Pelizaeus Merzbacher Disease in Brain (IMAGE) University of Wisconsin-Madison Caption White areas in the brain of a healthy dog show axons (neural conductive fibers) with normal myelin sheathing (white) are pictured. The brain of a dog that models a genetic disease called Pelizaeus Merzbacher shows a total absence of myelin insulation. Studies in the lab of Ian Duncan at the University of Wisconsin-Madison suggest myelin may slowly develop in the spinal cord but not brain in this often-fatal disease. Credit Josh Mayer Usage Restrictions None License Licensed content 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.