2025-03-14 京都大学
<関連情報>
- https://www.kyoto-u.ac.jp/ja/research-news/2025-03-14-1
- https://www.kyoto-u.ac.jp/sites/default/files/2025-03/web_2503_Amita-4a5e3f57f7057e877d2495d468d27e70.pdf
- https://www.pnas.org/doi/10.1073/pnas.2426861122
霊長類線条体へのドーパミンシグナル伝達の蛍光検出と刺激と報酬の関連性 Fluorescence detection of dopamine signaling to the primate striatum in relation to stimulus–reward associations
Gaoge Yan, Hidetoshi Amita, Satoshi Nonomura, +2 , and Masahiko Takada
Proceedings of the National Academy of Sciences Published:March 13, 2025
DOI:https://doi.org/10.1073/pnas.2426861122
Significance
Reward-anticipatory behavior following a reward-predicting stimulus is achieved through Pavlovian conditioning. Dopamine (DA) released within the striatum, the main input station of the basal ganglia, plays a key role in this behavior. However, it remains unclear what type of DA signal is conveyed to the striatum in relation to stimulus-reward associations. To detect DA transients in the anterior striatal sectors responsible for the stimulus-reward associations, we applied fiber photometry with a fluorescent DA sensor to monkeys being engaged in a Pavlovian conditioning task. Our study demonstrates that this technique is useful to capture the DA transients in brain structures of the task-performing monkeys, and that the DA transients vary depending on the striatal territories.
Abstract
Dopamine (DA) signals to the striatum play critical roles in shaping and sustaining stimulus-reward associations. In primates, however, the dynamics of the DA signals remain unknown since conventional methods are not necessarily appropriate in terms of the spatiotemporal resolution or chemical specificity sufficient for detecting the DA signals. In our study, fiber photometry with a fluorescent DA sensor was employed to identify reward-related DA transients in the monkey striatum. This technique, which directly monitors local DA release, reveals a reward prediction error signal in the anterior putamen originating from midbrain DA neurons. Further, DA transients in the head of the caudate nucleus exhibit a value-based response to reward-predicting stimuli. These signals have been found to arise from two separate groups of DA neurons in the substantia nigra pars compacta. The present results demonstrate that fluorescence DA monitoring is applicable to detect DA signals in the primate striatum for investigating their roles.
