剥夺左眼和单眼学习与雏鸡脑内Jun样蛋白表达的相关性研究

利用免疫组化技术,观察并比较剥夺一侧视觉及单眼一次性味觉厌恶回避学习后Ｊｕｎ样蛋白在雏鸡ＨＶ和ＬＰＯ的表达,结果表明正常雏鸡ＨＶ、ＬＰＯＪｕｎ表达几乎没有,剥夺左眼和单眼视觉学习后均可使Ｊｕｎ样蛋白增高。根据阳性神经元记数结果表明：１．视剥夺２．５、４、２４小时后可使Ｊｕｎ样蛋白的表达逐渐增高,而且它们之间的差异显著;２．剥夺左眼２小时和２４小时后训练,并分别于１０分钟、７０分钟记忆保持测验后可看到Ｊｕｎ样蛋白表达继续增多;３。无论单纯视剥夺组还是单眼视觉学习组,各组ＬＰＯＪｕｎ样蛋白的表达均明显高于ＨＶ的Ｊｕｎ样蛋白表达,它们之间差异显著。     

荷苞牡丹碱对雏鸡单眼视剥夺后记忆形成过程的改善作用

了雏鸡左眼视剥夺２小时后,进行一次性被动回避学习的记忆形成过程;以及ｒ一氨基丁酸（ｒ－ａｍｉｎｏ－ｂｕｔｙｒｉｃａｃｉｄＧＡＢＡ）的受体颉颌颃剂荷苞牡丹碱（ｂｉｃｕｃｕｌｌｉｎｅＢｉｃ）,对雏鸡左眼视剥夺后记忆形成过程的改善作用。实验结果表明：１．雏鸡左眼视剥夺２小时后,仅能形成较好的短时记忆,中时记忆和长时记忆难以形成;２．训练前１０分钟颅内注射荷苞牡丹碱,对雏鸡左眼视剥夺２小时后的记忆缺失有明显的改善作用,形成了较好的中时记忆和长时记忆。     

视剥夺及视剥夺学习后Jun样蛋白在雏鸡两侧半球中不同表达的研究

该实验利用免疫组化技术,在已有实验的基础上进一步观察比较了左眼视剥夺及单眼学习后,Ｊｕｎ样蛋白在雏鸡两侧半球ＨＶ和ＬＰＯ中表达的差异。实验结果表明：１．视剥夺２、２４、４８、７２小时后观测到Ｊｕｎ样蛋白在左、右半球ＨＶ和ＬＰＯ中的表达逐渐增高,并且于视剥夺４８小时表达到达峰值。同时仅在视剥夺２小时后观测到两半球ＬＰＯ中Ｊｕｎ样蛋白的表达存在差异,在其余各视剥夺时程中两侧半球的ＬＰＯ、ＨＶ中Ｊｕｎ样蛋白的表达均无显著差异。２．视剥夺２小时和２４小时后均在学习后７０分钟组中观测到Ｊｕｎ样蛋白在左、右半球的ＨＶ和ＬＰＯ中表达的显著升高,而在视剥夺２小时学习后１０分钟只观测到左半球ＨＶ和ＬＰＯ中Ｊｕｎ样蛋白表达的显著升高,在视剥夺２４小时学习后１０分钟中仅观测到左半球ＬＰＯ中Ｊｕｎ样蛋白的显著升高。同时也仅在视剥夺２小时学习后１０分钟观测到两侧半球ＨＶ、ＬＰＯ中Ｊｕｎ样蛋白表达的显著性差异。３．无论单纯视剥夺组还是单眼学习组,各组同侧半球中ＬＰＯＪｕｎ样蛋白的表达显著高于ＨＶ的Ｊｕｎ样蛋白的表达现象在视剥夺４８小时后消失。     

视剥夺及视剥夺学习后Jun样蛋白在雏鸡两侧半球中不同表达的研究

该实验免疫组化技术,在已有实验的基础上进一步观察比较了左眼视剥夺及单眼学习后,Ｊｕｎ样蛋白在雏鸡则半ＨＶ和ＬＰＯ中表达的差异,实验表明：１．视剥夺２．２４、４８、７２小时后观测到Ｊｕｎ样蛋白在左、右半球ＨＶ和ＬＰＯ中的表达逐渐增高,并且于视剥夺４８小时表达到达峰值。同时仅在视剥夺２小时后观测到两半球ＬＰＯ中Ｊｕｎ样蛋白的表达存在差异,在其余各视剥夺时程中两侧半球的ＬＰＯ、ＨＶ中Ｊｕｎ样蛋白的表达均     

单眼视剥夺2小时对雏鸡记忆保持的影响

以2日龄雏鸡为研究对象,采用一次性被动回避学习模型,以不透明胶纸封贴一侧眼的方法,研究2日龄雏鸡单侧眼视剥夺2小时后对视觉学习记忆的影响,并与双眼学习条件下的记忆情况进行比较;试图探讨雏鸡在视觉信息加工过程中左、右半球的作用。实验结果表明：剥夺一侧眼（无论左或右）2小时后对雏鸡的短时记忆无影响,明显干扰雏鸡的中期和长时记忆,特别是剥夺左眼干扰更明显。     

雏鸡单眼学习与脑内阿片肽类含量的相关研究

本实验以一日龄雏鸡为实验对象 ,采用一次性味觉厌恶性回避反应和放射免疫测定法 ,分析比较了剥夺雏鸡左眼 2 4小时后 ,右眼学习组 ,非学习组和正常对照组其脑幽亮脑啡肽 (LEK) ,β -内啡肽 (β -ED)和强啡肽 (Dyn)含量的变化 ,从而探讨剥夺左眼视觉强烈干扰雏鸡记忆形成过程的可能机理。实验结果 :1 正常组和剥夺左眼非学习组的两半球之间的LEK ,β -ED和Dyn均为左半球的含量低于右半球 ,特别是LEK其差异达到显著性水平 (P <0 .0 5 )。 2 剥夺左眼非学习组的脑内LEK含量与对照组非常接近 ;β -ED的含量则明显升高 ,与对照组同侧半球相比 ,差异显著 (P <0 .0 5 ) ;Dyn含量有所下降 ,其右半球与对照组同侧半球相比差异显著 (P <0 .0 5 )。 3 剥夺左眼学习组脑内LEK含量与其他两组相比较均无显著差异。而 β -ED的含量则低于非学习组 ,高于对照组 ,但是差异未达到显著性水平 ;Dyn的含量则相反高于非学习组 ,低于对照组 ,其右半球的Dyn含量与非学习组同侧半球相比 ,异达到显著性水平 (P <0 .0 5 )。结果提示 :剥夺左眼视觉引起的应激反应可能是干扰雏鸡记忆形成过程的重要因素 ,其次学习训练有助于脑内肽类物质达到新的平衡。     

快速眼动相(REM)睡眠剥夺对大鼠记忆巩固的影响

本实验应用小站台水环境技术剥夺大鼠快速眼动相(REM)睡眠,比较了在学习后不同时间剥夺REM睡眠对记忆巩固的影响异同,结果证明:大鼠在学习后,立即剥夺REM睡眠24小时对记忆巩固明显不利;如在立即剥夺REM睡眠24小时后再让其恢复自由睡眠24小时,记忆成绩无明显改善;学习后允许自由睡眠24小时对记忆巩固明显有利;如在自由睡眠24小时后再行REM睡眠剥夺24小时,记忆成绩仍保持良好。说明学习后一段时间自由睡眠对于记忆的巩固是重要的,剥夺REM睡眠对于记忆的巩固明显不利。     

不同刺激强度训练后一日龄小鸡的记忆形成

一日龄小鸡,分别接受不同浓度的回避性刺激物邻氨基苯甲酸甲酯（ＭｅＡ）训练,间隔一定时间后测试记忆保持。主要结果为：５％和２０％ＭｅＡ训练,分别使动物记忆保持１５分钟和５０分钟左右,相当于记忆形成多阶段模型中的ＳＴＭ和ＩＴＭ阶段。４０％ＭｅＡ训练,记忆保持到训练后８－１０小时,相当于不依赖新糖蛋白合成的ＬＴＭ形成的早期阶段。只有６０％以上浓度的ＭｅＡ训练才使记忆保持至少２４小时。上述结果提示,利用弱化训练的方法,不仅可以将ＳＴＭ,ＩＴＭ和ＬＴＭ分离开,而且可把ＬＴＭ形成的早期阶段分离出来独立研究,增加了对ＬＴＭ新的理解,为进一步探讨记忆形成机制提供了一条新的途径。     

不同动物学习模型及记忆形成机制研究进展

本文介绍了近几年来利用雏鸡的一次性回避学习模型、果蝇的视觉辩别学习模型和大鼠的步入学习模型等多种动物学习模型对记忆形成的阶段性以及件随记忆形成过程所发生的神经系统的形态学、生物化学变化以及基因表达与记忆形成关系的研究．这些研究为深入探索记忆的形成过程提供了新的实验资料．     

延迟干扰对记忆巩固的影响的综述研究

众多研究表明最小化学习后的干扰刺激能显著提升记忆效果,且学习后干扰刺激的不同类型也会影像记忆,而在学习新材料之后进行短暂的觉醒休息有助于与新的学习行为相关的神经活动自动重演,以促进记忆的短时保持和长时保存,由此假设在觉醒休息时之前的记忆路径被增强。本文回顾总结了延迟干扰对记忆巩固影响的研究进展,并提出未来研究展望。     

一日龄小鸡的不同记忆阶段中Jun样蛋白在脑内HV和LPO的表达

以一日龄小鸡为研究对象,采用一次性动回避反应试验和免疫组织化学结合的方法,选择六个时间点对Ｊｕｎ样蛋白在小鸡左右侧脑内ＨＶ和ＬＰＯ两部位的表进行了探讨。     

Adult visual experience promotes recovery of primary visual cortex from long-term monocular deprivation

Prolonged visual deprivation from early childhood to maturity is believed to cause permanent visual impairment. However, there have been case reports of substantial improvement of binocular vision in human adults following lifelong visual impairment or deprivation. These observations, together with recent findings of adult ocular dominance plasticity in rodents, led us to re-examine whether adult primary visual cortex (V1) is capable of any recovery following long-term monocular deprivation starting in development. Using mice as a model, we find that monocular deprivation from early development to mature ages (well past the critical period) severely impaired binocular vision by reducing the amplitude of responses elicited by stimulation of the deprived eye. Surprisingly, we find little effect on nondeprived eye responses. Restoration of binocular vision in mature adults yields modest but significant improvement of visual responses in V1. Remarkably, we find that when binocular vision is followed by occlusion of the nondeprived eye, visual responses in V1 recover almost fully, as measured by visual evoked potential amplitude, spatial frequency threshold, and single-unit activity. We conclude that adult V1 can recover from long-term deprivation when provided with an optimal regimen of visual experience.     

The Nootropic Properties of Ginseng Saponin Rb1 are Linked to Effects on Anxiety

Previous studies have shown that crude ginseng extracts enhance performance on shock-motivated tasks. Whether such performance enhancements are due to memory-enhancing (nootropic) properties of ginseng, or to other non-specific effects such as an influence on anxiety has not been determined. In the present study, we evaluated both the nootropic and anxiolytic effects of the ginseng saponin Rb1. In the first experiment, 80 five-day-old male chicks received intraperitoneal injections of 0, 0.25, 2.5 or 5.0 mg/kg Rb1. Performance on a visual discrimination task was evaluated 15 minutes, 24 and 72 hours later. Acquisition of a visual discrimination task was unaffected by drug treatment, but the number of errors was significantly reduced in the 0.25 mg/kg group during retention trials completed 24 and 72 hours after injection. Animals receiving higher dosages showed trends towards enhancement initially, but demonstrated impaired performance when tested 72 hours later. Rb1 had no effect on response rates or body weight. In the second experiment, 64 five-day-old male chicks received similar injections of Rb1 (0, 0.25, 2.5 or 5.0 mg/kg) and separation distress was evaluated 15 minutes, 24 and 72 hours later. Rb1 produced a change in separation distress that depended on the dose and environmental condition under which distress was recorded. These data suggest that Rb1 can improve memory for a visual discrimination task and that the nootropic effect may be related to changes in anxiety.     

The nootropic properties of ginseng saponin Rb<Subscript>1</Subscript> are linked to effects on anxiety

Previous studies have shown that crude ginseng extracts enhance performance on shock-motivated tasks. Whether such performance enhancements are due to memory-enhancing (nootropic) properties of ginseng, or to other non-specific effects such as an influence on anxiety has not been determined. In the present study, we evaluated both the nootropic and anxiolytic effects of the ginseng saponin Rb₁. In the first experiment, 80 five-day-old male chicks received intraperitoneal injections of 0, 0.25, 2.5 or 5.0 mg/kg Rb₁. Performance on a visual discrimination task was uvaluted 15 minutes, 24 and 72 hours later. Acquisition of a visual discrimination task was unaffected by drug treatment, but the number of errors was significantly reduced in the 0.25 mg/kg group during retention trials completed 24 and 72 hours after injection. Animals receiving higher dosages showed trends towards enhancement initially, but demonstrated impaired performance when tested 72 hours later. Rb₁ had no effect on response rates or body weight. In the second experiment, 64 five-day-old male chicks received similar injections of Rb₁ (0, 0.25, 2.5 or 5.0 mg/kg) and separation distress was evaluated 15 minutes, 24 and 72 hours later. Rb₁ produced a change in separation distress that depended on the dose and environmental condition under which distress was recorded. These data suggest that Rb₁ can improve memory for a visual discrimination task and that the nootropic effect may be related to changes in anxiety.     

Sleep deprivation selectively impairs memory consolidation for contextual fear conditioning

Many behavioral and electrophysiological studies in animals and humans have suggested that sleep and circadian rhythms influence memory consolidation. In rodents, hippocampus-dependent memory may be particularly sensitive to sleep deprivation after training, as spatial memory in the Morris water maze is impaired by rapid eye movement sleep deprivation following training. Spatial learning in the Morris water maze, however, requires multiple training trials and performance, as measured by time to reach the hidden platform is influenced by not only spatial learning but also procedural learning. To determine if sleep is important for the consolidation of a single-trial, hippocampus-dependent task, we sleep deprived animals for 0–5 and 5–10 h after training for contextual and cued fear conditioning. We found that sleep deprivation from 0–5 h after training for this task impaired memory consolidation for contextual fear conditioning whereas sleep deprivation from 5–10 h after training had no effect. Sleep deprivation at either time point had no effect on cued fear conditioning, a hippocampus-independent task. Previous studies have determined that memory consolidation for fear conditioning is impaired when protein kinase A and protein synthesis inhibitors are administered at the same time as when sleep deprivation is effective, suggesting that sleep deprivation may act by modifying these molecular mechanisms of memory storage.     

Two critical periods of protein and glycoprotein synthesis in memory consolidation for visual categorization learning in chicks

A protein synthesis inhibitor, anisomycin (ANI), and an inhibitor of glycoprotein synthesis, 2-deoxygalactose (2-D-gal), were used to investigate memory consolidation following visual categorization training in 2-day-old chicks. ANI (0.6 micromole/chick) and 2-D-gal (40 micromoles/chick) were injected intracerebrally at different time intervals from 1 hr before to 23 hr after the training. Retention was tested 24 hr post-training. Both ANI and 2-D-gal injections revealed two periods of memory sensitivity to pharmacological intervention. ANI impaired retention when injected from 5 min before to 30 min after the training or from 4 hr to 5 hr post-training, thus demonstrating that consolidation of long-term memory in this task requires two periods of protein synthesis. 2-D-Gal first produced an amnesia when it was injected in the interval from 5 min before to 5 min after the training. Injections made between 5 min and 5 hr post-training were without effect on the retention. The second period of memory impairment by 2-D-gal started at 5 hr post-training and lasted until 21 hr after the training. Administration of 2-D-gal made 23 hr after the training did not influence retention in the test at either 24 hr or 26 hr. These results are consistent with the hypothesis that two waves of protein and glycoprotein synthesis are necessary for the formation of long-term memory. The prolonged duration of performance impairment by 2-D-gal in the present task might reflect an extended memory consolidation period for a categorization form of learning.     

Nifedipine blocks retention of a visual discrimination task in chicks.

Reports that the dihydropyridine Ca2+ channel antagonists may facilitate memory led to the present study of the behavioral effects of nifedipine. Ninety-two 4-day-old male chicks received 0, 100 nM, 100 microM, or 10 mM nifedipine. Drugs were administered in volumes of 2 microliters into the fourth cerebral ventricle 5 min before training on a visual discrimination task. Nifedipine did not produce any detectable changes in behavior during acquisition trials. Retention, however, was impaired 24 h after training in the 100 nM and 100 microM nifedipine-treated chicks, which made significantly more errors than controls. Nifedipine did not affect the amount of time required to complete the task. No effects on body weight gain were detected, suggesting that the memory impairment was not due to a change in feeding behavior. These data are discussed in terms of the role of calcium-dependent processes in memory.