Central neuroendocrine regulation of brain water permeability.

The brain vasculature, especially capillaries, may function in a very dynamic fashion under neuroendocrine control to regulate the internal environment of the brain. This is exemplified by new observations on the regulation of brain water permeability using the tracer H215O in vivo in adult rhesus monkeys. These studies reveal that brain water permeability, and hence brain water content and volume, are, at least in part, under the influence of the central noradrenergic system and centrally released vasopressin.