Identification of the Neural Basis of Human Taste by Interregional Brain Activity Estimation and Ultra-High-Field MRI

2023 Fiscal Year Final Research Report

• Project/Area Number: 21H02806
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 51020:Cognitive and brain science-related
• Research Institution: Araya Inc. (Research & Development Department) (2022-2023); National Institute for Physiological Sciences (2021)
• Principal Investigator: Chikazoe Junichi 株式会社アラヤ(研究開発部), 研究開発部, チームリーダー (40456108)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 機能的MRI / 味覚 / 超高磁場MRI

Outline of Final Research Achievements

Brain activity of approximately 40 subjects was measured using ultra-high-field MRI during the presentation of five basic taste stimuli (sweet, bitter, sour, salty, and umami). The brain representations of these five basic tastes in the insular cortex were analyzed using univariate analysis, and no discriminative clusters were observed for each taste. We applied the method for eliminating secondary brain activity developed in the visual stimulation experiments to the taste data, analytically removing components that could be explained by brain activity in brain regions (occipital, temporal, parietal, frontal, etc.) except for the taste areas (insula and orbitofrontal cortex), to see if a taste map could be found, but no spatially completely separate taste map was found.

Free Research Field

神経科学

Academic Significance and Societal Importance of the Research Achievements

本研究は、五つの基本味覚に対する脳活動を超高磁場MRIで詳細に計測し、島皮質における味覚表象の解明を試みた点で学術的意義が高い。従来の単変量解析では味覚弁別クラスタが観察されなかったが、視覚刺激実験で開発した副次的脳活動除去法を適用することで、味覚野以外の脳領域の影響を排除した新たな解析アプローチを提示した。ネズミにおける報告と異なり、ヒトにおいては完全に分離した味覚マップは発見されなかったものの、この手法は味覚処理メカニズムの理解を深める可能性を示した。この結果は、ネズミとヒトで基本味覚の表象が異なるフォーマットで行われている可能性を示唆している。