease in the percent of time spent in closed arm (%CAT) was considered as fear...

We investigated the localization of GABA(A) and GABA(C) receptors in horizontal cells (HCs) and HC axon terminals (ATs) dissociated from goldfish retina, using whole-cell patch-clamping recordings. Applications of GABA on HCs induced two groups with inward currents at the holding potential of -50 mV: One was a sustained inward current in the H1 cell, with one type of HCAT (AT1), and the other w...

The pharmacology of nicotinic receptor-mediated seizures was investigated in C3H mice. Eleven nicotinic agonists and six antagonists were administered centrally (i.c.v.). Epibatidine and epiboxidine were the most potent agonists tested, whereas acetylcholine and the alpha7*-selective compounds 3-(2,4-dimethoxybenzylidene)-anabaseine (GTS-21) and anabasine, were the least potent. Nicotine-induce...

To investigate the physiological effects of melatonin receptors in the Xenopus tectum, we have used the fluorescent indicator Fluo-4 AM to monitor calcium dynamics of cells in tectal slices. Bath application of KCl elicited fluorescence increases that were reduced by melatonin. This effect was stronger at the end of the light period than at the end of the dark period. Melatonin increased gamma-...

We have previously provided functional evidence that glycine and GABA are contained in the same synaptic vesicles and coreleased at the same synapses in lamina I of the rat spinal dorsal horn. However, whereas both glycine receptors (GlyRs) and GABA(A) receptors (GABA(A)Rs) are expressed on the postsynaptic target, under certain conditions inhibitory events appeared to be mediated by GlyRs only...

the effects of cholecystokinin (cck) receptor antagonists on hypothermia induced by cocaine or morphine have been studied in mice. in the present work, subcutaneous (sc) injection of cocaine (50-150 mg/kg) or morphine (125-500 mg/kg) induced hypothermia in mice. administration of ccka receptor antagonist mk-329 (0.5-1.5 mg/kg), cckb receptor antagonist l-365, 260 (0.5-1.5 mgl kg) and cck recept...

Previous studies have demonstrated that tonic responses of trigeminal ganglion neurons to maintained whisker deflections are transformed to mainly phasic responses in thalamocortical neurons. The high tonic responsiveness of thalamic reticular neurons suggests that thalamic inhibition may contribute to this suppression of tonic activity. To test this hypothesis we recorded responses of thalamoc...