Introductory remarks (second day): neurosecretion

Abstract

Our session today needs few words of introduction, for most of the foundations for our programme this morning have already been laid during the papers and discussions yesterday. It is perhaps only in relation to the secretory activities of neurons (which we shall discuss later this morning), and in particular the use of the term ‘neurosecretion’ that some comments of mine might be appropriate and useful. For many years those of us who are interested in the field of neuroendocrinology have appropriated the word ‘neurosecretion’ to describe certain specific elements in the central nervous system which appear to be engaged in endocrine activity. The earliest of these specialized neurons to be described, namely those tracts linking the hypothalamus and pituitary pars nervosa in vertebrates, and those linking the brain and the sinus gland in crustaceans and the corpora cardiaca of insects, were clearly distinguishable by histological means from other neurons. Moreover, in terms of function and biochemistry also these classical neurosecretory systems seemed to have distinct characteristics. Unlike other neurons they released peptide hormones into the bloodstream and this, and some other features, formed the basis for the original neurosecretion concept proposed by Scharrer and Bargmann.