Objective: The paper outlines not only physiological and stress-related activity of the hypothalamic-pituitary-adrenal (HPA) axis, but also interactions between the HPA axis and other neurotransmitters.
Review: The hypothalamic-pituitary-adrenal axis plays an important role in adaptation of the organism to stressful situations, as it controls and co-ordinates stress-induced increases in the secretion of glucocorticoids. Abnormalities in the HPA axis activity are associated with various mental disorders, e.g. depression or posttraumatic stress disorder (PTSD). The HPA axis activity is modulated by many neurotransmitter systems (including glutamatergic, GABA-ergic, and serotoninergic) and by neurosteroids.
Conclusions: Chronic stress induces abnormalities in the HPA activity and leads to an excessive glucocorticoid secretion. Explanation of the mechanism regulating the HPA axis activity is most important for understanding response of the organism to aversive stimuli. The presented findings indicate that CRF subtype 1 receptor antagonists may represent a novel group of drugs for the pharmacotherapy of depression and/or anxiety disorders.