Pituitary-regulatory substances of the hypothalamus are synthesised within specialised neurones by a process known as neurosecretion. The general concept of neurosecretion underlies our understanding of the way in which neural information is converted into chemical messages. The notion was first proposed by Scharrer and colleagues in the 1930s; they recognised that certain nerve cells in the brain of insects and fish, and in the neurohypophysial system of mammals resembled gland cells.
Scharrer suggested that some nerve cells were capable of acting like glands of internal secretion and so introduced the term neurosecretion to describe this phenomenon.