Brain Injury (image) University of Pennsylvania School of Medicine Share Print E-Mail Caption SNTF stained axons (brown) shortly after traumatic brain injury are pictured. The undulating course suggests damage to the internal skeleton, and the SNTF stain shows the high calcium concentration- activated enzymes that destroy the axon from the inside out. Credit The laboratory of Douglas Smith, MD, Perelman School of Medicine, University of Pennsylvania Usage Restrictions None Share Print E-Mail 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.