Exploring the link between genetics, chronic stress and depression

Depression is a very debilitating mental illness that affects about 7% of the American Population (aada.org, 2017) and up to about 350 million people worldwide. Since the cause for depression and the reason why some individuals are more vulnerable than others are currently unclear, studying paradigms that model depression in animals, such as the learned helplessness paradigm, is useful to explore possible mechanisms and devise new treatments. To explore a possible link between genetics, chronic stress and depression, we have exposed mice vulnerable to stress to an inescapable forced swim paradigm. During the forced swim test, the mice were monitored to see how “helpless” they were via monitoring and recording movement. Afterwards, mice brains were collected, sliced and stained to assess neuronal activity and examined under a microscope. Increased immobility and reduced neuronal activation were observed in mice vulnerable to stress compared to their control littermates. Further quantification of neuronal activation will inform about brain regions responsible for the learned helplessness model of depression