A team at the Mark and Mary Stevens Neuroimaging and Informatics Institute at USC's Keck School of Medicine has developed a noninvasive method for seeing how blood flow and cellular organization line up across the layers of the living human brain. The work, published in Nature Communications, introduces a metric called the cerebral blood flow-cell-body staining intensity similarity index, or CCSI.
The cerebral cortex is not uniform. Its folded layers differ in how many cells they contain and what types those cells are, and each layer needs a steady delivery of oxygen and nutrients. Until now, researchers have had few ways to check whether blood supply in a living brain actually matches where the cells are concentrated - a question that has mostly been approachable through postmortem tissue.
That matters because the brain stores almost no energy of its own. As the researchers put it, brain cells depend on a constant and tightly regulated supply from the bloodstream, and the new index gives a way to ask whether that supply is positioned where the cellular demand is across different parts of the cortex. The team suggests CCSI could help clarify how blood vessels, cells, and the machinery that produces cellular energy work together to support brain function.
The hope, according to the study authors, is that the measure may eventually reveal early signs of disease and point toward potential treatments. For now, CCSI is a new measurement tool rather than a diagnostic test, and its value will depend on what researchers find when they apply it across healthy and diseased brains.