The magnocellular neuroendocrine system is a very important region of the hypothalamus which is involved in control of uterine contractions during parturition, the milk let-down reflex, and maternal behavior via oxytocin as well as the regulation of fluid homeostasis, vasoconstriction, stress responses, and possibly memory via vasopressin. The release of oxytocin and vasopressin are governed by the activity of these large magnocellular neurons. Dr. Weiss will identify the inputs to these neurons in normal animals since it is likely that the afferents play an critical role in determining their activity. He will then examine the influence of lactation and water deprivation on these synaptic inputs. Discerning the synaptic plasticity following physiological stimuli will contribute greatly to our knowledge of how the brain organizes actions and maintains our vital functions. Given the relationship of this hypothalamic region to regulation of fluid balance and the cardiovascular system, basic research may lead to better understanding of the neural regulation of hypertension and heart disease which are a major cause of death in middle-age males in our society.
