Scientists have spent decades studying the brain's cells, connections, genes, and proteins. Yet another essential part of brain biology has received far less attention: lipids. These fatty molecules make up the membranes surrounding neurons, contribute to the myelin insulation that protects nerve fibers, and play important roles in communication between brain cells.
Although lipids are fundamental to brain function, scientists have struggled to map where different types are located. Conventional imaging techniques cannot easily distinguish individual lipid molecules, leaving a major gap in our understanding of the brain's chemical organization. "So scientists have had only a blurry picture of how lipids differ from one part of the brain to another," says Giovanni D'Angelo, professor at The Kristian Gerhard Jebsen Foundation Chair in Nutrition and Metabolism at EPFL.
"That gap matters, because changes in brain lipids are increasingly linked to conditions from depression to Alzheimer's disease." Researchers at EPFL have now taken a major step toward filling that gap. A team led by D'Angelo, Luca Fusar Bassini, and Gioele La Manno has created a detailed map showing how lipids are distributed throughout the mouse brain. Their Lipid Brain Atlas reveals that these molecules are arranged in highly organized patterns.
Some match familiar anatomical structures, while others expose chemical boundaries that previous approaches had overlooked. The patterns are so distinctive that researchers could identify where a brain tissue sample originated simply by examining its lipid composition. Scientists Identify 539 Distinct Chemical Zones in the Brain To construct the atlas, researchers used mass spectrometry imaging, a technique that allows them to identify lipid molecules across thin sections of brain tissue.
A laser scans each slice one location at a time, producing detailed information about which lipids are present and where they are found. The team examined 172 different lipids in 109 brain slices collected from 11 mice. This generated approximately 7 million measurements, which scientists combined into a comprehensive 3D reconstruction using machine learning tools developed specifically for the project.
The resulting atlas revealed 539 chemically distinct territories, which the researchers named "lipizones." Each has a characteristic combination of lipids, creating a recognizable chemical signature. Many of these regions correspond to established brain structures and cell types. Others reveal unexpected relationships between groups of nerve cell bodies and distant regions connected by their fibers.
Extract — continue reading at the source.
