The amygdala is a temporal lobe structure in the brain that is critical for aversive emotions, particularly fear. Studies of rats, mice, rabbits, nonhuman primates, and humans indicate that nuclei within the amygdala are involved in the genesis of both innate and learned fears. Understanding the role of the amygdala in fear has led to progress in the development of treatments for disorders of fear and anxiety in humans. 2009 Elsevier Ltd All rights reserved.