Establishment of the way to identify and isolate the heat-sensitive primary sensory neurons for understanding the peripheral mechanisms of heat pain.

2016 Fiscal Year Final Research Report

• Project/Area Number: 15K15204
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Pain science
• Research Institution: Chubu University
• Principal Investigator: KATANOSAKA Kimiaki 中部大学, 生命健康科学部, 准教授 (50335006)
• Research Collaborator: HIBINO Yuhei 中部大学, 大学院・生命健康科学研究科, 大学院生 ; SHIMIZU Rie 中部大学, 生命健康科学部, 研究補助員
• Project Period (FY): 2015-04-01 – 2017-03-31
• Keywords: 温度受容体 / 熱痛覚 / 一次感覚ニューロン / 侵害受容器 / TRPV1 / TRPV2 / CGRP / DRG

Outline of Final Research Achievements

In this research, we utilized heat-dependent phosphorylation of ERK kinase in nociceptive primary sensory neurons, to explore an unknown heat-sensitive neuron that detects noxious heat higher than 50 degree C. In DRG neurons of TRPV1-KO mice, phosphorylated ERK (pERK) was emmerged after heat stimuli over 50 degree C, sugesting that these neurons would be the nociceptors specific to intensive heat. A substantial part of these pERK-positive neurons in TRPV1-KO mice were CGRP-positive peptidergic neurons, but IB4-negative. In addition, all of the cultured DRG neurons that exhibited heat threshold higher than 50 degree C were completely TRPV2-negative as far as we examined. As shown in these results, using pERK as an indicator of nociceptor activation, we succseded in identification of a certain type of nociceptor specialized to detect a particular stimulus. And thus, we have finally identified and characterized the inteisive heat-sensitive nociceptor, which is independent of TRPV1 and V2.

Free Research Field

疼痛学、感覚生理学、神経生理学