Dietmar R. Thal is in the Department of Neuropathology at the University of Bonn Medical Center, Sigmund Freud Strasse 25, D-53105 Bonn, Germany. Kelly Del Tredici and Heiko Braak are at the Institute for Clinical Neuroanatomy at Johann Wolfgang Goethe University, D-60590 Frankfurt am Main, Germany.(D.R.T.) (At 2004-06-09)