title: Changes in the distribution of nerve fibers immunoreactive to calcitonin gene-related peptide according to growth and aging in rat molar periodontal ligament.
abstract: OBJECTIVE
  To analyze the age-dependent changes in nerve fibers immunoreactive to calcitonin gene-related peptide (CGRP-ir) in the periodontal ligaments of rats.
  
  
  METHODS
  Thirty male Wistar-ST rats were divided into growing groups (5, 9, and 15 weeks of age) and aging groups (6, 12, and 24 months of age) (n = 5 in each group). Eight serial sagittal sections, 5 microm thick, were cut parallel to the distobuccal root of the maxillary right first molar. These tissues were stained with a rabbit monoclonal antibody against CGRP. The observation area was divided into three parts (mesial, apical, and distal) and observed using a light microscope.
  
  
  RESULTS
  CGRP-ir nerve fibers were primarily distributed in the apical periodontal ligament in the growing group, with significantly more fibers than in the aging group.
  
  
  CONCLUSIONS
  CGRP-ir nerve fibers in the periodontal ligament are dense during the growth period and decrease gradually with aging, indicating that CGRP may affect periodontal tissue with growth and aging.
authors.affiliation: Orthodontic Science, Department of Orofacial Development and Function, Tokyo Medical and Dental University, Tokyo, Japan. sulsul82.orts@tmd.ac.jp
authors.forename: Hangsul
authors.initials: H
authors.lastname: Jung
authors.forename: Mariko
authors.initials: M
authors.lastname: Horiuchi
authors.forename: Kunimichi
authors.initials: K
authors.lastname: Soma
mesh_terms: D000375:Aging / Q000502:physiology*; D000818:Animals; D015740:Calcitonin Gene-Related Peptide / Q000032:analysis / Q000378:metabolism*; D008297:Male; D008963:Molar / Q000254:growth & development / Q000294:innervation; D009412:Nerve Fibers / Q000378:metabolism*; D010513:Periodontal Ligament / Q000254:growth & development* / Q000294:innervation* / Q000502:physiology; D011817:Rabbits; D051381:Rats; D017208:Rats, Wistar; D018709:Statistics, Nonparametric
chemical_list: D015740:Calcitonin Gene-Related Peptide