Involvement of merkel cells in pain or itch sensation

2020 Fiscal Year Final Research Report

• Project/Area Number: 19K23784
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Multi-year Fund
• Review Section: 0704:Neuroscience, brain sciences, and related fields
• Research Institution: Hyogo University of Health Sciences
• Principal Investigator: Hirosato Kanda 兵庫医療大学, 薬学部, 助教 (80842088)
• Project Period (FY): 2019-08-30 – 2021-03-31
• Keywords: メルケル細胞 / 痒み

Outline of Final Research Achievements

Merkel cell is distributed in the skin and act as an mechano-sensor for tactile stimuli. It is known that merkel cell composes the synapse with sensory nerve endings and transmit a tactile information by releasing neurotransmitters. Here, we examined the functional classification of sensory nerve endings which are terminated at Merkel cells. We further examined whether Merkel cells are involved in generation of pain or itch sensation. We found that the Merkel cells which are located in the skin specifically contacted with Aβ fiber. On the other hand, the Merkel cells in the whisker hair follicle contacted with peripherin and neurofilament H-double positive nerve fiber. Although acetylcholine is known as a neurotransmitter in CNS, it mediates itch sensation in the peripheral tissues. We found that Merkel expressing region of whisker hair follicle highly expressed ChaT mRNA. These results suggest the possibility that Merkel cell might be involved in itch sensation.

Free Research Field

神経科学

Academic Significance and Societal Importance of the Research Achievements

これまでメルケル細胞の生理的意義として、体外からの触刺激に対する活性化機構や神経伝達機構が明らかとなってきた。しかしながら、メルケル細胞やメルケル終盤の病態における機能的・構造的変化について不明な点が多い。本研究の位置づけとして、メルケル細胞と疼痛・痒みとの関連性を新たに示唆するものであり、今後メルケル細胞をターゲットとした新規鎮痛・掻痒緩和薬の開発等に繋がる可能性がある。