A spatial map of lipids across the adult mouse brain could provide a reference for investigating lipid biomarkers in neurological disease, according to a study published in Nature.
The work was led by Luca Fusar Bassini and colleagues at the École Polytechnique Fédérale de Lausanne in Switzerland. The researchers examined how membrane lipids are organized across brain regions, cell types, neural connections, and physiological states.
Lipids form cell membranes and are major components of myelin, axons, dendrites, and synapses. Altered lipid metabolism has been associated with several neurological conditions, but interpreting these changes requires an understanding of normal lipid variation across the brain. Measurements from bulk tissue may overlook this spatial complexity.
The team used matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) to analyze 109 brain sections from 11 mice. The method used a 5-µm laser spot and 25-µm spacing between measurement points, producing lipid data from 7.2 million locations.
The initial analysis detected 26,874 mass spectral peaks, of which 1,400 passed noise-quality checks. Downstream analyses focused on 172 nonredundant lipids annotated with high confidence. The imaging data were aligned with the Allen Mouse Brain Atlas to compare lipid patterns with established anatomical, cellular, and connectivity information.
Computational analysis divided the brain into 539 lipid-defined regions, termed “lipizones.” These regions distinguished grey matter, white matter, cortical layers, ventricular structures, and other anatomical areas.
For biomarker research, the findings show that lipid concentrations must be interpreted in their anatomical context. A lipid associated with disease in one region may have a different baseline abundance or biological role elsewhere. The atlas could therefore help researchers select appropriate sampling locations, interpret tissue-based lipidomic results, and distinguish disease-related changes from normal regional variation.
The lipizones also revealed differences in oligodendrocyte and myelin-associated lipids across white matter. Some lipid patterns linked distant but connected brain regions, indicating that spatial lipidomics may capture information about axons and their terminals that is not readily available from gene-expression maps alone.
Pregnancy produced broader lipid changes than those observed between male and nonpregnant female mice. These included altered sphingolipid signals in white matter and localized remodeling in cortical layer 4. The findings highlight physiological state as another variable that may affect lipid biomarker interpretation.
The atlas may support future comparisons with mouse models of neurodegenerative, demyelinating, metabolic, or inflammatory disease. However, it does not establish diagnostic biomarkers, and findings in mice require validation in human tissue and clinical samples.
This article was originally published by our sister publication, The Analytical Scientist.
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