Brain volumetrics across the lifespan of the rhesus macaque

The rhesus macaque is a long-lived nonhuman primate (NHP) with a brain structure similar to humans, which may represent a valuable translational animal model in which to study human brain aging. Previ-ous magnetic resonance imaging (MRI) studies of age in rhesus macaque brains have been prone to low statistical power, unbalanced sex ratio and lack of a complete age range. To overcome these problems, the current study surveyed structural T1-weighted magnetic resonance imaging scans of 66 animals, 34 females (aged 6-31 years) and 32 males (aged 5-27 years). Differences observed in older animals, in-cluded enlargement of the lateral ventricles and a smaller volume in the frontal cortex, caudate, puta-men, hypothalamus, and thalamus. Unexpected, greater volume, were measured in older animals in the hippocampus, amygdala, and globus pallidus. There were also numerous differences between males and females with respect to age in both white and gray matter regions. As an apparent model of normative human aging, the macaque is ideal for studying induction and mitigation of neurodegenerative disease.(c) 2023 Elsevier Inc. All rights reserved.

Automated summary

This study found that the rhesus macaque, a long-lived nonhuman primate with a brain structure similar to humans, can serve as a valuable animal model for studying human brain aging. By conducting magnetic resonance imaging scans on 66 macaques, the researchers observed changes in brain structures in older animals, such as enlargement of the lateral ventricles and volume reductions in the frontal cortex, caudate, putamen, hypothalamus, and thalamus. Additionally, there were differences between males and females in both white and gray matter regions. The rhesus macaque presents an ideal model for studying the onset and mitigation of neurodegenerative diseases.