Alterations in monoamine levels and oxidative systems in frontal cortex, striatum, and hippocampus of the rat brain during chronic unpredictable stress

Replacement Stress Article

Because all of us, as psychology majors feel stressed most of the time, I thought it appropriate to research chronic stress to see if what is happening physiologically. The frontal cortex and striatum have high dopamine content, while the hippocampus has a high concentration of gluco-corticoid receptors. These brain regions are connected to each other and have been proposed to play a role in stress responses. In the present study, the researcher hypothesized that these brain regions could be vulnerable to chronic stress exposure, and the changes in central monoamine levels. Rats were the participants of this study, weighing between 180 g and 220 g. For control and stressed groups, three rats were in each cage. The rats were randomly divided into two groups a control non-stress and stressed group. The non-stress group was undisturbed in the cage for a week. The stressed group was subjected to two different types of stressor in an unpredictable manner for a week. The stressed group was divided again into two groups depending on when the rats were to be killed; one group was to be killed immediately following the last stressor and the other group was killed 24 hours after the last stressor. The stressors comprised of fasting, isolation, tail pinching, restraint, overnight wet cage bedding, forced swimming, day-night reversal, cold restraint, water deprivation, foot shock, and cold exposure. This study demonstrated that the rats exposed to the stressed elements had a decrease in dopamine and serotonin levels in the frontal cortex, striatum, and hippocampus. This means that there could be a decrease in neurons in the brain, thus less synapse; meaning that there are less opportunities to increase knowledge intake. This study also demonstrates increased oxidative systems in the frontal cortex, striatum, and the hippocampus. But the monoamine concentrations did not show any significant difference. Although, psychology majors are not privy to the same type of chronic stressors as these rats were, we feel tons of pressure to do well. This study demonstrates what could possibly happen to us if we continue to push ourselves as hard as we do.

 AHMAD, A., RASHEED, N., BANU, N., & PALIT, G. (2010). Alterations in monoamine levels and oxidative systems in frontal cortex, striatum, and hippocampus of the rat brain during chronic unpredictable stress. Stress: The International Journal on the Biology of Stress, 13(4), 355-364. doi:10.3109/10253891003667862

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