Seven-transmembrane domain (7TM) receptors have important functions in cell-cell communication and can assemble into dimers or oligomers. Such complexes may allow specific functional cross-talk through trans-activation of interacting 7TMs, but this hypothesis requires further validation. Herein, we used the GABAB receptor, which is composed of two distinct subunits, GABAB1, which binds the agon...

γ-aminobutyric acid (GABA) is the main inhibitory neurotransmitter in the central nervous system, and disturbances in the GABAergic system have been implicated in numerous neurological and neuropsychiatric diseases. The GABAB receptor is a heterodimeric class C G protein-coupled receptor (GPCR) consisting of GABAB1a/b and GABAB2 subunits. Two GABAB receptor ligand binding sites have been descri...

Pre- and postsynaptic adenosine 5'-triphosphate-sensitive potassium (ATP-K+) currents were studied using whole-cell recordings from substantia nigra zona compacta "principal" neurons in midbrain slices. The GABAA and GABAB receptor-mediated synaptic potentials were unaffected by the ATP-K+ channel inhibitor glibenclamide (30 microM) or by the opener diazoxide (500 microM), indicating that ATP-K...

Repeated administration of morphine sensitizes animals to the stimulant and rewarding properties of the drug. It may also alter the expression and function of GABA receptors within the ventral tegmental area (VTA), a midbrain region that is implicated in morphine action. In the present study, the effect of activation of GABAB receptor subtypes within the VTA on morphine-induced incentive sensit...

Repeated administration of morphine sensitizes animals to the stimulant and rewarding properties of the drug. It may also alter the expression and function of GABA receptors within the ventral tegmental area (VTA), a midbrain region that is implicated in morphine action. In the present study, the effect of activation of GABAB receptor subtypes within the VTA on morphine-induced incentive sensit...

GABA (γ-aminobutyric acid), the predominant inhibitory neurotransmitter in the mature mammalian brain, is excitatory for neurons during early development upon GABAA receptor activation. In astrocytes, GABA induces intracellular Ca2+ transients by activation of both, GABAA and GABAB receptors. GABAB receptor-mediated [Ca]i increases are involved in neuron-glia interaction by potentiating inhibit...

The apical tuft of layer 5 pyramidal neurons is innervated by a large number of inhibitory inputs with unknown functions. Here, we studied the functional consequences and underlying molecular mechanisms of apical inhibition on dendritic spike activity. Extracellular stimulation of layer 1, during blockade of glutamatergic transmission, inhibited the dendritic Ca2+ spike for up to 400 ms. Activa...

Autoantibodies to the γ-aminobutyric acid receptor, subtype B (GABAB), are a known cause of limbic encephalitis. The spectrum of clinical manifestations attributable to this antibody is not well defined at the present time. Here we present a case of GABAB encephalitis presenting with encephalopathy, status epilepticus, dysautonomia, and acute heart failure. To our knowledge, heart failure and d...