Ovarian steroids and serotonin neural function

The serotonin neural system originates from ten nuclei in the mid- and hind brain regions. The cells of the rostral nuclei project to almost every area of the forebrain, including the hypothalamus, limbic regions, basal gangli a, thalamic nuclei, and cortex. The caudal nuclei project to the spinal cor d and interact with numerous autonomic and sensory systems. This article re views much of the available literature from basic research and relevant cli nical research that indicates that ovarian steroid hormones, estrogens and progestins, affect the function of the serotonin neural system. Experimenta l results in nonhuman primates from this laboratory are contrasted with stu dies in rodents and humans. The sites of action of ovarian hormones on the serotonin neural system include effects within serotonin neurons as well as effects on serotonin afferent neurons and serotonin target neurons. Theref ore, information on estrogen and progestin receptor-containing neurons was synthesized with information on serotonin afferent and efferent circuits. T he ability of estrogens and progestins to alter the function of the seroton in neural system at various levels provides a cellular mechanism whereby ov arian hormones can impact mood, cognition, pain, and numerous other autonom ic functions.