Caggiula A R, Epstein L H, Stiller R
Department of Psychology, University of Pittsburgh, PA 15260.
Psychopharmacology (Berl). 1989;99(3):389-92. doi: 10.1007/BF00445564.
Male rats on a 22-h food deprivation schedule were injected daily with a low dose of nicotine and allowed to drink sweetened milk for 10 min in a test cage in the colony room. Nicotine initially suppressed milk intake but complete tolerance developed within 10 days so that the amount of intake did not differ from saline controls. The role of temporal cues was tested on the next day by changing the timing of cues, and omitting others that normally preceded nicotine injection while keeping constant the physical environment within which injection and testing took place and the drug-test interval. Changing the timing of injection significantly suppressed milk intake. These results show that tolerance to the anorectic effects of a low dose of nicotine is partially dependent on the presence and timing of cues associated with tolerance acquisition.
按照22小时食物剥夺时间表喂养的雄性大鼠，每天注射低剂量尼古丁，并在饲养室的测试笼中让它们饮用加糖牛奶10分钟。尼古丁最初抑制牛奶摄入量，但在10天内产生了完全耐受性，因此摄入量与生理盐水对照组没有差异。第二天，通过改变提示时间来测试时间线索的作用，省略通常在注射尼古丁之前的其他线索，同时保持注射和测试所处的物理环境以及药物测试间隔不变。改变注射时间显著抑制了牛奶摄入量。这些结果表明，对低剂量尼古丁厌食作用的耐受性部分取决于与耐受性获得相关的线索的存在和时间。
