1. Neuroscience Section, MRC Cyclotron Unit, Hammersmith Hospital, Du Cane Rd, London W12 0HS, Psychopharmacology Unit, University of Bristol, Bristol BS8 1TD, UK
2. Neuroscience Section, MRC Cyclotron Unit, Hammersmith Hospital, Du Cane Rd, London W12 0HS, Epilepsy Research Group, Institute of Neurology, Queen Square, London WC1N 3BG