title: Tooth loss might not alter molecular pathogenesis in an aged transgenic Alzheimer's disease model mouse.
abstract: OBJECTIVE
  Previous studies have reported that tooth loss is a risk factor of Alzheimer's disease (AD). However, the association between tooth loss and cognition and the impact of tooth loss on the molecular pathogenesis of AD remain elusive. In this study, we tested the effect of tooth loss on learning and memory and on the molecular pathogenesis of AD in an aged AD model mice.
  
  
  METHODS
  We divided 14-month-old amyloid precursor protein (APP) transgenic mice, an AD model mouse line, into upper molar extracted group (experimental) and molar intact group (control). At 18 months old, we analysed not only the changes of amyloid-beta (Aβ), pyramidal cells in the brain but also the learning and memory ability with step-through passive avoidance test.
  
  
  RESULTS
  The amount of Aβ and the number of pyramidal cells in the hippocampus were not significantly different between the experimental and control group. Similarly, the difference of learning and memory ability could not be distinguished between the groups.
  
  
  CONCLUSIONS
  Neither molecular pathogenesis of AD nor associated learning and memory were aggravated by tooth loss in these mice. The limited results of this study which used the aged mice may help the dental profession to plan and explain treatments to patients with AD, which must be designed while taking into account the severity of the AD symptoms.
authors.affiliation: Department of Advanced Prosthodontics, Hiroshima University Graduate School of Biomedical & Health Sciences, Hiroshima, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Oue
authors.affiliation: Department of Advanced Prosthodontics, Hiroshima University Graduate School of Biomedical & Health Sciences, Hiroshima, Japan.
authors.forename: Yasunari
authors.initials: Y
authors.lastname: Miyamoto
authors.affiliation: Department of Advanced Prosthodontics, Hiroshima University Graduate School of Biomedical & Health Sciences, Hiroshima, Japan.
authors.forename: Katsunori
authors.initials: K
authors.lastname: Koretake
authors.affiliation: Department of Advanced Prosthodontics, Hiroshima University Graduate School of Biomedical & Health Sciences, Hiroshima, Japan.
authors.forename: Shinsuke
authors.initials: S
authors.lastname: Okada
authors.affiliation: Department of Advanced Prosthodontics, Hiroshima University Graduate School of Biomedical & Health Sciences, Hiroshima, Japan.
authors.forename: Kazuya
authors.initials: K
authors.lastname: Doi
authors.affiliation: Department of Neurophysiology and Brain Science, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan.
authors.forename: Cha-Gyun
authors.initials: CG
authors.lastname: Jung
authors.affiliation: Department of Biochemistry, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Michikawa
authors.affiliation: Department of Prosthetic Dentistry, Ohu University School of Dentistry, Koriyama, Japan.
authors.forename: Yasumasa
authors.initials: Y
authors.lastname: Akagawa
mesh_terms: D000375:Aging; D000544:Alzheimer Disease / Q000473:pathology; D000818:Animals; D004195:Disease Models, Animal; D006624:Hippocampus / Q000166:cytology; D007858:Learning; D008568:Memory; D051379:Mice; D008822:Mice, Transgenic; D016388:Tooth Loss / Q000473:pathology*
keywords: Alzheimer's disease; Tg2576; amyloid-β; tooth loss