Oleoyl Glycine-induced reduction of Nicotine Seeking: Bioanalytical & Behavioral Approaches

项目总结

PROJECT SUMMARY Tobacco use continues to be a substantial public health issue with more than 16 million individuals in the United States suffering from a tobacco-related disease. While there are currently seven nicotine cessation pharmacotherapies approved by the Food and Drug Administration, nicotine cessation success rates remain low. Varenicline is considered to be the most effective treatment with a cessation success rate estimated at 26%. A majority of smokers report a desire to quit smoking, and yet even with current treatments most are unsuccessful in their attempts. With the deleterious health effects of tobacco and the current disparity between smokers’ desire and ability to quit smoking, research into novel nicotine addiction treatments is critical for improvement of public health. A recent study highlighted a novel endogenous compound demonstrating promise as a nicotine cessation treatment in murine models of nicotine reward and withdrawal. Following a report in which tobacco smokers who sustained ischemic injury to their insular cortex reported reduced craving and less severe withdrawal symptoms compared to smokers with injury to other brain areas, a mouse model of mild traumatic brain injury was employed to identify neurochemicals that may offset nicotine reward and dependence. In the model, n- oleoyl glycine (OlGly) was discovered to be increased in the insular cortex. In addition to the report in smokers with ischemic stroke, other human imaging and animal studies suggest the insular cortex plays a role in drug addiction, craving, and seeking. Subsequently, exogenous administration of the n-acyl amino acid, OlGly, prevented nicotine-induced conditioned place preference (CPP) through a peroxisome proliferator-activated receptor alpha (PPAR-α) dependent mechanism and ameliorated mecamylamine-precipitated nicotine withdrawal in mouse models. Here, we hypothesize: exogenous OlGly reduces nicotine seeking behavior through direct actions in the insular cortex to dampen nicotine-induced dopamine release. Aim 1 will determine if the insular cortex is critical for the attenuation of nicotine seeking behavior by OlGly and if repeated nicotine exposure dysregulates OlGly in the insular cortex. Aim 2 will utilize in vivo G-protein coupled receptor dopamine sensors to investigate whether OlGly reduces nicotine-induced dopamine release in the nucleus accumbens. Completion of the proposed research will lead to an increased understanding of neural substrates and underlying mechanisms of action involved in the attenuation of nicotine seeking by OlGly, as well as the role of OlGly in nicotine addiction.