ABSTRACT
Regulatory function of the human (and animal) body depends on the integrated and co-ordinated activity of two major control systems: the endocrine system and the nervous system. That there is a close interrelationship between the function of the mind and endocrine hormone secretion is an old concept of western medicine that came from findings such as the association of depression with dysfunction of the hypothalamic-pituitary-adrenal (HPA) axis.1 The field of neuroendocrinology arose out of observations pointing to significant influences being exerted by hormones, and related peptides, on the brain and vice versa. Research into this “neuroendocrine” hypothesis accelerated from the early 1970s as the technologies became increasingly available for the isolation, characterization and measurement of neurotransmitters, hypothalamic peptides, pituitary and other endocrine hormones. Emerging techniques are opening up new ways of examining brain chemistry; proton magnetic spectroscopy, for example, has recently been used to show the marked reorganization of brain chemical networks that occurs with normal ageing.2
