对体液免疫反应的条件反射性调节

以饮糖精水作为条件刺激(conditioned stimulus,CS),腹腔注射免疫抑制剂环磷酰胺作为非条件刺激(unconditioned stimulus,UCS)训练Wistar大鼠,3天后腹腔注射卵清蛋白(ovalbunfin,OVA)抗原,观察再次单独条件刺激对原发性体液免疫反应的作用。结果发现．一次CU-UCS结合训练导致CS组大鼠对再现糖精水产生厌恶反应,外周血中抗OVA-IgG抗体水平显著低于UCS组。两次CS-UCS结合训练并多次给予条件刺激后,CS组大鼠抗OVA-IgG的条件性免疫抑制效应与一次CS-UCS结合训练及再次给予一次条件刺激的反应类同。这些结果证明条件刺激增强了环磷酰胺对动物原发性体液免疫反应的抑制作用．这种条件性体液免疫抑制作用是相对稳定和有限度的,不易受条件反射建立参数的影响。     

杏仁核c-fos的表达与条件反射性免疫抑制

以糖精水为条件刺激（conditioned stimulus,,CS）,免疫抑制剂-环磷酰胺为非条件刺激 （(unconditioned stimulus,,UCS),在两次CS-UCS结合训练后,观测不同时程再次单独呈现条件刺激对条件反射性免疫抑制和味觉厌恶性行为反应的变化以及大鼠杏仁核各亚核团内c-fos蛋白表达的影响。结果表明,条件反射性免疫抑制作用在训练后第5天较强,第30天基本消失,而味觉厌恶性条件反射始终稳定保持到第30天。条件反射组大鼠杏仁中央核c-fos蛋白表达在第5天非常密集,而第30天明显减少,与细胞免疫功能改变在时程和趋势上具有一致性。通过c-fos蛋白表达时程差异比较,提示杏仁中央核可能既与条件性的味觉厌恶性行为建立有关,也是参与介导CS诱导的免疫抑制效应的重要核团。     

条件反射性免疫抑制激活过程中下丘脑核团c-fos的表达

利用经典条件反射性免疫抑制的动物模型,以糖精水为条件刺激（CS）,免疫抑制剂-环磷酰胺为非条件刺激 （UCS）,观测两次CS-UCS结合训练后,再次条件刺激诱发条件反射性免疫抑制作用的动态改变,获得条件反射性免疫抑制和味觉厌恶性条件反射各自保持的情况,并在此基础上,采用c-fos免疫组化技术, 进一步观察再次条件刺激诱发条件反射性免疫抑制反应时大鼠下丘脑各核团内FOS蛋白的表达情况。结果表明,条件反射性免疫抑制作用在训练后第5天较强,第30天基本消失,而味觉厌恶性条件反射始终稳定保持到第30天。进一步研究显示出,下丘脑室旁核FOS蛋白表达在第5天非常密集,而第30天几乎没有表达,与细胞免疫功能改变在时程和趋势上具有一致性。通过FOS蛋白表达时程差异比较,提示下丘脑室旁核可能是CNS内介导CS诱导的免疫抑制效应的重要核团。     

味觉厌恶性条件反射与条件反射性免疫抑制的研究

以环磷酰胺的注射为非条件刺激（ＵＣＳ）,糖精水的摄入为条件刺激（ＣＳ）,并以血白细胞和淋巴细胞数量及脾淋巴细胞的转化反应为免疫指标,糖精水的饮用量为行为指标,通过改变条件刺激与非条件刺激结合的次数来观察条件反射性厌恶行为与条件反射性免疫抑制的反应。结果表明不管是一次性的还是两次性的ＣＳ－ＵＣＳ结合训练都能使动物明显地建立起味觉厌恶性条件反射,然而条件反射性免疫抑制只在两次性ＣＳ－ＵＣＳ结合训练后才     

厌恶性条件反射与脑中c-fos的表达

Ｆｏｓ免疫组织化学法作为一种神经功能活动形态定位法,已在大鼠厌恶性条件反射的神经机制的研究中得到应用。无论是在味觉厌恶性条件反射的研究中,还是在听觉刺激与电击相结合的厌恶性条件反射的研究中,都证明了条件反射建立后,条件刺激能诱导出与非条件刺激相似的ｃ－ｆｏｓ表达的分布,这提示条件反射学习沟通了条件刺激和非条件刺激这两种不同刺激在大脑中的传导通路。     

乳头体和隔区在大鼠条件性味觉痕迹的形成和保存中的作用

本工作是在前一工作的基础上,进一步研究分别电损毁有关回路的乳头体、隔区,对以糖精水为条件刺激。氯化锂腹腔注射引起中毒作为非条件刺激的条件性糖精厌恶痕迹的形成和保存的影响。结果表明,无论是损毁乳头体,或者隔区,对条件性糖精厌恶痕迹的形成和保存均无影响。说明在本实验条件下,这种条件性味觉痕迹的形成与保存,不依赖边缘系统的乳头体、海马、隔区这些回路的参与,这就进一步说明味觉信号的记忆确有其不同于视、听觉信号的记忆的机制的。     

厌恶与恐惧情绪习得的性别差异研究:一项ERP研究

采用事件相关电位技术（ERPs）,用条件性习得范式探讨厌恶与恐惧情绪习得的性别差异。行为结果表明,在成功习得厌恶、恐惧和中性情绪之后,男女性在唤醒度维度上,性别差异显著;脑电结果表明,在早期N1和P2成分,厌恶情绪与恐惧情绪的习得无显著性别差异;但男女不同性别在N2成分上差异显著,主要表现为女性在厌恶、恐惧、中性这三类CS的N2成分均差异显著,但男性仅厌恶与中性情绪的CS差异显著。结果表明在负性情绪的习得中,女性比男性更敏感。     

味觉厌恶性条件反射建立后脑内c-Fos的表达

以新异味觉刺激糖精水的摄入为条件刺激,以腹腔注射环磷酰胺(CY,免疫抑制剂)或氯化锂(LiCl)为非条件刺激,分别使大鼠建立味觉厌恶性条件反射.在条件刺激日,糖精水在学习组大鼠下列脑区中诱发出密集的Fos表达下丘脑、杏仁核、边缘皮质等,而非学习组在这些区域中却没有或只有少量表达.另外,在丘脑前背侧核、扣带回、下丘脑外侧核、穹隆下器、压部后颗粒皮质、视上核,CY组的Fos表达明显多于LiCl组;而在伏核、杏仁基底外侧核、腹外侧隔核,LiCl组的Fos表达明显多于CY组,这种差异可能是两种药物的不同药理性质所致.     

非条件刺激降低再评估对条件性恐惧消退的影响

诸多情绪障碍治疗的关键在于促进条件性恐惧反应的消退, 研究证明非条件刺激再评估能够引起恐惧反应的变化。本研究将非条件刺激降低再评估范式应用于消退训练, 以主观预期值、皮电反应作为恐惧反应指标, 考察恐惧习得后非条件刺激强度降低对条件性恐惧消退的影响, 并运用评价性条件作用探讨非条件刺激再评估的作用机制。结果表明：在消退阶段, 降低组对条件刺激的皮电反应显著低于控制组。同时评价性条件作用结果显示：经过非条件刺激再评估, 降低组较控制组对条件刺激的评价更为正性。说明非条件刺激降低再评估有效改变条件刺激的负性效价, 降低个体的恐惧反应、促进恐惧消退。     

条件反射性抗体反应增强的动态分析——以OVA为非条件刺激物

研究了条件反射性抗体反应增强模型的建立。被试为49只雄性成年Wistar大鼠,采用糖精水作为条件性刺激,一种蛋白抗原卵清蛋白作为非条件性刺激配对给予大鼠,两者结合后,在初次抗体应答下降阶段再次单独给予条件刺激,用酶联免疫吸附法分时段检测抗体水平的变化。发现条件组在条件刺激后15,20,25天左右抗体水平明显高于对照组。这一过程与初次抗体应答的规律类似。这些结果证实经一次条件训练,单独给予条件刺激能诱导出明显的条件反射性抗体反应增高。     

Conditioned taste aversion with sucrose and tactile stimuli in the pond snail Lymnaea stagnalis

A new form of taste aversion conditioning was established in the pond snail Lymnaea stagnalis. An associative memory, lasting 24h, was produced in the pond snail with 20 pairings of 100 mM sucrose as the conditioned stimulus (CS) and mechanical stimulation to the head as the unconditioned stimulus (UCS). Animals exposed to reverse pairings of the CS and UCS failed to learn the association. The learning was characterized by a shift in the response to the UCS from a whole-body withdrawal response to the cessation of feeding behavior.     

The interval between the CS and the UCS as a determiner of generalization performance

Rats were trained in a conditioned taste aversion paradigm in order to determine whether a trace interval between the conditioned stimulus (CS) and the unconditioned stimulus (UCS) would result in the forgetting of stimulus attributes. Accordingly, subjects were conditioned with milk (CS), given either an immediate or a delayed injection of lithium chloride (UCS), and tested 48 h later with either milk or chocolate milk, a generalized flavor. The rats conditioned immediately following the presentation of the CS avoided milk more than chocolate milk, indicating discrimination between the two flavors. Those conditioned after a trace interval avoided both flavors equally, suggesting a loss of stimulus attributes of the original CS. Delay rats, however, still exhibited substantial learning when compared with controls not experiencing the UCS. These results allege a role for the forgetting of stimulus attributes during a trace interval in addition to following a complete learning episode.     

Conditioned taste aversion is enhanced when the unconditioned stimulus is presented in a different context

Using a conditioned taste aversion procedure with rats as the subjects, two experiments examined the effect of presenting a conditioned stimulus (CS saccharin solution) in one context followed by an unconditioned stimulus (US LiCl) in a different context. Experiment 1 showed that animals which received the above-mentioned procedure (Group D) showed a more marked conditioned aversion to the CS than animals which were given both the CS and the US in the same context (Group S). Experiment 2 found that in both Group D and Group S, aversion to the CS increased when the subjects were exposed to the conditioned context after the conditioning. These findings supported the argument that the strength of the CS-US association acquired during conditioning is compared with that of the context-US to determine the magnitude of aversion revealed to the CS.     

The effect of manipulating CS hedonic value on the magnitude of a conditioned taste aversion

This study was designed to assess how the hedonic value of a conditioned stimulus (CS) might mediate the strength of a conditioned taste aversion (CTA). Results indicated that as the hedonic value of the CS increased, the severity of the aversion associated with the CS attenuated.     

The effect of manipulating CS hedonic value on the magnitude of a conditioned taste aversion

This study was designed to assess how the hedonic value of a conditioned stimulus (CS) might mediate the strength of a conditioned taste aversion (CTA). Results indicated that as the hedonic value of the CS increased, the severity of the aversion associated with the CS attenuated.