Nicotine Exposure during Adolescence Regulates Behavioral Responsiveness to Mood-Eliciting Stimuli in Adulthood

• Other Authors: Maffeo, Melissa (authoraut)
• Format: Others
• Language: English; English
• Published: Florida State University
• Subjects: Psychology
• Online Access: http://purl.flvc.org/fsu/fd/FSU_migr_etd-2803

Approximately three million adolescents abuse nicotine in the United States today, and the vast majority of smokers began smoking during adolescence. Given that the adolescent brain is still undergoing growth and development, the neurobiological effects of nicotine exposure during this developmental period beg to be addressed. It has been shown that smokers have a greater incidence of depressive disorders than do non-smokers, yet when nicotine (NIC) is given to adult laboratory animals, it induces antidepressive behaviors. This suggests that adolescence may be a vulnerable period for the development of NIC-induced depressive behaviors. Nicotine (NIC) exerts its rewarding effects via activation of nicotinic acetylcholine receptors (nAChRs) located in the ventral tegmental area (VTA) and nucleus accumbens (NAc), brain regions involved in regulating mood and motivated behavior. We examined the short- and long-term behavioral consequences of chronic exposure to NIC (0.4 or 1.0 mg/kg s.c.; twice daily) during adolescence (postnatal day 30-45) in male rats. Assessments were made either 24 hours or 15 days after the last NIC injection and were based on behavioral reactivity to stress- and anxiety-eliciting situations, as well as responses to natural reward. Here we report that NIC exposure during adolescence results behavioral profiles indicative of increased anxiety, behavioral despair and anhedonia, suggesting that adolescence is a critical period for the development of NIC-induced mood disorders. === A Thesis submitted to the Department of Psychology in partial fulfillment of the requirements for the degree of Master of Science. === Spring Semester, 2008. === March 27, 2008. === Mood, Rodent, Reward Circuitry, Nicotine === Includes bibliographical references. === Carlos Bolanos, Professor Directing Thesis; Mohamed Kabbaj, Committee Member; Lisa Eckel, Committee Member; Jeanette Taylor, Committee Member.