Effects of social defeat stress loading on a rat lumbar disc herniation model

2023 Fiscal Year Final Research Report

• Project/Area Number: 19K09557
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 56020:Orthopedics-related
• Research Institution: Fukushima Medical University
• Principal Investigator: Konno Shinichi 福島県立医科大学, 医学部, 教授 (70254018)
• Co-Investigator(Kenkyū-buntansha): 関口 美穂 福島県立医科大学, 医学部, 教授 (00381400)
• Project Period (FY): 2019-04-01 – 2024-03-31
• Keywords: 下行性疼痛抑制系 / 神経障害性疼痛 / ストレス負荷

Outline of Final Research Achievements

This study was examined changes in pain-related behaviors and substances with and without stress loading using a rat nucleus pulposus applied model for lumbar disc herniation. Social defeat stress prolonged the period of lowered mechanical pain threshold in the nucleus pulposus applied model. It was suggested that a decrease in astrocyte in the periaqueduct gray matter (PAG) in the descending pain inhibitory system may affect in pain threshold prolonged by restraint stress load is due to the decrease in dopamine levels in the nucleus accumbens. It was unable to assess differences in anxious behavior in the present study. Further investigation is needed to take into account the effects of the timing of behavior under stress, the duration of stress load, and the duration of pain.

Free Research Field

脊椎脊髄病

Academic Significance and Societal Importance of the Research Achievements

臨床に即した腰椎椎間板ヘルニアの病態モデルを用いて、ストレス負荷の有無により疼痛閾値の低下の持続により疼痛の慢性化を評価した。社会的・身体的ストレスが下行性疼痛抑制系の脳機能の低下に関連することを提示した。臨床での個々の症例の慢性化の機序は複雑であり、また、正常の疼痛刺激に対する反応経路が異なることを推測し、多面的な評価と早期治療の必要性を啓発する足がかりとなることが期待できる。