The amygdala serves as a communications hub between the parts of the brain that process incoming sensory signals and the parts that interpret them. It signals that a threat is present, and triggers a fear response or anxiety. Emotional memories stored in the central part of the amygdala play a role in a variety of anxiety disorders.

Research has also examined the hippocampus, another part of the brain responsible for processing threatening or traumatic stimuli. Part of the hippocampus’ role is to encode information into memories.

Studies have revealed that the hippocampus tends to be smaller in people who have undergone severe stress because of child abuse or military combat. Researchers believe that this reduced size inhibits the hippocampus from properly processing traumatic events.

Other scientists have determined that the basal ganglia and striatum in the brain are involved in specific anxiety disorders, like OCD.

A 2011 study from Stanford located a part of the brain that could function like an on/off switch.

Researchers found a certain brain circuit that when stimulated in mice proved to inhibit their anxiety, the mice began to freely explore open areas they typically shunned out of fear of predator attacks.

The mice's new willingness to explore open areas of gtheir pen increased significantly as soon as light was pulsed into the novel brain circuit. Pulsing that same circuit with a different frequency of light produced the opposite result and the mice instantly became more inhibited and anxious.

Not surprisingly, the anxiety-reducing brain circuit is located in the part of the brain that is associated with fear. According to one of the researchers in the study, Neuroscientist Karl Deisseroth, a new technique that allowed the reseachers to focus on a singular circuit within that brain structure. By adding photosensitive proteins from algae and bacteria onto certain nerve cells in the brain, they were able to activate or suppress those cells by shining different wavelengths of light onto them.

This new technique, known as optogenetics, will be able to shed more light on anxiety disorders and the possibilities of controlling them, many hope the discovery will lead to new anti-anxiety treatments.

References
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