6-OHDA-lesions of the nucleus accumbens disrupt the acquisition but not the maintenance of ethanol consumption in the alcohol-preferring P line of rats.
The aim of the present study was to determine whether reduction of dopamine (DA) innervation to the nucleus accumbens (ACB) alters the maintenance and/or acquisition of ethanol drinking in female alcohol-preferring P rats. Compared with sham-lesioned animals, bilateral microinjections of 6-OHDA (12 micrograms/2.4 microliters/site) into the ACB did not alter the consumption of 10% ethanol in rats that had prior experience of ethanol drinking, with both sham- and 6-OHDA-lesioned groups recovering to presurgical consumption levels at similar rates. On the other hand, the identical lesion procedure disrupted the acquisition of ethanol intake in rats with no ethanol-drinking experience prior to the lesions. A sham-lesioned group attained an ethanol intake of approximately 7 g/kg/day in 1 week, which was maintained over the following 2-week period, while the ethanol intake of the 6-OHDA-lesioned group was approximately 60% lower after 1 week and 30% lower at the end of 3 weeks. DA content of the ACB was 60% lower in both groups of the 6-OHDA-treated rats compared with the controls. The results suggest that different neural mechanisms may underlie the acquisition and maintenance of ethanol drinking behavior; the ACB DA system appears to play an important role in the acquisition of ethanol drinking.
Ikemoto
S
S
Department of Psychiatry, Indiana University School of Medicine, Indianapolis 46202, USA.
McBride
W J
WJ
Murphy
J M
JM
Lumeng
L
L
Li
T K
TK
D018663:Adrenergic Agents; D000428:Alcohol Drinking / Q000235:genetics / Q000503:physiopathology*; D000818:Animals; D001931:Brain Mapping; D004298:Dopamine / Q000502:physiology*; D005260:Female; D005838:Genotype; D009042:Motivation; D009714:Nucleus Accumbens / Q000187:drug effects / Q000503:physiopathology*; D016627:Oxidopamine; D051381:Rats; D011919:Rats, Inbred Strains
D018663:Adrenergic Agents; D016627:Oxidopamine; D004298:Dopamine