Neurochemical Responses in Stress: Relationships Between the Hypothalamic-Pituitary-Adrenal and Catecholamine Systems

Abstract
The purpose of this chapter is to review some of the neurochemical responses that occur during stress and to assess their potential significance for the organism. Of the myriad stress responses that have been recorded, two systems stand out: the hypothalamic-pituitary-adrenocortical (HPA) system, and the sympathetic-adrenomedullary (SA) system. While most research has tended to focus on one or other of these systems, we believe the existence of these two parallel systems to be biologically significant. It is the relationship between these two systems that intrigues us, and this will be the focus of our review.