Ikemoto S, McBride W J, Murphy J M, Lumeng L, Li T K
Department of Psychiatry, Indiana University School of Medicine, Indianapolis 46202, USA.
Alcohol Clin Exp Res. 1997 Sep;21(6):1042-6.
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.
本研究的目的是确定减少伏隔核（ACB）的多巴胺（DA）神经支配是否会改变雌性嗜酒P大鼠乙醇摄入的维持和/或习得。与假损伤动物相比，向ACB双侧微量注射6-羟基多巴胺（6-OHDA，12微克/2.4微升/位点）并未改变有乙醇饮用经验的大鼠对10%乙醇的消耗量，假损伤组和6-OHDA损伤组均以相似的速率恢复到手术前的消耗水平。另一方面，相同的损伤程序破坏了损伤前无乙醇饮用经验的大鼠乙醇摄入的习得。假损伤组在1周内乙醇摄入量达到约7克/千克/天，并在随后的2周内维持该水平，而6-OHDA损伤组在1周后乙醇摄入量降低约60%，在3周结束时降低30%。与对照组相比，两组6-OHDA处理的大鼠ACB中的DA含量均降低了60%。结果表明，乙醇饮用行为的习得和维持可能有不同的神经机制；ACB DA系统似乎在乙醇饮用的习得中起重要作用。
