Nader K, Bechara A, Roberts D C, van der Kooy D
Department of Anatomy and Cell Biology, University of Toronto, Ontario, Canada.
Behav Neurosci. 1994 Dec;108(6):1128-38. doi: 10.1037//0735-7044.108.6.1128.
The researchers studied whether 2 separate motivational systems in the brain underlie the rewarding effects of morphine. The brainstem tegmental pedunculopontine nucleus (TPP) is involved in mediating the motivational effects of opiates in nondeprived (drug-naive) rats, whereas dopamine transmission is necessary in mediating the motivational effects of opiates in deprived rats (opiate withdrawal). The results show that heroin's motivational properties obey the same boundary between a nondeprived and a deprived motivational state. Bilateral ibotenic acid lesions of the TPP blocked the acquisition of a place preference for an environment paired with 0.05 mg/kg heroin (a dose that induces no withdrawal aversion) but had no effect on place preference for an environment paired with 0.5 mg/kg heroin (a dose that does induce withdrawal aversion). Dopamine antagonist pretreatment produced the opposite pattern of results.
研究人员探究了大脑中两个独立的动机系统是否构成吗啡奖赏效应的基础。脑干被盖脚桥核（TPP）参与介导阿片类药物在未被剥夺（未接触过药物）大鼠中的动机效应，而多巴胺传递在介导阿片类药物在被剥夺大鼠（阿片类药物戒断）中的动机效应时是必需的。结果表明，海洛因的动机特性在未被剥夺和被剥夺的动机状态之间遵循相同的界限。TPP的双侧鹅膏蕈氨酸损伤阻断了对与0.05毫克/千克海洛因配对环境的位置偏好的获得（该剂量不会引起戒断厌恶），但对与0.5毫克/千克海洛因配对环境的位置偏好没有影响（该剂量会引起戒断厌恶）。多巴胺拮抗剂预处理产生了相反的结果模式。
