Abstract
In-vivo neuroimaging allows the investigation of brain circuits involved in the experience of anxiety and of receptor changes associated with anxiety disorders. This review focuses on studies by research groups who have compared brain activation maps in different forms of anxiety and on binding studies of the benzodiazepine-GABAA receptor. Activation studies have revealed the involvement of many brain areas depending on the condition and the paradigm. However, the orbitofrontal cortex/anterior insula and the anterior cingulate are implicated in all the studies and may represent the nodal point between somatic and cognitive symptoms of any form of anxiety. Most studies of binding at the benzodiazepine-GABAA receptor are not interpretable because of substantial methodological problems, however, regional and/or global reductions are the most consistent finding in panic disorder.