W. Maxwell Cowan (1932-2002) was an internationally renowned neurobiologist and the chief scientific officer at the Howard Hughes Medical Institute (HHMI) in Chevy Chase, Maryland. Thomas C. SA1/4dhof is an HHMI investigator and professor of molecular genetics at the University of Texas Southwestern Medical Center at Dallas. Charles F. Stevens is an HHMI investigator at the Salk Institute for Biological Studies and adjunct professor of Pharmacology and of Neuroscience at the University of California, San Diego, School of Medicine.