1. Center for Reproductive Medicine and Infertility, Weill Medical College of Cornell University (J.M.C., Z.R.), New York, New York 10021
2. Laboratory of Neuroendocrinology, Rockefeller University (R.D.R., B.S.M.), New York, New York 10021
3. Department of Psychology, University of California (W.G.B.), Santa Barbara, California 93106
4. Divisions of Reproductive Sciences and Neuroscience, Oregon National Primate Research Center (C.L.B.), Beaverton, Oregon 97006