Age-related cognitive impairment is associated with low serum concentrations of testosterone and CSF levels of amyloid beta 42 in male cynomolgus monkeys (Macaca fascicularis).

Aged memory-impaired cynomolgus monkeys had significantly lower levels of cerebrospinal amyloid (Aβ42 ) and serum testosterone compared with young animals and non-memory-impaired controls. Our findings confirm similar findings in the human and substantiate the usefulness of the cynomolgus monkey as a spontaneous model for aging-associated senile dementia of the Alzheimer type.