1. From the Department of Medicine (H.J., W.Z., X.W., J.L., C.M.E., K.S.) and Center for the Study of Sex Differences in Health, Aging, and Disease (H.J., W.Z., X.W., J.L., C.M.E., K.S.), Georgetown University, Washington, DC; Department of Physiological Science and Laboratory of Neuroendocrinology (R.W., A.P.A.), Brain Research Institute, University of California, Los Angeles, Calif.