A significant component of the reinforcing properties of ethanol may be its pronounced anxiolytic effect, and individuals with clinically diagnosed anxiety disorders are at greatly increased risk for ethanol abuse and dependence. With prolonged use, withdrawal from ethanol is associated with increased anxiety, in addition to the sensation of ethanol craving. This is believed to lead to a cycle of continued ethanol use. We are beginning to understand the biological basis of these processes, and this application is targeted toward continued exploration of the mechanisms of ethanol-induced anxiolysis and withdrawal-induced anxiogenesis. INIA West has identified target genes comprised of families coding for neuronal potassium channels. We are particularly interested in a large conductance voltage- and calcium- regulated current, the BK current. Previous behavioral studies indicate that these ion channels are highly sensitive to low concentrations of ethanol, and anatomical studies demonstrate that they are heavily expressed in the central amygdala nucleus (CeA). The amygdala formation has a critical role in the action of anxiolytic drugs such as ethanol, and may be the most appropriate brain area for investigating the mechanisms of ethanol's regulation of anxiety. Thus, we believe that alterations in these channels in the amygdala may affect EtOH-mediated anxiolysis and withdrawal-induced anxiogenesis. Studies done in the laboratory of our primary proposed collaborator, Dr. Candice Contet (Scripps Research Institute) indicate that chronic ethanol exposure using the chronic intermittent ethanol model regulate gene expression of subunits of the BK channel in the amygdala. These important groundwork studies have been based on behavioral experiments, and it is now appropriate to carry out mechanistic studies at the cellular level that address interactions between ethanol and BK channels in the extended amygdala. Therefore, we propose to use pharmacologic and genetic manipulations to characterize the specific contribution of these channels to the action of ethanol on neuronal excitability in the CeA. Ultimately, a better understanding of alcohol-induced alterations in these ion channels systems in the CeA could facilitate development of novel therapies for treatment of alcoholism.
Alcohol dependence is a chronic disease characterized by uncontrollable excessive consumption of alcohol. Currently available pharmacological interventions have limited beneficial effects. This project will be investigating a candidate mechanism underlying alcohol dependence, a potassium channel that regulates neuronal activity in critical brain regions implicated in effects of alcohol. The outcome of this project will contribute to develop more effective pharmacological therapeutics to ameliorate and/or
|Li, Qiang; Madison, Roger; Moore, Scott D (2014) Presynaptic BK channels modulate ethanol-induced enhancement of GABAergic transmission in the rat central amygdala nucleus. J Neurosci 34:13714-24|