2026-03-30 京都大学
＜関連情報＞
- https://www.kyoto-u.ac.jp/ja/research-news/2026-03-30
- https://www.kyoto-u.ac.jp/sites/default/files/2026-03/web_2603_Matsumoto-ff9e811ee5e3d696d8af05ad0537d153.pdf
- https://www.nature.com/articles/s41467-026-70634-6
霊長類の意思決定において、腹側線条体は選択肢の価値情報をどの選択肢を選ぶのかを決定する選択指令に変換する役割を持つ Role of the primate ventral striatum as a neural hub bridging option valuation and action selection
Masafumi Nejime,Mengxi Yun,Yawei Wang,Takashi Kawai,Jun Kunimatsu,Hiroshi Yamada,Ken-ichi Inoue,Masahiko Takada & Masayuki Matsumoto
Nature Communications Published:28 March 2026
DOI:https://doi.org/10.1038/s41467-026-70634-6
Abstract
Making appropriate decisions relies on the brain’s capacity to evaluate the expected outcomes of available options and select the most rewarding action. The ventral striatum and midbrain dopamine neurons have been implicated in the option valuation process, consistent with the brain’s reinforcement learning theory in which these brain structures encode and update value representations of expected outcomes. Extending beyond this framework, we found that the dopamine–ventral striatum system plays a more proactive role in action selection. We recorded single-unit activity from ventral striatum neurons in macaque monkeys as they sequentially evaluated an option, decided whether to perform an action to choose it, and expressed that motor action. The activity of these neurons initially reflected the value of the option but gradually shifted to reflect monkey’s action selection, as if the ventral striatum translates the value information into the action. Moreover, optogenetic facilitation of dopamine input to the ventral striatum as well as electrical stimulation of this region altered monkey’s action selection. Our findings reveal a previously unappreciated function of the ventral striatum as a neural hub that bridges option valuation and action selection, and demonstrate the contribution of dopamine in the process leading to action selection within this region.
