The posterior VTA is important in mediating the reinforcing effects of ethanol and the acquisition of ethanol taking. Rats self-administered ethanol directly into the posterior VTA (Rodd-Henricks, McKinzie et al. 2000) and selectively bred alcohol-preferring P-rats self-administered lower concentrations than Wistar rats, indicating a heightened sensitivity (Gatto, McBride et al. 1994, Rodd, Melendez et al. 2004). Operant responding can be established for ethanol self-administration in the shell, but not the core NAc region (Engleman, Ding et al. 2009). Thus, similarly to other drugs of abuse (Rodd-Henricks, McKinzie et al. 2002), the mesopontine dopamine system and the NAc shell region are critical in mediating the reinforcing effect of ethanol and likely to contribute to the initial stages of acquisition of ethanol drinking behavior.
