Shelton Keith L
Department of Pharmacology and Toxicology, Virginia Commonwealth University School of Medicine, Richmond, Virginia 23298-0613, USA.
Behav Pharmacol. 2007 May;18(3):219-29. doi: 10.1097/FBP.0b013e328157f460.
Few studies exist exploring the discriminative stimulus effects of inhalants and none that have trained an interoceptive discrimination using the inhaled route. This study was designed to assess if it was possible to train an inhaled toluene discrimination. The second objective was to determine whether the discrimination was based on interoceptive or exteroceptive stimulus effects. Eight B6SJLF1/J mice were trained to discriminate 10 min of exposure to 6000 ppm inhaled toluene vapor from air, using a standard food-reinforced operant procedure. Toluene vapor produced robust, concentration-dependent, discriminative stimulus effects, with concentrations of 4000 ppm and higher producing full substitution. Substitution of inhaled toluene vapor for the training condition was exposure-time dependent. A minimum of 7 min of exposure to 6000 ppm was required to produce complete substitution. Injected intraperitoneal toluene produced dose-dependent full substitution for inhaled toluene vapor. Both inhaled and intraperitoneal ethylbenzene produced similar levels of partial substitution for 6000 ppm toluene vapor. Inhaled isoflurane vapor produced no substitution for toluene vapor. These results show that a toluene vapor discrimination can be successfully trained in mice and the discrimination is selective for toluene compared to ethylbenzene and isoflurane. The results also suggest that the discrimination was likely to have been based primarily on interoceptive rather than exteroceptive stimulus effects.
很少有研究探索吸入剂的辨别刺激效应，且没有一项研究通过吸入途径训练内感受辨别。本研究旨在评估是否有可能训练小鼠对吸入甲苯的辨别能力。第二个目标是确定这种辨别是基于内感受还是外感受刺激效应。使用标准的食物强化操作性程序，对8只B6SJLF1/J小鼠进行训练，使其能够辨别吸入6000 ppm甲苯蒸气10分钟与吸入空气的差异。甲苯蒸气产生了强烈的、浓度依赖性的辨别刺激效应，4000 ppm及更高浓度的甲苯蒸气能产生完全替代。用吸入甲苯蒸气替代训练条件时，与暴露时间有关。至少暴露于6000 ppm的甲苯7分钟才能产生完全替代。腹腔注射甲苯能产生剂量依赖性的完全替代吸入甲苯蒸气的效果。吸入和腹腔注射乙苯对6000 ppm甲苯蒸气都产生了相似程度的部分替代。吸入异氟烷蒸气不能替代甲苯蒸气。这些结果表明，小鼠能够成功地训练出对甲苯蒸气的辨别能力，并且与乙苯和异氟烷相比，这种辨别对甲苯具有选择性。结果还表明，这种辨别可能主要基于内感受而非外感受刺激效应。
