Nerve fiber structures (IMAGE) Forschungszentrum Juelich Caption The fiber structure of pigeons and various mammals in comparison. The 3D-PLI method shows the directions of the nerve fibers color-coded. The depictions seen here do not reflect the true sizes - a human brain is about 500 times larger than pigeon brain. Credit Copyright: HHU Düsseldorf / Herold et al. Usage Restrictions Please give credit. 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.