This volume contains the proceedings of the ninth "Colloque medecine et recherche" of the Fondation IPSEN devoted to research on Alzheimer's disease. This symposium was held in Lyon on June 21, 1993, on the topic, "Amyloid Protein Precursors in Development, Aging and Alzheimer's Disease." The choice of this venue and of this particular subject was not a matter of chance. As far as the history of medicine and neurology is concerned, Lyon is doubtless one of the most famous cities in France and the F ondation IPSEN had to organize one of its meetings in this city which has been regarded for...