Konstandi M, Kafetzopoulos E
Department of Pharmacology, Medical School, University of Ioannina, Greece.
Pharmacol Biochem Behav. 1993 Apr;44(4):751-4. doi: 10.1016/0091-3057(93)90001-a.
In this study, we tested the effects of nucleus accumbens or corpus striatum lesions on the abolition of latent inhibition induced by d-amphetamine. In the latent inhibition paradigm, animals learn to ignore a repeatedly presented nonreinforced stimulus. In this paradigm, the repeated nonreinforced preexposure to a stimulus retards subsequent conditioning to that stimulus. Pharmacological manipulations that enhance the dopaminergic function (e.g., d-amphetamine) abolish this ability to ignore an irrelevant stimulus. Previous studies have revealed a major role of the nucleus accumbens in the d-amphetamine-induced abolition of latent inhibition because intraacumbens injections of the drug mimic its systemic effects. The results of this study, however, revealed a significant increase in the disruption of latent inhibition by d-amphetamine between corpus striatum-lesioned and sham-operated rats, but a marginal difference between nucleus accumbens lesioned and sham-operated rats, which had been preexposed to the stimulus. These findings indicate that the corpus striatum plays also a major role in the disruption of latent inhibition by d-amphetamine. It seems, therefore, that the nucleus accumbens and corpus striatum may represent a functionally common system regarding the expression of latent inhibition, although different experimental manipulation can favor the one structure over the other, reflecting probably their complex function.
在本研究中，我们测试了伏隔核或纹状体损伤对消除由右旋苯丙胺诱导的潜伏抑制的影响。在潜伏抑制范式中，动物学会忽略重复呈现的无强化刺激。在此范式中，对刺激的重复无强化预暴露会延迟随后对该刺激的条件作用。增强多巴胺能功能的药理学操作（如右旋苯丙胺）会消除这种忽略无关刺激的能力。先前的研究表明，伏隔核在右旋苯丙胺诱导的潜伏抑制消除中起主要作用，因为向伏隔核内注射该药物可模拟其全身效应。然而，本研究结果显示，在预先暴露于刺激的纹状体损伤大鼠和假手术大鼠之间，右旋苯丙胺对潜伏抑制的破坏作用显著增加，但伏隔核损伤大鼠和假手术大鼠之间的差异很小。这些发现表明，纹状体在右旋苯丙胺对潜伏抑制的破坏中也起主要作用。因此，似乎伏隔核和纹状体在潜伏抑制的表达方面可能代表一个功能上共同的系统，尽管不同的实验操作可能更有利于其中一个结构而非另一个，这可能反映了它们复杂的功能。
