Ito Rutsuko, Robbins Trevor W, Everitt Barry J
Department of Experimental Psychology, University of Cambridge, Downing Street, Cambridge CB1 1BB, UK.
Nat Neurosci. 2004 Apr;7(4):389-97. doi: 10.1038/nn1217. Epub 2004 Mar 21.
Nucleus accumbens (NAc) dopamine is widely implicated in mediating the reinforcing effects of drugs of abuse. However, the precise function of the NAc itself in drug self-administration has been difficult to establish. Here we show a neural double-dissociation of the behavioral processes that underlie cocaine self-administration in rats. Whereas selective excitotoxic lesions of the NAc core had only a minor effect on the acquisition of responding for cocaine under a standard schedule of continuous reinforcement, these lesions profoundly impaired the acquisition of drug-seeking behavior that was maintained by drug-associated conditioned reinforcers and assessed using a second-order schedule of cocaine reinforcement. In contrast, selective excitotoxic lesions of the NAc shell did not impair drug self-administration or the acquisition of cocaine-seeking, but they did attenuate the psychostimulant effects of cocaine. These results further our understanding of how the NAc controls drug-seeking and drug-taking behavior.
伏隔核（NAc）多巴胺在介导滥用药物的强化作用方面具有广泛影响。然而，NAc本身在药物自我给药中的精确功能一直难以确定。在此，我们展示了大鼠可卡因自我给药行为过程的神经双分离现象。虽然在连续强化的标准方案下，NAc核心的选择性兴奋性毒性损伤对可卡因应答的习得仅有轻微影响，但这些损伤严重损害了由药物相关条件强化物维持并使用可卡因强化二阶方案评估的觅药行为的习得。相比之下，NAc壳的选择性兴奋性毒性损伤并未损害药物自我给药或可卡因觅求行为的习得，但确实减弱了可卡因的精神兴奋作用。这些结果进一步加深了我们对NAc如何控制觅药和服药行为的理解。
