1. H. Lundbeck A/S, 2500 Valby, Denmark.
2. Mario Negri Institute of Pharmacological Research, 20157 Milano, Italy.
3. The Kenneth S. Warren Institute, Ossining, NY 10562, USA.
4. University of Messina, 98122 Messina, Italy.
5. Consiglio Nazionale delle Ricerche, Institute of Neuroscience, 20129 Milano, Italy.