1. Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, Missouri 63110, USA
2. Laboratories for Neuroscience Research in Neurosurgery, Boston Children's Hospital, Boston, Massachusetts 02115, USA
3. F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, Massachusetts 02115, USA;
4. Department of Neurosurgery, Harvard Medical School, Boston, Massachusetts 02115, USA
5. Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts 02115, USA
6. Spencer Center for Vision Research, Byers Eye Institute, Stanford University, Palo Alto, California 94303, USA
7. Department of Neurology, Harvard Medical School, Boston, Massachusetts 02115, USA