GABA-A receptors play a pivotal role in many brain diseases. Epilepsy is caused by acquired conditions and genetic defects in GABA receptor channels regulating neuronal excitability in the brain. The latter is referred to as GABA channelopathies. In the last two decades, major advances have been made in the genetics of epilepsy. The presence of specific GABAergic genetic abnormalities leading t...

GABA concentration jump experiments performed on membrane patches predict that postsynaptic GABA(A) receptors will become desensitized following the release of the contents of a single GABA-containing synaptic vesicle. To examine this we used a single synaptic bouton stimulation technique to directly examine whether postsynaptic GABA(A) receptors in cultured cerebellar granule cells exhibit tra...

GABA(A) receptors are the principal sites of fast synaptic inhibition in the brain. These receptors are hetero-pentamers that can be assembled from a number of subunit classes: alpha(1-6), beta(1-3), gamma(1-3), delta(1), epsilon, theta;, and pi, but the majority of receptor subtypes is believed, however, to be composed of alpha, beta, and gamma2 subunits. A major mechanism for modulating GABA(...

BACKGROUND AND PURPOSE Heterologous expression of alpha1, beta2 and gamma2S(gamma1) subunits produces a mixed population of GABA(A) receptors containing alpha1beta2 or alpha1beta2gamma2S(gamma1) subunits. GABA sensitivity (lower in receptors containing gamma1 or gamma2S subunits) and the potentiation of GABA-activated chloride currents (I(GABA)) by benzodiazepines (BZDs) are dependent on gamma2...

We investigated the mechanisms underlying the modulation of transmitter release from bipolar cells. Three currents, measured under whole-cell patch clamp in the tiger salamander retinal slice, were used to identify the sites of modulation and to establish their pharmacological profile. (1) A light-elicited inhibitory current was measured in bipolar cells that could be blocked by picrotoxin. Thi...

Together, acid-sensing ion channels (ASICs) and epithelial sodium channels (ENaC) constitute the majority of voltage-independent sodium channels in mammals. ENaC is regulated by a chloride channel, the cystic fibrosis transmembrane conductance regulator (CFTR). Here we show that ASICs were reversibly inhibited by activation of GABA(A) receptors in murine hippocampal neurons. This inhibition of ...

Background: The ventral tegmental area (VTA) is well known for its role in cardiovascular control. It is demonstrated that about 20-30% of the VTA neurons are GABAergic though their role in cardiovascular control is not yet understood. This study is carried out to find the effects of GABA A and GABA B receptors on cardiovascular response of the VTA. Methods: Experiments were performed on uretha...

Application of 4-(aminomethyl)cyclohexanecarboxylic acid (tranexamic acid; TAMCA) to the central nervous system (CNS) has been shown to result in hyperexcitability and convulsions. However, the mechanisms underlying this action are unknown. In the present study, we demonstrate that TAMCA binds to the gamma-aminobutyric acid (GABA) binding site of GABA(A) receptors in membranes from rat cerebral...

introduction: (s)- 3,5-dihydroxyphenylglycine (dhpg) is an agonist for group i metabotropic glutamate receptors. dhpg-induced synaptic depression of excitatory synapses on hippocampal pyramidal neurons is well known model for synaptic plasticity studies. the aim of the present study was to examine the effects of dhpg superfusion on excitatory synapses on pyramidal and fast-spiking gabaergic cel...

Pattern adaptation is very important for visual function, while the mechanisms that mediate pattern adaptation, especially in the dorsal lateral geniculate nucleus (LGNd), are still unclear. Iontophoresis of the antagonists and agonists of GABA receptors were employed to separately investigate the contribution of GABA(A) and GABA(B) receptors to pattern adaptation of LGNd cells. When GABA(A) re...