Researchers discovered that an abundance of white blood cells in the spleen can send messages to the brain which trigger behavioral changes after mice endure repetitious stress. The behavioral change comes in the form chronic anxiety. Researchers say that this study only reinforces the idea that the immune system is a relevant target for treatment of mental health conditions.
The goal of the study is to fully describe the relationship between the immune system and stress in animals that experience “repeated social defeat” so doctors may improve the well-being of patients who suffer from chronic psychological stress.
In this study, researchers determined that the immune cell changes persisted for almost a month after the mice experienced the stress. Stem cells move from the bone marrow to the spleen and become white blood cells, making it a reservoir of inflammatory cells which can cause anxiety and other cognitive problems. One researcher described the spleen’s reservoir of white blood cells as “stress memory”.
In their previous work, Ohio State researchers have documented an increased prevalence of long-term anxiety and depression in mice exposed to chronic stress, a model that has been compared to post-traumatic stress disorder in people.
The research was supported by the National Institutes of Health.