Chapter 3 - Neuropeptides in the cerebrospinal fluid

Abstract

Publisher Summary This chapter describes the neuropeptides in the cerebrospinal fluid (CSF). Despite the fact that the mammalian anterior pituitary gland lacks a direct nerve supply from the brain, the central nervous system regulates the secretion of each adenohypophyseal hormone through releasing factors synthesized and secreted by neurons in the hypothalamus. It is believed that the hypothalamic peptidergic neurons producing the hypophysiotropic hormones are in turn regulated by neurotransmitters, especially of the monoaminergic variety, and that the peptidergic neuron acts as a neuroen-docrine transducer converting neuronal information from the brain into chemical information. With the characterization of all the postulated hypothalamic releasing factors it has been clearly established that the hypothalamus regulates the secretion of adenohypophyseal hormones. Two major hypotheses have been proposed regarding the means by which hypothalamic hormones reach the portal vessel circulation of the pituitary stalk for transport to the anterior pituitary. Much evidence, both anatomic and radioautographic, has been put forward to demonstrate the functions of the ependyma and their ability to concentrate peptides from the CSF.