Our immune system reacts to stress in a stronger way than expected.
Experiments with mice, conducted at Ohio State University, discovered new properties of the immune system. Monocytes, contained in the tissues and blood, are able to produce symptoms of anxiety. This could be one of the reasons for the bad mood when having stress. It could also help combat such conditions.
During the experiment, social stress was induced in rodents: an extremely active male was integrated into the mouse family. The animals involuntarily obeyed him, which made them systematically feel anxiety and stress. The extent of anxiety and stress depended on the frequency of experiencing social defeat. It is worth mentioning a previously proven fact that microglia (the environment that supports the nervous tissue) is the first level of protecting the brain from immune agents. It activates its immune effect during the prolonged stress, making the monocytes penetrate into the brain from the blood and bone marrow.
The scientists have found an equitable two-way communication between the peripheral and central nervous systems. This relationship also affects the behavior. Monocytes are inflammatory cells that rush to the affected area. They typically appear in the muscle tissue or organ parenchyma in case of a trauma, but when a person experiences stress they stream into the nervous tissue of the brain, causing an inflammatory reaction there, which slightly violates the structure of the gray and white matter and affects the centers of fear and anxiety. These centers are located in the frontal lobe, hippocampus and amygdala.