Main cerebral networks involved in the response to stress. ACTH, adrenocorticotrophic hormone; Amy, amygdala; CRF, corticotrophin-releasing factor; 5-HT, serotonin (5-hydroxytryptamine); LC, locus coeruleus; MAN, medullary autonomic nuclei; NE, norepinephrine (noradrenaline); NO, nitric oxide; ParaΣ, parasympathetic system; Σ, sympathetic system; RN, raphe nuclei; VP, vasopressin.