Hypothalamo-pituitary-adrenocortical and sympatho-adrenomedullar systems in stress response

Abstract

The hypothalamic-pituitary-adrenocortical and sympatho-adrenomedullar systems are majoreffector systems that serve to maintain homeostasis during exposure to various stressors. The neurochemicalpathways controlling activation of hypothalamic-pituitary-adrenocortical and sympatho-adrenomedullar systemsare of special interest. Catecholamines, present in specific brain areas as well as in peripheral tissues are respon-sible for adequate stress response regulating the relationships between the hypothalamic-pituitary-adrenocorticaland sympatho-adrenomedullar functions. In last decade, numerous studies have demonstrated differential sym-pathoneural and adrenomedullary responses during exposure to different stressors. Some stressors provoke thestrongest reaction of adrenocortical activity than that of adrenomedularry, while others do the opposite. Each typeof stressor has its own central neurochemical and peripheral neuroendocrine »signature«with quantitative andqualitative distinct mechanisms.