2002- | Emeritus Professor, MRC Laboratory for Molecular Cell Biology , UCL

1993-2002 | Scientist, MRC Laboratory for Molecular Cell Biology, University College London

1979-2002 | Professor of Biology, Biology Department, University College London

1971-2002|  MRC Developmental Neurobiology Programme, Biology Department, University College London

1969-1971 | Postdoctoral Fellow in Immunology, National Institute for Medical Research, Mill Hill, London

1965-1968 | Resident in Neurology, Massachusetts General Hospital, Boston

1963-1965 | Intern and Assistant Resident in Medicine, Royal Victoria Hospital, Montreal