Bipolar Disorder (BD) is a multifactorial brain disorder in which patients experience radical shifts in mood and undergo periods of depression followed by periods of mania. It has been known for some time that both environmental and genetic factors play important roles in the disease. For instance, being exposed to high levels of stress for long periods, and especially during childhood, has been associated with the development of BD.
Immediate early genes (IEGs) are a class of genes that respond very rapidly to environmental stimuli, and that includes stress. IEGs respond to a stressor by activating other genes that lead to neuronal plasticity, the ability of brain cells to change in form and function in response to changes in the environment. Ultimately, it is the process of neuronal plasticity that gives the brain the ability to learn from and adapt to new experiences.