Our lab studies the brain from its surroundings. Specifically, we seek to understand how cerebrospinal fluid (CSF) and the choroid plexus shape the brain microenvironment in brain aging and neurodegenerative disorders like Alzheimer’s disease. CSF bathes the entire central nervous system, providing a rich menu of active factors for brain cells and promptly removing their wastes. Most of CSF is produced by the choroid plexus, a secretory epithelial tissue that also forms the blood-CSF barrier to selectively gate the entry of blood-borne molecules and immune cells into the brain. In our lab, we use longitudinal in vivo imaging approach combined with neuroimmunology and multi-omics tools in rodent models and human tissues to answer the pressing questions: how does age- and disease-driven choroid plexus dysfunction harms brain microenvironment? How are the damages propagated to brain cells and accelerate neurodegeneration? Can we reverse or supplement for the deficits by taking advantage of the choroid plexus and its exceptional ability to secrete factors? Together, we aim to develop mechanisms to fine-tune and improve brain microenvironment and inspire new therapies.