GABA transmission in the deep layers of the superior colliculus/deep mesencephalic reticular formation (deep SC/Me) mediates several motor responses, including those expressed after systemic administration of dopamine agonists. In the present study we examined the role of the deep SC/Me in the modulation of the acoustic startle reflex and its enhancement by the dopamine D(1) agonist SKF 82958. ...

Presynaptic GABA(B) receptors (GABA(B)R) control glutamate and GABA release at many synapses in the nervous system. In the present study we used whole-cell patch-clamp recordings of spontaneous excitatory and inhibitory synaptic currents in the presence of TTX to monitor glutamate and GABA release from synapses in layer II and V of the rat entorhinal cortex (EC)in vitro. In both layers the rele...

The G-protein-coupled receptor (GPCR) activated by the neurotransmitter GABA is made up of two subunits, GABA(B1) and GABA(B2). GABA(B1) binds agonists, whereas GABA(B2) is required for trafficking GABA(B1) to the cell surface, increasing agonist affinity to GABA(B1), and activating associated G proteins. These subunits each comprise two domains, a Venus flytrap domain (VFT) and a heptahelical ...

OBJECTIVES: The aim of the present investigation was to determine whether the catecholaminergic system is involved in gabaergic and serotoninergic effects on gonadotrophin secretion during sexual development. To this end, we studied the effect of GABAergic and serotoninergic systems on hypothalamic catecholamine content at different stages of sexual development. METHODS: The effect of GABA A an...

Editor’s key points † Inhaled anaesthetics act by potentiating inhibitory type A GABA (GABAA) receptors to produce some of their desired, and perhaps undesired, effects. † Using cultured hippocampal neurones, inverse agonists selective for a5 subunit containing GABAA receptors reduced receptor potentiation by volatile anaesthetics. † Potentiation of a5 subunit-containing GABAA receptors might c...

gamma-Aminobutyric acid (GABA)-gated Cl- influx was studied in rat brain "microsacs." Midazolam caused a shift to the left of the GABA log dose-response curve. Pentobarbital produced a similar shift plus an increase in maximum response. Diazepam, flurazepam and desalkylflurazepam also enhanced GABA-gated Cl- flux. Their effects were blocked by Ro15-1788, a benzodiazepine antagonist. Acute diaze...

Isovaline is a non-proteinogenic amino acid that has analgesic properties. R-isovaline is a proposed agonist of the γ-aminobutyric acid type B (GABA(B)) receptor in the thalamus and peripheral tissue. Interestingly, the responses to R-isovaline differ from those of the canonical GABA(B) receptor agonist R-baclofen, warranting further investigation. Using whole cell recording techniques we explo...

Background and Purpose Antagonists of excitatory neurotransmitters are effective in limiting ischemic damage to the brain and spinal cord, but use in clinical stroke may be limited by side effects. Agonists of inhibitory neurotransmitters, such as •y-aminobutyric acid (GABA), may provide similar neuroprotection with less severe side effects. This study examines the effect of an agonist and anta...