(IMAGE) Institute for Bioengineering of Catalonia (IBEC) Caption Light microscopy image of a section of post-mortem human frontal cortex from a patient with Braak grade VI (most advanced) Alzheimer's disease. Neurons with high levels of tau protein can be seen. Credit Institute for Bioengineering of Catalonia (IBEC) Usage Restrictions Give credit License Original 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.