Dopamine involvement in Acetaldehyde drinking behaviour: role of Ropinirole on.

Rats self-administer acetaldehyde(ACD), ethanol's first metabolite, directly into cerebral ventricles (1), and multiple ICV infusions of ACD produce conditioned place preference (2). ACD, such as alcohol and other substances of abuse, interacts with dopaminergic reward system (3) and its reinforcing and addictive properties have been assessed through an operant-conflict conditioning procedure (4). Since dopamine D2receptor over-expression in the Nacc attenuates alcohol intake (5), this study aims at exploring the effects of ropinirole administration during abstinence, on ACD relapse. The protocol has been scheduled into 3 different periods: training ( animals have been trained to self-administer ACD solution 3,2%v/v in order to obtain the induction and maintenance of an operant-drinking behavior), deprivation ( rats have undergone repeated 1-week ACD abstinence during and received ropinirole at 0,03 mg/kg/day i.p.); and relapse (rats increase their operant behavior following deprivation). Our results indicate that ropinirole is able to reduce reinstatement of ACD operant-drinking behavior, confirming that hypo-dopaminergic activity is responsible for drug seeking behavior and relapse following abstinence. Further investigation could help considering ropinirole as a therapeutical tool for preventing alcohol drinking relapse. 1.Brown et al.(1979) Psychopharmacology 64:271-276. 2. Smith et al. (1984) Alcohol 1:193-195. 3. Melis M et al (2007)Eur J Neurosci. 26:2824-2833. 4.Cacace S et al., AlcoholClinExpRes 2012; 36(7):1278-87 5. Thanos et al. J Neurochem.2001;78:1094-1103.