During early neuronal development, GABA functions as an excitatory neurotransmitter, triggering membrane depolarization, action potentials, and the opening of plasma membrane Ca(2+) channels. These excitatory actions of GABA lead to a number of changes in neuronal structure and function. Although the effects of GABA on membrane biophysics during early development have been well documented, litt...

Early sensory processing can play a critical role in sensing environmental cues. We have investigated the physiological and behavioral function of gain control at the first synapse of olfactory processing in Drosophila. Olfactory receptor neurons (ORNs) express the GABA(B) receptor (GABA(B)R), and its expression expands the dynamic range of ORN synaptic transmission that is preserved in project...

Neonatal forelimb removal in rats results in the development of inappropriate hindlimb inputs in the forelimb-stump representation of primary somatosensory cortex (S-I) that are revealed when GABA(A) and GABA(B) receptor activity are blocked. Experiments carried out to date have not made clear what information is being suppressed at the level of individual neurons. In this study, three potentia...

Ventral tegmental area (VTA) GABA neurons are critical substrates modulating the mesocorticolimbic dopamine system implicated in natural and drug reward. The aim of this study was to evaluate the effects of ethanol on glutamatergic and GABAergic modulation of VTA GABA neuron electrical synaptic transmission. We evaluated the effects of systemic ethanol (0.05-2.0 g/kg i.p.), the N-methyl-D-aspar...

The contribution of GABAergic mechanisms in thalamic relay nuclei to spike and wave discharges (SWDs) during spontaneous seizures was assessed using the WAG/Rij strain of rats, an established genetic model of absence epilepsy, in combination with single-unit recordings and microiontophoretic techniques in the ventrobasal thalamic complex in vivo. Spontaneous SWDs occurring on the electroencepha...

Zinc is abundantly present in the CNS, and after nerve stimulation is thought to be released in sufficient quantity to modulate the synaptic transmission. Although it is known that this divalent cation inhibits the GABAergic synaptic currents, the underlying mechanisms were not fully elucidated. Here we report that zinc reduced the amplitude, slowed the rise time, and accelerated the decay of m...

We have recently found that GABA(C) receptor subunit transcripts are expressed in the superficial layers of rat superior colliculus (SC). In the present study we used immunocytochemistry to demonstrate the presence of GABA(C) receptors in rat SC at protein level. We also investigated in acute rat brain slices the effect of GABA(A) and GABA(C) receptor agonists and antagonists on stimulus-evoked...

Increased GABAergic neurotransmission of the basal ganglia output nuclei projecting to the motor thalamus is thought to contribute to the pathophysiology of Parkinson's disease. We investigated the functional role of thalamic GABA(B) receptors in a rodent model of Parkinson's disease. First, we examined the effects of blockade of GABA(B) receptors in the ventromedial thalamic nucleus of rats wi...

Barbiturates enhance GABA receptor (sodium-independent) binding at 0°C to bovine brain membranes about 2-fold in chloride-containing buffer but not in chloride-free phosphate or Tris/ citrate buffer. This effect is observed in frozen and thawed, thoroughly washed membranes from various regions of bovine brain as well as washed membranes prepared from unfrozen rat cerebral cortex; it is destroye...

In the present study, the correlated activities of adjacent ganglion cells of transient subtype in response to full-field white light stimulation were investigated in the chicken retina. Pharmacological studies and cross-correlation analysis demonstrated that application of the GABA(A) receptor antagonist bicuculline (BIC) significantly down-regulated the correlation strength while increasing t...