Changes in cerebral nociceptive responses with chronic trigeminal neuralgia

Research Project

Project/Area Number	16K19215
Research Category	Grant-in-Aid for Young Scientists (B)
Allocation Type	Multi-year Fund
Research Field	Pain science
Research Institution	Ibaraki Prefectural University of Health Science
Principal Investigator	Kaku Yuki 茨城県立医療大学, 保健医療学部, 准教授 (50551363)
Project Period (FY)	2016-04-01 – 2020-03-31
Project Status	Completed (Fiscal Year 2019)
Budget Amount *help	¥4,290,000 (Direct Cost: ¥3,300,000、Indirect Cost: ¥990,000) Fiscal Year 2018: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000) Fiscal Year 2017: ¥520,000 (Direct Cost: ¥400,000、Indirect Cost: ¥120,000) Fiscal Year 2016: ¥3,120,000 (Direct Cost: ¥2,400,000、Indirect Cost: ¥720,000)
Keywords	慢性疼痛 / 体性感覚野 / フラビン蛋白蛍光イメージング / 三叉神経痛 / フラビン蛋白蛍光
Outline of Final Research Achievements	Few studies have investigated how the cortical somatosensory cortex is involved in the mechanism of chronic pain in the trigeminal nerve area. The purpose of this study was to examine the response of the somatosensory cortex in chronic pain model over time and to describe the relationship between chronic pain and changes in the cerebral response. To record the cerebral response in the same individual over time, we used the flavoprotein fluorescence imaging. However, the reproducibility of the recording was insufficient depending on the type and depth of anesthesia, and it was difficult to fully analyze the sensory response in the narrow area of the trigeminal nerve area. Therefore, in order to obtain basic knowledge using a chronic inflammation model that is easy to analyze, we investigated the cortical responses in a knee joint chronic inflammation model. As a result, flavin imaging recording revealed the enhancement of the cortical response associated with chronic inflammation.
Academic Significance and Societal Importance of the Research Achievements	慢性疼痛の神経メカニズムを解明することは慢性疼痛性疾患の治療薬の新規開発、新しい治療法の開発のために重要である。今回の結果により、身体に慢性炎症を起こすと、大脳皮質の過剰な反応が出現することが示唆された。この大脳の過剰反応と慢性的な痛みとの因果関係はまだ明らかになっていないが、新規治療薬の効果を調べる実験研究において、治療薬投与によって大脳皮質の反応がどのように変化するかを調べることで、鎮痛効果を客観的に評価することが出来る可能性が考えられ、医療的・社会的意義があると思われる。