Dennis-Dominik Rosmus stood at the microscope in Augsburg, staring not just at brain tissue, but at a revolution in motion—one where over 30 protein markers glowed in concert, revealing cellular conversations never seen before. At the University of Augsburg and Leipzig, Rosmus and his team have pioneered CODEX-CNS, a breakthrough microscopy technique that simultaneously maps more than 30 proteins in human brain tissue, unveiling a hidden population of immune cells lurking near amyloid-β plaques in Alzheimer’s patients. This isn’t just a technical leap; it’s a window into the brain’s cellular ecosystem, offering fresh hope for understanding—and ultimately treating—one of medicine’s most stubborn diseases.
For decades, Alzheimer’s research has been constrained by tools that could only glimpse fragments of the brain’s complexity. Now, CODEX-CNS stitches those fragments into a single, high-resolution tapestry, capturing how cells interact in their natural neighborhoods. The discovery of a distinct microglial population—immune cells clustering tightly around a specific form of amyloid-β plaque—suggests these cells may play a previously unrecognized role in driving inflammation and neurodegeneration. This spatial precision is transformative: it doesn’t just show what cells are present, but where they are and who they’re talking to, a detail critical for decoding diseases like Alzheimer’s and cancer alike.
The implications stretch far beyond dementia. Professor Peter Wieghofer, who leads cellular neuroanatomy at Augsburg, emphasizes the method’s versatility—CODEX-CNS can be adapted to study tumors, retinal diseases, and other organs. Already, Ph.D. student Cavanagh Gohlich is applying the technique to age-related macular degeneration, building on her experience developing CODEX-CNS at Oregon State University with Prof. Bahareh Ajami. As part of the Augsburg Research School (AUGMENT), Gohlich represents the next generation of scientists poised to leverage this tool across neurological and immune disorders.
Published in Nature Neuroscience, the study marks a turning point in spatial proteomics. By decoding the microenvironments that shape cell behavior, CODEX-CNS opens paths to personalized therapies—ones that could target not just plaques, but the very immune responses that fuel disease progression. As research expands, so does the promise: a future where the brain’s secrets are no longer hidden in the dark, but illuminated, one protein at a time.