NSF Award
9809907
98-09907 CHODOBSKI Vasopressin or antidiuretic hormone is a "neurohormone," that is a hormone produced by nerve cells ("neurons"). It was originally found in specialized groups of neurons located in a region of the brain termed the "hypothalamus". These neurons send long thread- like processes ("axonal fibers") to the pituitary gland where their vasopressin is released into the blood stream. Two major physiological actions of this neurohormone, as its names imply, are the conservation of water and the maintenance of blood pressure in response to the loss of body fluids. Normal central nervous system (CNS) function is critically dependent upon the maintenance of an optimal composition and volume of intra- and extracellular fluids. Small changes in these parameters can alter neuronal signaling and information processing. An increasing body of evidence indicates that vasopressin is not only secreted into the blood stream, but is also released within the CNS to regulate brain fluid balance. However, the sources of centrally-released vasopressin are incompletely characterized. Recent observations by Dr. Chodobski and his collaborators indicate that one potential source of this central vasopressin is the choroid plexus, an organ that is located within the cerebral ventricles (fluid-filled chambers inside the brain) and that is the primary site of cerebrospinal fluid formation. It is therefore hypothesized that the choroid plexus-derived vasopressin is involved in the regulation of fluid economy in the brain. The objectives of this project are to elucidate the mechanisms underlying the synthesis, release, and putative actions in the CNS of choroidal vasopressin. To this end, choroid plexus cell culture systems and animal models will be used. The experiments will involve molecular, cellular, and physiological approaches. The studies proposed in this application will generate data to fill the 'information gap' in an important area of neuronal microenvironmen t maintenance.
