Simulations of Filopodia (IMAGE) University of Copenhagen - Niels Bohr Institute Caption Computer simulations of filopodia dynamics indicate that a rotating actin structure inside the tube results in friction between the membrane and the actin, leading to the spiral form that is observed. Credit (Credit: Niels Bohr Institute) Usage Restrictions (Credit: Niels Bohr Institute) 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.