Determinants of female reproductive senescence: differential roles for the ovary and the neuroendocrine axis.

Aging in women is a complex process that begins with the transition into reproductive senescence and evolves to impact not just women's procreative potential but also multiple health-related parameters including longevity. Although somatic aging is an equal opportunity nemesis, certain disease states correlate highly with ovarian failure and the menopause, such as osteoporosis, diabetes, cardiovascular disease, and compromised cognitive function. Epidemiological studies suggest that a delayed natural menopause confers longevity and decelerates the appearance of many of the debilitating morbidities associated with the menopause. However, recent randomized clinical trials assessing the benefits of menopausal hormone therapy during the postmenopause clearly suggest that attenuation of the negative consequences of reproductive aging involves much more than a simple add back of ovarian steroids in the postmenopause. Conflicts between observations in epidemiological studies and in randomized clinical trials give good reason for continued innovative research focused on identifying the mechanisms that bring about the transition from peak reproductive potential to female reproductive quiescence. This article provides a brief update on our current understanding of the physiological and cellular mechanisms that precipitate and/or commit women to transit into reproductive senescence.