title: The periodontal Ruffini endings in brain derived neurotrophic factor (BDNF) deficient mice.
abstract: Innervation and terminal morphology in the lingual periodontal ligament of the incisor were investigated in brain derived neurotrophic factor (BDNF) heterozygous mice and littermate wild-type mice (aged two months) using immunohistochemistry for protein gene product 9.5 (PGP 9.5), a general neuronal marker. In addition, computer-assisted quantitative analysis was performed for a comparison of neuronal density in the periodontal ligament between heterozygous and wild-type mice. In wild-type mice, the periodontal ligament was found to be richly innervated by the mechanoreceptive Ruffini endings and nociceptive free nerve endings in the alveolus-related part of the periodontal ligament. The periodontal Ruffini endings in the wild-type mice incisor ligament were classified into two types: type I with ruffled outlines, and type II with a smooth outline. BDNF heterozygous mice showed malformations of the type I Ruffini endings which included fewer nerve fibers and fewer ramifications than those in wild-type mice as well as smooth outlines of the axon terminals. Quantitative analysis under a confocal microscope showed a roughly 18% reduction in neuronal density in the periodontal ligament of the heterozygous mice. These findings suggest that the development and maturation of the periodontal Ruffini endings require BDNF.
authors.affiliation: Divisions of Oral Anatomy, Department of Oral Biological Science, Niigata University Graduate School of Medical and Dental Sciences, Gakkocho-dori, Niigata, Japan.
authors.forename: Bashar Anas
authors.initials: BA
authors.lastname: Alkhamrah
authors.forename: Natalia
authors.initials: N
authors.lastname: Hoshino
authors.forename: Yoshiro
authors.initials: Y
authors.lastname: Kawano
authors.forename: Fumiko
authors.initials: F
authors.lastname: Harada
authors.forename: Kooji
authors.initials: K
authors.lastname: Hanada
authors.forename: Takeyasu
authors.initials: T
authors.lastname: Maeda
mesh_terms: D000818:Animals; D019208:Brain-Derived Neurotrophic Factor / Q000235:genetics*; D018507:Gene Expression Regulation, Developmental; D005838:Genotype; D006579:Heterozygote; D007180:Incisor / Q000254:growth & development / Q000294:innervation; D008465:Mechanoreceptors / Q000166:cytology* / Q000254:growth & development*; D051379:Mice; D018345:Mice, Knockout; D010513:Periodontal Ligament / Q000254:growth & development* / Q000294:innervation*
chemical_list: D019208:Brain-Derived Neurotrophic Factor