APOLIPOPROTEIN E-IMMUNOREACTIVITY IN AGED RHESUS-MONKEY CORTEX - COLOCALIZATION WITH AMYLOID PLAQUES

In the present study, we examined the relationship between ApoE and am yloid containing profiles within the cerebral cortex of young, middle aged, and aged Rhesus monkeys. Polymerase chain reaction analyisis rev ealed a pattern consistent with the ApoE e4 phenotype in the rhesus mo nkey similar to that reported in humans. We found numerous ApoE immuno reactive plaques within the temporal neocortex and amygdala, whereas t he hippocampus contained only a few such plaques. Although virtually a ll ApoE-immunoreactive plaques coexpressed beta-amyloid, most plaques were beta A4 positive/ApoE immunonegative within the aged monkey corte x. Moreover, we observed a close correspondence between ApoE and thiof lavin-positive (i.e., amyloid) plaques suggesting that ApoE may play a critical role in the conversion of beta A4 to its -pleated form. Beca use ApoE, beta A4 and beta amyloid are expressed in plaques within the aged Rhesus macaque cortex, this species may provide an in vivo model for investigations aimed at clarifying the interactions between these proteins in normal and pathologic aging.