The involvement of amygdala nucleus in chronic stress induced changes on ingestive behavior of wistar rats.

ABSTRACT

Organisms are constantly subjected to stimuli that can be construed as stressors. Stress regulation is a highly integrated process controlled largely by the brain. The role of amygdala in stress tolerance has attracted continued interest because of its central role in processing emotional information. In the present study, the Wistar albino rats were subjected to chronic swimming (physical) stress and chronic immobilization (psychological) stress for 60 days with or without bilateral lesions of the nucleus of amygdala. Their food intake, water intake and body weight were measured. Exposure to stressors significantly decreased the body weight, food and water intake whereas amygdala lesioning significantly increased the body weight (P<0.001), food intake (P<0.001) and water intake (P<0.001).However, the stress induced decrease observed in the body weight and food intake of the amygdala lesioned groups was significantly more (P<0.001) during immobilization stress than swimming stress. It can be concluded that amygdala nucleus appears to play a prominent role in minimizing the stress induced changes in the food intake and body weight; and this role was more evident in immobilization stress than a physical stress. Thus, the present study support the notion that the amygdala nucleus play a definite role in minimizing stress induced changes in the ingestive behavior and its role in psychological stress is more prominent.