1. Clarian Neuroscience Institute, Indianapolis Neurosurgical Group, and Indiana University Department of Neurosurgery, Indianapolis, Indiana;
2. College of Medicine, University of Illinois at Urbana-Champaign, Urbana, Illinois;
3. University of California, Irvine, Orange, California; and
4. Section of Pediatric Neurosurgery, Children's Hospital; and
5. Department of Cell Biology, University of Alabama at Birmingham School of Medicine, Birmingham, Alabama