Declumping Neurons (IMAGE) University of Pennsylvania School of Medicine Caption Dense FUS protein fibrils form in the absence of nuclear-import receptors (NIRs, left), but are disrupted when NIRs are present (right). Credit James Shorter, Perelman School of Medicine, University of Pennsylvania; Cell 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.