1. Laboratoire de Chimie Physiologique, I.C.P. and Université Catholique de Louvain, avenue Hippocrate 75, B-1200 Brussels, Belgium
2. Department of Pharmacological Sciences, The Medical School, University of Newcastle upon Tyne, Newcastle upon Tyne NE2 4HH, U.K.
3. Department of Pediatric Neurology, Université Catholique de Louvain, avenue Mounier 10, B-1200 Brussels, Belgium