Plaques And Tangles (IMAGE) WashU Medicine Caption Tissue from the hippocampal region of the brain is stained brown to display the tau protein. The triangular shapes are neurofibrillary tangles. Amyloid plaques are the round, less dense structures, which contain amyloid-beta, but are stained only for tau in this image. Credit Washington University School of Medicine 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.