Abstract
Nonhuman primate models are required to understand aging and age-related pathologies. The gray mouse lemur Microcebus murinus, a small prosimian primate, develops age-dependent deficits that are comparable to the decline observed during normal and pathological aging in humans. Importantly, not all old gray mouse lemurs are equally affected by age-related behavioral and cognitive problems. Some are profoundly impaired, while others perform as well as younger animals. Moreover, brain atrophy is detected only in some animals and thus appears to be an age-related pathological condition more than an inevitable effect of age. Finally, a subset of aged animals display neuropathological lesions observed also in Alzheimer's disease: β-amyloid deposition mainly in diffuse plaques and tau protein aggregation in some pyramidal neurons of the entorhinal cortex and hippocampus. Overall, these age-related changes indicate that gray mouse lemurs could be used as a potential translational model to study age-associated deficits and disorders.