This FOA seeks applications for proof-of-concept testing and development of new technologies and novel approaches for recording and modulation of neural cells and circuits, to address major challenges and enable transformative understanding of dynamic signaling in the central nervous system. Preliminary feasibility data are not required, and it is expected that the proposed research may be high-risk, but if successful could profoundly change the course of neuroscience research. Applications may propose development of instrumentation hardware and/or devices and associated software, and/or molecular constructs for sensing and manipulating neural activity. Approaches may utilize any modality such as optical, electrical, magnetic, or acoustic recording/manipulation, to target neuronal electrical signals or other forms of neural activity, including intracellular signaling and engagement of non-neuronal cells in circuit function.