Age-associated changes of cerebrospinal fluid amyloid-β and tau in cynomolgus monkeys

Nonhuman primates (NHPs) are useful for the study of age-associated changes in the brain as a model that is biologically closely related to humans. For example, with age, all NHPs analyzed to date, develop beta-amyloid (A beta) plaques as seen in humans. Nevertheless, it is still unclear if NHPs have human-like age-associated changes in A beta and tau protein in cerebrospinal fluid. The present study was an attempt to specifically address these issues. Cerebrospinal fluid levels of A beta and phosphorylated tau were measured in 37 and 22 cynomolgus monkeys, respectively, with ages ranging from 4 to 22-year-old. The result from the present study revealed significant age-associated declines in A beta 42 levels but not in A beta 40 and phosphorylated tau levels. This finding appears to parallel changes seen with human aging, in which decreased levels of A beta 42 can be seen in normal older adults, and supporting that cynomolgus monkeys would be a useful model for studying age-related neurologic disorders associated with Alzheimer-like cerebral proteopathy. (C) 2014 Elsevier Inc. All rights reserved.