The objective of this volume is to provide recent information on neura l regulation in the endocrine system in vertebrates. Classical studies have revealed that certain neurons synthesize and release chemical me ssengers into the blood vascular system. These neurons are endocrine d evices that link the brain with the endocrine glands and other target organs. In vertebrates the hypothalamus is the seat of chemical coordi nation and integration of environmental and hormonal cues to modulate function of the pituitary, and, consequently, the functions of other e ndocrine glands. Information generated during the past few decades has resulted in profound alterations in the conceptual fabric of endocrin ology. From the wealth of information that emerged on neuropeptides of the central nervous system, and connectivities of various brain cente rs, it has become clear that several extra-hypothalamic sites are also involved in regulation of hypophysial hormones.