This study will assess the safety and tolerability of ascending single oral doses of SAM-760 in healthy young adult and healthy elderly subjects. The secondary objectives are to provide the concentrations of SAM-760 in the blood and to evaluate the effect of a high-fat meal on the concentrations in the blood of SAM-760 administered to healthy young adult subjects, and to evaluate the effects of concomitant administration of ketoconazole on the safety and the concentrations of SAM-760 in the blood of a single dose of SAM-760 in healthy young adult subjects.