%B Neuroimage %I Elsevier %T Brain synaptic efficiency is preserved in early but not in late stages of Alzheimer's disease: A PET-FDG stimulation study %P S344 %L eprints3427 %A Pietro Pietrini %A Maura L. Furey %A Alessio Dani %A Gene E. Alexander %A Marc J. Mentis %A Ulderico Freo %A Stanley I. Rapoport %A Mark B. Schapiro %D 1997 %C Copenhagen, Denmark