Brain morphometric discrepancies between cynomolgus and rhesus macaques

Cynomolgus and rhesus macaques are widely used in biomedical research due to their physiological proximity to humans, and both are often referred to as macaques. However, the brain morphology of cynomolgus and rhesus macaques differs. Interestingly, as shown here by a Jacobian-determinant-based approach, the smaller cynomolgus brain is not only a scaled-down version of the rhesus macaques. For instance, the gray-to-white matter ratio differs significantly between the two species.