Introduction and Perspectives This volume is based on the proceedings of the 7th annual symposium on the topic Neuroimmune Circuits, Infectious Diseases and Drugs of Abuse, Bethesda, Maryland, Oc- ber 7-9, 1999. This symposium, as in the past, focused on newer knowledge concerning the relationship between the immune and nervous systems with regards to the effects of drugs of abuse and infections, including AIDS, caused by the immunodeficiency virus...