Genetic tracing to reveal the whole brain mapping of taste information processing

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K09828
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 57010:Oral biological science-related
• Research Institution: Hiroshima University
• Principal Investigator: SUGITA Makoto 広島大学, 医系科学研究科(歯), 教授 (50235884)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 味覚 / ニューロン / 発生工学的トレーシング

Outline of Final Research Achievements

Genetic tracing was combined with immunohistochemistry to functionally characterize bitter taste-relaying neurons in the PBN and the amygdala, which were labeled by the transneuronal tracer tWGA-DsRed originating from T2R-expressing taste receptor cells. In the PBN, the tWGA-DsRed-labeled neurons were located rostrally in the external lateral PBN, and caudally in the medial PBN. The tWGA-DsRed-labeled neurons in the medial and the external lateral PBN exhibited the distinct immunoreactivity to CGRP and substance P, suggesting differences in the neuron types between the neurons in the medial and external lateral PBN. The tWGA-DsRed-labeled neurons were also located in the medial amygdala. Subsets of tWGA-DsRed-labeled, bitter taste-relaying neurons in the medial amygdala enhanced their excitatory responses to the conditioned stimulus saccharin after conditioned taste aversion learning.

Free Research Field

口腔生理学

Academic Significance and Societal Importance of the Research Achievements

発生工学的トレーシングを用い、特定の味細胞に選択的に経ニューロン性トレーサーを発現させることにより、特定の味細胞を起始点とする味覚経路ニューロンを上行性経路に沿って標識・可視化することが可能となる。それにより特定の味覚経路ニューロンを可視化限定して、細胞機能を解析することができ、特定の味覚経路ニューロンに選択的に作用する薬剤を選出することが可能となる。そして特定の味覚経路ニューロンが保有する細胞機能・分子機能を標的として、味覚異常、味覚誘発行動の異常、情動障害、拒食・過食への新しい治療法が創出される。