Aprepitant and Fosaprepitant Time-on-Target PET (Positron Emission Tomography) Study (0869-183)

Inclusion Criteria: * Generally healthy * Female participants must be of non-childbearing potential * Non-smoker or has not used nicotine or nicotine-containing products for at least 6 months Exclusion Criteria: * History of a clinically significant psychiatric disorder over the last 5 to 10 years * History of stroke, chronic seizures, or major neurological disorder * History of clinically significant endocrine, gastrointestinal, cardiovascular, hematological, hepatic, immunological, renal, respiratory, or genitourinary abnormalities or diseases * History of neoplastic disease * Excessive consumption of alcohol (3 drinks/day) or caffeinated beverages (6 servings/day) * Major surgery, donated or lost 1 unit of blood within 4 weeks * Participated in another investigational study within 4 weeks * History of significant drug allergy or any clinically significant adverse experiences related to EMEND™, dexamethasone, or ondansetron * History of significant multiple and/or severe allergies * History of anaphylactic reaction or significant intolerability to prescription or non-prescription drugs or food * Current drug/alcohol abuse, or history of such within 2 years * Participation in a PET study or other study involving administration of a radioactive substance or ionizing radiation within the prior 12 months * Extensive radiological examination within the prior 12 months * Magnetizable metal prostheses or devices (Magnetic Resonance Imaging (MRI) hazard) * History of claustrophobia