Region-specific age at onset of beta-amyloid in dogs

Cortical patterns of beta-amyloid (A beta) deposition were evaluated in 40 beagle dogs ranging in age from 2 to 18 years. A beta deposition in the prefrontal, occipital, parietal and entorhinal cortices was visualized by using an antibody against A beta 1-42. A logistic regression was used to estimate differences in age-at-onset and rate of deposition of A beta as a function of brain region. The earliest and most consistent site of A beta deposition with age was in the prefrontal cortex. Entorhinal A beta deposition was not consistently observed until the age of 14 years, but was present in a subset of dogs under the age of 14 pears. These regional vulnerabilities to A beta accumulation are similar to those seen in the aging human. By using parameters derived from regression analyses, it may be possible to predict the presence of A beta within specific brain regions in individual dogs. We propose that these models will be a useful tool to evaluate interventions that delay the age of onset ol slow the rate of accumulation of A beta in the dog. (C) 2000 Elsevier Science Inc. All rights reserved.