The National Institute of Neurological Disorders and Stroke (NINDS), the National Institute on Drug Abuse (NIDA) and the National Institute of Mental Health (NIMH) invite research grant applications aimed at developing non-human lentiviral in vivo model systems for study of the neurologic complications of AIDS, with or without a history of drug use. Recent advances in the development of the SIV model system highlight the power of animal model systems for study of the mechanisms underlying the pathology associated with lentiviral infection in the nervous system. These models will be key for developing therapeutic approaches for the treatment of patients suffering from NeuroAIDS and for understanding the basic biology of infection with HIV/AIDS.