1Laboratoire de Neurobiologie Cellulaire et Neuroendocrinologie, CNRS UMR 6558, Université de Poitiers, 86022 Poitiers-Cedex, France;
2Faculté des Sciences de Fés, Laboratoire de Physiologie Animale, Fés, Morocco;
3Section on Neuroendocrinology, Laboratory of Developmental Neurobiology, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892-4480, USA
4Corresponding Author and address: Jack Falcón, Section on Neuroendocrinology, Laboratory of Developmental Neurobiology, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892-4480, USA
Received 13 October 1999; accepted 7 november 1999
Acknowledgements: The study was supported by the CNRS, University of Poitiers, and Fondation Langlois (Rennes). We thank Françoise Chevalier, Gaël Epistolin and Nathalie Girard for their technical assistance.