Ethanol is reinforcing within the nucleus accumbens shell (NACsh), but the underlying mechanisms remain unclear. Ethanol can potentiate the function of the GABAA, GABAB, and serotonin-3 (5-HT3) receptors. Therefore, the current study tested the hypothesis that activation of these receptors would be involved in the reinforcing effects of ethanol in the NACsh. An intracranial self-administration ...

In the present study we analyzed effects of bilateral microinjections of muscimol (a GABAA agonist) and baclofen (a GABAB agonist) into the nucleus tractus solitarius (NTS) on bradycardic and pressor responses to chemoreflex activation (potassium cyanide, 40 μg/rat iv) in awake rats. Bilateral microinjections of muscimol (25 and 50 pmol/50 nl) into the NTS increased baseline mean arterial press...

Neuronal G-protein-gated potassium (GIRK) channels mediate the inhibitory effects of many neurotransmitters. Although the overlapping distribution of GIRK subunits suggests that channel composition varies in the CNS, little direct evidence supports the existence of structural or functional diversity in the neuronal GIRK channel repertoire. Here we show that the GIRK channels linked to GABAB rec...

GABAB receptors assemble from GABAB1 and GABAB2 subunits. GABAB2 additionally associates with auxiliary KCTD subunits (named after their K(+) channel tetramerization-domain). GABAB receptors couple to heterotrimeric G-proteins and activate inwardly-rectifying K(+) channels through the βγ subunits released from the G-protein. Receptor-activated K(+) currents desensitize in the sustained presence...

The serotonergic tone of the dorsal raphe (DR) is regulated by 5-HT1A receptors, which negatively control serotonergic activity via the activation of G protein-coupled inwardly rectifying K+ (GIRK) channels. In addition, DR activity is modulated by local GABAergic transmission, which is believed to play a key role in the development of mood-related disorders. Here, we sought to characterize the...

It is generally accepted that the bicuculline-resistant responses to GABA are mediated through the activation of GABAB receptors that mediate a slow IPSP. However, a number of reported observations are difficult to reconcile with this model. Specifically, GABAB antagonists only partially block bicuculline-resistant GABA responses, and both 4-aminopyridine (4-AP) and carbachol have been reported...

Intracellular recordings were obtained from the basolateral amygdala in in vitro rat brain slice preparations to examine whether gamma-aminobutyric acid (GABA)B receptors are altered after in vivo kindling-induced epileptogenesis. Stimulating the stria terminalis evoked excitatory (EPSPs) and inhibitory (IPSPs) postsynaptic potentials in control neurons, and epileptiform bursting or enhanced EP...