 This is a placebo-controlled, single-center, multiple ascending dose study. Seven healthy volunteers will be enrolled into 2 sequential cohorts, for a total of 14 enrolled subjects. The study will be conducted using two doses of valproate 250 mg PO bid, followed by 500 mg PO bid. At each dose level, 7 cognitively intact normal elderly subjects will be entered into the study with two subjects randomly selected to receive placebo while the other five subjects receive the designated dose of valproate. 