Department of Pharmacology and Physiology of the Nervous System, Institute of Psychiatry and Neurology, ul. Sobieskiego 9, 02-957 Warsaw, Poland.
Department of Forensic Medicine, Warsaw Medical University, ul. Oczki 1, 02-007 Warsaw, Poland.
Alcohol. 2021 Feb;90:67-73. doi: 10.1016/j.alcohol.2020.12.002. Epub 2020 Dec 19.
Ethanol can have both an aversive and rewarding effect, which may have a significant relationship to its individual preference. So far, the reasons for the high and low ethanol preference in the WHP (Warsaw High Preferring) and WLP (Warsaw Low Preferring) lines have not been found. WHP rats spontaneously drink over 5 g/kg/day of ethanol, while WLP rats drink under 2 g/kg/day. The purpose of the work was to study the sensitivity of WHP and WLP rats to the aversive effects of ethanol at doses of 1.5 g/kg and 2.0 g/kg in the conditioned taste aversion (CTA) procedure. Lower doses (0.5 and 1.0 g/kg, i.p. [intraperitoneally]) were tested earlier and only 1.0 g/kg produced a slight aversion in WLP rats. The secondary aim was to check the additional potential factors (blood ethanol concentration, pain sensitivity, anxiety-related behavior, learning, and memory) that may constitute an important differentiating feature of the WHP and WLP lines. For this purpose, the following tests were conducted: blood ethanol concentration, novel object recognition (NOR), flinch-jump, hot-plate, and elevated plus maze (EPM). The 1.5 g/kg i.p. dose of ethanol caused the development of an aversion only in WLP rats and the aversion extinguished in the post-conditioning phase. The 2.0 g/kg i.p. dose of ethanol resulted in the development of an aversion in both the tested groups, with the aversion being maintained throughout the whole post-conditioning period only in the WLP rats. There were no differences between the lines in terms of the blood ethanol concentration and the EPM tests. WHP rats had a higher pain sensitivity compared to WLP rats in flinch-jump and hot-plate tests. WLP rats showed a shorter exploration time for both objects compared to WHP in the NOR test. In conclusion, WHP and WLP rats differ in sensitivity to the aversive effects of ethanol. This difference may partially explain their opposite ethanol preference.
乙醇既具有厌恶效应又具有奖赏效应，这可能与其个体偏好有很大关系。到目前为止，WHP（华沙高偏好）和 WLP（华沙低偏好）品系中高乙醇和低乙醇偏好的原因尚未找到。WHP 大鼠自发饮用超过 5g/kg/天的乙醇，而 WLP 大鼠饮用少于 2g/kg/天。本工作的目的是研究 WHP 和 WLP 大鼠在条件味觉厌恶（CTA）程序中对 1.5g/kg 和 2.0g/kg 剂量乙醇的厌恶效应的敏感性。较低剂量（0.5 和 1.0g/kg，腹腔内）早些时候进行了测试，只有 1.0g/kg 使 WLP 大鼠产生轻微厌恶。次要目的是检查可能构成 WHP 和 WLP 品系重要区分特征的其他潜在因素（血乙醇浓度、疼痛敏感性、焦虑相关行为、学习和记忆）。为此，进行了以下测试：血乙醇浓度、新物体识别（NOR）、惊跳-跳跃、热板和高架十字迷宫（EPM）。1.5g/kg 腹腔内乙醇剂量仅在 WLP 大鼠中引起厌恶反应，且在条件后阶段厌恶反应消失。2.0g/kg 腹腔内乙醇剂量导致两组测试均产生厌恶反应，仅在 WLP 大鼠中，厌恶反应在整个条件后阶段持续存在。在血乙醇浓度和 EPM 测试方面，两组之间没有差异。与 WLP 大鼠相比，WHP 大鼠在惊跳-跳跃和热板测试中具有更高的疼痛敏感性。在 NOR 测试中，与 WHP 大鼠相比，WLP 大鼠对两个物体的探索时间更短。总之，WHP 和 WLP 大鼠对乙醇的厌恶效应的敏感性不同。这种差异可能部分解释了它们相反的乙醇偏好。
