The Cellular and Molecular Determinants of Hippocampus Size in a Female Monkey Model of Depression

Abstract

Alterations in the structure and function of the hippocampus are implicated in the pathophysiology of depression, though the cellular and molecular mechanisms contributing to those mechanisms are unknown. Reduced hippocampal volume is reported in depressed patients, yet the interpretation of human studies is confounded by subject heterogeneity. Although the hippocampus is functionally differentiated such that the anterior hippocampus is associated with emotional functioning, few human studies report separate regional analyses. Moreover, animal models of depression have historically been male rodents, and relatively little research has been conducted in regard to female depression, despite the 2-fold increased prevalence of depression in women and known effects of estrogen in the brain. Detailed evaluations of the hippocampus in a nonhuman primate model of depression in which the neurobiology more closely resembles that of humans while still allowing experimental control over potential confounds would help clarify these issues and further elucidate the mechanisms responsible for hippocampal alterations in depression.