Mammals, that probably represent the most sophisticated metazoans, show an highly complex pattern of interactions between the immune and the neuroendocrine systems (Weigent and Blalock, 1987, 1995). However, in an evolutionary perspective, the roots of these interactions must be traced back to the defense mechanisms which are also present in simpler (and older) forms of life. Many studies have examined separately the immune and the neuroendocrine systems. However, the fact that in mammals the two systems intercommunicate poses the question of their coordinated development. In terms of evolution, there are two theoretically possible answers to the observed dialogue between immune and neuroendocrine components.
Prof Enzo Ottaviani provides a summary on the mutual origination theories of these two complex systems on the scientific blog site SciTopics
