Effects of Nicotine Withdrawal on Anxiety and Depression-Like Behaviors in Nicotine Preferring Rat Lines
Project no. 24210 · Status: Kapanmış (Yayın bekleniyor) · 2022
Summary
<p>There are two main stages in the development of nicotine addiction: In the first stage (intoxication), nicotine activates mesocorticolimbic system (reward system); this leads to the development of conditioned learning. Second stage is the withdrawal (negative affect) stage. During this stage, when the access to nicotine is ceased, the activity in the mesocorticolimbic reward system decreases, the activity in the stress system increases and withdrawal symptoms appear. Withdrawal symptoms include somatic signs, increased anxiety and depressive mood (anhedonia). In this study, differences in somatic signs, withdrawal-induced anxiety and depression-like behaviors in rats selectively-bred for high nicotine preference (P) and control Sprague-Dawley (C) rats will be investigated. Nicotine-preferring rats are produced in our laboratories using selective breeding technique. They consume water that contains nicotine more compared to water only. There will be 8 experimental groups in this study: Water-receiving control males (WCM), water-receiving control females (WCF), water-receiving nicotine-preferring males (WPM), water-receiving nicotine-preferring females (WPF), nicotine withdrawn control males (NCM), nicotine withdrawn control females (NCF), nicotine withdrawn nicotine-preferring male (NPM) and nicotine withdrawn nicotine-preferring females (NPF). Nicotine will be administered orally for 6 weeks using two-bottle-choice method. Following nicotine administration, nicotine treatment will be ceased and nicotine withdrawal will be initiated. Withdrawal period will last for 1 week. Somatic signs will be measured on the first day, anxiety-like behavior will be measured on the first and second day, and depressive-like behavior will be measured every day during withdrawal. Sucrose-preference and light-dark box tests will be performed to measure depression (anhedonia) and anxiety-like behaviors, respectively. This study will be the first to show the differences in anxiety-like behavior between nicotine-preferring and control animals. We expect to observe increased depression-like behavior in nicotine-preferring animals compared to controls during withdrawal. The results obtained from our research will help to elucidate the hereditary factors that cause differences between individuals in terms of nicotine addiction.</p>