Jacqueline A. Maffucci and Andrea C. Gore
Traditionally, the onset and progression of menopause in humans has been attributed to ovarian follicular decline. Because the follicles are the primary source of circulating estrogens, these age-related changes lead to a number of symptoms such as hot flashes, mood swings, irritability, and depression, as well as increased risk of osteoporosis, cardiovascular disease, and age-associated diseases. Recent research indicates that along with the ovarian changes at menopause, the hypothalamic and pituitary levels of the reproductive axis also undergo significant changes during reproductive aging. Indeed, current research suggests a neural, as well as hormonal, mechanism involved in the menopausal process. A number of animal models are available to study these processes, most commonly the nonhuman primates and rodents, and to a lesser extent, avian systems. Here, we will discuss Old and New World monkey models, rats, mice (wild type, transgenic, and genetically modified), and birds as models for reproductive aging. An overview of the reproductive aging process will be discussed for each model, along with their advantages, disadvantages, and biomedical relevance. In addition, we will present recent findings pertaining to the mechanisms for the onset of reproductive aging in all of these models, focusing on the hypothalamic-pituitary-gonadal axis, and emphasizing molecular changes and hormonal output.
Was this article helpful?