The authors are grateful for the contributions of the Office of the Chief Medical Examiner of the State of Maryland; the Office of the Chief Medical Examiner of Kalamazoo County, Michigan; the Office of the Chief Medical Examiner, University of North Dakota School of Medicine; Gift of Life of Michigan; and the Office of the Chief Medical Examiner of Santa Clara County, California, in assisting the Lieber Institute for Brain Development in the acquisition and curation of brain tissue donations for this study. Additional samples were provided by the Stanley Medical Research Foundation and the University of Maryland Brain and Tissue Bank. The authors are deeply grateful to the brave and generous families who consented to the brain donation of their deceased next of kin. The authors thank Richard Straub, Ph.D., and Shizhong Han, Ph.D., for insightful discussions. The authors thank the Lieber and Maltz families for their support, which funded the acquisition of brain tissue and the analytic work of this project.