共查询到20条相似文献，搜索用时 171 毫秒
1.
[目的]观察益智仁水提取物(A lp in ia oxyphylla M iq.fru it,AOF)对脑老化小鼠海马SOD活力及海马蛋白含量的影响.[方法]选用健康成年昆明种小鼠60只,雌雄各半,随机数字表法将其分成5组:对照组、模型组、脑复康组、AOF低剂量组、AOF高剂量组.用D-半乳糖皮下注射诱导小鼠脑老化模型,采用学习记忆行为训练和生化测定结合的方法,观察AOF对小鼠学习记忆能力的影响,测定海马组织超氧化物歧化酶(SOD)和海马蛋白含量.[结果]①AOF对脑老化小鼠学习记忆能力的影响:模型组达标所需训练次数显著高于对照组(p<0.01),AOF低、高剂量组达标所需训练次数显著低于模型组(p<0.01).②AOF对脑老化小鼠海马SOD活力的影响:模型组小鼠海马SOD活力显著低于对照组(p<0.05),AOF低、高剂量组小鼠海马SOD活力显著高于模型组(p<0.05).③AOF对脑老化小鼠海马蛋白含量的影响:与对照组比,模型组小鼠海马蛋白含量显著降低(p<0.01);与模型组相比,AOF低、高剂量组小鼠海马蛋白含量显著增高(p<0.01).[结论]AOF可提高脑老化小鼠海马SOD活力,增加海马蛋白含量,对D-半乳糖诱导脑老化小鼠的学习记忆障碍具有显著的改善作用. 相似文献
2.
大黄酚对东莨菪碱致小鼠学习记忆障碍的作用及脑内NO和NOS的影响 总被引：1，自引：0，他引：1
目的:研究大黄酚对东莨菪碱致小鼠空间学习记忆障碍的作用及脑内NO和NOS的影响.方法:将昆明种小鼠随机分组,设立正常对照组、东莨菪碱模型组及大黄酚小剂量组(0.1mg·kg-1)、中剂量组(1.0mg·kg-1)、大剂量组(10mg·kg-1).各组分别腹腔注射给药,对照组和模型组给溶剂,大黄酚组给大黄酚,于第5天给药30min后,除对照组腹腔注射生理盐水外,其它各组注射东莨菪碱1mg·kg-1,20min后进行Morris水迷宫测试,测试5d后处死,取其脑组织进行NO和NOS测定.结果:大黄酚各剂量组可明显改善东莨菪碱所致小鼠的空间学习记忆障碍,并可以降低小鼠脑内NO含量和NOS活性.结论:大黄酚能明显改善东莨菪碱所致小鼠空间学习记忆障碍,并降低其脑内NO含量及NOS活性. 相似文献
3.
目的:研究大黄素对脑缺血再灌注小鼠记忆功能的保护作用.方法:采用改进的Himori法暂时性阻断小鼠两侧颈总动脉制备脑缺血再灌注损伤模型,进行避暗实验、穿梭实验、常压耐缺氧实验、断头耐缺氧实验和亚硝酸钠中毒耐缺氧实验,观察大黄素(10.0,1.0,0.1 mg·kg-1,ip)对脑缺血再灌注小鼠记忆功能和耐缺氧能力的影响,并对各剂量组小鼠脑组织和血液中谷胱甘肽过氧化物酶(glutathione peroxidase,GSH-PX)活力和超氧化物歧化酶(superoxide dismutase,SOD)活力进行测定.结果:大黄素可改善脑缺血再灌注损伤所致的记忆功能障碍,明显延长小鼠耐缺氧生存时间,增加GSH-PX和SOD活力.结论:大黄素对脑缺血再灌注损伤小鼠记忆功能有保护作用,其作用机制可能是通过增强抗氧化酶GSH-PX和SOD活力,提高脑组织对氧自由基的清除能力和耐缺氧能力,从而减轻缺血再灌注引起的脑组织损伤. 相似文献
4.
栀子苷对急性乙醇中毒致小鼠学习记忆障碍的改善作用 总被引：2，自引：0，他引：2
目的:研究栀子苷(geniposide)对急性乙醇中毒小鼠空间学习和记忆障碍的改善作用.方法:采用一次灌胃乙醇(50%,7mL·kg-1)造成小鼠空间学习记忆障碍,应用Morris水迷宫实验观察栀子苷(10,20,40mg·kg-1,ig,10d)对乙醇致空间学习记忆障碍模型小鼠的保护作用.结果:栀子苷各剂量组均能改善急性乙醇中毒所致的小鼠空间学习和记忆障碍,能明显缩短寻找站台潜伏期和游泳路径.结论:栀子苷可预防急性乙醇中毒所致的空间学习和记忆障碍. 相似文献
5.
目的:探讨牛磺酸锌(TZC)拮抗汞对神经系统的损害作用.方法:选用健康Wistar大鼠64只,昆明种小鼠60只分别随机分组,对照组、染汞组、汞+TZC组,大鼠采用Y迷宫,小鼠采用穿梭实验,观察染汞组和不同浓度TZC组的鼠学习记忆能力的变化.结果:汞可导致大鼠学习记忆能力下降(P<0.05),不同浓度的TZC均可缓解汞致大鼠学习记忆能力下降(P<0.05).结论:TZC在一定程度上能拮抗汞对神经系统毒性作用. 相似文献
6.
目的:探寻萸姜药效组分对小鼠急性心肌缺血的影响.方法:以腹腔注射ISO制备小鼠常压缺氧模型和急性心肌缺血模型,对照丹参片组观察不同浓度萸姜药效组分对小鼠耐常压缺氧与急性心肌缺血的作用;以腹腔注射Pit制备小鼠急性心肌缺血模型,对照硝苯地平片组观察不同浓度萸姜药效组分对小鼠急性心肌缺血的作用.结果:小鼠耐常压缺氧和ISO致小鼠急性心肌缺血实验结果显示,复方丹参片组能明显延长小鼠存活时间(P＜0.05)及有效抑制小鼠心电图S-T段抬高(P＜0.05),萸姜药效组分的高、中、低剂量对小鼠存活时间无显著影响(P＞0.05),对小鼠心电图S-T段无显著影响(P＞0.05).Pit致小鼠急性心肌缺血实验结果显示,硝苯地平组与萸姜组分高剂量组均能有效抑制小鼠心电图S-T段抬高(P＜0.05),萸姜组分低剂量组对小鼠心电图S-T段无显著影响(P＞0.05).结论:萸姜药效组分对Pit致小鼠急性心肌缺血具有明显的改善作用. 相似文献
7.
唐晓光 《赤峰学院学报(自然科学版)》2011,27(3):147-148
目的：探讨不同剂量的青藏龙胆对CCl4所致的小鼠肝损伤的保护作用.方法：先采用青藏龙胆给药,再采用CCl4所致的小鼠肝损伤模型,用赖氏法测定小鼠血清丙氨酸氨基转移酶ALT含量,肝脏常规切片,观察病理组织学改变.结果：不同剂量的青藏龙胆组血清ALT含量明显低于CCl4组,镜下病理显示青藏龙胆对四氯化碳所致的小鼠急性化学性肝损伤有保护作用. 相似文献
8.
《大连大学学报》2015,(6):75-77
探讨白术醇提取物(AME)对老年小鼠记忆障碍的改善及海马乙酰胆碱酯酶(AChE)活力的影响。实验动物分为5组:对照组选用4月龄昆明种小鼠(12只),老年组与AME组选用18月龄昆明种小鼠(48只)。采用避暗实验检测小鼠的记忆能力,生化测定小鼠海马AChE活力的变化。结果显示:(1)避暗实验中,与对照组比,老年组小鼠的步入潜伏期明显缩短(P<0.05),错误次数明显增多(P<0.01);与老年组比,中、高剂量AME组小鼠的步入潜伏期明显延长(P<0.05,P<0.01),错误次数明显减少(P<0.05)。(2)生化测定表明,与对照组比,老年组小鼠海马AChE活力显著增加(P<0.01);与老年组比,中、高剂量AME组小鼠的ACh E活力显著降低(P<0.01)。结果提示AME对老年记忆障碍有一定的改善作用,机制可能与其降低海马AChE活力有关。 相似文献
9.
目的:观察烟碱类似物ZY-1在细胞水平上对Aβ产生的影响及对转基因阿尔茨海默病小鼠学习记忆的作用.方法:在转染高表达烟碱受体亚型的SH-EP1-α4β2nAChR细胞株进行放射配基结合实验;Western blotting检测ZY-1对于转染了APP695质粒的SH-EP1-α4β2nAChR细胞产生Aβ的影响;在双转基因阿尔茨海默病小鼠B6C3-Tg(APPswe/PSEN1dE9)85Dbo/J品系通过Morris水迷宫试验和跳台试验观察ZY-1对小鼠学习记忆的影响.结果:①受体亚型结合分析,亲和力常数Ki= 21.5 nmol·L-1,亲和力很高,显示ZY-1有α4β2亚型结合特异性.②烟碱激动剂尼古丁和ZY-1可以显著降低细胞内Aβ水平.③Morris水迷宫试验和跳台试验表明,ZY-1中、高剂量对模型小鼠的空间学习记忆有显著改善作用.结论:ZY-1可能具备了作为AD治疗药物进一步开发的潜力,确切的成药性仍需进一步的试验来证明. 相似文献
10.
《赤峰学院学报(自然科学版)》2008,(Z2)
目的:研究糖尿清水丸对正常及糖尿病小鼠血糖的影响。方法:给小鼠尾静脉注射四氧嘧啶建立糖尿病小鼠模型。通过葡萄糖氧化酶法测血糖。观察糖尿清高、低剂量对正常小鼠血糖的影响,观察糖尿清不同剂量对糖尿病小鼠血糖的影响。结果:糖尿清水丸对正常小鼠血糖的影响无显著性差异(P>0.05),高剂量组对糖尿病小鼠有降血糖作用(P<0.05)。 相似文献
11.
经典恐惧条件化是研究情绪学习记忆的重要动物模型;条件化恐惧消退是一主动的、新的学习过程而非原有恐惧记忆的简单遗忘.目前,对于恐惧消退神经机制的了解还远滞后于恐惧条件化本身.本文综述了近年来条件化恐惧消退神经机制研究的主要成果,重点对前额叶与杏仁核在恐惧消退中的作用进行了讨论. 相似文献
12.
Two experiments examined the counterconditioning of an aversively motivated response in rats. Presentation of a highly palatable sugar solution (maltose in Experiment 1; sucrose in Experiment 2) to thirsty rats was used as the counterconditioning treatment. In Experiment 1, the counterconditioning procedure was found to be effective in modifying both a newly acquired and a cue-reactivated fear memory. In Experiment 2, the counterconditioning effect was shown to occur when the fear memory was reactivated with a noncontingent exposure to the unconditioned stimulus rather than the conditioned stimulus. This outcome supports the interpretation of counterconditioning as a modification of some central representation of the original training memory, rather than the acquisition of a competing peripheral response. The methodological implications of the present approach to counterconditioning are considered. 相似文献
13.
The present study employed a Pavlovian-instrumental-transfer paradigm to investigate the role of conditioned fear in appetitive discrimination learning. Each of three Pavlovian training procedures was used to establish a conditioned fear excitor (CS+), a “neutral” CS (CSo), and a conditioned fear inhibitor (CS?). Then, the CSs were administered to rats in the three groups contingent upon the rewarded response in a difficult visual discrimination. In addition, half of each group received shock punishment for each incorrect response. Relative to CSo, CS+ facilitated performance in contrast to the usual interfering effect of conditioned suppressors; conversely, CS? retarded performance even when its reinforcing action (fear inhibition) was potentiated by punishment for the incorrect response. These results, together with other findings showing a reversed outcome when the CSs are administered for the incorrect response, indicate that Pavlovian conditioning comprises both general signaling and affective functions, the former reflecting a basic “expectancy” or nominal type of cognitive processing in the rat. 相似文献
14.
Recent research has shown that learned fear emerges in a response-specific sequence. For example, an odor conditioned stimulus (CS) previously paired with shock elicits behavioral expressions of fear like avoidance at a younger age than it elicits other behavioral expressions of fear like potentiation of the startle response (Richardson, Paxinos, & Lee, 2000). In the present study, the question of whether learned fear is expressed in a manner appropriate to the animal’s age at training or its age at testing was explored in three experiments, all using a within-subjects design. The results suggest that learned fear is expressed in a manner appropriate to the rat’s age at training, not its age at testing. The Discussion section focuses on the implications of these findings for (1) the developmental analysis of memory and (2) the idea that an aversive CS elicits a central state of fear. 相似文献
15.
The efficacy of conditioned inhibition in a novel conditioned stimulus/conditioned inhibitor (CS/CI) compound was tested in 6-, 10-, and 14-week-old kittens. The conditioned response was suppression of respiration elicited by a 5.1-sec CS paired with a brief, mild footshock. During original inhibitory training, a CI was presented 2 sec after the onset of the CS, and the stimuli coterminated 3 sec later without the shock. As previously reported, the CI trained in this paradigm is more potent in older kittens but passes a summation test in all age groups (Dess & Soltysik, 1989). In the transfer test, the order of the CS and CI was reversed, so that the CI preceded the CS with no stimulus overlap. Transfer of inhibition to this new compound was virtually absent in the 6-week-old kittens and nearly perfect in the 14-week-old kittens. The CI alone (before CS onset) elicited a strong fear response in the youngest kittens, moderate fear in the 10-week-old group, and very little fear in the oldest group. The transferability of inhibitory training to a different temporal configuration of the CS and CI is absent at 6 weeks of age and fully developed 8 weeks later. 相似文献
16.
Although a number of studies have demonstrated nearly complete retention of fear in a conditioned suppression task, they provide little information about the nature of the memory for the CS. The purpose of the present experiment was to investigate the retention of an attribute of a tonal CS that had been paired with shock and was thus capable of eliciting a conditioned emotional response (CER) in rats. The Kamin blocking effect was utilized to detect changes in the memory of CS attributes. Either 1 or 21 days following conditioning to a tone, separate groups of rats received compound conditioning in which either the original or a novel tone was combined with a light. Subsequent measurement of suppression to the added element (light) indicated that only the original CS produced blocking at the short delay, but that both original and novel tones resulted in blocking at the 21-day interval. This increase in the extent of blocking suggests that memory for specific attributes of the CS does diminish as a function of time. 相似文献
17.
Benzodiazepine administration prevents the use of error-correction mechanisms during fear extinction
Genevra Hart Nathan M. Holmes Justin A. Harris R. Frederick Westbrook 《Learning & behavior》2014,42(4):383-397
Three experiments examined the effect of systemic administration of the benzodiazepine midazolam on extinction and re-extinction of conditioned fear. Experiment 1 demonstrated that midazolam administration prior to extinction of a conditioned stimulus (CS) impaired that extinction when rats were subsequently tested drug free; however, extinction was spared if rats were extinguished, reconditioned, and re-extinguished under midazolam. Experiment 2 provided a replication of this effect within-subjects; rats were conditioned to two CSs (A and B), extinguished to one (A-), reconditioned to both, and then extinguished/re-extinguished to both stimuli in compound (AB-), under either vehicle or midazolam. On the drug-free test, rats given midazolam froze more to the CS that had been extinguished (B) than the one that been re-extinguished (A). The final experiment examined whether extinction under midazolam was regulated by prediction error. Rats were trained with three CSs (A, B, C) and extinguished to two (A-, C-). These stimuli then underwent additional extinction under midazolam or vehicle, with one CS now presented in compound with the non-extinguished CS (AB-, C-). Rats were then tested for fear of A relative to C. Rats given vehicle showed a deepening of extinction to A relative to C, as is predicted from error-correction models; however, rats given midazolam failed to show any such discrepancy in responding. The results are interpreted to indicate that the drug reduced prediction error during extinction by reducing fear, and rats were able to re-extinguish fear via a retrieval mechanism that is independent of prediction error. 相似文献
18.
Thomas R. Minor 《Learning & behavior》1990,18(2):212-226
Lick-suppression tests were used in seven experiments to assess the transsituational transfer of fear in the learned helplessness paradigm. Two sources of fear combined to suppress test drinking in inescapably shocked rats. A situational odor was strongly associated with shock pretreatments and mediated the transfer of conditioned fear during testing. Fear of the pretreatment odor was greater following inescapable shock than after escapable shock or restraint. This conditioned suppression was retained for at least 72 h after pretreatment. Neophobia was enhanced as a second, nonassociative reaction to inescapable shock. Unconditioned fear was augmented by a novel odor in the test context, but otherwise was weak and dissipated within 72 h. However, neophobia was necessary for differential conditioned suppression in inescapably shocked rats. The pretreatment odor elicited fear only when tested in a novel context. Initial habituation to the test apparatus reduced conditioned fear. These data provide additional evidence for odor-mediated transfer of helplessness. Conditioned fear and neophobia are discussed in relation to recent anxiety interpretations of the phenomenon. 相似文献
19.
Kenneth A. McNish Stephanie L. Betts Susan E. Brandon Allan R. Wagner 《Learning & behavior》1997,25(1):43-52
Two experiments of Pavlovian conditioning with rabbits evaluated the effects of initiating or continuing a conditioned stimulus (CS) after a paraorbital unconditioned stimulus (US). In Experiment 1, backward pairings, in which a CS came on after the US, produced a CS that appeared inhibitory on a measure of eyeblink conditioning but excitatory on a potentiated-startle measure of conditioned fear. In Experiment 2, extending the duration of a CS that came on prior to the US, so that it continued after the US, decreased eyeblink conditioned responses, whereas it increased conditioned fear. The data from the two experiments confirm and extend those of Tait and Saladin (1986), supporting the suppositions of AESOP (Wagner & Brandon, 1989) that conditioned eyeblink and conditioned fear can be dissociated under various temporal relationships between the CS and US. 相似文献
20.
Verónica S. Valentinuzzi Daniel E. Kolker Martha Hotz Vitaterna Elenice A. M. Ferrari Joseph S. Takahashi Fred W. Turek 《Learning & behavior》2001,29(2):133-142
We examined context-dependent and tone-cued fear conditioning during the activity and rest periods of C57BL/6J mice. Wheel-running activity was measured continuously as a marker of circadian phase. To control the effects of light on the response, the animals were kept in a skeleton photoperiod (two 15-min light pulses per day, indicating the beginning and the end of the day). Half the animals were trained and tested for context-dependent fear conditioning 2 h after the morning light pulse; the other half were trained and tested 2 h after the evening light pulse. Animals were tested every 24 h for 5 days to analyze the conditioned response and the rate of extinction. They were then trained for tonecued fear conditioning at the same time and tested for 5 consecutive days. A significant difference between the morning and the evening groups was observed in the conditioning level and extinction rate of context-dependent fear conditioning, but not in tone-cued fear conditioning. These results suggest a modulating effect of the biological clock on the context fear-conditioning pathway. 相似文献