Anxiety Disorders
Anxiety has been developing a larger presence in the public eye. This is due to not only ever the increasing numbers of people affected by anxiety, but also to more public awareness programs. Although it is normal to have some stress and anxiety in life, when that anxiety is affecting your daily activities it can become hard to deal with. This is where treatment such as medication, therapy, or exercise can be utilized.
What Is Happening In The Brain
The brain region called the dentate gyrus (DG), the hippocampus, and the amygdala have been implicated in the molecular signaling pathways contributing to high levels of anxiety. Glucocorticoids use glucocorticoid receptors to initiate the ERK-MAPK pathway, resulting in the kinases (enzymes that catalyze phosphorylation) MSK1 and Elk-1 to be activated. Histone H3 is acetylated and phosphorylated by them – this will ‘tag’ the histone – and causes typically silent genes to be transcribed.
In studies using animal models, these molecular signaling mechanisms have proven to play an important role in long-term behavioral modification. GABA also plays an important role in the hippocampus and memory formation. The problem with anxiety disorders such as PTSD is an inappropriately strong negative memory formation to stressful situations.
In summary, an individual’s environment causes a challenge, which causes activation of histone, which leads to epigenetic changes. Because of those changes, we are getting gene expression in the DG that leads to memory formation in the hippocampus. Anxiety makes this worse: treat the anxiety and this can be somewhat lessened.
Negative Memory Bias
In our class discussions, we questioned whether or not people suffering from depression also form the strong negative memories associated with anxiety disorders such as PTSD. In my research, I found that patients with depression typically exhibit a negative memory bias, in which there is an inaccurate recollection of frequency, duration, or specific details of past occasions and occurrences.
Patients have been found to remember more negative than positive words in free-recall tasks, and researchers have also found that it takes significantly longer to retrieve happy memories while in a depressive state than in a happy mood state, and negative memory retrieval time was unaffected by mood state. The negative memory bias typically affects only memories involving the self; this could be due to depressed individuals holding more negative self-schemas.
Exercise and Reducing Anxiety
Exercise is being prescribed more and more by doctors as a way to reduce stress and anxiety. Animal models for researching anxiety have shown that access to voluntary exercise has major benefits on their health, such as better sleep quality, neurogenesis in the DG, and improved cognitive, impulsive, and emotional behavior. Exercise increases the amounts of GABA and decreases amounts of ERK, both of which lead to less of the histone tag discussed earlier. This means you are not making the stress-induced memories causing anxiety.
Society has become more focused on exercise in relation to physical health, but there are many more benefits than just that. The endorphins and neurotransmitters released through exercise are helpful in combating not only depression and stress, but also anxiety too.
