1. Department of Neurological Surgery, Keck School of Medicine, University of Southern California, Los Angeles, California
2. Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California
3. Vilhelm Magnus Center, Institute for Surgical Research, and Department of Neurosurgery, Ullevål University Hospital and Rikshospitalet, University of Oslo, Oslo, Norway, and Department of Clinical Neuroscience, Karolinska Institute, Stockholm, Sweden