Different behavioral functions of dopamine in the nucleus accumbens and ventrolateral striatum: A microdialysis and behavioral investigation
Different behavioral functions of dopamine in the nucleus accumbens and ventrolateral striatum: A microdialysis and behavioral investigation
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DOI：
10.1016/s0306-4522(98)00617-4
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发表时间：
1999-01-01
期刊：
影响因子：
3.3
通讯作者：
Salamone, JD
中科院分区：
文献类型：
--
作者：
Cousins, MS;Trevitt, J;Salamone, JD
本研究通过三个实验探讨了中脑腹外侧核和纹状体内多巴胺的行为功能。在第一个实验中，透析探针被植入大鼠的延髓核或腹外侧纹状体，这些大鼠先前被训练对固定间隔的杠杆按压时间表进行食物强化反应。在透析试验期间，观察到对多巴胺释放的时间表和部位依赖性影响。总的来说，杠杆按固定间隔30秒的时间表产生了更大的增加细胞外多巴胺比响应固定间隔120秒的时间表。固定间隔30秒的时间表也伴随着更高的杠杆按压率。大鼠与延髓核探针的位置表现出显着更高的增加多巴胺的释放比大鼠腹外侧纹状体的位置。一个额外的透析实验表明，多巴胺的基线水平被抑制1.0 μ M河豚毒素在类似的程度上，在丘脑核和腹外侧纹状体。在第三个实验中，6-羟基多巴胺被局部注射到脑桥核或腹外侧纹状体，以消耗多巴胺。中脑核多巴胺耗竭仅产生轻微的操作性反应降低，而腹外侧纹状体多巴胺耗竭的大鼠显示出与对照组和中脑核多巴胺耗竭组不同的低水平反应。因此，这些结果有点矛盾，多巴胺释放量增加最多的结构（即延髓核）也是多巴胺耗竭对操作性反应影响很小的终末区域。腹外侧纹状体多巴胺似乎在很大程度上允许杠杆按压，因为腹外侧纹状体中的正常多巴胺水平对于反应至关重要，尽管多巴胺水平在行为会话期间波动不大。(C)1999年IBRO。出版社：Elsevier Science Ltd
Three experiments were conducted to investigate the behavioral functions of dopamine in the nucleus accumbens and ventrolateral striatum. In the first experiment, dialysis probes were implanted in the nucleus accumbens or ventrolateral striatum of rats previously trained to respond on fixed interval lever pressing schedules for food reinforcement. During the dialysis test session, both schedule- and site-dependent effects on dopamine release were observed. Overall, lever pressing on a fixed interval 30-s schedule produced a greater increase in extracellular dopamine than did responding on a fixed interval 120-s schedule. The fixed interval 30-s schedule was also accompanied by a higher rate of lever pressing. Rats with nucleus accumbens probe placements showed significantly higher increases in dopamine release than rats with ventrolateral striatal placements. An additional dialysis experiment showed that baseline levels of dopamine were suppressed by 1.0 mu M tetrodotoxin to a similar extent in the nucleus accumbens and ventrolateral striatum. In the third experiment, 6-hydroxydopamine was injected locally into either the nucleus accumbens or the ventrolateral striatum in order to deplete dopamine. Nucleus accumbens dopamine depletions produced only a minor decrease in operant responding, whereas rats with ventrolateral striatal dopamine depletions showed low levels of responding that differed from both the control group and from the group that had accumbens dopamine depletions.Thus, these results are somewhat paradoxical, in that the structure that showed the greatest increase in dopamine release (i.e. the nucleus accumbens) was also the terminal region at which dopamine depletions had very little effect on operant responding. Ventrolateral striatal dopamine appears to be largely permissive over lever pressing, in that normal levels of dopamine in the ventrolateral striatum are critical for responding, although dopamine levels do not fluctuate much during behavioral sessions. (C) 1999 IBRO. Published by Elsevier Science Ltd.