Learning and memory are associated with oscillations in the activity of neural networks in the hippocampus and its associated structures. Many theories of memory propose key roles for these oscillations in memory storage and retrieval, but testing these ideas requires new approaches to determine the activity of defined neural populations during network oscillations that accompany learning and memory. To address this challenge the project will develop and apply state-of-the-art tools to enable kilohertz frame rate imaging of neural activity reported by genetically encoded voltage sensors targeted to specific neural populations. The project will provide training in the development of imaging tools and cutting edge methods for systems neuroscience. The project will be well suited to candidates aiming to apply engineering skills to neuroscience questions, or to candidates with a strong background in neuroscience who wish to contribute to development of transformative new technologies. All candidates should aim to contribute to a new understanding of brain function and provide a foundation for novel future investigations of brain disorders.