Chronic psychosocial stress exposes Alzheimer's disease phenotype in a novel at-risk model.

Because of the extensive individual variations in the time of onset and severity of the prevalent sporadic form of Alzheimer's disease (AD), a patient-related external factor must be assumed to play a significant role in the development of the disease. Since stress is increasingly recognized as an external factor in the development of AD, a number of labs, including this lab, have shown that chronic stress or corticosterone administration worsens the AD phenotype in both transgenic and non-transgenic models of the disease. Recently we develop a novel at-risk model that correlates with seemingly normal individuals who are predisposed to develop AD. This review is a summarized recount of the findings we have reported on the effect of chronic psychosocial stress in this at-risk model of AD. Behavioral (learning and memory tests), electrophysiological and molecular findings indicated that even mild chronic psychosocial stress clearly transforms this seemingly normal rat model to a full-fledge AD phenotype.