title: Calbindin D28K-like immunoreactive nerve fibres in the predentine of rat molar teeth.
abstract: Immunoelectron-microscopy was applied to reveal the existence of nerve fibres and terminals showing calbindin D28k (CB)-like immunoreactivity (IR) in the rat molar tooth pulp. In the root pulp, thick, smooth-surfaced CB-IR nerve fibres were in bundles accompanying the blood vessels. In the coronal pulp, the fibres arborized repeatedly and extensively. CB-IR nerve fibres had a predominantly thick, smooth-surfaced appearance, though parts appeared thin and beaded. Occasionally some thin, varicose CB-IR nerve fibres ran along the odontoblasts, penetrating into the predentine alongside the dentinal tubules. They could be traced for approx. 10-20 microns into the predentine from the pulp-predentine border. Immunoelectron-microscopy revealed that only some of the nerve terminals in the predentine showed CB-IR, and that predentinal CB-IR nerve terminals were located close to the odontoblast processes. No synaptic structures were observed between them. The presence of CB-IR nerve terminals in the predentine suggests that many, if not all, CB-IR nerve fibres could be nociceptors. The CB could be involved in Ca2+ homeostasis during the activation of nociceptors.
authors.affiliation: Department of Oral Anatomy and Developmental Biology, Osaka University Faculty of Dentistry, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Miyawaki
authors.forename: S H
authors.initials: SH
authors.lastname: Youn
authors.forename: K
authors.initials: K
authors.lastname: Ochi
authors.forename: T
authors.initials: T
authors.lastname: Maeda
authors.forename: K
authors.initials: K
authors.lastname: Kurisu
authors.forename: S
authors.initials: S
authors.lastname: Wakisaka
mesh_terms: D000818:Animals; D001808:Blood Vessels / Q000648:ultrastructure; D064092:Calbindin 1; D064026:Calbindins; D002118:Calcium / Q000378:metabolism; D003782:Dental Pulp / Q000098:blood supply / Q000294:innervation / Q000648:ultrastructure; D003804:Dentin / Q000294:innervation* / Q000648:ultrastructure; D006706:Homeostasis; D008297:Male; D016253:Microscopy, Immunoelectron; D008963:Molar; D009411:Nerve Endings / Q000648:ultrastructure; D009412:Nerve Fibers / Q000648:ultrastructure*; D009419:Nerve Tissue Proteins / Q000032:analysis*; D009619:Nociceptors / Q000378:metabolism / Q000648:ultrastructure; D009804:Odontoblasts / Q000648:ultrastructure; D051381:Rats; D017207:Rats, Sprague-Dawley; D064030:S100 Calcium Binding Protein G / Q000032:analysis*; D013569:Synapses / Q000648:ultrastructure; D019228:Tooth Crown / Q000648:ultrastructure; D014092:Tooth Root / Q000648:ultrastructure
chemical_list: C576500:Calb1 protein, rat; D064092:Calbindin 1; D064026:Calbindins; D009419:Nerve Tissue Proteins; D064030:S100 Calcium Binding Protein G; D002118:Calcium