Stress and Tau Phosphorylation (IMAGE) Salk Institute Caption Top left: In unstressed animals the hippocampus, which is involved in the formation of memories and learning, is free of phosphorylated tau. Top right: Subjecting mice to low-level chronic emotional stress -- the kind we experience in everyday life—leads to widespread tau phosphorylation, a key step in the formation of neurofibrillary tangles (black streaks), one of the hallmarks of Alzheimer's disease. Bottom: While acute stress effects are reversible, repeated stress leads to cumulative increases in phosphorylated tau, a portion of which is sequestered in an insoluble, and potentially pathogenic, form. Credit Image courtesy of Dr. Paul E. Sawchenko and Dr. Robert A. Rissman, Salk Institute for Biological Studies Usage Restrictions News media reproduction to illustrate this story permitted with proper attribution as provided above. For one time use only. 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.