The purpose of this study is to investigate the relationship between the plasma concentrations of the study drug and the amount of the study drug bound to the D3 receptors of the brain after dosing of a new compound GSK618334.

This imaging study will be an open label, non-randomised PET receptor occupancy study using healthy male volunteers. The time course and degree of D3 receptor occupancy (RO) after single doses of GSK618334 will be determined using 11C-PHNO as a PET ligand labeling dopamine receptor. The PK/PD relationship between plasma concentrations of GSK618334 and D3 RO will be described. Potential relationships between D3 RO and functional magnetic resonance imaging (fMRI) endpoints will be assessed as an exploratory aim.

Inclusion Criteria:

• healthy, male subjects aged between 30 and 55 old inclusive.
• normal body weight.
• normal ECG and vital signs.
• agree to use acceptable contraceptive methods required.
• capable of giving written informed consent.

Exclusion Criteria:

• smoker or uses other nicotine-containing products.
• certain medical conditions including heart disease, neurological disease, gastrointestinal disease, kidney or liver dysfunction - abnormal laboratory tests.
• certain psychiatric conditions and use of certain psychoactive drugs .
• positive blood alcohol or urine drug test.
• alcohol intake over 14 drinks per week.
• participation in another drug trial within 30 days or a study involving significant radiation exposure.
• donation of more than 450 mL blood within the 56 days.
• family history of cancer (one or more first-degree relative diagnosed before the age of 55 years old).
• having cardiac pacemaker or other electronic device.
• suffers from claustrophobia or feels that he will be unable to lie still on his back in the PET camera.

Patient-level data for this study will be made available through www.clinicalstudydatarequest.com following the timelines and process described on this site.