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- Genre: Masters Thesis
Description
Nicotine is thought to underlie the reinforcing and dependence-producing effects of tobacco-containing products. Nicotine supports self-administration in rodents, although measures of its reinforcing effects are often confounded by procedures that are used to facilitate acquisition, such as food restriction, prior reinforcement training, or response-contingent co-delivery of a naturally reinforcing light. This study examined whether rats acquire nicotine self-administration in the absence of these facilitators. A new mathematical modeling procedure was used to define the criterion for acquisition and to determine dose-dependent differences in rate and asymptote levels of intake. Rats were trained across 20 daily 2-h sessions occurring 6 days/week in chambers equipped with active and inactive levers. Each active lever press resulted in nicotine reinforcement (0, 0.015, 0.03, 0.06 mg/kg, IV) and retraction of both levers for a 20-s time out, whereas inactive lever presses had no consequences. Acquisition was defined by the best fit of a logistic function (i.e., S-shaped) versus a constant function (i.e., flat line) for reinforcers obtained across sessions using a corrected Akaike information criterion (AICc) as a model selection tool. The results showed an inverted-U shaped function for dose in relation to the percentage of animals that acquired nicotine self-administration, with 46% acquiring at 0.015 mg/kg, 73% at 0.03 mg/kg, and 58% at 0.06 mg/kg. All saline rats failed to acquire as expected. For rats that acquired nicotine self-administration, multiple model comparisons demonstrated that the asymptote (highest number of reinforcers/session) and half learning point (h; session during which half the assymptote had been achieved) were justified as free parameters of the reinforcers/session function, indicating that these parameters vary with nicotine dose. Asymptote exhibited an inverted U-shaped function across doses and half learning point exhibited a negative relationship to dose (i.e., the higher the dose the fewer sessions to reach h). These findings suggest that some rats acquire nicotine self-administration without using procedures that confound measures of acquisition rate. Furthermore, the modeling approach provides a new way of defining acquisition of drug self-administration that takes advantage of using all data generated from individual subjects and is less arbitrary than some criteria that are currently used.
ContributorsCole, Natalie (Author) / Neisewander, Janet L (Thesis advisor) / Sanabria, Federico (Thesis advisor) / Bimonte-Nelson, Heather A. (Committee member) / Olive, Michael F (Committee member) / Arizona State University (Publisher)
Created2011
Description
Nicotine and tobacco use, whether it be through cigarette smoking or other devices, creates negative health conditions in pilots. The literature that was reviewed pertained to nicotine withdrawal symptoms and their negative impact on pilot performance. There have been studies conducted in order to explore how these symptoms impact pilot performance using cigarettes as the only nicotine device and does not specify the nicotine levels or the frequency of use. This thesis extends this work to examine the relationship between the nicotine withdrawal symptoms and the nicotine behaviors of pilots. It was hypothesized that the extent of withdrawal symptoms may differ by device and by nicotine levels and frequency of use, with higher levels and more frequent use being associated with more severe withdrawal symptoms. These behaviors included the device they use to take nicotine whether it be cigarettes, vaporizers, e-cigarettes, or smokeless tobacco. The behaviors also included exploration of how nicotine levels relate to withdrawal symptoms whether the nicotine level is as low as 3mg or high as 36mg. The last relationship that was explored was that between the withdrawal symptoms presented in pilots and how often they used nicotine, whether it be often as every day or less frequent as 1-2 times a year. It was found that there is no statistical relationship between nicotine withdrawal symptoms and the nicotine habits such as device used, nicotine level used, and frequency of use.
ContributorsBartlowe, Halie Marie (Author) / Cooke, Nancy J. (Thesis advisor) / Nullmeyer, Robert (Committee member) / Wende, Anthony (Committee member) / Arizona State University (Publisher)
Created2019