EFFECTS OF NİCOTINE ADMINISTRATION ON ANXIETY TESTS IN NICOTINE-PREFERRING RAT LINES
Project no. 20417 · Status: Kapanmış · 2018
Summary
Genetic vulnerability contributes significantly to the individual variability observed in nicotine dependence. Selective breeding for sensitivity to a particular effect of abused drugs has produced rodent lines useful for studying genetic vulnerability to drug addiction. However, there are no studies that use rodent lines selectively bred for oral nicotine preference. We examined the differences in anxiety-like behavior between a high nicotine-preferring rat line and their controls. At the beginning of the study, all rats, naïve to any drug, were exposed sequentially to open field, elevated plus maze and marble burying paradigms. In the second step, all rats received nicotine in drinking water for 8 weeks. Anxiety tests were repeated on the last two weeks of chronic nicotine treatment. Elevated plus maze testings under basal conditions and during chronic nicotine treatment showed that the open arm preference, time spent in the open arms, and latency to enter the closed arms were higher, whereas open arm avoidance index was lower in the nicotine-preferring rats compared to the controls. Nicotine-preferring rats excreted less fecal pellets and spent more time in the central zones of open field arena; they buried less marbles in the marble burying test. These findings indicate a lower level of anxiety-like behavior in nicotine-preferring rat line under basal conditions and during chronic nicotine treatment. We interpreted the overall results as increased novelty-seeking behavior in nicotine-preferring rat line. Therefore, we conclude that the selectively bred nicotine-preferring rat line could be a very useful animal model to study nicotine dependence.