新生期注射纳洛酮和脑啡肽对幼年大鼠分辨学习的影响

本文用Ｓｐｒａｑｕｅ－Ｄａｗｌｅｙ大鼠为实验动物,从生后一日龄起每日皮下分别注射１次纳洛酮（１０,５０,１００,２００μｇ／１００ｇｂ．ｗ）、甲硫氨酸脑啡肽（ＭＥＫ）（２０μｇ／１００ｇｂ．ｗ）,对照组注射等量的生理盐。连续注射１４ｄ,观察１６日龄幼鼠的吸乳迷津分辨学习（ＡＤＬ）、３０日龄幼鼠的Ｙ迷津明暗分辨学习（ＢＤＬ）行为与４５日龄幼鼠前脑蛋白含量的变化,结果表明,５０μｇ／１００ｇｂ．ｗ纳洛     

头端延髓腹外侧区血管加压素在刺激中脑dPAG区诱发防御性升压反应中的…

雄性Ｓｐｒａｇｕｅ－Ｄａｗｌｅｙ大鼠,用乌拉坦（７００ｍｇ／ｋｇ）和氯醛糖（３０ｍｇ／ｋｇ）腹腔麻醉。在双侧头端延髓腹外侧区（ｒＶＬＭ区）每侧微量注射血管加压素（ＡＶＰ）（１０ｐｍｏｌ／０．１μｌ）可引起平均动脉压（ＭＢＰ）升高,心率（ＨＲ）变化不明显,每侧微量注射ＡＶＰ的Ｖ１受体拮抗剂ｄ（ＣＨ２）５［Ｔｙｒ（Ｍｅ）＾２］ＡＶＰ（０．１ｎｍｏｌ／０．１μｌ）后ＭＢＰ和ＨＲ无明显变化。若预先在ｒＶＬ     

双功能抗体介导的胃癌杀伤效应

将诱变的αＣＤ３杂交瘤（ＴＫ~－）与ＰＤ４杂交瘤（ＨＧＰＲＴ~－）融合,获得分泌双功能抗体（ＢｓＡｂ）的四体杂交瘤Ｃ３．ＢｓＡｂＣ３可分别与ＣＤ３分子及胃癌相关抗原Ｐ４０反应．体外杀伤试验证实,当效靶比为４０：１,ＢｓＡｂＣ３浓度为１ｍｇ／Ｌ时,其杀伤效应可达７７．６％．该杀伤效应具有明显的特异性,仅Ｐ４０阳性表达的靶细胞可被溶解,体内杀伤试验证实,裸鼠接种胃癌细胞后５ｄ,以ＢｓＡｂＣ３活化的外周血淋巴细胞（ＰＢＬｓ）经局部皮下注射处理,可使移植胃癌完全消退（５／５）．这一明显的治疗作用可能与局部注射途径有关,可供临床应用参考．     

米非司酮对大白鼠子宫内膜抗着床作用的组织化学观察

３０只雌性ＳＤ大鼠分为五组,即Ａ组（阴性对照组）,Ｂ组（孕三烯酮阳性对照组１ｍｇ／ｋｇ）,Ｃ组（米非司酮实验组,Ｃｌ１２ｍｇ／ｋｇ,Ｃ２６ｍｇ／ｋｇ,Ｃ３３ｍｇ／ｋｇ）。用组织化学方法观察米非司酮对子宫内膜一氧化氮合成酶（ＮＯＳ）、琥珀酸脱氢酶（ＳＤＨ）、乳酸脱氢酶（ＬＤＨ）、酸性磷酸酶（ＡＣＰ）、硷性磷酸酶（ＡＬＰ）活性和糖原含量的影响。实验结果显示：ＮＯＳ,ＳＤＨ和ＡＬＰ活性较阴性对照组弱,ＬＤＨ和ＡＣＰ活性较阴性对照组强,糖原含量略低于阴性对照组。     

风信子花被外植体年龄对花器官分化的影响

离体培养风信子（ＨｙａｃｉｎｔｈｕｓｏｒｉｅｎｔａｌｉｓＬ．）不同年龄的花被外植体诱导花器官直接再生的实验表明：１．在ＭＳ附加６ＢＡ２ｍｇ／Ｌ、２,４Ｄ０．１ｍｇ／Ｌ的培养基上,年龄Ｖ的外植体大量衰老,基本丧失器官再生能力,处于年龄段ＩＩ～ＩＶ的外植体可发生玻璃化反应。２．玻璃化反应的外植体转移至ＭＳ附加６ＢＡ０．２ｍｇ／Ｌ、ＮＡＡ０．００５ｍｇ／Ｌ的培养基上继续培养３０ｄ后可再生正常的花被片,表明降低培养基中外源激素浓度能够阻止玻璃化反应继续发生。３．在ＭＳ附加６ＢＡ２ｍｇ／Ｌ、２,４Ｄ０．１ｍｇ／Ｌ的培养基上,外植体形态学下部可再生雌蕊状早期结构。平均每块外植体分化雌蕊状早期结构数以年龄Ⅲ的外植体最多     

云南松成熟胚的体细胞胚胎的发生研究

云南松（Ｐｉｎｕｓ ｙｕｎｎａｎｅｓｉｓ Ｆｒａｎｃｈ）是我国特产的一种优良森林树种。本研究采用云南松成熟合子胚为起始外植体,在含２,４－Ｄ１０ｍｇ／Ｌ,ＫＴ和ＢＡ各４ｍｇ／Ｌ的改良Ｐ６培养基上得到胚发生培养物。将白色半透明的胚性愈伤组织（含早期原胚）在含２,４－Ｄ１．０ｍｇ／Ｌ,ＫＴ和ＢＡ各０．４ｍｇ／Ｌ的培养基上保持并增殖。在附加９,０００ｍｇ／Ｌ肌醇的高渗培养基（含ＮＡＡ０．５ｍｇ／Ｌ,ＫＴ     

东北地区蒿属植物比较形态学研究——II.叶表皮结构

本通过扫描电子显微镜,对东北地区蒿属（Ａｒｔｅｍｉｓｉａ）植物,莳萝蒿组（Ａ．ｓｅｃｔ．Ａｂｓｉｎｔｈｉｕｍ ＤＣ）,艾蒿组（Ｓｅｃｔ．Ａｂｒｏｔａｎｕｍ Ｂｅｓｓ）,艾组（Ｓｅｃｔ．Ａｒｔｅｍｉｓｉａ）,龙蒿组（Ｓｅｃｔ．Ｄｒａｃｕｍｃｕｌｕｓ Ｂｅｓｓ）,牡蒿组（Ｓｅｃｔ．ｌａｔｉｏｂｕｓ Ｙ．Ｒ．Ｌｉｎｇ）３６种成熟代表植物叶表皮形态学特征进行了详尽的比较研究。其中表皮细胞大小、形状不等。     

一种新的α—纤维蛋白原酶对血小板聚集的影响

ＳＤＳ－聚丙烯酰胺凝胶电泳（ＳＤＳ－ＰＡＧＥ）检测中国眼镜蛇毒蛋白酶水解纤维蛋白原的作用方式,发现该蛋白酶可迅速水解纤维蛋白原Ａα链,对γ链作用较弱,对Ｂβ链无作用,是一种新型的α－纤维蛋白原本科,用比浊法测定血小板聚集率,证实中国眼镜蛇毒蛋白酶低剂量（）０．０２５）ｍｇ／ｋｇ）、中剂量（０．０５ｍｇ／ｋｇ）以及高剂量（０．１ｍｇ／ｋｇ）体内给药浓度依赖性地抑制ＡＤＰ（１０μｍｏｌ／Ｌ）和胶原（１     

向日葵下胚轴原生质体高频率愈伤组织形成与根发生

向日葵籽苗下胚轴原生质体,培养在含有ＢＡ０．５ｍｇ／Ｌ,２,４－Ｄ０．５ｍｇ／Ｌ,ＮＡＡ０．１ｍｇ／Ｌ和葡萄糖０．５５ｍｇ／Ｌ的改良Ｋａｏ培养基中,２４～２８ｈ后,原生质体开始分裂。包埋在琼脂糖０．６％中的原生质体,培养５ｄ后,分裂频率达９５％以上。生长旺盛的小愈伤组织转移到含有２ｉｐ０．１ｍｇ／Ｌ,ＩＡＡ０．０１ｍｇ／Ｌ,腺嘌呤４０ｍｇ／Ｌ和ＧＡ３０．０１ｍｇ／Ｌ的Ｔｈｏｍｐｓｏｎ液体培养基上１３ｄ后,原生质体诱导的少数愈伤组织发生根分化。     

马尾松成熟合子胚的体细胞胚胎发生和植株再生

采用马尾松（Ｐｉｎｕｓｍ ａｓｓｏｎｉａｎａ Ｌａｍ ｂ．）成熟合子胚为起始外植体,在含２,４－Ｄ １０ ｍ ｇ／Ｌ,ＫＴ和ＢＡ 各４ ｍ ｇ／Ｌ的ＤＣＲ培养基上得到胚发生培养物。将白色半透明的愈伤组织（含早期原胚）在含２,４－Ｄ１．０ ｍ ｇ／Ｌ,ＫＴ和ＢＡ 各０．４ ｍ ｇ／Ｌ的ＤＣＲ培养基上保持并增殖。在附加９０００ ｍ ｇ／Ｌ肌醇的ＤＣＲ高渗培养基上得到粗壮的后期原胚。ＡＢＡ 和活性炭同时使用能促进子叶胚的形成,最高频率为３５．１％ 。在无激素培养基上,成熟体细胞胚萌发并进一步形成完整小植株     

大鼠脑内caveolin-1蛋白的表达及其在分辨学习中的作用

Caveolin-1（Cav—1）蛋白作为细胞质膜结构小窝（caveolae）的标志蛋白,在胆固醇运输、膜组装、信号转导和细胞转化过程中扮演重要的角色。为了探讨Cav-1蛋白在中枢神经系统可塑性及学习记忆中的作用,本文以Sprague—Dawley大鼠为实验对象,利用蛋白质免疫印迹杂交方法观察了Car-1蛋白在不同年龄大鼠脑内表达的特征,并研究了Y-迷宫训练前后Cav-1蛋白表达的变化。结果表明：（1）大鼠不同脑区Cav-1蛋白表达的年龄特征不同。海马内的表达属青年鼠最高,其次是老年鼠和幼年鼠;皮层内的表达属幼年鼠最高,其次是老年鼠,青年鼠最低;小脑内的表达无明显年龄差异。（2）Y-迷宫训练引起青年鼠海马和前额叶皮层内Cav-1蛋白的表达显著增加。结果提示,Cav-1蛋白与动物脑发育和学习记忆有密切关系,可能参与中枢可塑性的调节。     

Participation of microRNA 124-CREB pathway: a parallel memory enhancing mechanism of standardised extract of Bacopa monniera (BESEB CDRI-08)

Bacosides, the effective component of standardised leaf extract of Bacopa monniera (BESEB CDRI-08) has been reported to have memory enhancing effect. Our previous reports suggested that BESEB CDRI-08 (BME) improves memory in postnatal rats by enhancing serotonin [5-hydroxytryptamine (5-HT)] metabolism, its transportation and subsequently activates 5-HT(3A) receptor during hippocampus-dependent learning. In this study, we examine whether the up-regulated 5-HT(3A) receptor activity by BME modulate microRNA 124-CREB pathway to enhance synaptic plasticity. Wistar rat pups received single dose of vehicle solution (0.5?% gum acacia?+?0.9?% saline)/BME (80?mg/kg)/mCPBG (10?mg/kg)/BME?+?mCPBG during the postnatal days (PND) 15-29. On PND 30, individuals were trained at brightness discrimination task and 24?h later, they were tested on the task. The BME treated group exhibited significantly lower percentage of errors during retention than acquisition. In addition, pre-miR-124 expression in hippocampus was significantly down-regulated in the BME and mCPBG?+?BME treated groups combined with a significant increase in the plasticity related genes, cAMP response element-binding protein, its phosphorylation and postsynaptic density protein 95. Our results suggest that this may be one of the mechanisms of bacosides present in BME for the memory enhancement.     

Excess Manganese-Induced Apoptosis in Chicken Cerebrums and Embryonic Neurocytes

Methyl mercury (MeHg) is a developmental neurotoxin that causes irreversible cognitive damage in offspring of gestationally exposed mothers. Currently, no preventive drugs are established against MeHg developmental neurotoxicity. The neuroprotective effect of gestational administration of a flavanoid against in utero toxicity of MeHg is not explored much. Hence, the present study validated the effect of a bioactive flavanoid, fisetin, on MeHg developmental neurotoxicity outcomes in rat offspring at postnatal weaning age. Pregnant Wistar rats were simultaneously given MeHg (1.5 mg/kg b.w.) and two doses of fisetin (10 and 50 mg/kg b.w. in two separate groups) orally from gestational day (GD) 5 till parturition. Accordingly, after parturition, on postnatal day (PND) 24, weaning F₁ generation rats were studied for motor and cognitive behavioural changes. Biochemical and histopathological changes were also studied in the cerebral cortex, cerebellum and hippocampus on PND 25. Administration of fisetin during pregnancy prevented behavioural impairment due to transplacental MeHg exposure in weaning rats. Fisetin decreased the levels of oxidative stress markers, increased enzymatic and non-enzymatic antioxidant levels and increased the activity of membrane-bound ATPases and cholinergic function in F₁ generation rats. In light microscopic studies, fisetin treatment protected the specific offspring brain regions from significant morphological aberrations. Between the two doses of fisetin studied, 10 mg/kg b.w. was found to be more satisfactory and effective than 50 mg/kg b.w. The present study shows that intake of fisetin during pregnancy in rats ameliorated in utero MeHg exposure-induced neurotoxicity outcomes in postnatal weaning F₁ generation rats.     

Degradation of kyotorphin by a purified membrane-bound-aminopeptidase from monkey brain: potentiation of kyotorphin-induced analgesia by a highly effective inhibitor, bestatin

Kyotorphin (Tyr-Arg) was rapidly degraded in rat brain homogenates and the Vmax and Km were 29.4 nmol/mg protein/min and 16.6 microM, respectively. This degradation was effectively inhibited by bestatin (IC 50; 0.08 microM) and p-chloromercuribenzoate (IC 50; 0.70 microM). Kyotorphin was also degraded by a membrane-bound aminopeptidase from monkey brains. The Vmax and Km of kyotorphin degradation by the aminopeptidase were 20.0 nmol/mg protein/min and 29.2 microM, respectively. The degradation of kyotorphin was also inhibited effectively by bestatin (KI; 0.4 microM). Co-administration with bestatin 50 micrograms (i.cist.) potentiated the analgesic effects of kyotorphin (i.cist.) by 4.8 times, and these effects were abolished by pretreatment with naloxone 0.5 mg/kg s.c. These results suggest that potentiation of analgesia by bestatin may be due to the protection against the degradation of kyotorphin and released enkephalin by a membrane-bound aminopeptidase.     

Maternal Zinc Supplementation Improves Spatial Memory in Rat Pups

A large body of evidence supports an opinion that adequate dietary zinc is essential for prenatal and postnatal brain development. Behavioural effects of maternal supplementation with ZnSO(4) were analysed in rat pups with the Morris water task performance, a hole board and a T-maze. Wistar females during pregnancy and lactation received a drinking water solution of ZnSO(4) at doses of 16 mg/kg (group Zn16) or 32 mg/kg (group Zn32). Behavioural tests were conducted on the 4-week-old male rat pups. Zinc concentration in the serum, hippocampus and prefrontal cortex of offsprings was determined by means of atomic absorption techniques. The Newman-Keuls multiple comparison test revealed an increase of climbing in the Zn16 group in comparison to the control group (Con) and the Zn32 group during the hole board test. ANOVA for repeated measures showed a significant memory improvement in both supplemented groups compared to the control in the probe trial on day 5 of the water maze test. ZnSO(4) treatment significantly elevated zinc levels in the rat serum. Follow-up data on brain content of zinc in the hippocampus revealed significant differences between the groups and in supplemented groups correlated with crossings above the original platform position. These findings suggest that pre- and postnatal zinc supplementation may improve cognitive development in rats.     

Determination of the effects on learning and memory performance and related gene expressions of clothianidin in rat models

Clothianidin (CLO) is one of the pesticides used to protect against insects, and its potential toxic effects on cognitive functions are not clearly known. This study aims to evaluate the possible effects of dose-dependent CLO on learning and memory in infant and adult male rats and the expression of related genes in the hippocampus. Doses of 2, 8 and 24 mg/kg of CLO were administered to newborn infant and adult albino Winstar rats in the form of gavage and dissolved in vehicle matter. Their cognitive and learning functions were evaluated by the Morris water maze and probe tests. Expression levels of N-methyl D-aspartate 1 (GRIN1), muscuranic receptor M1, synoptophysin (SYP) and growth-associated protein 43 (GAP-43) of tissues isolated from the hippocampus were determined using the real-time PCR method. In the Morris water maze test, no change (p > 0.05) was exhibited in the adult and infant rats after CLO was applied, although there was a significant difference (p < 0.05) in performance between infants and the control group after 24 mg/kg was applied in the probe test. Also, expression levels GRIN1, M1, SYP, GAP-43 did not change when compared to the control (p > 0.05). Our study shows that exposure to high doses of CLO causes deterioration of cognitive functions in infant rats.     

Free radical induced increase in protein carbonyl is attenuated by low dose of adenosine in hippocampus and mid brain: implication in neurodegenerative disorders

There is strong evidence that oxidative stress participates in the etiology of neurodegenerative diseases such as Alzheimer's disease and Parkinson's disease. In the previous studies we have already shown that a combination of alpha-tocopherol and ascorbic acid protect neurons against tert-butyl hydroperoxide (t-BuOOH) induced neurotoxicity in different brain regions including hippocampus and mid brain. In this work, we examined the neuroprotective effect of low dose of adenosine against protein oxidation (protein carbonyls) in parallel with the level of reduced glutathione (GSH) in hippocampus and mid brain regions of mouse brain. The t-BuOOH was injected intraperitoneally in three concentrations (50, 100, 150 mg/kg b.w.) for 10 days. Results showed dose dependent increase in protein carbonyl (PC) in hippocampus and mid brain region. This increase was accompanied by a significant (p < 0.05) decline in GSH content in both brain regions of t-BuOOH treated mice. Adenosine (1 mg/kg b.w.) protected both hippocampus and mid brain neurons against protein oxidation as evidenced by reduction in protein carbonyl content. The GSH content was significantly (p < 0.05) increased after the treatment of adenosine in both brain regions. These data show that prior treatment with low dose of adenosine attenuates the oxidative protein damage with parallel increase in the GSH level in hippocampus and mid brain of t-BuOOH induced mice.     

Effects of zinc pre-treatment on blood glutathione,serum zinc and kidney histological organisation in male rats exposed to cadmium

The effects of sub-chronic exposure to cadmium (Cd) on the blood glutathione, serum zinc and on the kidney histological organisation in rats as well as the possible protective role of zinc (Zn) are the object of this study. For this purpose, 60 male Wistar rats (8 weeks old) were divided into three groups: the first group was exposed to Cd in the form of CdCl₂, administered in five doses (each of 0.4 mg Cd/kg b.w.) on days 5, 10, 15, 20 and 25, giving a total dose of 2 mg Cd/kg b.w., i.p.; the second group was simultaneously exposed to Zn and Cd with the same timeline and the same doses of Cd as the first group but with, in addition, injections of Zn in the form of ZnCl₂, administered in doses of 0.8 mg Zn/kg b.w., giving a total dose of 4 mg Zn/kg b w, i.p.; a control group received 0.5 mL of physiological saline in an identical manner. Intoxication with Cd was followed by a significant decrease in blood glutathione, increase in oxidized glutathione as well as histological damage in kidneys. Pre-treatment with Zn exhibited a protective role against Cd toxicity with a significant decrease in serum zinc content. This fact may be explained by an excessive use of zinc in metallothionein synthesis as a cadmium detoxification agent.     

A Single Neonatal Injection of Ethinyl Estradiol Impairs Passive Avoidance Learning and Reduces Expression of Estrogen Receptor α in the Hippocampus and Cortex of Adult Female Rats

Although perinatal exposure of female rats to estrogenic compounds produces irreversible changes in brain function, it is still unclear how the amount and timing of exposure to those substances affect learning function, or if exposure alters estrogen receptor α (ERα) expression in the hippocampus and cortex. In adult female rats, we investigated the effects of neonatal exposure to a model estrogenic compound, ethinyl estradiol (EE), on passive avoidance learning and ERα expression. Female Wistar-Imamichi rats were subcutaneously injected with oil, 0.02 mg/kg EE, 2 mg/kg EE, or 20 mg/kg 17β-estradiol within 24 h after birth. All females were tested for passive avoidance learning at the age of 6 weeks. Neonatal 0.02 mg/kg EE administration significantly disrupted passive avoidance compared with oil treatment in gonadally intact females. In a second experiment, another set of experimental females, treated as described above, was ovariectomized under pentobarbital anesthesia at 10 weeks of age. At 15–17 weeks of age, half of each group received a subcutaneous injection of 5 μg estradiol benzoate a day before the passive avoidance learning test. Passive avoidance learning behavior was impaired by the 0.02 mg/kg EE dose, but notably only in the estradiol benzoate-injected group. At 17–19 weeks of age, hippocampal and cortical samples were collected from rats with or without the 5 μg estradiol benzoate injection, and western blots used to determine ERα expression. A significant decrease in ERα expression was observed in the hippocampus of the estradiol-injected, neonatal EE-treated females. The results demonstrated that exposure to EE immediately after birth decreased learning ability in adult female rats, and that this may be at least partly mediated by the decreased expression of ERα in the hippocampus.     

The effect of late prenatal and/or early postnatal zinc deficiency on the development and some biochemical aspects of the cerebellum and hippocampus in rats

In rats, late prenatal and/or early postnatal zinc deficiency results in behavioural anomalies in adult animals, but not in overt dysmorphogenesis of the central nervous system. Cerebellar and hippocampal development occurs mainly in the first three weeks postnatally and zinc accumulates specifically in the mossy fibres of the hippocampus during this period.In the present investigation, rat pups were suckled by dams fed a zinc-deficient (<0.5 mg/kg) diet either from day 19 of pregnancy or from parturition. Control animals were restricted-fed the same diet supplemented with 100 mg zinc/kg. Studies were performed on pups either on day 18 postpartum in the case of animals fed the experimental diets from parturition, or on day 20 for pups which received treatment from day 19 of gestation.Cerebellar and hippocampal weights were lower in pups suckling from zinc-deficient dams but zinc levels were not affected in either organ, although histological evidence suggested less zinc in the hippocampal mossy fibres. Incorporation of H-thymidine into cerebellar and hippocampal DNA was not affected by maternal zinc status, nor was the activity of the zinc metalloenzyme alkaline phosphatase.The activity of the myelin-marker enzyme 2′, 3′-cyclic nucleotide 3′-phosphohydrolase was substantially lower in both regions of the brain in zinc deprived pups, especially in the hippocampus. Activity of the zinc metalloenzyme L-glutamic acid dehydrogenase was also diminished in both tissues from 20-day-old pups and in the hippocampi of 18-day-old animals.The data suggest that cerebellar and hippocampal DNA synthesis is not seriously affected by late prenatal and/or early postnatal zinc depletion, but that the activities of two enzymes associated with neural function are. The possibility is raised that these defects may be associated with the behavioural changes observed in rats subjected to zinc impoverishment during the period of maximal cerebellar and the hippocampal development.