Inclusion Criteria:

General Inclusion criteria:

• Subjects under 60 years are only male.
• Subjects from 60 to 85 may be male or female
• Subjects that have a Health insurance
• Subjects will be asked to refrain from caffein for at least 12 hours

Specific inclusion criteria for part 2:

• Subjects with

Specific inclusion criteria for part 3:

• Subjects with Alzheimer diseased based on the DSM IV and NINCDS-ADRDA criteria. With a MMS between 15 and 26 (included).
• Subjects capable of giving an informed consent and accompagined by a person of confidence

Specific inclusion criteria for part 4:

• Subjects with ADNFLE with or without demonstrated mutation on the nicotinic receptors

Exclusion Criteria:

General exclusion criteria:

• Subjects with abnormal MRI findings at visual inspection
• Subjects with a history of significant medical disordres, or requiering chronic treatment that interfere with the cholinergic system
• Subjects with abnormal plasma biological analysis
• Subjects with significant past and present history of hypertension, cardiovascular disease and diabetes mellitus
• Subjects who have pacemakers, aneurysm clips (metal clips) metallic prostheses (including heart valves and cochlear implants) or shrapnel fragments.
• Subjects incapable of giving an informed consent

Specific exclusion criteria for part 2:

• Subjects with a smoking history in the last five years

Specific exclusion criteria for part 3:

• Subjects with a smoking history in the last five years

Specific exclusion criteria for part 4:

• Subjects with a smoking history in the last five years