The Alzheimer's disease (AD) is clinically characterized by the progressive appearance of amnesic disorders, which are followed by a clinical syndrome associating aphasia, apraxia and agnosia. In this picture are added behavioural problems, marked for example by decision-making or judgment confusions and disturbances of the orientation. The therapeutic perspectives are based especially on molecular targets that are the peptide Abeta, the protein tau or the facilitating molecular ways of neurodegeneration.