Yanjun Sun

The Sun lab aims to elucidate the neural circuit mechanisms that underlie learning and memory, with a focus on spatial navigation and contextual representation in both health and disease. Understanding one's environment and remembering relevant context are essential for survival, and the hippocampus plays a central role in these processes. We are particularly interested in how the hippocampus and subiculum encode complex features of the environment—such as boundaries, corners, and 3D geometry—and how these representations guide behavior and memory formation. Our lab combines in vivo calcium imaging, viral-genetic circuit mapping, single-cell and spatial transcriptomics, and computational modeling to investigate how specific cell types in the hippocampal formation contribute to spatial coding, memory, and disease-related circuit alterations. For example, we recently discovered that distinct populations of subicular neurons encode concave and convex geometric features—providing insight into how the brain reconstructs spatial layout. We also identified hippocampal neurons that are selectively engaged during drug-context associations, laying the groundwork for developing targeted interventions for addiction.