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

Abstract

The hypothalamic-pituitary-adrenocortical and sympatho-adrenomedullar systems are major effectors systems that serve to maintain homeostasis during exposure to various stressors. The neurochemical pathways controlling activation of hypothalamic-pituitary-adrenocortical and sympatho-adrenomedullar systems are of special interest. Catecholamines present in specific brain areas as well as in peripheral tissues are responsible for adequate stress response regulating the relationships between the hypothalamic-pituitary-adrenocortical and sympatho-adrenomedullar functions. In last decade, numerous studies have demonstrated differential sympathoneural and adrenomedullary responses during exposure to different stressors. Some stressors provoke the strongest reaction of adrenocortical activity than that of adrenomedularry, while others do the opposite. Each type of stressor has its own central neurochemical and peripheral neuroendocrine "signature" with quantitative and qualitative distinct mechanisms.