In this paper, Arora and colleagues expand on their previous work on GIRK channels in the ventral tegmental area (VTA) presenting evidence that a single exposure to cocaine reduces inhibitory GABAergic transmission to dopamine (DA) neurons in the ventral tegmental area. Mice receiving i.p. injections of cocaine saw a short lived (1-5 days) decrease in GABAb mediated G-protein coupled inwardly-rectifying potassium (GIRK) currents in DA neurons in the VTA. This decrease parallels an NMDA-mediated increase in the frequency of glutamatergic neurotransmission. Chronic cocaine injections had no additional effects beyond those seen with single injections. Though they found no change in mRNA levels for GABAb receptors, GIRK channels, or RGS-2 (a G-protein... |