Zhou F C, Zhang J K, Lumeng L, Li T K
Department of Anatomy, Indiana University School of Medicine, Indianapolis 46202, USA.
Alcohol. 1995 Sep-Oct;12(5):403-12. doi: 10.1016/0741-8329(95)00010-o.
The mesolimbic dopamine system of the brain, in particular the nucleus accumbens (Acb), is long known to be involved in reward behavior. When compared with the alcohol-nonpreferring NP rats, the alcohol-preferring P rats exhibit lower dopamine (DA) levels in the Acb as well as in other forebrain areas (20). In the present study, the DA innervation density, as determined by tyrosine hydroxylase (TH) immunostaining, was found lower in the selective cingulum cortex and the shell of the Acb of the P compared with that of NP rats. These structures cluster in the medial aspect of the mesolimbic system. There were no differences in other major DA mesolimbic brain regions. The subpopulation of DA neurons in the ventral tegmental area (VTA) projecting to the Acb was found to be smaller in the P than in the NP rats, as shown by horseradish peroxidase tracing and TH immunocytochemistry double staining. However, the total number of the DA neurons in the VTA, the major mesolimbic DA center, was found to be similar in the P and NP rats. These results indicate a selective reduction of catecholaminergic innervation in the dopaminergic medial mesolimbic system in the P rats and suggest that the P and NP rat lines should be a useful model for the investigation of DA involvement in alcohol drinking as well as other reinforced behaviors.
长期以来，人们都知道大脑的中脑边缘多巴胺系统，尤其是伏隔核（Acb），与奖赏行为有关。与不偏好酒精的NP大鼠相比，偏好酒精的P大鼠在伏隔核以及其他前脑区域的多巴胺（DA）水平较低（20）。在本研究中，通过酪氨酸羟化酶（TH）免疫染色确定，与NP大鼠相比，P大鼠的选择性扣带回皮质和伏隔核壳中的DA神经支配密度较低。这些结构聚集在中脑边缘系统的内侧。其他主要的中脑边缘多巴胺脑区没有差异。如辣根过氧化物酶追踪和TH免疫细胞化学双重染色所示，投射到伏隔核的腹侧被盖区（VTA）中的DA神经元亚群在P大鼠中比在NP大鼠中更小。然而，主要的中脑边缘多巴胺中心VTA中的DA神经元总数在P大鼠和NP大鼠中相似。这些结果表明P大鼠的多巴胺能中脑边缘内侧系统中的儿茶酚胺能神经支配选择性减少，并表明P大鼠和NP大鼠品系应是研究多巴胺参与饮酒以及其他强化行为的有用模型。
