Chronic stress induced tissue malondialdehyde level in amygdala nucleus lesioned wistar rat

Chronic Stress has significant adverse effects on health and is a risk factor for many illnesses. The idea that the brain categorizes stressors and uses response pathways that vary according to the category has gained significant support in the recent years. The present study was designed to elucidate the possible role of amygdala nucleus on chronic physical and chronic psychological stress induced tissue lipid peroxidation level. Adult Wistar albino rats were divided into three major groups normal, sham lesioned and amygdala lesioned. Each group was further subdivided into control groups and stress groups. In each group ten animals were taken. The amygdala lesion was performed according to the stereotaxic coordinates by Paxinos and Watson. The stressed group of rats were subjected to chronic swimming (Physical) and chronic immobilization (Psychological) stress for 60 days. Tissue MDA levels (nanomoles of MDA/g wet tissue) was estimated by Kartha and Krishnamurthy method. MDA levels of heart, liver and kidneys were estimated. The stress induced increase in MDA level in amygdala lesioned rats was significantly more (P<0.001) during immobilization stress than swimming stress. The data of the present study support the hypothesis that the brain recognizes at least two major categories of stressor, which has been referred to as physical and psychological. Further, our study also provides the supportive evidence that the response of a psychological stress to a greater extent is regulated by amygdala nucleus.