Thiele T E, Roitman M F, Bernstein I L
Department of Psychology, University of Washington, Seattle 98195, USA.
Alcohol Clin Exp Res. 1996 Sep;20(6):1023-8. doi: 10.1111/j.1530-0277.1996.tb01941.x.
When consumption of a novel taste (conditioned stimulus; CS) is followed by exposure to a toxin, organisms will avoid consumption of that taste in the future. This learned response, known as a conditioned taste aversion (CTA), can be demonstrated using a variety of drugs, including lithium chloride (LiCl) and ethanol. c-Fos immunohistochemistry was used to examine neural activation in the rat brainstem associated with drug administration and with a CS taste previously paired with these drugs. Relative to saline controls, animals injected with either LiCl (76 mg/kg) or ethanol (3.5 g/kg) displayed greater c-Fos expression in area postrema, nucleus of the solitary tract (NTS), and lateral parabrachial nucleus. At these doses, LiCl- and ethanol-injected groups did not differ from each other. For establishing a CTA, intraoral infusion of a 0.15% saccharin solution was followed by injection of either LiCl or ethanol. Both LiCl and ethanol produced quantitatively similar CTAs. Relative to unpaired control groups, saccharin paired with either drug induced significant c-Fos expression in NTS. Thus, like LiCl, ethanol and tastes that have become aversive by virtue of their association with ethanol activate brainstem regions hypothesized to play a role in CTA learning.
当摄入一种新口味（条件刺激；CS）后紧接着接触一种毒素时，生物体在未来会避免摄入那种口味。这种习得的反应，称为条件性味觉厌恶（CTA），可以使用多种药物来证明，包括氯化锂（LiCl）和乙醇。采用c-Fos免疫组织化学法来检测大鼠脑干中与药物给药以及先前与这些药物配对的CS口味相关的神经激活情况。相对于生理盐水对照组，注射LiCl（76 mg/kg）或乙醇（3.5 g/kg）的动物在最后区、孤束核（NTS）和外侧臂旁核中表现出更强的c-Fos表达。在这些剂量下，注射LiCl和乙醇的组之间没有差异。为了建立CTA，在经口输注0.15%的糖精溶液后注射LiCl或乙醇。LiCl和乙醇产生的CTA在数量上相似。相对于未配对的对照组，与任何一种药物配对的糖精在NTS中诱导出显著的c-Fos表达。因此，与LiCl一样，乙醇以及因与乙醇关联而变得令人厌恶的口味会激活假定在CTA学习中起作用的脑干区域。
