The choroid plexuses, which lie in the ventricles of the brain, are the major producers of the cerebrospinal fluid which bathes the mammalian nervous system. These tissues are critical to the maintenance of the fluid environment which surrounds and cushions the brain and spinal chord. A number of receptors for insulin and insulin-like growth factors have been localized, however, the correlation between these growth factors and the central nervous system has not been determined. This research project will examine the effects of insulin-like growth factors on the choroid plexus ion transport mechanisms which are essential to cerebrospinal fluid formation. The intermediate steps in the cellular responses to the insulin-like growth factors will be identified. Comparisons will be made between the mature and infant rat; choroid plexus transport capability and cerebrospinal fluid production are not fully developed in infant rats, and specific insulin-like growth factor receptor density varies with age. This research will establish a link between growth factor- receptor coupling and choroid plexus physiology and will identify the developmental differences in insulin-like growth factor action on the choroid plexus.
