BRAIN STRUCTURES AND LIFE-SPAN IN PRIMATE SPECIES

In haplorhine primates, when the effect of body weight is removed, bra in weight is correlated with maximum recorded life-span. In this paper we have analyzed the relationships between volumes of specific brain structures and life-span. When the effect of body weight is removed, t he volumes of many brain structures are significantly, positively corr elated with maximum recorded life-span. However, the volumes of the me dulla and most first-order sensory structures do not correlate with li fe-span. The cerebellum is the brain structure that best correlates wi th life-span. Parts of the cerebellum are particularly vulnerable to a ge-related loss of mass in humans. For another measure of the life cyc le, female reproductive age, a similar set of brain structures is sign ificantly, positively correlated (again with the exceptions of the med ulla and most first-order sensory structures). There are some differen ces between the structures correlated for life-span and female reprodu ctive age. For example, the hippocampus and lateral geniculate nucleus correlate with female reproductive age but do not correlate with life -span. In strepsirhine primates, when the effect of body weight is rem oved, total brain weight does not significantly correlate with either life-span or female reproductive age. However, the volumes of some bra in structures in strepsirhines do correlate with these life-cycle para meters. The centromedial complex of the amygdala is the only structure to correlate with life-span in both strepsirhine and haplorhine prima tes. This structure participates in the regulation of blood pressure a nd in the stress response, which may be key factors governing life-spa n.