Neural mechanisms for reward-risk integration

2019 Fiscal Year Final Research Report

• Project/Area Number: 19K21209
• Project/Area Number (Other): 18H06086 (2018)
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Multi-year Fund (2019); Single-year Grants (2018)
• Review Section: 0704:Neuroscience, brain sciences, and related fields
• Research Institution: Kyoto University
• Principal Investigator: Sasaki Ryo 京都大学, 医学研究科, 助教 (70817931)
• Project Period (FY): 2018-08-24 – 2020-03-31
• Keywords: 意思決定

Outline of Final Research Achievements

We investigated the causal role of a variety of brain areas in the behavioral choices by reversible inactivation with microinjection of a GABAA receptor agonist, muscimol. We were careful to identify the target area and successfully localized it using MRI image injecting the gadolinium in advance. When muscimol was injected into bilateral ventrolateral prefrontal cortex (vlPFC) while the monkey was performing the task, the sensitivity to risky choice was gradually weakened over time, although the sensitivity to expected value was remained to be consistent. Interestingly, the interaction between risk and expected value was also weakened. Our results suggest that the integration of risk/return and expected value might be accomplished in vlPFC. We will also discuss about the role of the other brain areas such as Orbitofrontal cortex (OFC), Nucleus accumbens (NAc) and Anterior cingulate cortex (ACC).　We also started the recording experiment from vlPFC.

Free Research Field

神経生理学

Academic Significance and Societal Importance of the Research Achievements

同一の課題を用いてマカクザルの腹側前頭前野（vlPFC）に、眼窩前頭皮質（OFC）、腹側被蓋野（VTA）など複数の脳領野の機能を検討し、さらにこれら複数領野から神経活動を同時記録し、複数領野多数ニューロン活動から直接的にサルの意思決定を推定することで複数の脳領野間のネットワークとしての役割を明らかになってきた点が意義深い。また、計算論的手法の切り口を組み合わせることで、新たな手法が確立すれば、巨大脳における全脳ネットワークの可視化を一気に加速でき創造性が高い。その結果、精神疾患の患者やギャンブル依存の患者の治療法に関する理解がより一層進み、革新的な医療応用につながることが期待される。