title: Effects of treadmill exercise on brain insulin signaling and β-amyloid in intracerebroventricular streptozotocin induced-memory impairment in rats.
abstract: OBJECTIVE
  The purpose of the study is to explore effect of 6 weeks treadmill exercise on brain insulin signaling and β-amyloid(Aβ).
  
  
  METHODS
  The rat model of Alzheimer's disease(AD) used in the present study was induced by the intracerebroventricular(ICV) streptozotocin(STZ). To produce the model of animal with AD, STZ(1.5mg/kg) was injected to a cerebral ventricle of both cerebrums of Sprague-Dawley rat(20 weeks). The experimental animals were divided into ICV-Sham(n=7), ICV-STZ CON(n=7), ICV-STZ EXE(n=7). Treadmill exercise was done for 30 min a day, 5 days a week for 6 weeks. Passive avoidance task was carried out before and after treadmill exercise.
  
  
  RESULTS
  The results of this study show that treadmill exercise activated Protein kinase B(AKT)/ Glycogen synthase kinase 3α (GSK3α), possibly via activation of insulin receptor(IR) and insulin receptor substrate(IRS) and reduced Aβ in the brain of ICV-STZ rats. More interestingly, treadmill exercise improved cognitive function of ICV-STZ rats. Finally, physical exercise or physical activity gave positive influences on brain insulin signaling pathway.
  
  
  CONCLUSIONS
  Therefore, treadmill exercise can be applied to improve AD as preventive and therapeutic method.
authors.affiliation: Exercise Biochemistry Laboratory, Korea National Sport University, Seoul, Korea.
authors.forename: Eun Bum
authors.initials: EB
authors.lastname: Kang
authors.affiliation: Exercise Biochemistry Laboratory, Korea National Sport University, Seoul, Korea.
authors.forename: Joon Yong
authors.initials: JY
authors.lastname: Cho
keywords: brain insulin signaling; intracerebroventricular-streptozotocin injection; treadmill exercise; β-amyloid