Brain and Body Collaborate to Proactively Prepare Immune Defenses Against Infections

Beijing, July 30 (China News Service) — A paper published in Nature Neuroscience, a professional academic journal under Springer Nature, argues that the brain can detect potential infection sources entering the surrounding environment and prepare the body's immune defenses in advance. This process may even begin in a virtual reality environment before physical contact occurs. The study indicates that the brain and body can actively collaborate to cope with infections.

The paper notes that threats from predators trigger a "fight-or-flight" response, but pathogens (such as bacteria and viruses) often pose a different type of risk silently. Contact with pathogens triggers the body's immune response, including a rapid innate immune cell reaction and a slower adaptive immune response. However, it was previously unclear how the brain and immune system collaborate before an infection occurs.

In this study, co-corresponding authors Camilla Jandus and Andrea Serino from the University of Lausanne, Switzerland, along with colleagues and collaborators, designed an experiment in a virtual reality environment. They exposed 248 healthy young people to virtual human faces—some with visible signs of infection (e.g., rashes or coughing), and others with neutral or fearful expressions. When the seemingly ill virtual figures entered the participants' peripersonal space (the close-range space around the body), the participants showed a stronger response to touch, indicating that the brain's peripersonal space system was in a state of high alert.

Using electroencephalography and functional magnetic resonance imaging to detect brain activity, researchers found that when infectious-looking figures approached, there were changes in the activity of brain regions involved in integrating sensory information and spatial awareness. This reaction did not occur when participants faced neutral or fearful faces. Blood samples from the participants showed that exposure to virtual infected figures was associated with increased activity indicators of innate lymphocytes (a key component of the immune system), which, compared to the control group, was more similar to the response to real infections such as flu vaccines.

The authors conclude that the brain can coordinate early physiological responses to potential infections, preparing the immune system in advance.