Neuroendocrine modulation of the "menopause": insights into the aging brain

The menopause marks the permanent end of fertility in women. It was once th ought that this dramatic physiological change could be explained simply by the exhaustion of the reservoir of ovarian follicles. New data from studies performed in women and animal models make us reassess this assumption. An increasing body of evidence suggests that there are multiple pacemakers tha t contribute to the transition to irregular cycles, decreasing fertility, a nd the timing of the menopause. We will present evidence that lends credenc e to the possibility that a dampening and desynchronization of the precisel y orchestrated neural signals lead to miscommunication between the brain an d the pituitary-ovarian axis, and that this constellation of hypothalamic-p ituitary-ovarian events leads to the deterioration of regular cyclicity and heralds menopausal transition.