Department of Pharmacology, University of Tennessee Health Science Center, Memphis, TN 38163, USA.
Neuropsychopharmacology. 2011 Dec;36(13):2629-38. doi: 10.1038/npp.2011.149. Epub 2011 Jul 27.
Cigarette smoking is a social behavior. Smoking is also accompanied by distinctive gustatory and olfactory stimulation. However, none of these factors affecting nicotine intake are modeled in existing preclinical studies. We report a novel model of adolescent nicotine self-administration (SA) in rats where licking on drinking spouts was used as the operant behavior to activate the concurrent delivery of nicotine (i.v.) and an appetitive olfactogustatory (OG) cue, and social interaction was required for stable SA. The operant chamber was divided by a panel that separated the SA rat and another rat serving as the demonstrator, who had free access to the OG cue but did not receive nicotine. Orofacial contacts were permitted by the divider. Conditioned taste aversion prevented solo rats to self-administer nicotine. However, stable nicotine (15-30 μg/kg, free base) SA was established in the presence of demonstrator rats with free access to the OG cue. Omitting the olfactory component of the cue prevented the acquisition of nicotine SA. Mecamylamine, a nicotinic antagonist, reduced licking behavior. Familiar peers were more effective demonstrators in facilitating the acquisition of nicotine SA than were unfamiliar rats. No sex difference in nicotine intake was found. These data indicate that the contingent OG cue is associated with the aversive property of nicotine that prevents subsequent drug intake. Social information encoded in olfaction not only permits the establishment of stable nicotine SA but also enhances nicotine intake. These findings implicate adolescent social interactions in promoting smoking behavior by surmounting the aversive property of nicotine.
吸烟是一种社会行为。吸烟也伴随着独特的味觉和嗅觉刺激。然而，这些影响尼古丁摄入的因素都没有在现有的临床前研究中建模。我们报告了一种新的青少年尼古丁自我给药（SA）大鼠模型，其中舔饮水口被用作操作性行为，以激活同时给予尼古丁（静脉内）和令人愉悦的嗅觉味觉（OG）线索，并且需要社交互动才能稳定 SA。操作室被一个隔板隔开，将 SA 大鼠和另一只作为示范者的大鼠分开，示范者可以自由接触 OG 线索，但不接受尼古丁。隔板允许口面部接触。条件性味觉厌恶阻止了单独的大鼠自我给予尼古丁。然而，在有自由接触 OG 线索的示范者存在的情况下，稳定的尼古丁（15-30μg/kg，游离碱）SA 得以建立。省略线索的嗅觉成分会阻止尼古丁 SA 的获得。美加明，一种烟碱拮抗剂，减少了舔舐行为。熟悉的同伴在促进尼古丁 SA 的获得方面比不熟悉的大鼠更有效。在尼古丁摄入量方面没有发现性别差异。这些数据表明，条件性 OG 线索与尼古丁的厌恶特性相关，阻止了随后的药物摄入。嗅觉中编码的社交信息不仅允许稳定的尼古丁 SA 的建立，而且还增强了尼古丁的摄入。这些发现表明，青少年社交互动通过克服尼古丁的厌恶特性，促进了吸烟行为。
