Ikemoto Satoshi, Qin Mei, Liu Zhong-Hua
Behavioral Neuroscience Branch, National Institute on Drug Abuse, National Institutes of Health, Department of Health and Human Services, Baltimore, Maryland 21224, USA.
J Neurosci. 2005 May 18;25(20):5061-5. doi: 10.1523/JNEUROSCI.0892-05.2005.
When projection analyses placed the nucleus accumbens and olfactory tubercle in the striatal system, functional links between these sites began to emerge. The accumbens has been implicated in the rewarding effects of psychomotor stimulants, whereas recent work suggests that the medial accumbens shell and medial olfactory tubercle mediate the rewarding effects of cocaine. Interestingly, anatomical evidence suggests that medial portions of the shell and tubercle receive afferents from common zones in a number of regions. Here, we report results suggesting that the current division of the ventral striatum into the accumbens core and shell and the olfactory tubercle does not reflect the functional organization for amphetamine reward. Rats quickly learned to self-administer D-amphetamine into the medial shell or medial tubercle, whereas they failed to learn to do so into the accumbens core, ventral shell, or lateral tubercle. Our results suggest that primary reinforcement of amphetamine is mediated via the medial portion of the ventral striatum. Thus, the medial shell and medial tubercle are more functionally related than the medial and ventral shell or the medial and lateral tubercle. The current core-shell-tubercle scheme should be reconsidered in light of recent anatomical data and these functional findings.
当投射分析将伏隔核和嗅结节归入纹状体系统时，这些部位之间的功能联系开始显现出来。伏隔核与精神运动性兴奋剂的奖赏效应有关，而最近的研究表明，伏隔核内侧壳和内侧嗅结节介导可卡因的奖赏效应。有趣的是，解剖学证据表明，壳和结节的内侧部分接收来自多个区域共同区域的传入神经。在此，我们报告的结果表明，目前将腹侧纹状体分为伏隔核核心、壳以及嗅结节的划分方式并不能反映苯丙胺奖赏的功能组织。大鼠很快学会了将D-苯丙胺自我注射到内侧壳或内侧结节，但未能学会将其注射到伏隔核核心、腹侧壳或外侧结节。我们的结果表明，苯丙胺的主要强化作用是通过腹侧纹状体的内侧部分介导的。因此，内侧壳和内侧结节在功能上的相关性比内侧与腹侧壳或内侧与外侧结节之间的相关性更强。鉴于最近的解剖学数据和这些功能发现，目前的核心-壳-结节方案应重新考虑。
