01:02am Monday 23 October 2017

Anxiety is not overcome in the brain’s fear center

Generally, the hippocampus, the switching point in the brain’s limbic system “transmits” information about memory and emotions to many other regions of the brain. According to the researchers, this can happen in two different ways: “Either like a radio station broadcasting its program and each person taking the bit that interests them, or like the post with specific addressees for different bits of information,” explains Klausberger, Head of the Department of Cognitive Neurobiology.

Using the “memory”, “goal-oriented behavior” and “anxiety” functions, the MedUni Vienna scientists investigated the flow of information. They were able to show that, in the case of memory, the information flow is widespread, possibly because several regions of the brain are involved with memory. However, in the case of goal-oriented behavior or anxiety, the hippocampus sorts the information and, using different neurons, sends it very specifically to those specialized centers in the brain responsible for these functions.

Causes of anxiety and how it is processed
However, at the same time they also discovered that anxiety is coded by certain neurons in the hippocampus and preferentially forwarded to a region that has not previously been associated with this function. If a person is anxious, the hippocampus does not pass the information to the amygdala, where feelings of fear are normally processed but to the prefrontal cortex, where decisions are made. Klausberger: “For example, imagine you are setting off on a very high “skywalk” in the mountains and you are anxious and unsure whether to proceed. In order to see the view, your curiosity has to prevail and overcome your anxiety. The decision of whether to indulge your curiosity and step out or to stay where you are and keep safe is taken in the prefrontal cortex.” Klausberger: “This answers a very basic question of neurobiology, namely how feelings of anxiety are manifested and processed in the brain.”

It is important to make a clear distinction between anxiety and acute fear, for example if you suddenly encounter a rattlesnake or a shark in the wild, which is often accompanied by the “freeze” response.

The information flow in the neurons of the hippocampus was analyzed in an animal model by means of an optogenetic and electrophysiological research method that uses light stimuli.

Five research clusters at MedUni Vienna
In total, five research clusters have been established at MedUni Vienna. In these clusters, MedUni Vienna is increasingly focusing on fundamental and clinical research. The research clusters include medical imaging, cancer research/oncology, cardiovascular medicine, medical neurosciences and immunology. In terms of content, this work falls within the subject area of the medical neuroscience cluster.

Service: Science
“Selective information routing by ventral hippocampal CA1 projection neurons.” S. Ciocchi, J. Passecker, H. Malagon-Vina, N. Mikus, T. Klausberger. Science, April 30, 2015.


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