アブストラクト（11巻1/2号：The Bulletin of Kanagawa Dental College）

The Bulletin of Kanagawa Dental College

English

Title　： Hypothalamic Nuclei Related to Circadian Rhythmicity in Dentinogenesis of the Rat Incisor
Subtitle　： ORIGINAL ARTICLES
Authors　： Osamu Ashida
Authors（kana）　：
Organization　： Department of Pedodontics, Kanagawa Dental College
Journal　： The Bulletin of Kanagawa Dental College
Volume　： 11
Number　： 1/2
Page　： 15-27
Year/Month　： 1983 / 3
Article　： Original article
Publisher　： Kanagawa Odontological Society
Abstract　： [Abstract] Out of 200 albino rats of Wistar strain, 146 rats were used for nucleus lesions with Actinomycin D, 40 rats for nucleus lesions with electrolysis, and 14 rats for Reserpine administration. About one week after operation the animals were sacrificed. Pb-EDTA, used as a time marker, was injected at noon everyday for several days before and after operation. Interaction between the LHA and VMH which was supposed to be related to daily dentin formation was not clear due to a small number of surviving animals with nucleus lesions. Bilateral lesions of the SCN (a primary oscillator) influenced appreciably the circadian rhythmicity of dentin deposition. However, lesions of the other hypothalamic nuclei also affected considerably the circadian rhythmicity of dentin formation. On the other hand, lesions of the caudate nucleus including a damaged hippocampus area brought about considerable fluctuations in the rhythmicity of daily dentin deposition. According to Tsuzuki-Kitamura, incremental bands of dentin in rat incisor, which are related to circadian rhythmicity, begin to appear at 2 weeks after birth and then become more conspicuous within the following 5 days. This is attributed to the establishment of the memorial system. Reserpine administration gave rise to 10% acceleration of daily dentin formation in the incisor. Therefore, it is likely that the circadian rhythmicity of dentinogenesis is more closely related to a secondary oscillator which is involved with the memorial system including the reticular formation.
Practice　： Dentistry
Keywords　： Hypothalamus, Dentinogenesis, Rat Incisor