伊莱恩Pranski优秀的技术援助和卡罗琳Suwyn和哈里列文三，M.保罗墨菲，重要谈话和Marla杠杆许多感谢。 RR - 00165，PO1AG026423，P50AG025688，AG030539，伍德拉夫基金会和埃默里大学研究委员会提供了资金。

第1部分：澄清组织匀浆的制备<ol><li> Dounce均质4次冰冷的缓冲液（0.1M磷酸盐缓冲生理盐水[钙+ + - 和镁+ + - 免费]加2个蛋白酶抑制剂的鸡尾酒[圣诞老人Cruz的]）体积不固定的皮质组织约30甚至杵中风（即加入400μl缓冲100毫克组织）。 </li><li>自旋匀浆为5分钟，在3000克（4℃）。小心取出-80澄清这些提取物的上清液和存储等分℃直至使用。 </li><li>确定使用一个bicinchoninic酸（BCA）法澄清的匀浆总蛋白浓度（微克/微升），根据制造商的说明（ThermoFisher）。 </li></ol>第2部分：SDS - PAGE样品制备<ol><li> 10-20％甘氨酸凝胶（Invitrogen公司），可装载每口井的最大音量是一个10〜25μl。总成交量包括2X SDS样品缓冲液和10倍的还原剂，使每口井可装载的最大音量是澄清匀浆加入10μl。澄清20％（W / V）皮质匀浆应该有一个总蛋白浓度大于5微克/μL，让每孔50μg总蛋白。小于5mg/ml蛋白质样品，将需要装载总蛋白少，每口井。然而，高蛋白质水平检测单体和聚合的Aβ（50 -60μg总蛋白是最佳）的最佳选择。 始终负载总蛋白相同的金额，每口井。 </li><li>对于每个凝胶，负载至少SeeBlue Plus2（Invitrogen公司），如分子量，加入10μl。作为阳性对照，运行10 - 100ng合成Aβ40或Aβ42肽（1xPBS稀释）在另一口井。 </li><li>准备上冰的反应混合物，使用刚刚解冻，澄清匀浆。 5-10秒的涡管，在干浴热在100 ° C，为5分钟，然后快速旋转所有的样本，以除去凝结在第。 </li></ol>第3部分：SDS - PAGE凝胶电泳<ol><li>加载到在10-20％的甘氨酸凝胶XCell确保锁迷你细胞Gelbox涡旋样本，采用甘氨酸SDS电泳缓冲液，根据制造商的说明（Invitrogen公司）， </li><li>运行在一个恒定的电压为125V约90分钟的凝胶。让样品的运行，直到4KDa标记带从凝胶底部约1厘米。 </li></ol>第4部分：将蛋白质从凝胶膜<ol><li>小心取出凝胶和塑料外壳内XCell II印迹模块组装转移夹心，根据制造商的说明（Invitrogen公司）。预湿的印迹垫和0.2μm的硝酸纤维素膜，Tris -甘氨酸转移缓冲液（20％甲醇），并删除任何气泡从印迹垫或过滤纸/膜夹心。 </li><li> XCell Gelbox，填补内宅与传输缓冲区，并填写DIH 2 O（甲醇暴露可以穿塑料gelbox随着时间的推移）的外室。 </li><li>运行在一个恒定的电流为25mA的2-3个小时的转移。 </li><li>当传送完成后，解构三明治和凝胶进入DIH 2 O和膜放入1xPBS，无论是在方形塑料培养皿（或其他合适的容器） 。 </li><li>为了可视化蛋白转移效率，凝胶可以染色只需蓝SafeStain（Invitrogen公司），并与丽春红红染色（西格玛Aldrich公司）的膜，无论是根据制造商的指示。这不会干预与免疫染色。如果染色揭示蛋白转移效率低下，修改在步骤3中的传输时间。 </li></ol>第5部分。抗原表位的检索和免疫印迹<ol><li>抗原修复在免疫抗体结合膜在揭示Aβ的抗原表位的重要一步。任何蒸锅，微波炉，或水洗澡，保持一个恒定的温度为100 ° C将足以。抗原检索在蒸笼，热密封膜在重型Kapak与1xPBS塑料填充袋，在室温下。莱平在预先加热的蒸笼袋;邮袋后，开始扩大，孵育一个额外的15分钟。允许膜慢慢冷却之前，从袋，防止过度起皱。 </li><li>在室温下，小心地取出热气腾腾的囊膜和冲洗1xPBS膜5分钟，其次是在TBS - T的5分钟冲洗（TRIS缓冲生理盐水，pH值8.0与0.05％Tween - 20的[适马] ），上轨道摇床。一小时孵育膜在封闭液（TBS - T的2.5％，脱脂牛奶），摇匀。如果不清洗，转印膜含有封闭液稀释的第一抗体（6E10 1:1,000 [1μg/ml1:5,000 [0.2μg/ml]稀释，Covance公司），避免泡沫的一盘菜或塑料袋第在室温下的轨道摇床孵育一小时，然后在4 ° C振荡（潜伏期较长，可能会提供更好的信号）。24-48小时</li><li>膜冲洗30分钟，在TBS - T（快速冲洗3 × 10分钟的冲洗）。 </li><li>孵育膜HRP标记的第二抗体（羊抗鼠，Amersham公司的ECL GE医疗），在1:10,000在封闭液稀释为90分钟，在室温下振动筛，。 </li><li>膜冲洗30分钟，在TBS - T（快速冲洗3 × 10分钟的冲洗）。 </li><li>在摇床，孵育5分钟新鲜SuperSignal西碧电化学发光试剂（ThermoFisher）膜，无绒滤纸吸干多余的试剂，并在电影盒放置的膜，塑料板材保护之间。如有必要，无粉尘Kimwipes吸干额外的SuperSignal试剂。 </li><li>暴露在柯达百玛士致辞片长达30分钟30秒的时间间隔，在电影开发和发展。 5分钟后，Aβ的单体带可能会饱和。 </li><li>膜可剥离翻天覆地的还原，加上30分钟，在室温下剥离缓冲区和reprobed如果需要额外抗体（TBS - T冲洗后）。 </li></ol>第6部分：代表免疫印迹： <img src="/files/ftp_upload/1916/1916fig1a.jpg" alt="图1a" /> <img src="/files/ftp_upload/1916/1916fig1b.jpg" alt="图1b" /> <img src="/files/ftp_upload/1916/1916fig1c.jpg" alt="图1c" /> 图1A - C。澄清的匀浆液，含有7人科目50μg总蛋白分析的多聚体的Aβ和APP的存在。免疫抗体6E10揭示Aβ的单体，二聚体，三聚体，四聚体，和应用程序在所有的老年痴呆症的情​​况下（顶部波段），以及丰富较高分子量在2例AD患者的Aβ多聚体。合成Aβ40证实低分子量乐队的身份。公元：阿尔茨海默氏症，DLB：Nondemented人类（一）30分钟的胶片曝光，（B）5分钟的胶片曝光，（C）30秒的胶片曝光：路易体，钕痴呆。

<ol>
	<li>Hardy, J., Selkoe, D. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+amyloid+hypothesis+of+Alzheimer's+disease:+progress+and+problems+on+the+road+to+therapeutics.">The amyloid hypothesis of Alzheimer's disease: progress and problems on the road to therapeutics.</a> Science. 297, 353-356 (2002).</li><li>Haass, C., Selkoe, D. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Soluble+protein+oligomers+in+neurodegeneration:+lessons+from+the+Alzheimer's+amyloid+beta-peptide.">Soluble protein oligomers in neurodegeneration: lessons from the Alzheimer's amyloid beta-peptide.</a> Nat. Rev. Mol. Cell. Biol. 8, 101-112 (2007).</li><li>Walker, L. C., LeVine, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+cerebral+proteopathies.">The cerebral proteopathies.</a> Neurobiol. Aging. 21, 559-561 (2000).</li><li>Selkoe, D. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Aging,+amyloid,+and+Alzheimer's+disease:+a+perspective+in+honor.">Aging, amyloid, and Alzheimer's disease: a perspective in honor.</a> of Carl Cotman. Neurochem. Res. 28, 1705-1713 (2003).</li><li>Walsh, D. M., Selkoe, D. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Abeta+oligomers+-+a+decade+of+discovery.">Abeta oligomers - a decade of discovery.</a> J. Neurochem. 101, 1172-1184 (2007).</li><li>Swerdlow, P. S., Finley, D., Varshavsky, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Enhancement+of+immunoblot+sensitivity+by+heating+of+hydrated+filters.">Enhancement of immunoblot sensitivity by heating of hydrated filters.</a> Anal. Biochem. 156, 147-153 (1986).</li><li>Ida, N., Hartmann, T., Pantel, J., Schr&#246;der, J., Zerfass, R., F&#246;rstl, H., Sandbrink, R., Masters, C. L., Beyreuther, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Analysis+of+hetergeneous+A4+peptides+in+human+cerebrospinal+fuid+and+blood+by+a+newly+developed+sensitive+Western+blot+assay.">Analysis of hetergeneous A4 peptides in human cerebrospinal fuid and blood by a newly developed sensitive Western blot assay.</a> J. Biol. Chem. 271, 22908-22914 (1996).</li></ol>

尽管Aβ聚集在阿尔茨海默氏病1,4,5的发病机制中的重要性，很少有研究描述或量化分配不同的Aβ多聚体在人脑皮层的组织样本2。常用的免疫组织化学技术不允许固定皮质组织中不同的多聚体的Aβ物种歧视。在不固定的皮质组织匀浆，Aβ的多聚体可以分离和生化评估使用凝胶电泳和抗体的检测方法。然而，有针对性的Aβ的抗原表位可能被隐藏在汇总和翻译后修饰的肽结构，防止聚集...

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		<div>
		<table border="1">
		<thead>
		<tr>
		<th>Material Name</th>
		<th>Type</th>
		<th>Company</th>
		<th>Catalogue Number</th>
		<th>Comment</th>
		</tr>
		</thead>
		<tbody>
		
<tr>
<td>Complete Protease Inhibitor Cocktail Tablets</td>
<td>&nbsp;</td>
<td>Santa Cruz Biotechnology</td>
<td>Sc-29130</td>
<td>1 tablet in 25ml buffer</td>
</tr>
<tr>
<td>BCA Protein Assay kit</td>
<td>&nbsp;</td>
<td>ThermoFisher Scientific</td>
<td>23225</td>
<td>&nbsp;</td>
<tr>
<td>XCell SureLock Mini-Cell and XCell II Blot Module Kit CE Mark</td>
<td>&nbsp;</td>
<td>Invitrogen</td>
<td>EI0002</td>
<td>&nbsp;</td>
<tr>
<td>Novex Tricine SDS Sample Buffer (2X)</td>
<td>&nbsp;</td>
<td>Invitrogen</td>
<td>LC1676</td>
<td>&nbsp;</td>
<tr>
<td>NuPAGE Sample Reducing Agent (10X)</td>
<td>&nbsp;</td>
<td>Invitrogen</td>
<td>NP0004</td>
<td>&nbsp;</td>
<tr>
<td>SeeBlue Plus2 Pre-Stained Standard</td>
<td>&nbsp;</td>
<td>Invitrogen</td>
<td>LC5925</td>
<td>&nbsp;</td>
<tr>
<td>Novex 10-20% Tricine Gel 1.0 mm, 10 well</td>
<td>&nbsp;</td>
<td>Invitrogen</td>
<td>EC6625BOX</td>
<td>&nbsp;</td>
<tr>
<td>Nitrocellulose membranes, 0.2 &mu;m pore size</td>
<td>&nbsp;</td>
<td>Invitrogen</td>
<td>LC2000</td>
<td>&nbsp;</td>
<tr>
<td>Novex Tricine SDS Running Buffer (10X)</td>
<td>&nbsp;</td>
<td>Invitrogen</td>
<td>LC1675</td>
<td>&nbsp;</td>
<tr>
<td>Novex Tris-Glycine Transfer Buffer (25X)</td>
<td>&nbsp;</td>
<td>Invitrogen</td>
<td>LC3675</td>
<td>&nbsp;</td>
<tr>
<td>SimplyBlue SafeStain</td>
<td>&nbsp;</td>
<td>Invitrogen</td>
<td>LC6060</td>
<td>Will not interfere with immunostaining</td>
</tr>
<tr>
<td>ATX Ponceau S Red staining solution</td>
<td>&nbsp;</td>
<td>Sigma Aldrich</td>
<td>09276</td>
<td>Will not interfere with immunostaining</td>
</tr>
<tr>
<td>Kapak heat sealable plastic sample pouches</td>
<td>&nbsp;</td>
<td>Fisher Scientific</td>
<td>0181225AA</td>
<td>&nbsp;</td>
<tr>
<td>6E10 mouse monoclonal antibody to A&beta;(1-16)</td>
<td>&nbsp;</td>
<td>Covance</td>
<td>SIG-39320</td>
<td>Dilute 1:1,000 up to 1:5,000 for WB</td>
</tr>
<tr>
<td>Tween 20</td>
<td>&nbsp;</td>
<td>Sigma Aldrich</td>
<td>P2287</td>
<td>&nbsp;</td>
<tr>
<td>ECL Mouse IgG, HRP-Linked Whole A&beta; (from sheep)</td>
<td>&nbsp;</td>
<td>GE Healthcare Life Sciences</td>
<td>NA931-1ML</td>
<td>Dilute at 1:10,000</td>
</tr>
<tr>
<td>SuperSignal West Pico Chemiluminescent Substrate</td>
<td>&nbsp;</td>
<td>ThermoFisher</td>
<td>34077</td>
<td>&nbsp;</td>
<tr>
<td>Kodak Biomax MR Film</td>
<td>&nbsp;</td>
<td>Carestream Health</td>
<td>870 1302</td>
<td>&nbsp;</td>		</tbody>
		</table>
		</div>

sds-page/immunoblot detection of a&beta; multimers in human cortical tissue homogenates using antigen-epitope retrieval

异常折叠和聚合的β-淀粉样蛋白（Aβ）肽被认为是启动在阿尔茨海默氏病的发病机制的神经退行性级联<sup&gt; 1</sup&gt;。 Aβ的主要是40 - 42 - 氨基肽自聚集成β-片丰富的淀粉样蛋白在阿尔茨海默氏病的脑老年斑的核心发现纤维很容易。越来越多的证据表明，低分子量，可溶性Aβ多聚体超过纤维状的Aβ淀粉样蛋白的毒性<sup&gt; 2</sup&gt;。低和高的分子重量脑组织中的多聚体的Aβ物种的识别和量化，是一种在阿尔茨海默氏病研究的重要目标，还聘用的方法可以适用于其他proteopathies有毒的多聚体的识别和表征<sup&gt; 3</sup&gt;。自然发生的Aβ多聚体可以与Aβ的特异性抗体免疫SDS -聚丙烯酰胺凝胶电泳检测。然而，多聚体的Aβ的分离和检测，需要高度集中的皮质匀浆和小孔径的硝酸纤维素膜抗原检索使用。在这里，我们描述为澄清人类皮质匀浆的技术准备，通过SDS - PAGE分离蛋白，抗原表位的检索/西方印迹抗体6E10Aβ肽的N -端区域。使用此协议，我们一贯检测Aβ的单体，二聚体，三聚体，四聚体，和更高的皮层组织中的分子量多聚体与阿尔茨海默氏症的病理的人类。

Watch this Scientific Journal Video about SDS-PAGE/Immunoblot Detection of AÎ² Multimers in Human Cortical Tissue Homogenates using Antigen-Epitope Retrieval at JoVE.com

SDS-PAGE/Immunoblot Detection of A&amp;#946; Multimers in Human Cortical Tissue Homogenates using Antigen-Epitope Retrieval

我们描述了一个准备的人脑皮层匀浆澄清，经SDS - PAGE分离蛋白，抗原修复，并与Aβ肽抗体免疫印迹技术。使用这个协议，我们一贯检测皮层组织与阿尔茨海默氏症的病理的人类单体和多聚体的Aβ。

SDS-PAGE/Immunoblot检测人脑皮层组织中的Aβ多聚匀浆使用抗原表位检索

The anomalous folding and polymerization of the &beta;-amyloid (A&beta;) peptide is thought to initiate the neurodegenerative cascade in Alzheimer's ...

sds-pageimmunoblot-detection-multimers-human-cortical-tissue

Research

JoVE Journal

Neuroscience

SDS-PAGE/Immunoblot Detection of A&beta; Multimers in Human Cortical Tissue Homogenates using Antigen-Epitope Retrieval

24.0K 次观看.  Emory University. 我们描述了一个准备的人脑皮层匀浆澄清，经SDS - PAGE分离蛋白，抗原修复，并与Aβ肽抗体免疫印迹技术。使用这个协议，我们一贯检测皮层组织与阿尔茨海默氏症的病理的人类单体和多聚体的Aβ。

视频: SDS-PAGE/Immunoblot Detection of A&#946; Multimers in Human Cortical Tissue Homogenates using Antigen-Epitope Retrieval

Cryopreservation of Cortical Tissue Blocks for the Generation of Highly Enriched Neuronal Cultures

In this study, we outline a standardized protocol for the successful cryopreservation and thawing of cortical brain tissue blocks to generate highly enriched neuronal cultures. For this protocol the freezing medium used is 10% dimethyl sulfoxide (DMSO) diluted in Hank's Buffered Salt Solution (HBSS). Blocks of cortical tissue are transferred to cryovials containing the freezing medium and slowly frozen at -1&deg;C/min in a rate-controlled freezing container. Post-thaw processing and dissociation of frozen tissue blocks consistently produced neuronal-enriched cultures which exhibited rapid neuritic growth during the first 5 days in culture and significant expansion of the neuronal network within 10 days. Immunocytochemical staining with the astrocytic marker glial fibrillary acidic protein (GFAP) and the neuronal marker beta-tubulin class III, revealed high numbers of neurons and astrocytes in the cultures. Generation of neural precursor cell cultures after tissue block dissociation resulted in rapidly expanding neurospheres, which produced large numbers of neurons and astrocytes under differentiating conditions. This simple cryopreservation protocol allows for the rapid, efficient, and inexpensive preservation of cortical brain tissue blocks, which grants increased flexibility for later generation of neuronal, astrocyte, and neuronal precursor cell cultures.

Here, we describe a method for efficient cryopreservation and thawing of cortical brain tissue blocks to generate highly enriched neuronal cultures. This simple protocol provides flexibility for later generation of neuronal, astrocyte, and neuronal precursor cell cultures.

生成高度丰富的神经文化皮层组织块冷冻保存

In this study, we outline a standardized protocol for the successful cryopreservation and thawing of cortical brain tissue blocks to generate highly ...

科研

神经科学

Time-lapse Live Imaging of Clonally Related Neural Progenitor Cells in the Developing Zebrafish Forebrain

Precise patterns of division, migration and differentiation of neural progenitor cells are crucial for proper brain development and function1,2. To understand the behavior of neural progenitor cells in the complex in vivo environment, time-lapse live imaging of neural progenitor cells in an intact brain is critically required. In this video, we exploit the unique features of zebrafish embryos to visualize the development of forebrain neural progenitor cells in vivo. We use electroporation to genetically and sparsely label individual neural progenitor cells. Briefly, DNA constructs coding for fluorescent markers were injected into the forebrain ventricle of 22 hours post fertilization (hpf) zebrafish embryos and electric pulses were delivered immediately. Six hours later, the electroporated zebrafish embryos were mounted with low melting point agarose in glass bottom culture dishes. Fluorescently labeled neural progenitor cells were then imaged for 36hours with fixed intervals under a confocal microscope using water dipping objective lens. The present method provides a way to gain insights into the in vivo development of forebrain neural progenitor cells and can be applied to other parts of the central nervous system of the zebrafish embryo.

The present video demonstrates a method which takes advantage of the combination of electroporation and confocal microscopy to perform live imaging on individual neural progenitor cells in the developing zebrafish forebrain. In vivo analysis of the development of forebrain neural progenitor cells at a clonal level can be achieved in this way.

在发展中国家斑马鱼的前脑的神经祖细胞克隆相关的定时实时成像

Precise patterns of division, migration and differentiation of neural progenitor cells are crucial for proper brain development and function1,2. To ...

High Sensitivity 5-hydroxymethylcytosine Detection in Balb/C Brain Tissue

DNA hydroxymethylation is a long known modification of DNA, but has recently become a focus in epigenetic research. Mammalian DNA is enzymatically modified at the 5th carbon position of cytosine (C) residues to 5-mC, predominately in the context of CpG dinucleotides. 5-mC is amenable to enzymatic oxidation to 5-hmC by the Tet family of enzymes, which are believed to be involved in development and disease. Currently, the biological role of 5-hmC is not fully understood, but is generating a lot of interest due to its potential as a biomarker. This is due to several groundbreaking studies identifying 5-hydroxymethylcytosine in mouse embryonic stem (ES) and neuronal cells. Research techniques, including bisulfite sequencing methods, are unable to easily distinguish between 5-mC and 5-hmC . A few protocols exist that can measure global amounts of 5-hydroxymethylcytosine in the genome, including liquid chromatography coupled with mass spectrometry analysis or thin layer chromatography of single nucleosides digested from genomic DNA. Antibodies that target 5-hydroxymethylcytosine also exist, which can be used for dot blot analysis, immunofluorescence, or precipitation of hydroxymethylated DNA, but these antibodies do not have single base resolution.In addition, resolution depends on the size of the immunoprecipitated DNA and for microarray experiments, depends on probe design. Since it is unknown exactly where 5-hydroxymethylcytosine exists in the genome or its role in epigenetic regulation, new techniques are required that can identify locus specific hydroxymethylation. The EpiMark 5-hmC and 5-mC Analysis Kit provides a solution for distinguishing between these two modifications at specific loci. The EpiMark 5-hmC and 5-mC Analysis Kit is a simple and robust method for the identification and quantitation of 5-methylcytosine and 5-hydroxymethylcytosine within a specific DNA locus. This enzymatic approach utilizes the differential methylation sensitivity of the isoschizomers MspI and HpaII in a simple 3-step protocol. Genomic DNA of interest is treated with T4-BGT, adding a glucose moeity to 5-hydroxymethylcytosine. This reaction is sequence-independent, therefore all 5-hmC will be glucosylated; unmodified or 5-mC containing DNA will not be affected. This glucosylation is then followed by restriction endonuclease digestion. MspI and HpaII recognize the same sequence (CCGG) but are sensitive to different methylation states. HpaII cleaves only a completely unmodified site: any modification (5-mC, 5-hmC or 5-ghmC) at either cytosine blocks cleavage. MspI recognizes and cleaves 5-mC and 5-hmC, but not 5-ghmC. The third part of the protocol is interrogation of the locus by PCR. As little as 20 ng of input DNA can be used. Amplification of the experimental (glucosylated and digested) and control (mock glucosylated and digested) target DNA with primers flanking a CCGG site of interest (100-200 bp) is performed. If the CpG site contains 5-hydroxymethylcytosine, a band is detected after glucosylation and digestion, but not in the non-glucosylated control reaction. Real time PCR will give an approximation of how much hydroxymethylcytosine is in this particular site. In this experiment, we will analyze the 5-hydroxymethylcytosine amount in a mouse Babl/C brain sample by end point PCR.

The EpiMark 5-hmC and 5-mC Analysis Kit can be used to analyze and quantitate 5-methylcytosine and 5-hydroxymethylcytosine within a spe cific locus. The kit distinguishes 5-mC from 5-hmC by the addition of glucose to the hydroxyl group of 5-hmC via an enzymatic reaction utilizing &beta;-glucosyltransferase (T4-BGT). When 5-hmC occurs In the context of CCGG, this modification converts a cleavable MspI site to a non-cleavable site.

BALB / C脑组织中的高灵敏度检测5 - hydroxymethylcytosine

DNA hydroxymethylation is a long known modification of DNA, but has recently become a focus in epigenetic research.   Mammalian DNA is enzymatically ...

Coherence between Brain Cortical Function and Neurocognitive Performance during Changed Gravity Conditions

Previous studies of cognitive, mental and/or motor processes during short-, medium- and long-term weightlessness have only been descriptive in nature, and focused on psychological aspects. Until now, objective observation of neurophysiological parameters has not been carried out - undoubtedly because the technical and methodological means have not been available -, investigations into the neurophysiological effects of weightlessness are in their infancy (Schneider et al. 2008).
While imaging techniques such as positron emission tomography (PET) and magnetic resonance imaging (MRI) would be hardly applicable in space, the non-invasive near-infrared spectroscopy (NIRS) technique represents a method of mapping hemodynamic processes in the brain in real time that is both relatively inexpensive and that can be employed even under extreme conditions. The combination with electroencephalography (EEG) opens up the possibility of following the electrocortical processes under changing gravity conditions with a finer temporal resolution as well as with deeper localization, for instance with electrotomography (LORETA).
Previous studies showed an increase of beta frequency activity under normal gravity conditions and a decrease under weightlessness conditions during a parabolic flight (Schneider et al. 2008a+b). Tilt studies revealed different changes in brain function, which let suggest, that changes in parabolic flight might reflect emotional processes rather than hemodynamic changes. However, it is still unclear whether these are effects of changed gravity or hemodynamic changes within the brain. Combining EEG/LORETA and NIRS should for the first time make it possible to map the effect of weightlessness and reduced gravity on both hemodynamic and electrophysiological processes in the brain. Initially, this is to be done as part of a feasibility study during a parabolic flight. Afterwards, it is also planned to use both techniques during medium- and long-term space flight.
It can be assumed that the long-term redistribution of the blood volume and the associated increase in the supply of oxygen to the brain will lead to changes in the central nervous system that are also responsible for anaemic processes, and which can in turn reduce performance (De Santo et al. 2005), which means that they could be crucial for the success and safety of a mission (Genik et al. 2005, Ellis 2000).
Depending on these results, it will be necessary to develop and employ extensive countermeasures. Initial results for the MARS500 study suggest that, in addition to their significance in the context of the cardiovascular and locomotor systems, sport and physical activity can play a part in improving neurocognitive parameters. Before this can be fully established, however, it seems necessary to learn more about the influence of changing gravity conditions on neurophysiological processes and associated neurocognitive impairment.

The effect of weightlessness and hypergravity on both hemodynamic and electrophysiological processes in the brain is going to be followed during parabolic flight by EEG and NIRS techniques. 
A feasibility study of a more complex experiment, which is planned to carry out during medium- and long-term space flight.

大脑皮质功能和神经在更改重力条件下的性能之间的一致性

Previous studies of cognitive, mental and/or motor processes during short-, medium- and long-term weightlessness have only been descriptive in nature, and ...

Generation of Neural Stem Cells from Discarded Human Fetal Cortical Tissue

Neural stem cells (NSCs) reside along the ventricular zone neuroepithelium during the development of the cortical plate. These early progenitors ultimately give rise to intermediate progenitors and later, the various neuronal and glial cell subtypes that form the cerebral cortex. The capacity to generate and expand human NSCs (so called neurospheres) from discarded normal fetal tissue provides a means with which to directly study the functional aspects of normal human NSC development 1-5. This approach can also be directed toward the generation of NSCs from known neurological disorders, thereby affording the opportunity to identify disease processes that alter progenitor proliferation, migration and differentiation 6-9. We have focused on identifying pathological mechanisms in human Down syndrome NSCs that might contribute to the accelerated Alzheimer's disease phenotype 10,11. Neither in vivo nor in vitro mouse models can replicate the identical repertoire of genes located on human chromosome 21. 
Here we use a simple and reliable method to isolate Down syndrome NSCs from aborted human fetal cortices and grow them in culture. The methodology provides specific aspects of harvesting the tissue, dissection with limited anatomical landmarks, cell sorting, plating and passaging of human NSCs. We also provide some basic protocols for inducing differentiation of human NSCs into more selective cell subtypes.

A simple and reliable method on isolation and culture of neural stem cells from discarded human fetal cortical tissue is described. Cultures derived from known human neurological disorders can be used for characterization of pathological cellular and molecular processes, as well as provide a platform to assess pharmacological efficacy.

从废弃的人类胎儿大脑皮质组织神经干细胞的生成

Neural stem cells (NSCs) reside along the ventricular zone neuroepithelium during the development of the cortical plate. These early progenitors ...

Functional Calcium Imaging in Developing Cortical Networks

A hallmark pattern of activity in developing nervous systems is spontaneous, synchronized network activity. Synchronized activity has been observed in intact spinal cord, brainstem, retina, cortex and dissociated neuronal culture preparations. During periods of spontaneous activity, neurons depolarize to fire single or bursts of action potentials, activating many ion channels. Depolarization activates voltage-gated calcium channels on dendrites and spines that mediate calcium influx. Highly synchronized electrical activity has been measured from local neuronal networks using field electrodes. This technique enables high temporal sampling rates but lower spatial resolution due to integrated read-out of multiple neurons at one electrode. Single cell resolution of neuronal activity is possible using patch-clamp electrophysiology on single neurons to measure firing activity. However, the ability to measure from a network is limited to the number of neurons patched simultaneously, and typically is only one or two neurons. The use of calcium-dependent fluorescent indicator dyes has enabled the measurement of synchronized activity across a network of cells. This technique gives both high spatial resolution and sufficient temporal sampling to record spontaneous activity of the developing network.
A key feature of newly-forming cortical and hippocampal networks during pre- and early postnatal development is spontaneous, synchronized neuronal activity (Katz &amp; Shatz, 1996; Khaziphov &amp; Luhmann, 2006). This correlated network activity is believed to be essential for the generation of functional circuits in the developing nervous system (Spitzer, 2006). In both primate and rodent brain, early electrical and calcium network waves are observed pre- and postnatally in vivo and in vitro (Adelsberger et al., 2005; Garaschuk et al., 2000; Lamblin et al., 1999). These early activity patterns, which are known to control several developmental processes including neuronal differentiation, synaptogenesis and plasticity (Rakic &amp; Komuro, 1995; Spitzer et al., 2004) are of critical importance for the correct development and maturation of the cortical circuitry.
In this JoVE video, we demonstrate the methods used to image spontaneous activity in developing cortical networks. Calcium-sensitive indicators, such as Fura 2-AM ester diffuse across the cell membrane where intracellular esterase activity cleaves the AM esters to leave the cell-impermeant form of indicator dye. The impermeant form of indicator has carboxylic acid groups which are able to then detect and bind calcium ions intracellularly.. The fluorescence of the calcium-sensitive dye is transiently altered upon binding to calcium. Single or multi-photon imaging techniques are used to measure the change in photons being emitted from the dye, and thus indicate an alteration in intracellular calcium. Furthermore, these calcium-dependent indicators can be combined with other fluorescent markers to investigate cell types within the active network.

Spontaneous activity of developing neuronal networks can be measured using AM-ester forms of calcium-sensitive indicator dyes. Changes in intracellular calcium, indicating neuronal activation, are detected as transient changes in indicator fluorescence with one- or two-photon imaging. This protocol can be adapted for a range of developmentally-dependent neuronal networks in vitro.

在开发皮层网络功能钙成像

A hallmark pattern of activity in developing nervous systems is spontaneous, synchronized network activity. Synchronized activity has been observed in ...

Quantification of Filamentous Actin (F-actin) Puncta in Rat Cortical Neurons

Filamentous actin protein (F-actin) plays a major role in spinogenesis, synaptic plasticity, and synaptic stability. Changes in dendritic F-actin rich structures suggest alterations in synaptic integrity and connectivity. Here we provide a detailed protocol for culturing primary rat cortical neurons, Phalloidin staining for F-actin puncta, and subsequent quantification techniques. First, the frontal cortex of E18 rat embryos are dissociated into low-density cell culture, then the neurons grown in vitro for at least 12-14 days. Following experimental treatment, the cortical neurons are stained with AlexaFluor 488 Phalloidin (to label the dendritic F-actin puncta) and microtubule-associated protein 2 (MAP2; to validate the neuronal cells and dendritic integrity). Finally, specialized software is used to analyze and quantify randomly selected neuronal dendrites. F-actin rich structures are identified on second order dendritic branches (length range 25-75 &#181;m) with continuous MAP2 immunofluorescence. The protocol presented here will be a useful method for investigating changes in dendritic synapse structures subsequent to experimental treatments.

Quantification of Filamentous Actin F-actin Puncta in Rat Cortical Neurons

Filamentous actin (F-actin) plays an important role in spinogenesis, synaptic plasticity, and synaptic stability. Quantification of F-actin puncta is therefore a useful tool to study the integrity of synaptic structures. This protocol describes the procedures of quantifying F-actin puncta labeled with Phalloidin in low-density primary cortical neuronal cultures.

大鼠皮层神经元丝状肌动蛋白（F-肌动蛋白）泪点的量化

Filamentous actin protein (F-actin) plays a major role in spinogenesis, synaptic plasticity, and synaptic stability. Changes in dendritic F-actin rich ...

Quantification of Endosome and Lysosome Motilities in Cultured Neurons Using Fluorescent Probes

In the brain, membrane trafficking systems play important roles in regulating neuronal functions, such as neuronal morphology, synaptic plasticity, survival, and glial communications. To date, numerous studies have reported that defects in these systems cause various neuronal diseases. Thus, understanding the mechanisms underlying vesicle dynamics may provide influential clues that could aid in the treatment of several neuronal disorders. Here, we describe a method for quantifying vesicle motilities, such as motility distance and rate of movement, using a software plug-in for the ImageJ platform. To obtain images for quantification, we labeled neuronal endosome-lysosome structures with EGFP-tagged vesicle marker proteins and observed the movement of vesicles using a time-lapse microscopy. This method is highly useful and simplify measuring vesicle motility in neurites, such as axons and dendrites, as well as in the soma of both neurons and glial cells. Furthermore, this method can be applied to other cell lines, such as fibroblasts and endothelial cells. This approach could provide a valuable advancement of our understanding of membrane trafficking.

The investigation of membrane trafficking is crucial for understanding neuronal functions. Here, we introduce a method for quantifying vesicle motility in neurons. This is a convenient method that can be adapted to the quantification of membrane trafficking in the nervous system.

使用荧光探针定量培养的神经元中的内体和溶酶体运动

In the brain, membrane trafficking systems play important roles in regulating neuronal functions, such as neuronal morphology, synaptic plasticity, ...

Visualization of Cortical Modules in Flattened Mammalian Cortices

The cortex of mammalian brains is parcellated into distinct substructures or modules. Cortical modules typically lie parallel to the cortical sheet, and can be delineated by certain histochemical and immunohistochemical methods. In this study, we highlight a method to isolate the cortex from mammalian brains and flatten them to obtain sections parallel to the cortical sheet. We further highlight selected histochemical and immunohistochemical methods to process these flattened tangential sections to visualize cortical modules. In the somatosensory cortex of various mammals, we perform cytochrome oxidase histochemistry to reveal body maps or cortical modules representing different parts of the body of the animal. In the medial entorhinal cortex, an area where grid cells are generated, we utilize immunohistochemical methods to highlight modules of genetically determined neurons which are arranged in a grid-pattern in the cortical sheet across several species. Overall, we provide a framework to isolate and prepare layer-wise flattened cortical sections, and visualize cortical modules using histochemical and immunohistochemical methods in a wide variety of mammalian brains.

This article describes a detailed methodology to obtain flattened tangential sections from mammalian cortices and visualize cortical modules using histochemical and immunohistochemical methods.

扁平哺乳动物皮层皮质模块的可视化研究

The cortex of mammalian brains is parcellated into distinct substructures or modules. Cortical modules typically lie parallel to the cortical sheet, and ...

Statistical Modelling of Cortical Connectivity Using Non-invasive Electroencephalograms

Non-invasive electrophysiological recordings are useful for the evaluation of nervous system function. These techniques are inexpensive, fast, replicable, and less resource-intensive than imaging. Further, the functional data produced have excellent temporal resolution, which is not achievable with structural imaging.
Current applications of electroencephalograms (EEG) are limited by data processing methods. Standard analysis techniques using raw time series data at individual channels are very limited methods of interrogating nervous system activity. More detailed information about cortical function can be achieved by examining relationships between channels and deriving statistical models of how areas are interacting, allowing visualization of connectivity between networks.
This manuscript describes a method for deriving statistical models of cortical network activity by recording EEG in a standard manner, then examining the interelectrode coherence measures to assess relationships between the recorded areas. Higher order interactions can be further examined by assessing the covariance between the coherence pairs, producing high-dimensional &#34;maps&#34; of network interactions. These data constructs can be examined to assess cortical network function and its relationship to pathology in ways not achievable with traditional techniques.
This approach offers greater sensitivity to network level interactions than is achievable with raw time series analysis. It is, however, limited by the complexity of drawing specific mechanistic conclusions about the underlying neural populations and the high volumes of data generated, requiring more advanced statistical techniques for evaluation, including dimensionality reduction and classifier-based approaches.

Standard EEG analysis techniques offer limited insight into nervous system function. Deriving statistical models of cortical connectivity offers far greater ability to investigate underlying network dynamics. Improved functional assessment opens new possibilities for diagnosis, prognostication, and outcome prediction in nervous system diseases.

使用非侵入性脑电图的皮质连通性统计建模

Non-invasive electrophysiological recordings are useful for the evaluation of nervous system function. These techniques are inexpensive, fast, replicable, ...