The lack of an inhibitory connection in the brain triggers fear
Fear is a collective term for a variety of emotions that are mainly felt in threatening situations. Fears are characterized by insecurity in emotional life. It is considered a prehistoric feeling, which serves as a protective mechanism in avoidable or actual danger situations. In the history of evolution, this emotion helped to recognize dangers in order to be able to react appropriately. But too much fear can also have the opposite effect by blocking the opportunity to act and thus preventing protective behavior in dangerous situations. Conversely, too little fear can hide real dangers and risks.
In search of possible triggers for increased anxiety or phobias, MedUni Vienna may have found an explanation.
The areas responsible for regulating emotional states in the brain, the amygdala (almond kernel) and the orbitofrontal cortex, apparently lack a "braking mechanism" that leads to a calming down when dangerous situations do not assume life-threatening proportions. With the help of functional magnetic resonance tomography (fMRI), the scientists were able to demonstrate to anxiety patients that an important inhibitory compound is present in the brain in a modified form and that they are therefore unable to control their fears. In healthy people, this mechanism causes fear to subside and the body can then return to normal.
In collaboration with the Center for Medical Physics and Biomedical Technology and the University Clinic for Psychiatry and Psychotherapy at MedUni Vienna, the scientists under Christian Windischberger were able to find out how the responsible areas in the brain are involved in emotion processing. From this, conclusions could be drawn as to how far they influence each other. Within the study, subjects were shown images with "emotional faces" while undergoing functional magnetic resonance imaging. These images showed people with emotional facial expressions such as laughing, crying, satisfaction or anger, which triggered neuronal activity in the brains of the test subjects.
The scientists could not see any changes on the outside. In healthy people, however, there was a neuronal braking mechanism that calmed the head. In the case of social phobics, on the other hand, the photos provided an "accelerator" and a very strong neural activity was noticeable "Especially with psychiatric illnesses, it can be assumed that there will not be complete failures, but rather imbalances in complex regulatory processes," said Ronald Sladky, First author of the study. The knowledge gained about the neuronal functions involved should now help to develop new approaches for therapeutic options. (fr)