LACK OF ALZHEIMER PATHOLOGY AFTER BETA-AMYLOID PROTEIN INJECTIONS IN RAT-BRAIN

In order to establish a direct relationship between beta-amyloid protein (betaAP) and in vivo neurotoxicity, we made intraparenchymal injections and Alzet pump infusions of betaAP into the hippocampus and cortex of adult rats. We tested a number of synthetic betaAP peptides (betaAP 1-40, 1-38, and 25-35) and peptide controls (scrambled and reversed 1-40, and scrambled and reversed 25-35) over a wide range of concentrations and in a variety of vehicles. The rats were sacrificed from 2-35 days following the implant, and the brains examined by standard immunohistochemical and histological methods used to evaluate the pathologies associated with Alzheimer's disease. We report the lack of Alzheimer related pathology and no significant morphological differences between the betaAP peptide and the peptide and vehicle control injections. These observations indicate that the simple intraparenchymal injection of betaAP in the rat brain is not an appropriate model of Alzheimer-related neurotoxicity.