discovered fear triggers in the brain
RWTH researchers involved in the study on the relationship between anxiety and Dopmanin
Coward or cool sock: How fearful or brave a person is depends, among other things, certain processes in the brain. An international team of scientists with the participation of Professor. Dr. med. Gerhard Gründer, head of the teaching and research area Experimental Neuropsychiatry RWTH was able to show for the first time that for anxious people a high concentration of dopamine in the amygdala present. This so-called amygdala is located in the temporal lobe below the cortex. Fueled or reduces the anxiety also is a more or less intensive exchange of this brain region to the anterior cingulate. The new basic research results, which were recently published in the prestigious specialist journal Nature Neuroscience, will help to develop new pharmacological and behavioral therapies for people with panic and other anxiety disorders.
"The knowledge that dopamine acts as an anxiety trigger is fundamentally new," reports the Aachen scientist. So far, this messenger substance - also popularly known as the happiness hormone - has been known to play a role in happy expectations. In addition, it has been scientifically proven that a reduced occurrence of dopamine in the brain stem is the cause of the movement disorders in Parkinson's patients, according to the deputy director of the Clinic for Psychiatry and Psychotherapy at the University Hospital Aachen.
With the help of a combined imaging process, the scientists have now succeeded in documenting the dopamine relevance in fear.
"In a first step, our test subjects were given a precursor of the messenger substance," reports the Aachen psychiatrist. This radioactive substance is converted into dopamine in the body - a neurochemical process that can be visualized in a positron emission tomograph (PET) and thus shows the dopamine concentration in the amygdala. In a subsequent examination in the magnetic resonance tomograph, the subjects were shown fear-inducing images and the reaction of certain areas of the brain to the presentation of these images was measured. In addition, the tendency of the test persons to be anxious was recorded with the help of a scaled questionnaire. "We were interested in the functional connectivity between the amygdala and the anterior cingulum in the frontal cortex," explains Gründer. It was shown that an intensive exchange of these two brain areas had an anxiety-reducing effect in the test subjects: "The more the brain areas communicated with one another, the lower the activity of the amygdala in perceiving stimuli that triggered fear."
The knowledge gained helps to better understand the neurobiology of fear in order to regulate it if necessary in the case of pathological disorders. Even if the dopamine concentration and the interaction between the amygdala and the anterior cingulum are certainly genetically and biographically shaped: According to the Aachen psychiatrist, the neurobiological control loop can be broken through psychotherapy and drugs. "In psychotherapy, patients can learn to control their fear perception over the long term by changing their behavior."
Source: Aachen [RWTH]
