Lack of connection in the brain triggers anxiety

Lack of inhibitory compound in the brain triggers anxiety

03/12/2013

Fear is a collective term for a variety of emotions, which is felt primarily in threatening situations. Characteristic of fears is the uncertainty of emotional life. It is considered a primitive human feeling, which serves as a protective mechanism in avoidable or actual dangerous situations. In the evolutionary story, this emotion helped to identify dangers and respond to them appropriately. However, too much anxiety can also have the opposite effect by blocking the ability to act and thus preventing protective behavior in dangerous situations. Otherwise, too little fear can hide real dangers and risks.

In the search for possible triggers for an increased sense of anxiety or phobias, the MedUni Vienna may have found an explanation.

The areas responsible for the regulation of emotional states in the brain, the amygdala (almond kernel) and the orbitofrontal cortex, apparently lack one „brake mechanism“, which leads to reassurance when dangerous situations do not take on life-threatening proportions. Using functional magnetic resonance imaging (fMRI), scientists have been able to demonstrate in fear patients that an important inhibitory compound is present in altered form in the brain and thus they are unable to control their fears. In healthy people, this mechanism leads to a subsidence of anxiety and the body can then return to its normal state.

In collaboration with the Center for Medical Physics and Biomedical Engineering and the Department of 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 the processing of emotions. It was possible to draw conclusions about how far they influence each other. Within the study subjects were shown "emotional face" images while undergoing functional magnetic resonance imaging. These images showed people with emotional facial expressions such as laughter, crying, contentment, or anger that triggered neuronal activity in the brain in the subjects.

Externally, the scientists were unable to detect any changes. In healthy people, however, there was a neuronal braking mechanism that calmed the head. In the case of psychophysicists, however, the photos made for an "accelerator" and a very strong neural activity was noticeable "Especially in psychiatric diseases, one can assume that it comes not to complete failures, but rather to imbalances in complex regulatory processes," said Ronald Sladky First author of the study. The gained insights into the involved neuronal functions should now help to develop new approaches for therapeutic options. (Fr)