Hikida Takatoshi, MacPherson Tom, Morita Makiko
Nihon Shinkei Seishin Yakurigaku Zasshi. 2017 Apr;37(2):35-8.
The nucleus accumbens (NAc), the ventral part of the striatum, plays a critical role in motivation, learning, and cognition in the basal ganglia circuit. Outputs of the NAc are transmitted through two parallel direct and indirect pathways. We have developed a reversible neurotransmission blocking (RNB) technique, in which neurotransmission of each pathway in the NAc is selectively blocked by specific expression of a transmission-blocking tetanus toxin (D-RNB or I-RNB). In visual cue and reversal tasks in the cross-maze, the NAc direct pathway was critical for learning acquisition. In contrast, the NAc indirect pathway was essential not only for learning flexibility, but also for subsequent acquisition of a new strategy. In place discrimination and serial reversal learning tasks in the IntelliCage, we showed that the NAc indirect pathway controls behavioral flexibility by suppressing the influence of previously correct behavioral strategies during the reversal stage. These basal ganglia circuit mechanisms provide new insight into pathophysiologies associated with compulsive behaviors, including addiction and obesity.
伏隔核（NAc）是纹状体的腹侧部分，在基底神经节回路的动机、学习和认知中起着关键作用。NAc的输出通过两条平行的直接和间接通路进行传递。我们开发了一种可逆性神经传递阻断（RNB）技术，其中通过特异性表达一种传递阻断破伤风毒素（D-RNB或I-RNB）来选择性阻断NAc中每条通路的神经传递。在十字迷宫的视觉线索和反转任务中，NAc直接通路对学习获得至关重要。相比之下，NAc间接通路不仅对学习灵活性至关重要，而且对随后新策略的获得也必不可少。在智能笼中的位置辨别和连续反转学习任务中，我们表明NAc间接通路通过在反转阶段抑制先前正确行为策略的影响来控制行为灵活性。这些基底神经节回路机制为与强迫行为相关的病理生理学提供了新的见解，包括成瘾和肥胖。
