Myelin Maps (image) Washington University School of Medicine Caption Scientists have found a way to use MRI scanning data to map myelin, a white sheath that covers some brain cell branches. Such maps, previously only available via dissection, help scientists determine precisely where they are at in the brain. Red and yellow indicate regions with high myelin levels; blue, purple and black areas have low myelin levels. Credit David Van Essen Usage Restrictions None Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.