1. Laboratoire de Neurobiologie Cellulaire, Département des Neurosciences, CNRS-UMR 6558, Faculté des Sciences (V.B., J.F.), F-86022 Poitiers, France
2. the Department of Biology, University of Houston (G.M.C.), Houston, Texas 77204-5513
3. the Section on Neuroendocrinology, Laboratory of Developmental Neurobiology, National Institute of Child Health and Human Development, National Institutes of Health (D.C.K., S.L.C.), Bethesda, Maryland 20892