A new study with mice may explain why we feel anxious when we’re under stress. Researchers found that when mice were exposed to prolonged stress, immune cells called monocytes were “called up” to the brain.
Study researcher John Sheridan, professor of oral biology and associate director of Ohio State’s Institute for Behavioral Medicine Research says, “In the absence of tissue damage, we have cells migrating to the brain in response to the region of the brain that is activated by the stressor. In this case, the cells are recruited to the brain by signals generated by the animal’s interpretation of social defeat as stressful.” The study was published in the Journal of Neuroscience.
The study mice were put through the kind of chronic stress a person might experience. In mouse terms, the process included letting a group of male mice live together long enough to establish a “hierarchy.” Later, an aggressive male mouse was added to the group. Feelings of “fight” or “flight” were triggered among the other male mice. The researchers found that the more cycles the mice went through, the higher their levels of anxiety. They also saw a connection between growing levels of anxiety and higher monocyte levels in the brains of the mice.
Researchers from Northwestern University’s Feinberg School of Medicine recently found that the “love hormone” oxytocin may also play a part in causing anxiety. Their study, also carried out with mice, found that oxytocin prompts the recall of past stressful situations, but can also boost anxiety and fear in response to the thought of future stress….. huffingtonpost.com 9/2/13