Fig. 3.

Ethanol (EtOH) fails to antagonize dopamine inhibition reversal (DIR) once it has been induced. Pooled results from recordings of pDAergic ventral tegmental area (VTA) neurons tested with dopamine (DA) over 80 minutes. Time indicated on the abscissa reflects time relative to the initiation of DA administration. For each neuron, a concentration of DA that produced >50% inhibition was applied for 80 minutes. After DIR was induced within the first 40 minutes, either 80 mM EtOH (▼; [DA] = 6.3 ± 0.8 μM, n = 12) or water (▪, [DA] = 5.3 ± 1.3 μM, n = 7) was added to the superfusate, and the recording was continued for 40 more minutes. No significant difference (1-way repeated measures ANOVA, F(16, 287) = 008, p > 0.005, for comparisons between EtOH and water conditions) in the effect of DA was observed from 40 to 80 minutes, indicating that once it is achieved, DIR is not antagonized by EtOH.