Pain Control by Light Using Optogenetics ~Development of Experimental Animals and Elucidation of Pain Mechanisms~

2020 Fiscal Year Final Research Report

• Project/Area Number: 18K08859
• 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: University of Miyazaki
• Principal Investigator: Maruta Toyoaki 宮崎大学, 医学部, 講師 (20363591)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: オプトジェネティクス / 疼痛 / 神経障害性疼痛 / 脊髄後根神経節 / Nav1.7 / Nav1.8 / Nav1.9 / ChR2

Outline of Final Research Achievements

We were able to generate all the planned mice (Nav1.7iCre/+;Ai32/+, Nav1.8iCre/+;Ai32/+, Nav1.9iCre/+;Ai32/+). We confirmed that the pain responses to mechanical and thermal stimuli were not different from the wild type. In addition, the blue LED light irradiation test on the sole of the foot showed a pain response of foot retraction. In addition, in a light aversion test, the animals were allowed to move freely between a blue LED light floor and a green LED light floor, and the time spent in the blue room was significantly shorter than in the wild type. We confirmed by tissue immunostaining that each Na+ channel and the photosensitive channel ChR2 were co-expressed in the dorsal root ganglia of the spinal cord.

Free Research Field

疼痛学、麻酔科学

Academic Significance and Societal Importance of the Research Achievements

当初の目的どおり、光照射で疼痛反応を起こすマウスを作製することができた。純粋に痛みの神経のみを興奮させて、疼痛反応を評価することができるようになった点が画期的である。今後は、このマウスを用いて、神経障害性モデルを作製し、行動評価を行ってみたい。また、長期光照射により神経障害性疼痛を発症させて、分子生物学的手法や組織免疫染色などを用いて、神経障害性疼痛の発症機序を細胞内分子レベルで解明したい。さらに、同様の手法で光照射で疼痛を感じにくくしたマウスを作製することも可能であり、神経障害性疼痛の機序解明に役立つであろう。