This Funding Opportunity Announcement (FOA) for Exploratory/Developmental (R21) grant applications seeks to enable neuroscience and behavioral research by soliciting research and development of novel, or significant enhancement of existing, tools and approaches to be used in brain and behavioral research. Such tools and approaches should be widely usable and could include those used for basic research, clinical research, or clinical use (e.g., assessment, diagnosis, and treatment of brain disorders). Research solicited under this program announcement is not limited to any particular type of technology, level of analysis, or approach. Multidisciplinary teams of researchers are encouraged to apply. Technologies appropriate for study, development and enhancement under this FOA include hardware, software, and wetware (and combinations thereof).