 This study will be a single-center, single dose, randomized, double-blind, placebo-controlled study in healthy Japanese male subjects. The study will consist of 2 parts: Part A young subjects and Part B elderly subjects. In Part A sequential cohorts of subjects will be treated with single ascending doses of E2307. The maximum tolerated dose MTD will be determined in Part A. Part B will be initiated after Part A is completed. In Part B one cohort of healthy elderly subjects will be treated with a single dose of E2307 at one dose level below the MTD. In part A, a total of 56 subjects will be enrolled into 7 cohorts sequentially and randomized 3:1 to receive either E2307 1 mg, 3 mg, 10 mg, 30 mg, 100 mg, 200 mg, or 300 mg or placebo. In part B, a total of 8 subjects will be randomized, 6 subjects to a single dose of E2307 and 2 subjects to placebo. 