The medial nucleus of the medial geniculate body in auditory processing

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K06908
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 46010:Neuroscience-general-related
• Research Institution: Kumamoto University
• Principal Investigator: Song Wen-Jie 熊本大学, 大学院生命科学研究部(医), 教授 (90216573)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 聴覚

Outline of Final Research Achievements

The medial geniculate body, or the auditory thalamus, is considered to have three subdivisions: the ventral nucleus, the dorsal nucleus, and the medial nucleus. Identification of these sub-nuclei, however, has been based largely on Nissl staining and eye judgement. The borders between the sub-regions are not always clear, and this has hindered the identification and the understanding of the function of the sub-nuclei. Finding a molecular marker for each subdivision will be an important step towards understanding the structure and function of the sub-nuclei. In this study, we identified several molecular markers for the medial subdivision (MGm). The discovery made it possible to label all MGm neurons in a specific manner, and the results showed that MGm projects to all auditory regions in the cortex, targeting primarily cortical layer 5. These results suggest that MGm controls directly the output of all auditory areas in the cortex.

Free Research Field

神経科学

Academic Significance and Societal Importance of the Research Achievements

内側膝状体は聴覚に重要な役割を果たしていると考えられているが、その機能の解明は、亜核の同定から始めなければならない。本研究の成果によって、三つの亜核の一つである内側核を分子的に同定できることが示されたため、内側膝状体研究のマイルドストン的な発見と言える。分子マーカーの同定により、内側核が全ての聴覚皮質領野に投射し、それらの出力を直接制御する回路も明らかとなった。これらの研究成果は内側核機能の完全解明に基礎と手段を提供するものである。聴覚はヒトのコミュニケーションや社会生活に不可欠な感覚機能で、本研究の成果は聴覚の理解、しいては聴覚障害の治療に繋がるため、その社会的意義も明らかである。