Distribution of Cold Receptor Transient Receptor Potential Melastatin 8-Immunopositive Axons in the Mouse Dental Pulp and Periodontal Tissue.
10.11620/IJOB.2017.42.4.169
- Author:
Tae Heon KIM
1
;
Jae Sik LEE
;
Yun Sook KIM
;
Yong Chul BAE
Author Information
1. Department of Dental Hygiene, Taegu Science University, Daegu 41453, Korea.
- Publication Type:Original Article
- Keywords:
TRPM8;
dental pulp;
periodontal tissue;
immunohistochemistry
- MeSH:
Animals;
Axons*;
Dental Pulp*;
Dentin;
Hyperalgesia;
Immunohistochemistry;
Incisor;
Mice*;
Mice, Transgenic;
Molar;
Mucous Membrane;
Neurons;
Odontoblasts;
Periodontal Ligament;
Sensation;
Tooth
- From:International Journal of Oral Biology
2017;42(4):169-174
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
Transient receptor potential melastatin 8 (TRPM8) plays a crucial role in innocuous cool sensation, acute cold pain and cold-induced hyperalgesia during pathologic conditions. To help understand TRPM8-mediated cold perception in the dental pulp and periodontal tissues, we examined the distribution of TRPM8-immunopositive (+) axons in molar and incisor pulp and periodontal tissues using transgenic mice expressing a genetically encoded axonal tracer in TRPM8+ neurons. In the radicular pulp of the molar teeth, a small number of TRPM8+ axons were observed. TRPM8+ axons branched frequently and extensively in the core of coronal pulp, forming a network in the peripheral pulp. Some TRPM8+ axons ascended between odontoblasts and were observed in the dentinal tubule. TRPM8+ axons were linear-shaped in the radicular pulp, whereas many TRPM8+ axons showed portions shaped like beads connected with thin axonal stands at the peripheral pulp. TRPM8 was densely expressed in the bead portions. In the incisor pulp, TRPM8+ axons were occasionally observed in the core of the coronal pulp and rarely observed at the peripheral pulp. TRPM8+ axons were occasionally observed and showed a linear shape rather than a bead-like appearance in the periodontal ligament and lamina propria of the gingival tissue. These findings, showing differential distribution of TRPM8+ axons between radicular and coronal portions of the molar pulp, between incisor and molar pulp, and between dental pulp and periodontal tissues, may reflect differential cold sensitivity in these regions.
