UC Irvine

Cigarette smoking is the leading preventable cause of death in the United States. Of those who smoke, 9 out of 10 report trying their first cigarette before the age of 18. Although most people who initiate tobacco use are teenagers, animal models for studying tobacco dependence have traditionally focused on how adult animals initiate, withdrawal from and relapse to cigarette smoking. Furthermore, cigarette smoke contains more than 7,000 constituents, including nicotine, yet pre-clinical research has focused on nicotine alone. Our lab began studying these constituents by creating cigarette smoke extract, CSE, a solution which contains the aqueous constituents present in cigarette smoke. Previous work from our lab found that CSE is more potent than nicotine alone and can enhance stress-induced reinstatement in adult male rats. In order to understand how the presence of tobacco smoke constituents may affect adolescents, I investigated the role of these constituents in models of smoking initiation and relapse. I found that the tobacco smoke constituents did not influence adolescent or adult acquisition of self-administration. Adolescents self-administered more low-dose nicotine than adults when their increased non-specific responding was corrected for. During reinstatement of drug seeking, I found that CSE enhanced stress- + cue-induced reinstatement of drug-seeking behavior with no effect of age. To investigate the role of tobacco smoke constituents on attenuation of adolescent self-administration, a novel smoking cessation pharmacotherapy, AT-1001, which is a selective α3β4 nAChR functional antagonist, was used. AT-1001 attenuated both CSE and nicotine self-administration in adolescent rats to a similar degree. My results suggest that both age and the presence of tobacco smoke constituents are important factors in establishing a proper model of tobacco dependence. Furthermore, my findings provide novel insights on adolescent initiation and relapse and offer an exciting potential for the development of a new tobacco dependence animal model that could help create innovative therapeutics to curb the addiction faced by many.