Hidden Origin of Anxiety Discovered in the Brain—and Scientists Now Know How to Stop It

Scientists have figured out where anxiety lives in the brains of mice, and better yet, how to control this emotion so to reduce its effect in stressful situations. The US team hopes this research can be replicated in humans and may one day treat certain anxiety-inducing conditions.

Anxiety appears to originate in an area of the brain called the hippocampus, according to the researchers' study on mice published online in Neuron. The team inserted tiny microscopes into the mice brains and recorded brain activity as the mice moved freely. Science Alert reported. The mice were then placed into environments known to induce stress. In this case, the stressful environment was made up of labyrinths in which some pathways led to open areas, NPR reported. Mice are naturally nervous in open areas as they are more vulnerable to predators here. As the mice roamed the dangerous environment, the microscopes in their brains began to pick up increased neural activity in the ventral part of the hippocampus.

Related: Anxiety, Stress and Depression At All-Time High Among Americans: Study

Once the team was able to identify the cells that became activated when the mice were anxious, they then then attempted to “switch” the cells off through a process known as optogenetics. In simplest terms, this procedure involves using light to control the brain. According to Scientific American, the process is really a combination of genetics and optics. Researchers specifically insert cells that are responsive to light into areas of the brain that they want to learn more about. By doing this, they can then use light to turn the cells on and off to better understand how the brain works with and without these cells.

02_02_mouse Mice with their anxiety cells switched off were more fearless in the stressful enviroments. Koichi Kamoshida/Getty Images

In this study, the team used light to turn off the anxiety cell. As a result, there was less activity in the anxiety cells in mice exposed to the same environment. In addition, the team purposely turned these cells “on” when the mice were in safe environments. They observed that this resulted in anxious behavior such as being less inclined to explore their environment, even though the environment posed no dangers.

Related: Sleeping Less Than Eight Hours Linked To Depression And Anxiety In New Study

Although the study was only carried out in mice, the researchers believe our anxiety cells likely exist in the same area of the brain.

"Now that we've found these cells in the hippocampus, it opens up new areas for exploring treatment ideas that we didn't know existed before," study research Jessica Jimenez from Columbia University's Vagelos College of Physicians & Surgeons said in a statement.

The next step is to learn if these cells are molecularly different from other types of brain cells. Figuring this out will help to identify receptors on the anxiety cells that may be a target for potential drugs.