* Just to give away some of the information coming in chapter 15, the neurotransmitter that mediates anxiety via the amygdala is none other than CRH (recall from chapter 5 that CRH mediates other aspects of the stress-response than merely releasing ACTH). Meanwhile, the receptor for the brain chemical that inhibits anxiety is called a benzodiazepine receptor. What is a benzodiazepine? No one is exactly sure what the anxiety-reducing benzodiazepine is in the brain that normally binds to the receptor, but we all know about the synthetic benzodiazepines—these are Valium and Librium, the anxiety-reducing tranquilizers.