Fig. 1
From: Early Life Stress, Depression And Parkinson’s Disease: A New Approach
The HPA axis and the main hormones secreted by each gland in the axis. CRH: corticotropin releasing hormone. ACTH: adrenocorticotropic hormone. A stressor (e.g., a threat to the life of the organism) triggers the paraventricular nucleus of the hypothalamus to synthesize and secrete CRH, which binds to specific receptors in the anterior pituitary. This stimulates the synthesis and release of ACTH which is released into the circulatory system. ACTH triggers the synthesis and secretion of glucocorticoids (cortisol in humans/corticosterone in rodents) from the adrenal cortex