published_or_final_version / abstract / toc / Pharmacology / Doctoral / Doctor of Philosophy

A rat model of novelty-seeking phenotype predicts vulnerability to nicotine relapse where locomotor reactivity to novelty is used to rank high (HR) versus low (LR) responders. This dissertation examines the neuropeptidergic and structural substrates of the expression of locomotor sensitization to a low dose nicotine challenge and associated social anxiety-like behavior following chronic intermittent nicotine exposure during adolescence in the LRHR phenotype. Data show the long-lasting nature of behavioral sensitization to nicotine and abstinence-related social anxiety-like behavior in nicotine pre-trained HRs compared to saline pre-trained controls. Moreover, this behavior is accompanied by an imbalance between the brain antistress/antianxiety, i.e., neuropeptide Y (NPY), and stress, i.e., corticotrophin releasing factor (CRF) systems in the amygdala. Moreover, a deficit in NPY signaling marked with decreased NPY and increased NPY Y2 receptor (Y2R) mRNA levels is observed in the hip pocampus, along with mossy fiber reorganization in nicotine pre-trained HRs. Furthermore, a Y2R antagonist administered 1 wk of abstinence reverses these behavioral, molecular and morphological effects in nicotine-exposed HRs. Additionally, the role of amygdalar synaptic plasticity in longlasting social withdrawal is also investigated by assessing brain-derived neurotrophic factor (BDNF) and spinophilin mRNA levels in HRs following a behaviorally-sensitizing nicotine regimen. A persistent increase in BDNF and spinophilin mRNA levels in the basolateral amygdala (BLA) is observed in nicotine pre-trained HRs even across a long (3-wk) abstinence spanning into young adulthood. This strongly suggests BDNFmediated long-lasting neuroplasticity within the BLA that may regulate abstinence-related negative affect in HRs. / Moreover, a cannabinoid receptor 1 (CB1R) antagonist, AM251 treatment during a short (1-wk) abstinence is ineffective in reversing social anxiety, nicotine-induced neuroplasticity and the neuropeptidergic changes in the amygdala, although it is effective in reversing the expression of locomotor sensitization to challenge nicotine even following a long (3-wks) abstinence. Furthermore, the identical AM251 treatment given during the late phase of a long (3-wk) abstinence further augments social withdrawal and associated BLA plasticity in nicotine pre-trained HRs. These findings implicate neuropeptidergic and neuroplastic changes in the hippocampus and the amygdala in vulnerability to the long-lasting behavioral effects of nicotine in the novelty-seeking phenotype. / by Cigdem Aydin. / Thesis (Ph.D.)--Florida Atlantic University, 2011. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2011. Mode of access: World Wide Web.

published_or_final_version / Medical Sciences / Master / Master of Medical Sciences

These results are interpreted as supporting an 'Arousal Modulation' model of cigarette smoking, i.e. smokers can use cigarette smoking as a device for controlling their level of arousal towards an 'optimum' by virtue of the biphasic stimulantdepressant dose response of nicotine and to some extent, by virtue of the effects of smoking behaviour in the absence of nicotine.

Abstract not available

published_or_final_version / Pharmacology / Master / Master of Philosophy

The purpose of the study was to determine the association of college student smokers' perceptions of nicotine dependence and measurements of loss of autonomy. The participants of the study were students enrolled in 7 randomly selected large (N > 170) core curriculum classes at Ball State University, during spring semester 2003. Using a cross-sectional data collection process, participants completed a 33 item survey consisting of questions from the Hooked on Nicotine Checklist and National College Health Risk Behavior Survey. The design of this study was to determine whether student smokers' perceive themselves as dependent on nicotine and how this was associated with a measurement on a loss of autonomy scale. Descriptive statistics, chi square, and univariate analyses were used to analyze the data. The majority, 64%, of participants had smoked sometime in their life, with 30% being classified as current smokers. Significant associations were found between the following variables: loss of autonomy and participants' perceptions of nicotine dependence, loss of autonomy and amount of cigarettes smoked, loss of autonomy and the number of years smoked, and perceptions of addiction and the number of years smoked. Gender and race were not found to be significantly associated with loss of autonomy or perception of nicotine dependence. Further analysis showed that as the consumption of cigarettes increases to an average of 2-5 cigarettes a day, chance of losing of autonomy also increases. / Department of Physiology and Health Science