The developmental studies on the differentiation into the odontoblasts as sensory receptor

2019 Fiscal Year Final Research Report

• Project/Area Number: 19K24104
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Multi-year Fund
• Review Section: 0907:Oral science and related fields
• Research Institution: Tokyo Dental College
• Principal Investigator: Tanaka Aoi 東京歯科大学, 歯学部, レジデント (80843573)
• Project Period (FY): 2019-08-30 – 2020-03-31
• Keywords: 象牙芽細胞 / TRP channel / PANX-1 channel / 神経線維 / 免疫組織化学 / RT-qPCR / 歯痛

Outline of Final Research Achievements

Odontoblasts act as dentin formation and sensory receptors. Recently, it was reported that transient receptor potential (TRP) channel and pannexin 1 (PANX-1) channel play important roles in odontoblast sensory reception. However, it is not known when odontoblasts begin to possess a sense reception function. The aim of this study was to clarify the development of odontoblasts as sense receptors.
Sections of mandibular first molars from postnatal day (PN) 0 to PN12 Wistar rats were prepared to investigate expression of TRP channel and PANX-1 channel.
We revealed that teeth at PN12 already expressed all of TRP channel, PANX-1 channel, and nerve fibers. The results of this study suggest that odontoblasts may acquire sensory receptor function after beginning to form root dentin, when TRP channel, PANX-1 channels, and nerve fibers are completely formed.

Free Research Field

小児歯科学

Academic Significance and Societal Importance of the Research Achievements

我々の研究成果において、象牙芽細胞の感覚受容機能は歯根が形成され始めた時に発現することが示唆されている。よって、歯は口腔内に萌出する前から、疼痛を受容できる機能を兼ね備えている可能性がある。小児歯科において、萌出直後の歯は歯質が未成熟であるうえに、清掃性が悪いため齲蝕となる可能性が高く、低年齢で処置が必要となることがしばしば認められる。乳歯は永久歯に比べて神経線維が疎であることが知られているが、萌出直後から象牙芽細胞の感覚受容機能は確立されているため、処置中に歯痛が伴わないように浸潤麻酔が必要不可欠となる。