Project Summary/Abstract Neurodegenerative diseases like Alzheimer's, Parkinson's, and Multiple Sclerosis affect millions of people globally. Researchers have made recent advances in studying these diseases by analyzing single cells in postmortem brain tissues. But these diseases are complex and hard to understand. We aim to create a comprehensive atlas of cell types and states in the human brain across the spectrum of neurodegenerative diseases. We plan to do this by harmonizing and analyzing data with BRAIN Initiative-generated reference data using state-of-the-art methods. By creating this atlas, we hope to identify potential targets for therapy and develop new treatments for these debilitating diseases. This project will provide a valuable resource for the neuroscience community by allowing a more comprehensive understanding of the cellular landscape in healthy and diseased brains, facilitating comparisons between normal and pathological conditions.