1. Graduate School of Medicine (D.-K.K., S.Y., G.H.S., J.-I.H., C.R.P., J.Y.S.), Korea University, Seoul 136–705, Republic of Korea;
2. Department of Life Science (J.I.K.), Gwangju Institute of Science and Technology, Gwangju 500–712, Republic of Korea;
3. School of Biological Sciences (K.K.), Seoul National University, Seoul 151–742, Republic of Korea;
4. Laboratory of Neuronal and Neuroendocrine Differentiation and Communication (H.V.), Inserm U982, University of Rouen, 76821 Mont-St-Aignan, France