Correlations between serum levels of beta amyloid, cerebrospinal levels of tau and phospho tau, and delayed response tasks in young and aged cynomolgus monkeys (Macaca fascicularis)

Background In an attempt to explore cynomolgus monkeys as an animal model for Alzheimer's disease, the present study focused on the Alzheimer's biomarkers beta amyloid 142 (A42) in serum, and total tau (t-tau) and phosphorylated tau (p-tau) levels in cerebrospinal fluid. Methods We measured biomarker levels in Young and Aged cynomolgus monkeys and correlated these with performance on three delayed response tasks. Results The A42 concentration of the Aged monkeys was significantly lower than in the Young subjects, while the t-tau and p-tau did not significantly differ between the groups. The Young subjects performed significantly better than the Aged individuals on the memory tests. Only A42 levels were significantly correlated with performance in the three delayed response tasks. Conclusions Circulating A42 levels were lower in Aged monkeys and were correlated with inferior performance on delayed response tasks in Aged animals; therefore, both measures may be useful in establishing cynomolgus monkeys as models for studies of AD.