EFFECTS OF NICOTINE WITHDRAWAL ON SUCROSE PREFERENCE IN NICOTINE PREFERRING RAT LINES
Project no. 20412 · Status: Kapanmış · 2018
Summary
Stress response and negative affect induced by withdrawal plays important roles in the development of drug addiction. In our laboratory, a nicotine-preferring (NP) rat line has been generated using selective breeding method. In this study, we aimed to reveal the regulatory effect of inherited genetic background on nicotine withdrawal-induced negative affect. Therefore, we studied the differences in basal and withdrawal induced-anhedonia between NP rat lines and their controls. This study involved 4 groups (n = 12): Control Males (CM), Females (CF), NP Males (NPM), and Females (NPF). In all groups, sucrose preference test was performed for seven days, followed by forced oral nicotine (50 ?g/ml) administration for eight weeks. Sucrose preference was repeated during withdrawal which lasted ten days. Data were analyzed using SPSS statistics software. When basal and withdrawal data were compared for sucrose consumption, there were effects of withdrawal (p = 0.042), days (p ? 0.001), line (p ? 0.001) and sex (p ? 0.001). Also, there were line and sex (p ? 0.001) and line and withdrawal (p = 0.039) interactions. CF, compared to other groups, consumed more sucrose during basal and withdrawal conditions. In withdrawal, attenuated sucrose consumption in all groups indicated anhedonia. There was significant sex difference in basal and withdrawal sucrose consumption between control groups. In NP groups, there was no sex difference in basal sucrose consumption while a sex difference has shown during withdrawal. Compared to basal status, the most significant decrease in hedonic level was observed in CFs. While CFs were anhedonic from the first day of withdrawal, anhedonia was not observed on the first day of withdrawal in CMs. NPFs consumed less sucrose than CF in both basal conditions and withdrawal. This indicates that NPFs experience more anhedonia than CFs. The sex difference in NP rats was decreased compared to controls and females showed similar behavior to males. There was a main effect of line (p = 0,031) and sex (p < 0,001) on hourly sucrose consumption data at 1st, 2nd, 4th, 6th and 24th hours on the first day of withdrawal. Additionally, there were line and sex, hours and line, hours and sex, hours, line and sex interactions. Also there was a main effect of hours (p < 0,001) on sucrose preference data and hours and line interaction. During withdrawal, CFs showed earlier anhedonia than CMs. CFs showed more severe hedonic attenuation than CMs. This result is similar with the studies that indicate women are more addict to nicotine than men. In sucrose consumption data NPFs showed more anhedonia than CFs during withdrawal. But there were no significant sex difference in NP rats. The negative affect shown in NP rat lines during withdrawal may contribute to the development of nicotine addiction.