Lewis M J, June H L
Department of Psychology, Howard University, Washington, D.C. 20059.
Alcohol. 1990 May-Jun;7(3):213-9. doi: 10.1016/0741-8329(90)90007-y.
Although generally considered to be a depressant drug, ethanol has both stimulant and depressant effects on behavior. This biphasic action of ethanol may be related to its reinforcing effects and to the neurobehavioral events that occur with changes in blood alcohol concentration (BAC). Ethanol was found to reduce the threshold and increase response rates for brain stimulation reward (BSR) at lateral hypothalamic, but not ventral noradrenergic bundle brain sites. These effects were also found to only occur when testing occurred on the ascending limb of the BAC. Studies of the effects of ethanol on open-field activity showed that the stimulant effects of low doses of ethanol were also seen only during the ascending limb of the BAC; depression was usually found during the descending limb. Neurochemical data from other investigators suggest that the facilitation of BSR and stimulation of activity may be mediated by mesolimbic dopamine systems.
尽管乙醇通常被认为是一种抑制性药物，但它对行为既有兴奋作用又有抑制作用。乙醇的这种双相作用可能与其强化作用以及随着血液酒精浓度（BAC）变化而发生的神经行为事件有关。研究发现，乙醇可降低下丘脑外侧脑区脑刺激奖赏（BSR）的阈值并提高反应率，但对腹侧去甲肾上腺素能束脑区无此作用。这些作用也仅在BAC上升阶段进行测试时才会出现。乙醇对旷场活动影响的研究表明，低剂量乙醇的兴奋作用同样仅在BAC上升阶段出现；而抑制作用通常出现在下降阶段。其他研究人员的神经化学数据表明，BSR的促进和活动的刺激可能由中脑边缘多巴胺系统介导。
