A workshop on Deep brain stimulation (DBS) was held on the NIH campus on March 3, 1999 to discuss the opportunities and needs for further research in DBS. As a result of the recommendations from this workshop the NIH issued an RFA "CONSORTIUM ON DEEP BRAIN STIMULATION FOR THE TREATMENT OF PARKINSON'S DISEASE AND OTHER NEUROLOGICAL DISORDERS" in September 1999. This RFA called for research on animal models, better electrodes and stimulator technology, clinical studies and trials, and studies of the mechanism of action of DBS. In response to the RFA, we have awarded several grants to investigators and have recruited a core group of investigators into a DBS consortium. This follow-up RFA is seeking applications that will expand the consortium and strengthen the research effort in the area of mechanisms of action of DBS. A companion RFA will be issued to request additional research to develop advanced methods of safe and effective stimulation of deep brain structures. As the third arm of the consortium, investigators interested in clinical trials of DBS are encouraged to contact NINDS staff to discuss opportunities to conduct clinical studies and trials in this area.