As summarized in the 2003 National Sleep Disorders Research Plan (http://www.nhlbi.nih.gov/health/prof/sleep/res_plan/index.html), multiple scientific areas in sleep and sleep disorders need additional research. In addition, therapy for a number of sleep disorders remains suboptimal, and the research workforce addressing sleep science is insufficient. The NHLBI, National Center on Sleep Disorders Research, and co-sponsoring member Institutes and Centers of the Trans-NIH Sleep Research Coordinating Committee therefore invite submission of grant applications proposing research to advance biomedical knowledge related to sleep or sleep disorders, improve understanding of the neurobiology or functions of sleep over the life-span, enhance timely diagnosis and effective treatment for individuals affected by sleep-related disorders, or implement and evaluate innovative community-based public health education and intervention programs. Because the nature and scope of the proposed research will vary from application to application, it is anticipated that the size and duration of each award will also vary. The total amount awarded and the number of awards will depend upon the mechanism, numbers, quality, duration , and costs of the applications received.