1. Department of Biological Sciences (D.K.O., M.S.), University of Delaware, Newark, Delaware 19716
2. Division of Medical Pharmacology (M.S.), Leiden/Amsterdam Center for Drug Research (LACDR), University of Leiden, 2300 RA Leiden, The Netherlands
3. Department of Psychology (M.K.G.), University of Delaware, Newark, Delaware 19716
4. CNS Diseases (G.W.D.), Bristol-Myers Squibb Pharma Company, Glenolden, Pennsylvnia 19036
5. Center for Neuroscience (S.L.), University of California, Davis, California 95616