Laboratorios de Conducta Animal y Neuroquímica, Facultad de Psicología, Universidad Nacional de Educación a Distancia, C/ Juan del Rosal 10, Ciudad Universitaria, 28040 Madrid, Spain.
Behav Brain Res. 2011 Feb 2;217(1):195-201. doi: 10.1016/j.bbr.2010.10.010. Epub 2010 Oct 23.
Autoradiography analysis of D1 and D2 dopamine receptors and c-Fos activity were performed in brain of rats classified as low drinkers (LD) and high drinkers (HD) according to schedule-induced polydipsia (SIP) performance. Previous studies have shown that groups selected according to their rate of drinking in SIP differ in behavioral response to dopaminergic drugs. This study reports differences between LD and HD rats in dopamine D1 and D2 receptor binding through different mesocorticolimbic brain areas. LD and HD rats showed opposite patterns of binding in dopamine D1 and D2 receptors in the nucleus accumbens, medial prefrontal cortex, amygdala, ventral tegmental area and substantia nigra. Whereas LD rats showed higher binding than HD rats for D1 receptors, HD rats showed higher binding than LD rats for D2 receptors (except in substantia nigra that were roughly similar). These neuroanatomical differences in dopamine receptor binding were also associated with an elevated c-Fos count in the medial prefrontal cortex of HD rats. In tandem with previous evidence, our results suggest a different dopaminergic function between LD and HD, and points to SIP as a behavioral model for distinguishing populations possibly vulnerable to dopaminergic function disorders.
根据习惯性多饮（SIP）表现，将大鼠分为低饮（LD）和高饮（HD）组，对其大脑中的 D1 和 D2 多巴胺受体和 c-Fos 活性进行放射自显影分析。先前的研究表明，根据 SIP 中饮酒率选择的组在对多巴胺能药物的行为反应方面存在差异。本研究通过不同的中脑边缘皮质脑区报告了 LD 和 HD 大鼠之间多巴胺 D1 和 D2 受体结合的差异。在伏隔核、内侧前额叶皮质、杏仁核、腹侧被盖区和黑质中，LD 和 HD 大鼠的多巴胺 D1 和 D2 受体结合呈现出相反的模式。与 HD 大鼠相比，LD 大鼠的 D1 受体结合更高，而与 LD 大鼠相比，HD 大鼠的 D2 受体结合更高（黑质除外，大致相似）。多巴胺受体结合的这些神经解剖差异也与 HD 大鼠内侧前额叶皮质中 c-Fos 计数的升高有关。与先前的证据一致，我们的结果表明 LD 和 HD 之间存在不同的多巴胺能功能，并指出 SIP 是一种区分可能易患多巴胺能功能障碍的人群的行为模型。
