Elucidation of the mechanism of hyperalgesia in a rat model of Parkinson's disease -Involvement of the hypothalamic paraventricular nucleus

2023 Fiscal Year Final Research Report

• Project/Area Number: 20K10177
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 57060:Surgical dentistry-related
• Research Institution: Osaka University
• Principal Investigator: NIWA Hitoshi 大阪大学, 大学院歯学研究科, 教授 (30218250)
• Co-Investigator(Kenkyū-buntansha): 前川 博治 大阪大学, 歯学部附属病院, 講師 (10711012)
• Project Period (FY): 2020-04-01 – 2024-03-31
• Keywords: パーキンソン病 / 痛覚過敏 / 視床下部室傍核 / オキシトシン / バゾプレシン / 副腎皮質刺激ホルモン放出ホルモン

Outline of Final Research Achievements

The mechanism of hyperalgesia as a non-motor symptom of Parkinson's disease (PD) is discussed. We hypothesized that hypothalamic paraventricular nucleus (PVN) dysfunction due to dopamine depletion in the substantia nigra striata associated with PD affects pain control mechanisms mediated by oxytocin (OXT), vasopressin (AVP), and adrenocorticotropin releasing hormone (CRH). Immunohistological analysis and blood biochemical tests in response to nociceptive stimuli were performed using a PD rat model created by injecting 6-OHDA into the medial forebrain bundle. The results showed that the hyperalgesic response in PD model rats is associated with decreased activity of OXT- and CHR-producing cells in the PVN.

Free Research Field

神経科学

Academic Significance and Societal Importance of the Research Achievements

パーキンソン病（PD)の主症状は運動障害であるが、非運動症状である痛覚過敏は患者のQOLを著しく低下させる。本研究は、PDにおける痛覚過敏のメカニズムの解明に焦点を当て、その原因として視床下部室傍核（PVN)が関与し、PVNに存在するオキシトシン(OXT)、および副腎皮質刺激ホルモン放出ホルモン（CRH)産生細胞の機能低下が原因となる可能性を、免疫組織学的手法と酵素免疫測定法を用い明らかにした。この結果は、PD患者の示す痛覚過敏の治療法につながる有用な研究となると考えられる。