Impaired Spatial Learning and Unaltered Neurogenesis in a Transgenic Model of Alzheimer's Disease After Oral Aluminum Exposure

Although it is well established that aluminum (Al) is neurotoxic, the potential role of this element in the etiology of Alzheimer's disease (AD) is not well established. In this study, we evaluated the effects of oral Al exposure on spatial learning, memory and neurogenesis in Tg2576 mice, an animal model of AD in which Abeta plaques start to be deposited at 9 months of age. Aluminum was given as Al lactate (11 mg/g of food) for 6 months. At 11 months of age a water maze test was carried out to evaluate learning and memory. Subsequently, mice were injected with bromodeoxyuridine (BrdU) and sacrificed 24 hours or 28 days after the last injection in order to assess proliferation, survival and differentiation of neurons. We observed impaired acquisition in the water maze task in Al-treated Tg2576 mice, as well as worse memory in the Al-exposed groups. In terms of neurogenesis, no effects of aluminum were observed in proliferation, survival and differentiation. The results of this investigation suggest that Tg2576 mice fed for 210 days with rodent chow supplemented with Al lactate at 11 mg/g of food have impaired spatial learning although their neurogenesis remains un-modified.