[11C]Yohimbine PET Study of alpha2-AR

Positron Emission Tomography Study of alpha2-adrenergic Receptors With [11C]Yohimbine

The main purpose of this study is to model tissue specific kinetics of [11C]Yohimbine in healthy male participants by positron emission tomography (PET) and the appropriate arterial input function (part A) ; to determine the reproducibility of measures (classical test-retest study, part B1) and to measure the blocking of [11C]Yohimbine uptake in the brain following single oral dose administration of clonidine (part B2).

Inclusion Criteria:

• Healthy male volunteers
• Age between 20 years and 35 years
• Weight between 50kg and 90kg
• Without neurologic or psychiatric history
• Without head trauma history including loss of consciousness superior to 30 minutes.
• Affiliated to a social security or similar scheme
• Not subject to any legal protection measures
• Participant must have signed an informed consent document indicating that they understand the purpose of, and procedures required for, the study and are willing to participate in the study and comply with the study procedures and restrictions

Exclusion Criteria:

• Allen test (assessing the arterial blood flow to the hand) indicating abnormal blood supply to the hand
• Subject with orthostatic hypotension
• Subject with alcohol or substance abuses history
• Subject with somatic drug therapies
• MRI contraindications (implanted or embedded metal objects in the head or body)
• PET contraindications
• Clonidine contraindications
• Exposed to 1 millisievert or more of ionizing radiation in the year before the start of this study
• Subject unable to sign written consent for participation in the study