Brain Research May Lead to Drugs That “Turn Off” Anxiety

A study on rats and anxiety has succeeded in finding a way to “turn off” the anxiety response in rats’ brains using a protein that leads the rats to remember a feeling of safety.

Although further study is necessary, the study suggests it may be possible to produce powerfully effective medications that will mimic the effects of desensitization training and offer hope to those suffering from chronic anxiety and post-traumatic stress disorder (PTSD).

The research, supported by the National Institutes of Mental Health, was conducted by researchers at the University of Puerto Rico School of Medicine and was reported in the June 4 issue of Science.

The study involved first inducing a condition like PTSD by training rats to associate a particular electronic tone with a mild electric shock.  By training the rats to stop moving in order to avoid the shock, the researchers could know that they had trained the rats to fear the electronic tone, even if no electric shock occurred.

Previous studies have used this training to test how well desensitization training works, and researchers have found that the way desensitization works is by creating new, safe memories to replace the old, scary ones that caused the anxiety in the first place.

In this new study, researchers experimented with a protein called brain-derived neurotrophic factor or BDNF.  BDNF is used in the brain to promote connections between synapses, a process involved in learning and memory formation.  By injecting BDNF into a spot in the rats’ brains that is involved in memory formation, the researchers were able to take rats who had been trained to fear an electronic tone and immediately remove their anxiety instantly, producing the same effects that normally take much longer with desensitization training.

The researchers also found that low levels of BDNF made it more difficult for rats to benefit from desensitization training.  Overall, the research offers great potential to develop medications that will assist in the treatment of anxiety and PTSD, according to Dr. Thomas Insel, director of the National Institutes of Mental Health.