1Department of Anatomy, Charing Cross & Westminster Medical School, St Dunstan's Road, London, W6 8RP, UK
2Cephalon Inc, 145 Brandywine Parkway, West Chester, PA 193804245, USA
3SmithKline Beecham Pharmaceuticals, Molecular Neuropathology Research, New Frontiers Science Park, Third Avenue, Harlow, Essex, CM19 5AW, UK
4McLellan Veterans Affairs Medical Center, 4300 W. 7th St, Little Rock, AR 72205, USA
5Department of Neuropathology, Institute of Neurological Sciences, Southern General Hospital, Glasgow, G51 4TF, UK
6Corresponding Author: Stephen M. Gentleman
ACKNOWLEDGEMENTS: Funded in part by NIH grant AG12411. S.M.G. was an Alzheimer's Disease Society Research Fellow. M.N. was funded on a Wellcome Trust Vacation Scholarship.
Received 28 January 1997: accepted 19 February 1997