Neural connections between the oculomotor neural integrators and the vestibulocerebellum

2020 Fiscal Year Final Research Report

• Project/Area Number: 19K16295
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 46030:Function of nervous system-related
• Research Institution: Nara Medical University
• Principal Investigator: Sugimura Taketoshi 奈良県立医科大学, 医学部, 助教 (60812526)
• Project Period (FY): 2019-04-01 – 2021-03-31
• Keywords: 視線保持 / 舌下神経前位核 / 神経積分器 / コリン作動性ニューロン / 前庭小脳 / 小脳

Outline of Final Research Achievements

Cerebellar functions are modulated by cholinergic inputs, the density of which varies among cerebellar regions. Although the prepositus hypoglossi nucleus (PHN), a brainstem structure involved in controlling gaze holding, is known as one of the major sources of these cholinergic inputs, the proportions of cholinergic neurons in PHN projections to distinct cerebellar regions have not been quantitatively analyzed. In this study, we identified PHN neurons projecting to the cerebellum by applying retrograde labeling with dextran-conjugated Alexa 488 in choline acetyltransferase (ChAT)-tdTomato transgenic rats and compared the proportion of cholinergic neurons in the PHN projections to four different regions of the cerebellum. The results suggest that the proportion of cholinergic neurons among cerebellar projections from the PHN differs depending on cerebellar target areas and the rostro-caudal regions of the PHN.

Free Research Field

神経科学

Academic Significance and Societal Importance of the Research Achievements

視覚を適切に働かせるには視線を保持することで視覚対象を網膜上で静止させる必要がある。視線の保持には神経積分器と呼ばれる脳幹の領域と前庭小脳との神経ネットワークが重要であることが示唆されているが、その神経回路についての実験的知見は乏しく詳細は明らかにされていない。本研究は、水平性視線保持に関与する神経積分器であるPHNと小脳との神経回路について、特にコリン作動性ニューロンに着目した新たな知見を提供した。