健康与遗传心理学研究室知识库

        新异味觉刺激糖精水(Sac)的摄入与腹腔注射免疫抑制剂环磷酞胺(CY)相结合，不仅可以建立味觉厌恶性条个l二反射(conditioned taste aversion, CTA)，同时也可以建立条件性免疫抑制反应(conditioned immunosuppression, CIS)。为了揭示这两种条件反射中枢机制的联系与区别，本研究分别用免疫抑制剂环磷酞胺(CY)和非免疫抑制剂氯化铿(LiCl)作为非条件刺激与糖精水结合建立CTA，以Fos免疫组化法检测条件刺激’F大鼠各脑区的神经活动情况，试图探索CTA的中枢机制、揭示CTA与CIS中枢神经活动的关系，进而寻找与免疫抑制调节有关的脑区。
        本研究包括两个实验，实验一采用单瓶给水、两次训练在大鼠中建立CTA，并用Fos免疫组化法检测条件刺激后大鼠各脑区的神经活动情况。因CTA仅须一次训练既可建立，而CIA则须两次训练，所以实验二采用一次训练，以观察CTA表达中大鼠各脑区的兴奋情况。
实验结果显示，学习组大鼠经过两次条件训练后，对再次提供的糖精水表现出明显的厌恶反应，同时糖精水在学习组大鼠(Sac+CY, Sac+LiCl)的广泛脑区中诱发出密集的c-FLI，这些区域包括扣带回、压部后颗粒皮质、额皮质、正中视前区、下丘脑室旁核、下丘脑视上核、下丘脑外侧区、下丘脑背侧核、下丘脑前核、杏仁基底外侧核、未定带、弯隆下器、底丘脑旁核、中央灰质外侧区等，而各对照组在这些脑区中只有少量的基础表达。另外，在岛乱颗粒皮质、下丘脑视上核、下丘脑外侧区、丘脑前背侧核、底丘脑旁核、中央灰质外侧区，CY学习组的Fos表达明显多于LiCI学习组，这些区域可能与条件性免疫抑制有关。
       一次训练后，学习组大鼠对再次提供的糖精水表现出明显的厌恶反应，糖精水在学习组大鼠的广泛脑区中诱导出密集的。-FLI，这些区域包括顶叶、扣带回、岛叶、杏仁基底外侧核、前连合核、下丘脑背侧核、未定带、丘脑前背侧核等，而对照组在这些脑区中没有或只有少量表达。无论是一次还是两次训练，糖精水在学习组大鼠的扣带回、杏仁基底外侧核、下丘脑背侧核、未定带中能诱导出明显的c-FLI，而对照组中却没有，所以这些脑区可能与CTA的表达有密切的关系。

   Conditioned taste aversion and conditioned immunosuppression (CTA and CIS) can be established by pairing of the CS saccharin with the UCS CY in rats. In the control group, LiCI was used as UCS,and c-Fos immunohistochemistry was used to detect the main areas involved conditioned taste aversion and conditioned immunosuppression.
  Three experiments were done. In experiment one, conditioned animals  received twice for continuous two days by pairing of CS saccharin (one-bottle) with the UCS (CY or LiCI). In experiment two, in order to remove the stress induced by the thirsty, conditioned animals received a single pairing of the CS saccharin (in addition to one bottle of saccharin and one bottle of water) with the UCS. On experiment three, in order to compare the difference of the strength of training between one-pairing and two-pairing, conditioned animals received a single pairing of the CS saccharin (one-bottle) with the UCS.
  The  result  shows  the  re-exposure  of  the  CS  saccharin  can  induce  dense  c-Fos-like immunoreactivity (C-FLI) in brain regions including Cingulate cortex (Cg), Retrosplenial granular cortex (RSG), Frontal cortex (Fr), Basolateral amydaloid nucleus (BL), Dorsomedial hypothalamic nucleus (DM), Zona incerta (ZI) Supraoptic nucleus (SO), Lateral hypothalamic nu.(LH) Median preoptic nucleus (MnPO), Hypothalamic paraventricular nucleus(PVN), Lateroanterior hypothalamic nu. (LA), Parasubthalamic nu. (PSTh), Subfornical organ (SFO), Lateral part of central gray (CGL). In the Dysgranular insular cortex (DI), SO, LH, Anterodorsal thalamic nucleus (AD), PSTh, the c-FLI in CY-paired group is denser than LiCI-paired group, these regions may be related with the CIS.
  Compareing between one-paired and two-paired training shows the two types training all can establish CTA, and there are same c-FLI in Cg, BL, ZI, DM between the one-paired and two-paired training group, so these regions may be related with the CTA.