This is a multiple ascending dose study to assess the safety, tolerability and pharmacokinetics of PF-05212377 (SAM-760) administered orally once a day for 14 days to healthy young adults and healthy elderly subjects. The study will be conducted under double-blind conditions (neither the investigator nor the subject will know if he/she has received PF-05212377 or a placebo). The Sponsor will know if the subject has received active treatment or a placebo.

Inclusion Criteria:

• Inclusion Criteria for young healthy population: Healthy male and/or female subjects of non-child bearing potential (WONCBP) between the ages of 18 and 55 years, inclusive. (Healthy is defined as no clinically relevant abnormalities identified at screening by a detailed medical history, full physical examination, including blood pressure and heart rate measurement, 12-lead ECG, neurological examination and clinical laboratory tests.)
• Inclusion Criteria for elderly population: Healthy male and/or female subjects of non-child bearing potential between the ages of 65 and 85 years, inclusive. Subjects must be in reasonably good health as determined by the investigator based on a detailed medical history, full physical examination (including blood pressure and pulse rate measurement), 12-lead ECG and clinical laboratory tests. Subjects with mild, chronic, stable disease (eg, controlled hypertension, non-insulin dependent diabetes, osteoarthritis) may be enrolled if deemed medically prudent by the investigator.

Exclusion Criteria:

• Presence or history of any disorder that may prevent the successful completion of the study.
• Other severe acute or chronic medical or psychiatric condition or laboratory abnormality that may increase the risk associated with study participation or investigational product administration or may interfere with the interpretation of study results and, in the judgment of the investigator, would make the subject inappropriate for entry into this study.
• A score of greater than or equal to 20 on the Beck Depression Inventory and/or a response of 1, 2, or 3 to the question related to suicide.
• History of seizure disorder and/or severe head trauma (other than a single childhood febrile seizure).
• Evidence or history of clinically significant hematological, renal, endocrine, pulmonary, gastrointestinal, cardiovascular, hepatic, psychiatric, neurologic, dermatologic, muscular or allergic disease or disorder (including drug allergies, but excluding untreated, asymptomatic, seasonal allergies at time of dosing).
• Any surgical or medical condition that may interfere with the absorption, distribution, metabolism, or excretion of the study treatment.
• Acute disease state (eg, nausea, vomiting, fever, or diarrhea) within 7 days before study Day 1.
• History of drug abuse within 1 year before study Day 1 or a positive urine drug screen.
• Admitted alcohol abuse or history of alcohol use that may interfere with the subject's ability to comply with the protocol requirements.
• Consumption of more than 14 drinks/week for females or 21 drinks/week for males (1 drink = 5 ounces (150 mL) of wine or 12 ounces (360 mL) of beer or 1.5 ounces (45 mL) of hard liquor) within 6 months of screening.
• Subjects who smoke more than 10 cigarettes per day.
• Pregnant or nursing females; females of childbearing potential.
• Males who are unwilling to abstain from sexual intercourse or use a condom with all child-bearing potential women for the duration of the study.