Researchers funded by the National Institute of Mental Health (NIMH) have discovered a high tech way to quell panic in rats. They have detected the brain’s equivalent of an “all clear” signal, that, when simulated, turns off fear. The discovery could lead to non-drug, physiological treatments for runaway fear responses seen in anxiety disorders. Rats normally freeze with fear when they hear a tone they have been conditioned to associate with an electric shock. Dr. Gregory Quirk and Mohammed Milad, Ponce School of Medicine, Puerto Rico, have now demonstrated that stimulating a site in the front part of the brain, the prefrontal cortex, extinguishes this fear response by mimicking the brain’s own “safety signal.”