一项新近发表于《神经元》（Neuron Available online 8 August 2013）的研究称，
来自日本京都大学等机构的科学家利用猕猴开展了该项实验。研究人员首先让猕猴注视目标图形，然后让猕猴从一组图形中选出目标图形，如果选对就给猕猴喝苹果汁作为奖励。观察发现，接下来如果给猕猴展示目标图形，由于会联想到苹果汁奖励，它脑内分泌多巴胺的神经细胞活动会增强，而在提示无关图形时，则没有明显变化。
此外，他们还发现，这类与记忆力有明显关联的神经元活动增强只在大脑的特定部位出现，而其他部位分泌多巴胺的神经细胞则仅在需要促进“行动欲望”时才会出现活动增强。
研究人员由此认为，提高行动欲望及提高记忆力的多巴胺神经细胞分布在脑内的不同区域。人类大脑结构与猕猴类似，应该也有类似现象。
研究人员表示，这一研究成果部分解释了为何
研究摘要：
Dopamine is essential to cognitive functions. However, despite abundant studies demonstrating that dopamine neuron activity is related to reinforcement and motivation, little is known about what signals dopamine neurons convey to promote cognitive processing. We therefore examined dopamine neuron activity in monkeys performing a delayed matching-to-sample task that required working memory and visual search. We found that dopamine neurons responded to task events associated with cognitive operations. A subset of dopamine neurons were activated by visual stimuli if the monkey had to store the stimuli in working memory. These neurons were located dorsolaterally in the substantia nigra pars compacta, whereas ventromedial dopamine neurons, some in the ventral tegmental area, represented reward prediction signals. Furthermore, dopamine neurons monitored visual search performance, becoming active when the monkey made an internal judgment that the search was successfully completed. Our findings suggest an anatomical gradient of dopamine signals along the dorsolateral-ventromedial axis of the ventral midbrain.
(本网站所有内容，凡注明来源为“医脉通”，版权均归医脉通所有，未经授权，任何媒体、网站或个人不得转载，否则将追究法律责任，授权转载时须注明“来源：医脉通”。本网注明来源为其他媒体的内容为转载，转载仅作观点分享，版权归原作者所有，如有侵犯版权，请及时联系我们。)
