In the last decade, there has been an explosion of new knowledge of the neuroscientific basis of alcohol-seeking behavior. Briefly, medications that modulate mesolimbic dopamine pathways by facilitating gamma amino butyric function and inhibiting the action of excitatory amino acids should reliably diminish alcohol's rewarding effects. Topiramate (a sulfamate-substituted fructo-pyranose derivative) has these characteristics. In support of this concept, we have shown in a phase-II-type medications clinical trial that topiramate is significantly superior to placebo at improving drinking outcomes and decreasing craving among (N = 150) alcohol-dependent individuals. Using the carefully controlled environment of the human laboratory, we are submitting a revised application containing a set of systematic studies to assess directly the mechanistic neuropharmacological processes that are associated with topiramate's anti-drinking effects. This will provide a more comprehensive understanding of the neurobiology of alcohol-seeking behavior and aid in the development of even more effective compounds for the treatment of alcohol dependence. Thus, the specific aims of the project are to: 1) determine the dose-relationship of acute effects of topiramate to reduce alcohol effects related to its abuse and addiction potential. We hypothesize that topiramate will reduce alcohol-induced craving, reward, and euphoria; 2) determine whether chronic treatment with an acutely effective dose of topiramate produces substantial reductions in alcohol-related cue-induced craving, thereby decreasing the potential for treatment relapse. We hypothesize that chronic topiramate administration will desensitize (reduce) alcohol craving produced by alcohol-related sensory cues; and 3) determine whether topiramate interactions with and without alcohol are associated with neurocognitive impairment. Clinical studies including ours have suggested that topiramate use may be associated with neurocognitive effects such as loss of concentration and memory impairment. In our own study, these effects were mild and not associated with reduced treatment compliance. Since alcohol's ability to produce neurocognitive impairment may be mediated through similar ionic mechanisms to that of topiramate, the proposed human laboratory setting affords us the unique opportunity to more clearly delineate topiramate's neurocognitive effects in both the presence and absence of alcohol. This study supports NIAAA's goal to develop effective medications for treating alcoholism and to understand the basic underpinnings of the disease.