Houpt T A, Philopena J M, Joh T H, Smith G P
E. W. Bourne Behavioral Research Laboratory, Department of Psychiatry, Cornell University Medical College, White Plains, NY 10605, USA.
Physiol Behav. 1996 Dec;60(6):1535-41. doi: 10.1016/s0031-9384(96)00326-5.
Intraoral infusions of sucrose or saccharin induce c-Fos-like immunoreactivity (c-FLI) in the intermediate nucleus of the solitary tract (iNTS) of rats after acquisition of a conditioned taste aversion (CTA). The induction of c-FLI in the iNTS may be a consequence of the shift in behavioral response from ingestive to aversive behaviors that characterize acquisition and expression of a CTA. To test this hypothesis, rats were intraorally infused with 0.3 mM quinine sulfate, an aversive taste, 1. prior to conditioning, 2. after 3 noncontingent (unpaired) infusions of quinine and toxic lithium chloride (LiCl) injections, 3. after conditioning with 3 contingent pairings of quinine and LiCl, and 4. after extinction with repeated unpaired infusions of quinine. Intraoral infusions of quinine induced c-FLI in the iNTS only after acquisition of a CTA against quinine; quinine failed to induce c-FLI in the iNTS of unconditioned, noncontingently treated, or extinguished rats. The pattern of c-FLI in the iNTS induced by expression of a CTA against quinine was quantitatively and anatomically similar to that elicited by sucrose in rats expressing a CTA against sucrose. We conclude that aversive responses per se are not sufficient to induce c-FLI in the iNTS. Furthermore, contingent pairing of quinine and LiCl does not cause a shift in behavioral response from palatable, ingestive behaviors to aversive behaviors as in acquisition of a CTA against sucrose. Thus, we also conclude that a shift in behavior from ingestive to aversive responses is not required for increased c-FLI expression in the iNTS during CTA expression. Therefore, the induction of c-FLI in the iNTS during expression of a CTA may be correlated with neuronal processes specific to acquisition and expression of a CTA.
在获得条件性味觉厌恶（CTA）后，经口内输注蔗糖或糖精可诱导大鼠孤束核中间核（iNTS）出现c-Fos样免疫反应性（c-FLI）。iNTS中c-FLI的诱导可能是行为反应从摄取行为转变为厌恶行为的结果，这是CTA获得和表达的特征。为了验证这一假设，给大鼠经口内输注0.3 mM硫酸奎宁（一种厌恶味觉），1. 在条件反射之前，2. 在3次非偶然（不配对）输注奎宁和有毒氯化锂（LiCl）注射之后，3. 在奎宁和LiCl进行3次偶然配对的条件反射之后，以及4. 在重复不配对输注奎宁进行消退之后。仅在获得针对奎宁的CTA后，经口内输注奎宁才会在iNTS中诱导c-FLI；奎宁未能在未处理、非偶然处理或已消退的大鼠的iNTS中诱导c-FLI。针对奎宁的CTA表达所诱导的iNTS中c-FLI的模式在数量和解剖学上与针对蔗糖的CTA表达的大鼠中蔗糖所引发的模式相似。我们得出结论，厌恶反应本身不足以在iNTS中诱导c-FLI。此外，奎宁和LiCl的偶然配对不会像针对蔗糖的CTA获得过程那样导致行为反应从可口的摄取行为转变为厌恶行为。因此，我们还得出结论，在CTA表达期间，行为从摄取反应转变为厌恶反应并非iNTS中c-FLI表达增加所必需。所以，CTA表达期间iNTS中c-FLI的诱导可能与CTA获得和表达所特有的神经元过程相关。
