A Skeptical Neuroendocrinologist

Abstract

To the extent that I understand the meaning of the designation, I suppose that I could claim to have become a neuroendocrinologist long before anyone thought that there was any point in coining the term. The etymology of “endocrine” is clear enough. An endocrine organ is a structure whose cells elaborate one or more chemical substances which pass, either directly or indirectly, into the bloodstream, through which they are transported to the cells of some target tissue, where they exercise their effects. The nervous system, from which comes the “neuro” part of “neuroendocrine,” is something very different, and consists of a vast network of interacting nerve cells, concentrated mainly in the brain and spinal cord, through whose axons and dendrites currents flow to and from muscle fibers and other tissues, as well as from peripheral sensory cells. My teachers of more than 50 years ago were already talking about the chemical transmission of nerve impulses across synapses. But while we were taught that, apart from the adrenal medulla, endocrine tissues are not controlled by secretomotor nerves, I am sure that we all understood that since both the neural and hormonal systems are involved in the orderly regulation of the organs and tissues, they have to operate in an integrated way. There was nothing very profound in this notion. Why therefore, I ask, prefix the term “endocrinology” with the word “neuro”? At the outset I have to say that I do not quite see what the fuss is all about.