1. Division of Neuroscience (H.F.U., S.G.K., V.T.G., V.S.D.) Oregon Regional Primate Research Center, Beaverton, Oregon 97006
2. Department of Physiology and Pharmacology (H.F.U.), Oregon Health Sciences University, Portland, Oregon 97201
3. Program in Neuroscience (R.B.W., R.D.F.), Stanford University, Stanford, California 94305