A comparative study of age-related brain pathology - are neurodegenerative diseases present in nonhuman animals

Although some aged dogs definitely have dementia-like conditions, they have rather different brain histopathology from that seen in Alzheimer's disease including the shape of senile plaques, severity of neuron loss and absence of neurofibrillary tangles. Aged wild-type mice never show such brain lesions at all. In addition, no cases of Parkinson's disease have been reported in nonhuman animals yet. The reason for this might be non-parallel aging of the whole body and brain. If such nonhuman animals had a longer life span, like humans, typical Alzheimer's and Parkinson's Lesions would be formed in the brain. As the rate of deposition of the misfolded proteins causing the lesions might be slow, nonhuman animals normally die before the Lesions appear. (C) 2004 Elsevier Ltd. All rights reserved.