Kalivas P W, Taylor S
Brain Res. 1985 Dec 9;358(1-2):70-6. doi: 10.1016/0006-8993(85)90949-7.
Many lines of evidence indicate an excitatory role by neurotensin (NT) on mesolimbic dopamine neurons in the ventral tegmental area (VTA). In support of this postulate, NT microinjection into the VTA of rats produces a dopamine-dependent increase in spontaneous motor activity that is associated with an increase in dopamine metabolism in the nucleus accumbens. In this study it was found that after daily intra-VTA injection with NT, both the motor hyperactivity and increase in dopamine metabolism were significantly enhanced. Further, the increased motor response to NT was present after 7 days without daily administration. While the augmented motor response could be produced with the carboxy-terminal fragment NT8-13, the NH2-terminal fragment, NT1-8, was ineffective. The enhancement of motor activity was only produced by NT injection into the A10 dopamine region and not adjacent nuclei. These results suggest that daily administration with NT into the VTA will potentiate the responsiveness of mesolimbic dopamine neurons to subsequent injection with NT.
多项证据表明，神经降压素（NT）对腹侧被盖区（VTA）的中脑边缘多巴胺神经元具有兴奋作用。为支持这一假设，向大鼠VTA微量注射NT会使自发运动活动出现多巴胺依赖性增加，这与伏隔核中多巴胺代谢增加有关。在本研究中发现，每日向VTA内注射NT后，运动亢进和多巴胺代谢增加均显著增强。此外，在7天未每日给药后，对NT的运动反应增强仍然存在。虽然羧基末端片段NT8 - 13可产生增强的运动反应，但氨基末端片段NT1 - 8无效。运动活动的增强仅通过向A10多巴胺区域而非相邻核团注射NT产生。这些结果表明，每日向VTA注射NT将增强中脑边缘多巴胺神经元对后续注射NT的反应性。
