Assessment of behavioral and anatomical changes in anterior Cingulate gyrus and Substantia nigra in stressed adult albino mice

Abstract

Introduction-Stress is defined as a reaction of the brain to external factors or internal situations, and which in turn controls the behavioral responses according to the situation. The neurons of the cognitive areas of the brain like cingulate gyrus and substantia nigra, which are mainly involved in memory and decision making are susceptible to stress. However, the magnitude of the effect depends upon two crucial factors the duration and nature of stress. Method- To investigate this,on adult Albino mice two type of stress procedure that is restraint and foot shock stress, was applied for the duration of 5days (short duration) and 21 days (long duration).In restraint stress mice were stressed 6 hrs/ day in a wire mesh restrainer while in foot shock stress mice were given intermittent electric foot shock using foot shock apparatus for three hours per day for the duration of 5 and 21 days. Result-The results of the behavioral tests showed that the severity of memory and learning deficit increased with the duration of stress irrespective of nature of stress. Severe neurodegenerative changes seen in anterior cingulate gyrus and substantia nigra on prolonged exposure to stress, hypertrophy of adrenal cortex and gastric ulcers observed in stressed animals compared to their age matched controls confirms the effect of stress. Conclusion- The study reveals the effect of stress on structural and functional plasticity, how it disturbs the cognitive process like learning and memory, how it results in behavioral deficits and will help us in understanding the neurobiology of the psychiatric disorders.