Noradrenergic neural systems have been expressly implicated in pathophysiological conditions induced by stress. The majority of experimental evidence supports a central role for brain noradrenaline in mediating the effects of stress and predisposing an organism to stress pathology as well as in producing a well-documented consequence of stress exposure-behavioral depression. This review briefly discusses the noradrenergic (NA) pathways involved, the functioning of NA synapses and their associated receptors and focuses directly upon the effects of stress on NA activity in the brain. These broad categories are discussed in terms of: 1. behavioral versus neurochemical explanations for the effects of stress; 2. the methods used to produce stress; 3. measurement of NA and its major metabolite ("turnover"); 4. regional brain effects of stress; 5. effects of pre-stress alterations in brain NA activity upon subsequent stress-induced brain NA changes; 6. correlation of stress-induced brain NA changes with peripheral manifestations of stress; and 7. predisposing factors in stress-induced neurochemical alterations.