The Role of Dynorphin / Kappa-Opioid Systems in Alcohol Dependence

点击翻译按钮获取中文摘要

DESCRIPTION (provided by applicant): A fundamental characteristic of excessive alcohol use is the comorbidity of alcohol dependence and disorders of affect. Self-medication of these negative affective states likely contributes to excessive alcohol use and relapse. Negative affective states produced by chronic alcohol exposure result from neuroadaptations in motivational and affective neurocircuitry that are not yet understood. The principal investigator's long-term goal is to identify effective pharmacotherapeutic targets for the treatment of alcoholism. The objective of this application, which is the next step in pursuit of that goal, is to understand the neuroadaptations in dynorphin / kappa-opioid systems that occur in response to chronic alcohol exposure and contribute to attenuated motivational and affective states. The central hypothesis is that compensatory neuroadaptations in dynorphin / kappa-opioid systems oppose the acute effects of alcohol, and promote excessive alcohol intake by altering negative affective behaviors. The rationale for the proposed studies is that identification of dynorphin targets will enable the development of pharmacotherapies designed to alleviate motivational and affective symptoms produced by alcohol dependence. The hypothesis will be tested by pursuing the following specific aims: Aim #1 will evaluate kappa opioid receptor antagonism within specific sites of the extended amygdala during acute withdrawal. Aim #2 will site-specifically evaluate the role of extended amygdala dynorphin systems in depressive- and anxiety-like behavior. Specific Aim #3 will maximize dependence-induced alterations in negative affective behaviors during acute and protracted withdrawal. All three aims will utilize animal models of ethanol reinforcement and affective behavior to allow for the systematic investigation of neurotransmitter systems and neurocircuitry that contribute to altered motivational and affective states produced by chronic ethanol exposure. These three specific aims will collectively help to identify important neuroadaptations that result from chronic alcohol exposure and provide much needed information regarding the neurocircuitry involved in altered motivational and affective systems. Such a contribution is significant because it will help to develop pharmacotherapeutic targets for the treatment of alcoholism that focus on the removal of attenuated motivational and negative affective states; a strategy that should greatly increase medication compliance and decrease rates of relapse.