Antibiotic Supplements Affect Electrophysiological Properties and Excitability of Rat Hippocampal Pyramidal Neurons in Primary Culture

Introduction: Antibiotic supplements are regularly used in neuronal culture media to control contamination; however, they can interfere with the neuronal excitability and affect electrophysiological properties. Therefore, in this study, the effect of penicillin/streptomycin supplements on the spontaneous electrophysiological activity of hippocampal pyramidal neurons was examined. Methods: Electrophysiological whole-cell patch-clamp recordings from rat hippocampal pyramidal cells in primary culture were performed to investigate the effects of antibiotic supplements on the intrinsic excitability of cultured cells. Results: The present findings indicated that presence of antibiotic supplements (penicillin/streptomycin) in the culture medium altered the intrinsic electrical activity of hippocampal pyramidal neurons in primary culture. These alterations included: 1) depolarized resting membrane potential; 2) a significant enhancement in the after-hyperpolarization amplitude; 3) a significant increase in the area under the action potential and in the decay and rise time of the action potential; 4) a significant broadening of action potential and 5) a significant reduction in the firing frequency. Conclusion: These findings suggest that addition of antibiotic supplements to culture media influences the neuronal excitability and alters the electrophysiological properties of cultured neurons, possibly through changing the ionic conductance underlying neuronal excitability. Key Words: Primary cell culture, Patch-clamp techniques, Hippocampus     

大豆体细胞组织培养再生植株的研究——Ⅰ 培养基、基因型、植物激素对诱导大豆再生植株的影响

本研究以野生大豆(Glycine soja Sieb et Zucc.)10品系、半野生大豆(Glycine gracilis Skv.)11品系、栽培大豆(Glycine max (L.)Merril)46品种(系)和5个杂种后代为材料,通过组织培养方法,研究了大豆体细胞组织再生植株的主要影响因素。并以器官分化和体细胞胚两种不同方式再生完整大豆植株。     

Growth of primary hippocampal neurons on multichannel silk fibroin scaffold

Particular attention has been given to axonal outgrowth of neurons to understand how topographical surface cues influence attachment and subsequent directional migration and growth. In present study, the silk fibroin (SF) scaffold with uniaxial channels was prepared by directional freeze-drying processes. The average pore diameter, the porosity, and pore density of the scaffold are 120 µm, 88 %, and 203 mm^?2, respectively. Further, hippocampal neurons were seeded onto the scaffold and the hippocampal neurons morphology was investigated. Cell-cell networks and cell-matrix interactions had been established by newly formed axons and the diversity of neurons was much higher after culturing 7 days. The neurons expressed β-III-tubulin and nerve filament, while glial fibrillary acidic protein immunofluorescence was barely above background. These results indicated that the SF scaffolds with uniaxial multichannels could be guided axons of neurons spread along the channels. SF scaffolds with oriented pores have a potential for nerve tissue regeneration.     

培养条件对甘蓝型黄籽油菜下胚轴的再生影响

以甘蓝型黄籽油菜GH01的下胚轴为材料，研究影响外植体芽再生的因素。试验结果表明，苗龄、预培养基的激素浓度和预培养时间、分化培养基等对芽再生频率均有较大影响。8d苗龄的下胚轴置MS 1．5mg／L2，4-D 0．1mg／L6-BA培养基预培养4d后，转分化培养基MS 4．0mg／L6-BA 0．05mg／LNAA 5．0mg／LAgNO3 0．6mg,／LGA3培养，可获得较高的芽再生频率。添加5mg／LAgNO3处理可防止外植体褐化并有利于芽分化；0．6mg／L GA3处理可促进胚状体形成，提高芽再生频率。GH01最高芽再生频率为40．50％。     

Effects of different organic additives on in vitro shoot regeneration of Celosia sp

Nowadays, many researches were conducted in minimizing tissue culture technology due to the overhead of cost needed. The purpose of this study was to investigate the effects of using five kinds of organic additives at four level concentrations responsive to the number of shoots produced for eight weeks in culture. Stem segment explants of Celosia sp. were cultured on MS medium that have been supplemented with different kinds of extract juice that serve as organic additives which are mature coconut, young coconut, papaya, banana and tomato at 20, 30, 50 and 70 ml L-1. The numbers of shoot on each explant were recorded and the mean of ten replicates explants were calculated. Among the media used, young coconut water at 70 ml L1- induced the highest shoot regeneration (14.21+/-8.26), followed by mature coconut water at 50 ml L-1 (13.14+/-10.33). Banana and tomato juice promote highest shoot regeneration of stem segments at 50 ml L-1 that produced 9.57+/-4.68 and 9.28+/-5.82 shoots per explants, respectively. While the lowest concentration which at 20 ml L-1 of papaya juice showed highest shoot regeneration (10.50+/-3.45) produced among the three other concentration tested. Statistical results showed that there were significant differences interactions effects (p<0.05) in terms of number of shoot regenerated between the types of extracts juices determined by ANOVA test. Comparing number of shoots regenerated that were cultured in control media, it showed higher than all of experimental medium composition. There were no big different in cost required in preparation of control media and the experimental media. Applications of five kinds of local fruit in tissue culture media should be considered since it responsive in shoot regeneration.     

不同培养基及激素配比对小麦幼胚离体培养的影响

为了建立一个适于优良小麦品种基因枪转化的高效组织培养体系,以2个冬性小麦品种京841和中麦9号为供试材料,探讨了不同培养基、不同激素配比对小麦幼胚离体培养的影响。结果表明,在MS、N6B5MS、B5和L34种培养基中,L3培养基的出愈率及分化率最高,两品种平均出愈率达到88.9%,分化率达到36.6%;以L3为基本分化培养基,同时添加ZT3mg/L和NAA1mg/L配比对愈伤组织诱导分化的效果最好,分化率平均达到55.9%。     

大豆愈伤组织继代培养的最佳条件研究

探讨基本培养基、培养条件、植物生长调节剂等因素对大豆继代培养的影响.大豆愈伤组织继代培养的最佳条件:以MS BA0.5 mg/L 2,4-D2.0 mg/L为培养基,pH在5.8～6.0之间,在1 000～1 500 Lx,2 h/d光照条件下,培养21 d后生长较好,愈伤组织生长量和增长倍数可分别达到11.23 g/瓶和10.23.     

水稻成熟胚组织培养研究

对珍汕 97B、明恢 6 3、H14 93、中花 11等 4个水稻品种的成熟胚在组织培养中愈伤组织诱导率和植株再生率的研究表明 ,在N6培养基中附加体积分数为 2× 10 -3 的 2 ,4 -D时诱导率最高。在相同的诱导培养基和分化培养基上 ,4个水稻品种的愈伤组织诱导率和植株再生率表现出极大的差异。粳稻H14 93表现最好 ,其诱导率和再生率分别达到 90 .6 %和 90 .0 % ;中花 11次之 ,分别为 85 .2 %和 6 6 .7% ;2个籼稻品种的愈伤组织诱导率较低 ,植株再生率几乎为 0。说明本试验中的诱导条件适合于粳稻品种 ,而对籼稻品种不利     

巴西橡胶树游离小孢子培养

以橡胶树品种海垦2号为材料,对橡胶树游离小孢子培养体系进行初步研究,为进一步建立其成熟培养体系提供基础。小孢子的提取采用直接研磨法和间接研磨法进行,结果发现以间接研磨法为佳,虽然工作量大,但污染率低、杂质少、培养效果好。对小孢子分别进行高温热击、Starvation Medium B溶液、对照预处理试验,发现用Starvation Medium B溶液预处理小孢子2 d有利于小孢子分化。不同的碳源比较发现麦芽糖培养效果较蔗糖好。对诱导培养基的组分、pH研究发现,以改良N6为基本培养基添加外源激素2,4-D 0.5 gm/L、KT 0.5 mg/L,pH 6.6时诱导效果好,小孢子分化率达8.33%。小孢子的分化以B途径为主,初步获得小孢子分化的细胞团和微愈伤。同时以橡胶树小孢子为受体进行电激转化试验,瞬时表达结果证明外源基因已导入部分小孢子基因组中。     

短光低温不育水稻宜D S成熟胚培养的研究

对短光低温不育水稻宜D S成熟胚在组织培养中的愈伤组织诱导和分化进行了研究,结果表明:愈伤组织诱导率与绿苗分化率之间无对应关系;诱导培养基的成分对转分化后的愈伤组织有后效作用,2,4-D与6-BA和NAA搭配使用比单独使用2,4-D诱导的愈伤组织更易于分化;同时还发现,不同诱导培养基诱导的愈伤组织在转分化后对分化培养基的要求不同.     

玉米芽尖再生体系的建立

以玉米骨干自交系郑58和丹598为试材,建立了芽尖再生体系,对芽尖再生的影响因素进行优化。结果表明,添加水解酪蛋白(CH)和光照条件可以提高玉米种子的发芽率;郑58和丹598在添加不同激素浓度时丛生芽诱导率达到最高;继代培养基中添加1.0 mg/L6-BA和1.0 mg/LIBA时外植体分化苗率最高。     

Regeneration of plantlets from single cells in potatoes

Regeneration of plantlets from isolated single cells of potato tubers can be achieved through several culturing procedures, each maintained on defined medium and under specific environmental conditions. High auxin and high temperature were favorable for cell proliferation while high cytokinin and alternating low temperature promoted embryoid formation and plantlet regeneration.     

In vitro study on regeneration of Gladiolus grandiflorus corm calli as affected by plant growth regulators

In this study, in vitro organogenesis of Gladiolus grandiflorus cultivar pink corm segments were evaluated by culturing corm calli in modified MS medium supplemented with 3% sucrose and 0.7% agar with different concentration of BAP (0, 1, 2 and 4 mg L(-1) medium) and NAA (0, 0.5, 1 and 2 mg L(-1) medium) in factorial experiment of Completely Randomized Design (CRD). In order to obtain Gladiolus calli, corm segments (Aprox. 5 x 5 x 1 mm in size) were kept in modified MS medium (Murashige and Skoog, 1962) that was supplemented with 1 mg L(-1) 2, 4-D, 3% sucrose and 0.7% agar. The results showed that increasing the concentration of BAP from 0 to 2 mg L(-1) medium simulated plantlet regeneration but no significantly effect was obtained on shoot and cormel organogenesis between 2 and 4 mg L(-1) BAP concentration in medium. Increasing of NAA content in media without BAP developed rootlet significantly. Interaction results showed that increasing BAP content against decreasing of NAA concentration stimulates the shoot and cormel proliferation.     

小麦不同外植体的组织培养效果研究

良好的组织培养效果是提高植物基因转化效率的基础。以山东省近年来育成并大面积推广的10个优良品种（系）为材料,对这些品种的花药、幼穗、幼胚和成熟胚的组织培养效果进行研究,旨在筛选每一基因型最适合于组织培养的外植体类型,为应用基因工程技术进行小麦遗传改良提供基础材料。结果表明,禽伤诱导率和再生成苗率与基因型和外植体类型（花药、幼穗、幼胚和成熟胚）密切相关。8802在花药和成熟胚培养中表现突出,花药出愈率达119．5％,愈伤分化成苗率19．9％;烟农19的幼穗愈伤直接分化成苗率最高,这43．5％;8802、烟农19和潍麦8号三个基因型的幼胚培养效果差异不显著,其愈伤分化成苗率分别为26．3％、24．5％和24．8％。蔗糖浓度在3％～9％之间,对成熟胚的愈伤组织诱导率影响很小。高浓度蔗糖降低愈伤生长速度。在一定蔗糖浓度下,愈伤诱导率与2,4-D浓度密切相关,高浓度的2,4-D对愈伤组织再生不利。MS＋4mg／L2,4-D对于成熟胚的脱分化相对较好,MS和MS＋0．4mg／L NAA＋0．6mg／L KT作为成熟胚的愈伤组织再生培养基,对不同基因型具有一定的适用性。     

琼脂浓度对水稻愈伤组织植株再生率和内源激素含量的影响

 以盐粳2号脱壳种子为外植体研究了培养基不同浓度琼脂对愈伤组织植株再生率的影响及可能的机理。在分别进行脱分化、分化和继代培养基中琼脂浓度试验时，当琼脂从0.5％提高到1.0％ 植株再生率均显著升高。在继代和分化培养基琼脂浓度均为1.0%时植株再生率最高，而脱分化培养基0.5%或1.0%琼脂和分化培养基1.0%琼脂 组合，再生率最高，两者均为1.0% 琼脂反而降低。试验还表明，随着培养基中琼脂浓度提高，愈伤组织含水量显著降低而脯氨酸含量上升。较高浓度（1.0%）琼脂继代培养的愈伤组织内源ABA含量显著高于较低浓度（0.5%）琼脂的，而ZRs含量则显著较低。同样，在分化培养过程中，较高浓度琼脂分化培养的愈伤组织内源ABA含量显著地高于较低琼脂的，而ZRs含量则相反，但差异不显著。 V 关键词：琼脂浓度：精     

大苞鞘石斛组织培养快繁研究

为筛选出大苞鞘石斛组培快繁体系各阶段最适培养基配方,以大苞鞘石斛无菌苗茎段为外植体,通过正交试验研究不同因素对大苞鞘石斛植株再生的影响。结果表明:拟原球茎诱导最适培养基为1/2MS+2,4-D0.2 mg/L+蔗糖30 g/L,诱导出的拟原球茎直径1.5 mm时将其从茎段上剥离,并接入原培养基继续诱导15~20 d;拟原球茎增殖最适培养基为1/2MS+NAA 1 mg/L+蔗糖30 g/L+椰乳10%,继代周期25~30 d;拟原球茎分化最适培养基为1/2MS+NAA 0.5 mg/L+蔗糖30 g/L+椰乳10%,分化培养需40 d;将分化的无菌苗继代于花宝2号3 g/L+蛋白胨2 g/L+IBA 1 mg/L+蔗糖30 g/L+椰乳10%生根诱导效果最好,培养45 d;生根壮苗最佳培养基为花宝1号3 g/L+蛋白胨2 g/L+蔗糖30 g/L+活性炭1 g/L,培养50 d。     

甘蓝型油菜带柄子叶高频率再生植株的研究

以甘蓝型油菜(Brassica napus)912品系带柄子叶为外植体,不同浓度6-BA与NAA激素组合的分化培养基诱导芽苗的分化,开展提高甘蓝型油菜带柄子叶再生频率的因素研究.发现甘蓝型油菜912品系带柄子叶在不同激素及浓度的6-BA与NAA组合中的再生频率、分化率存在显著差异.通过无菌苗苗龄、诱导分化前2,4-D的预培养以及添加AgNO3等因素的系统分析,结果表明甘蓝型油菜912品系带柄子叶在诱导分化前经过1.0mg/L 2,4-D的MS培养基中预培养3d,在最适培养基MS0 6-BA 4.0mg/L NAA 0.02mg/L 3.5mg/L AgNO3中,可较大程度地提高植株再生频率,再生频率和分化频率分别为70%和269.5%,初步建立了甘蓝型油菜912品系的高频率再生植株体系.     

稻曲病菌分离技术的初探

用7种培养基和2种分离方法对稻曲病菌的培养及分离技术进行了研究。结果表明,胁本哲氏培养+抑制细菌生长的氯霉素(50 μg/mL)是分离稻曲病菌最适宜的培养基。稻谷是厚垣孢子产生的理想培养基。厚垣孢子悬液法可用于稻曲病菌的快速分离,而稻曲球不同层次组织块分离法可从保存长时间的稻曲球分离到稻曲病菌。     

Increased induction of embryogenesis and regeneration in anther cultures ofSolanum tuberosum L.

Summary A new method is presented for anther culture. Anthers are cultivated on cubes of solid medium, surrounded by liquid medium. This allows changes of media composition at any time. When embryos or callus were produced, the liquid initiation medium was removed and replaced with regeneration medium. The best yield of embryos and the best regeneration frequency were obtained when the initiation medium contained 2,4-dichlorophenoxyacetic acid (2,4-D). Regeneration of shoots from callus was stimulated on double layer medium, with the callus placed on top of a solid medium, partly submerged in the overlaying liquid medium. The best gelling agent for shoot multiplication media was agarose, but gellan gum was a good alternative. Both the production of flower buds and embryogenesis in anther cultures was inhibited by an increased concentration of CO₂ in the air surrounding the donor plants.     

油葵子叶外植体不定芽再生体系的建立

对油葵子叶外植体在含有不同激素浓度的培养基上进行了诱导、分化及成苗的研究,建立起一套完整的再生体系.在MS添加IAA 1mg/L和6-BA 4mg/L的培养基上诱导的愈伤质量较好,在MS添加IAA 0.01mg/L和6-BA 0.04mg/L的分化培养基上能够实现较高的不定芽再生.基因型间再生能力差异明显,8份材料中以康地6R为最佳.不定芽在1/2MS培养基上能健康成苗.