Actin Fibers (IMAGE) University of North Carolina Health Care Caption Left: Green actin fibers create architecture of the cell. Right: With cytochalasin D added, actin fibers disband and reform in the nuclei. Credit UNC School of Medicine Usage Restrictions credit properly 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.