The periodontal Ruffini endings in brain derived neurotrophic factor (BDNF) deficient mice.
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.
Alkhamrah
Bashar Anas
BA
Divisions of Oral Anatomy, Department of Oral Biological Science, Niigata University Graduate School of Medical and Dental Sciences, Gakkocho-dori, Niigata, Japan.
Hoshino
Natalia
N
Kawano
Yoshiro
Y
Harada
Fumiko
F
Hanada
Kooji
K
Maeda
Takeyasu
T
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*
D019208:Brain-Derived Neurotrophic Factor