1. Department of Neuroscience, School of Medicine, Korea University, Seoul 136-705, Korea
2. Department of Biotechnology, School of Life Sciences and Biotechnology, Korea University, Seoul 136-701, Korea
3. Dipartimento di Scienze Farmaceutiche and Dipartimento di Medicina Clinica e Sperimentale-Sezione di Farmacologia, Universitià, di Ferrara, 44100 Ferrara, Italy