The role of neuroinflammation in the onset of chronic pain associated with aging and its potential for therapeutic target

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K08971
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 55050:Anesthesiology-related
• Research Institution: Kochi University
• Principal Investigator: Kawano Takashi 高知大学, 教育研究部医療学系臨床医学部門, 教授 (40380076)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 慢性痛 / 神経障害性痛 / 高齢

Outline of Final Research Achievements

Using a neuropathic pain model (SNL) rat, we explored the impact of aging on pain mechanisms. Young rats displayed a higher frequency of stimulation-induced hyperalgesia-like behavior compared to older rats. As there was no age-related difference in the stimulus responsiveness of the affected nerve fibers, it is inferred that central mechanisms contribute to the age-related intensification of pain. Subsequently, we assessed BDNF expression and cytokine levels in the hippocampus of SNL rats. The results revealed that SNL surgery significantly reduced hippocampal BDNF expression and elevated inflammatory cytokine levels in aged rats compared to young rats. Additionally, a significant correlation was found between hippocampal BDNF expression, inflammatory cytokine levels, and the frequency of hyperalgesia-like behavior.

Free Research Field

麻酔科学、疼痛学

Academic Significance and Societal Importance of the Research Achievements

高齢者の慢性痛はQOLを大きく損なうだけでなく、認知障害や抑うつなどの神経認知異常の引き金ともなる。今回、我々は高齢者の慢性痛の代表である神経障害性痛の病態において、脳由来神経栄養因子（BDNF）の低下および脳内神経炎症が重要な役割を果たしていることを明らかにした。特に、BDNFは加齢とともに低下し、ミクログリア機能にも影響を与えることから、高齢者の慢性痛の症状に共通する機序として脳内神経炎症が関与していると推測される。本研究成果により、高齢者の慢性痛治療において、脳内神経炎症を標的とした有効でQOLを向上させる新規治療法の開発が期待される。