This is supported by 973 MOST grant (Grant No. 2011CB504402, 2012CB947602), National Natural Science Foundation of China (Grant No. 91132724, U1332136) and the 'Hundred Talents Project' of Chinese Academy of Science. The protocol was approved by the Committee on the Ethics of Animal Experiments of the USTC (Permit Number: USTCACUC1103013).

1，构建外科器械注：为了确保鱼的过程中和运行后，滴麻醉液乙基3 - 氨基苯甲酸酯（MS-222，或三卡因）在半浓度（0.015％）与1滴/秒的过鱼的嘴的速度仍然活着使用图1中所示的自制滴灌系统。 <ol><li>使一个框， 如图1A（长度为28厘米，宽为10厘米，高度为5厘米），把一个海绵（长度为6厘米，宽度为9厘米，高度为4厘米）的中间，并打开一个差距就可以了。 </li><li>就光固化粘结（ 图1B），那么这将被插入到鱼口针的末端平滑的球形表面。确保该针的表面是光滑的，以防止鱼的口中被损坏。 </li><li>添加MS-222（左腔，长度为6厘米的半集中，宽度为10℃米，高度为8厘米）和盐水（右室中，长为4厘米，宽为10厘米，高度为8厘米）到水库， 如图1C所示。注：新鲜的MS-222推荐。 </li><li>在0.03％的MS-222，持续2分钟麻醉鱼。 </li><li>将鱼在海绵的间隙，并与两对销钉，插入后面的胸鳍和泄殖腔孔，分别为11旁修复的鱼。 </li><li>连接鱼的口中，MS-222，和饲养用水和T型管， 如图1C所示 。 </li><li>打开连接到MS-222的管中。 </li></ol> 2，从右键顶盖逆行标记视网膜神经节细胞注：在开始之前，用消毒70-75％乙醇所有设备，确保没有乙醇仍然存在。 <ol><li>罗辛：稍微去除皮肤在整个头骨sclerectome（颅骨背视图显示在图2A和2B </strong&gt;的）。 </li><li>清除：用生理盐水冲洗头骨，然后用洗耳球吹干。 </li><li>最初的腐蚀：腐蚀颅骨与蚀刻剂，持续10秒。 </li><li>结算：彻底擦干，用棉签蚀刻剂，然后用生理盐水冲洗干净并擦干。 </li><li>保护：为了保护头骨在其他领域，除了从多余的腐蚀右侧顶盖，覆盖这些领域与光固化粘结，然后暴露于蓝光便携式光源治愈它。 </li><li>完整的腐蚀：把蚀刻剂在正确的顶盖中心区再次为完整的蚀刻2分钟。注：由于旧鱼头骨钙化，腐蚀会需要更长的时间。 </li><li>结算：彻底擦干，用棉签蚀刻剂，然后用生理盐水冲洗干净，再擦干。 </li><li>骷髅开口道：小心地用钳子，露出右顶盖（ 图2D取出malacic颅骨（ 图2C） </strong&gt;）。 </li><li>结算：从擦拭用明胶海绵块孔粘液和血液涌出，并用生理盐水冲洗，直到出血停止。 </li><li>染料放置：把染料（组织标签粘贴）对整个右侧顶盖和明胶海绵覆盖。 </li><li>分离：覆盖从同一动物的无菌尺度的孔中。 </li><li>密封：将光固化粘结到秤上，然后再次治愈它与蓝色光，持续40秒。 </li><li>复兴：洗债券的表面和振兴动物用生理盐水。 </li><li>护理和繁殖：保持鱼在28.5°C胚胎培养基（ZFIN）5天喂2次/日。不包括鱼，其染料不能留在顶盖5天的实验。注：胚胎培养基（EM）解决方案是对鱼的生存至关重要，温度是DiI荧光标记的关键因素。 </li></ol> 3，Wholemounting视网膜和成像<ol><li>视网膜之前将鱼在暗场2小时谁lemount。 </li><li>用冰水麻醉的鱼。 </li><li>穿刺在角膜缘的孔，并通过与金星剪刀去除角膜做眼罩。 </li><li>取出透镜并随后把视网膜的中心用冰冷的1×PBS。 </li><li>冲洗视网膜和巩膜用冰冷的1×PBS之间的间隙，直到没有色素残留。 </li><li>切断视神经的光盘。 </li><li>保持RGC层上方并保持视网膜与自制玻璃勺（ 图3A和3B）。甲滴管也可用于传输在视网膜上。 </li><li>把视网膜中一滴冰冷的30％甘油的上一个与RGC层向上（ 图3C）的幻灯片。 </li><li>除去甘油，然后压平视网膜上切割视网膜成四个象限（ 图3D）之前的载玻片上。保持视网膜展开与RGC层向上将是展平视网膜有帮助的。 </li><li>滴冰冷的50％甘油在T他视网膜洗去色素的片段。 </li><li>去除甘油，然后下降20微升冰冷的75％甘油在视网膜上。 </li><li>覆盖样品与1.8厘米×1.8厘米见方的盖玻片。 </li><li>密封盖玻片指甲油。建议在视网膜的直接成像。 </li><li>非隔行扫描图像中的20X物镜下整个视网膜（NA = 0.70）与DP72 CCD（每个图像是1360×1024像素）。每个字段有三个不同的侧重点。 </li><li>延伸的每个字段的深度与在软件“扩展景深”的工具。 </li><li>组装一台虚拟视网膜Photomerge的照片的功能。 </li><li>选择680×512象素的三个字段（实际面积为350微米的264微米，0.092毫米2）在视网膜上的每个方位，以分析视网膜神经节细胞的平均密度（ 图4A）。 </li><li>获得与测量的功能区域 - 在图像中创建一个多边形要素软件。 </li><li>通过公式计算视网膜神经节细胞的总数量“视网膜神经节细胞数量=命运X面积”9。 </li></ol>

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We have nothing to disclose.

视网膜神经节细胞逆行标记是重要的研究视网膜神经节细胞存活的哺乳动物，但它并没有在斑马鱼中使用。替代的方法，HE染色7和抗体染色8，是不是金标准，用于计数视网膜神经节细胞数，和转基因品系与标记的RGC的所有还没有被构造12,13。在这段视频中，我们介绍一种方法逆行标记视网膜神经节细胞在成年斑马鱼视网膜。虽然大约1％的轴突投射到嗅球或其它区域14?...

由于成年斑马鱼有很强的能力视神经损伤1后再生轴突，一个适当的方法来计算整个视网膜神经节细胞是必不可少的，以评估视网膜神经节细胞的存活和再生2。基于逆行标记视网膜神经节细胞在哺乳动物和金鱼3的方法- 5，我们构建了从成年斑马鱼的顶盖标记视网膜神经节细胞的方法。对于成年斑马鱼，两个关键技术问题应该注意：成年斑马鱼的头骨是非常小的6;他们生活在一个水环境。在这里，我们把头骨与腐蚀剂，最大限度地减少与钻5相关的危险。然后，我们封孔与光固化粘结手术后从而提高动物的生存。 此前，其他一些技术被采用来计算间接的方式视网膜神经节细胞数量。 HE染色的视网膜切片标签的所有类型的细胞中的RGCL 7。在整个Ř抗体标记etina，如胰岛-1，也可以标记无长突细胞8。虽然从视神经残端逆行标记可以标记在视网膜上所有的RGC，它不能被采用在挤压模型，因为它会造成额外损伤视神经。以逆行标签的优势从顶盖，我们已经研究视网膜神经节细胞的存活和再生的视神经损伤。结果表明，几乎所有的视网膜神经节细胞存活和视网膜神经节细胞的90％以上再生的顶盖在第一周的美眉模型9。 为了成功地标记所有视网膜神经节细胞，DiI荧光贴与其他几个商业染料10比较后选择。首先，它是专为在体内组织标记而设计的。其次，它是亲脂性染料，它不能扩散在水中。此外，这种荧光可以持续很长的时间，这使得它非常适合进行视网膜神经节细胞存活的研究。

<table border="0" cellpadding="0" cellspacing="0" width="608">
	<tbody>
		<tr height="37">
			<td height="37" style="height:37px;width:152px;">MS222</td>
			<td style="width:152px;">Sigma Aldrich</td>
			<td style="width:152px;">E10521</td>
			<td style="width:152px;">USA</td>
		</tr>
		<tr height="37">
			<td height="37" style="height:37px;width:152px;">DiI</td>
			<td style="width:152px;">Invitrogen</td>
			<td style="width:152px;">N22880</td>
			<td style="width:152px;">USA</td>
		</tr>
		<tr height="37">
			<td height="37" style="height:37px;width:152px;">lightcuring bond</td>
			<td style="width:152px;">Heraeus Kulzer&#160;</td>
			<td style="width:152px;">Durafill bond</td>
			<td style="width:152px;">Germany</td>
		</tr>
		<tr height="55">
			<td height="55" style="height:55px;width:152px;">Gluma Etch</td>
			<td style="width:152px;">Heraeus Kulzer&#160;</td>
			<td style="width:152px;">Gluma Etch 35 Gel</td>
			<td style="width:152px;">Germany</td>
		</tr>
		<tr height="73">
			<td height="73" style="height:73px;width:152px;">Blue LED</td>
			<td style="width:152px;">Shenruo Medical Equipment Co.</td>
			<td style="width:152px;">Power Blue Light Curing Unit</td>
			<td style="width:152px;">China</td>
		</tr>
	</tbody>
</table>

retrograde labeling of retinal ganglion cells in adult zebrafish with fluorescent dyes

由于逆行标记视网膜神经节细胞（RGC的）可以从死亡地点隔离视网膜神经节细胞胞体，它已成为黄金标准的视网膜神经节细胞的存活和再生的实验计数视网膜神经节细胞。许多研究在哺乳动物进行了视神经损伤后视网膜神经节细胞研究生存。然而，视网膜神经节细胞在成年斑马鱼的逆行标记尚未报道，尽管一些替代的方法可以在视网膜神经节细胞层（RGCL）计数细胞数。考虑到成年斑马鱼头骨的小尺寸和死亡的钻探头骨后，高风险，我们打开头骨与酸蚀刻的帮助和密封孔与光固化债券，这可能会显著提高患者的生存率。吸收染料5天之后，几乎所有的视网膜神经节细胞被标记。由于这种方法不需要横切视神经，它是不可替代的视网膜神经节细胞存活的研究在成年斑马鱼视神经损伤后。在这里，我们介绍一步该方法步骤，并提供有代表性的成果。

如图4B-D显示，DiI荧光阳性细胞的数目是三分之二DAPI +细胞RGCL的。在正常视网膜中，整个视网膜（ 图4E）的一个蒙太奇图像显示的DiI +视网膜神经节细胞分布在整个视网膜上，但在再生的视网膜（ 图4F），如在中心区域的RGC没有再生到其目标在第一个星期，他们不能被标记。 <img alt="图1...

Watch this Scientific Journal Video about Retrograde Labeling of Retinal Ganglion Cells in Adult Zebrafish with Fluorescent Dyes at JoVE.com

Retrograde Labeling of Retinal Ganglion Cells in Adult Zebrafish with Fluorescent Dyes

We introduce an efficient method to retrograde label retinal ganglion cells (RGCs) in adult zebrafish.

视网膜神经节细胞逆行标记的成年斑马鱼与荧光染料

As retrograde labeling retinal ganglion cells (RGCs) can isolate RGCs somata from dying sites, it has become the gold standard for counting RGCs in RGCs ...

retrograde-labeling-retinal-ganglion-cells-adult-zebrafish-with

Research

JoVE Journal

Neuroscience

9.4K 次观看.  University of Science and Technology of China. We introduce an efficient method to retrograde label retinal ganglion cells (RGCs) in adult zebrafish.

视频: Retrograde Labeling of Retinal Ganglion Cells in Adult Zebrafish with Fluorescent Dyes

Labeling and Imaging Cells in the Zebrafish Hindbrain

Key to understanding the morphogenetic processes that shape the early vertebrate embryo is the ability to image cells at high resolution. In zebrafish embryos, injection of plasmid DNA results in mosaic expression, allowing for the visualization of single cells or small clusters of cells 1 . We describe how injection of plasmid DNA encoding membrane-targeted Green Fluorescent Protein (mGFP) under the control of a ubiquitous promoter can be used for imaging cells undergoing neurulation. Central to this protocol is the methodology for imaging labeled cells at high resolution in sections and also in real time. This protocol entails the injection of mGFP DNA into young zebrafish embryos. Embryos are then processed for vibratome sectioning, antibody labeling and imaging with a confocal microscope. Alternatively, live embryos expressing mGFP can be imaged using time-lapse confocal microscopy. We have previously used this straightforward approach to analyze the cellular behaviors that drive neural tube formation in the hindbrain region of zebrafish embryos 2. The fixed preparations allowed for unprecedented visualization of cell shapes and organization in the neural tube while live imaging complemented this approach enabling a better understanding of the cellular dynamics that take place during neurulation.

Key to understanding the morphogenetic processes that shape the early embryo is the ability to image cells at high resolution. We describe here a technique for labeling single cells or small clusters of cells in whole zebrafish embryos with membrane-targeted Green Fluorescent Protein.

在斑马鱼后脑细胞标记和成像

Key to understanding the morphogenetic processes that shape the early vertebrate embryo is the ability to image cells at high resolution. In zebrafish ...

科研

神经科学

An Isolated Retinal Preparation to Record Light Response from Genetically Labeled Retinal Ganglion Cells

The first steps in vertebrate vision take place when light stimulates the rod and cone photoreceptors of the retina 1. This information is then segregated into what are known as the ON and OFF pathways. The photoreceptors signal light information to the bipolar cells (BCs), which depolarize in response to increases (On BCs) or decreases (Off BCs) in light intensity. This segregation of light information is maintained at the level of the retinal ganglion cells (RGCs), which have dendrites stratifying in either the Off sublamina of the inner plexiform layer (IPL), where they receive direct excitatory input from Off BCs, or stratifying in the On sublamina of the IPL, where they receive direct excitatory input from On BCs. This segregation of information regarding increases or decreases in illumination (the On and Off pathways) is conserved and signaled to the brain in parallel.
The RGCs are the output cells of the retina, and are thus an important cell to study in order to understand how light information is signaled to visual nuclei in the brain. Advances in mouse genetics over recent decades have resulted in a variety of fluorescent reporter mouse lines where specific RGC populations are labeled with a fluorescent protein to allow for identification of RGC subtypes 2 3 4 and specific targeting for electrophysiological recording. Here, we present a method for recording light responses from fluorescently labeled ganglion cells in an intact, isolated retinal preparation. This isolated retinal preparation allows for recordings from RGCs where the dendritic arbor is intact and the inputs across the entire RGC dendritic arbor are preserved. This method is applicable across a variety of ganglion cell subtypes and is amenable to a wide variety of single-cell physiological techniques.

This article provides a description of how to dissect and record from the isolated retinal preparation in mouse. In particular, we describe how to record light responses from a fluorescently labeled ganglion cell population and subsequently identify and analyze its morphology.

一个孤立的视网膜制备，记录从基因标记的视网膜神经节细胞的光反应

The first steps in vertebrate vision take place when light stimulates the rod and cone photoreceptors of the retina 1.  This information is then ...

Optical Imaging of Neurons in the Crab Stomatogastric Ganglion with Voltage-sensitive Dyes

Voltage-sensitive dye imaging of neurons is a key methodology for the understanding of how neuronal networks are organised and how the simultaneous activity of participating neurons leads to the emergence of the integral functionality of the network. Here we present the methodology of application of this technique to identified pattern generating neurons in the crab stomatogastric ganglion. We demonstrate the loading of these neurons with the fluorescent voltage-sensitive dye Di-8-ANEPPQ and we show how to image the activity of dye loaded neurons using the MiCAM02 high speed and high resolution CCD camera imaging system. We demonstrate the analysis of the recorded imaging data using the BVAna imaging software associated with the MiCAM02 imaging system. The simultaneous voltage-sensitive dye imaging of the detailed activity of multiple neurons in the crab stomatogastric ganglion applied together with traditional electrophysiology techniques (intracellular and extracellular recordings) opens radically new opportunities for the understanding of how central pattern generator neural networks work.

Here we present the methodology for fast and high resolution fluorescent voltage-sensitive dye imaging of detailed activity of neurons in the crab stomatogastric ganglion.

蟹电压敏感染料Stomatogastric神经节神经元的光学成像

Voltage-sensitive dye imaging of neurons is a key methodology for the understanding of how neuronal networks are organised and how the simultaneous ...

Transfection of Mouse Retinal Ganglion Cells by in vivo Electroporation

The targeting and refinement of RGC projections to the midbrain is a popular and powerful model system for studying how precise patterns of neural connectivity form during development. In mice, retinofugal projections are arranged in a topographic manner and form eye-specific layers in the Lateral Geniculate Nucleus (dLGN) of the thalamus and the Superior Colliculus (SC). The development of these precise patterns of retinofugal projections has typically been studied by labeling populations of RGCs with fluorescent dyes and tracers, such as horseradish peroxidase1-4. However, these methods are too coarse to provide insight into developmental changes in individual RGC axonal arbor morphology that are the basis of retinotopic map formation. They also do not allow for the genetic manipulation of RGCs.
Recently, electroporation has become an effective method for providing precise spatial and temporal control for delivery of charged molecules into the retina5-11. Current retinal electroporation protocols do not allow for genetic manipulation and tracing of retinofugal projections of a single or small cluster of RGCs in postnatal mice. It has been argued that postnatal in vivo electroporation is not a viable method for transfecting RGCs since the labeling efficiency is extremely low and hence requires targeting at embryonic ages when RGC progenitors are undergoing differentiation and proliferation6. 
In this video we describe an in vivo electroporation protocol for targeted delivery of genes, shRNA, and fluorescent dextrans to murine RGCs postnatally. This technique provides a cost effective, fast and relatively easy platform for efficient screening of candidate genes involved in several aspects of neural development including axon retraction, branching, lamination, regeneration and synapse formation at various stages of circuit development. In summary we describe here a valuable tool which will provide further insights into the molecular mechanisms underlying sensory map development.

Transfection of Mouse Retinal Ganglion Cells by in vivo Electroporation

We demonstrate an in vivo electroporation protocol for transfecting single or small clusters of retinal ganglion cells (RGCs) and other retinal cell types in postnatal mice over a wide range of ages. The ability to label and genetically manipulate postnatal RGCs in vivo is a powerful tool for developmental studies.

小鼠视网膜神经节细胞的转染在体内电穿孔

The targeting and refinement of RGC projections to the midbrain is a popular and powerful model system for studying how precise patterns of neural ...

Retrograde Fluorescent Labeling Allows for Targeted Extracellular Single-unit Recording from Identified Neurons In vivo

The overall goal of this method is to record single-unit responses from an identified population of neurons. In vivo electrophysiological recordings from individual neurons are critical for understanding how neural circuits function under natural conditions. Traditionally, these recordings have been performed 'blind', meaning the identity of the recorded cell is unknown at the start of the recording. Cellular identity can be subsequently determined via intracellular1, juxtacellular2 or loose-patch3 iontophoresis of dye, but these recordings cannot be pre-targeted to specific neurons in regions with functionally heterogeneous cell types. Fluorescent proteins can be expressed in a cell-type specific manner permitting visually-guided single-cell electrophysiology4-6. However, there are many model systems for which these genetic tools are not available. Even in genetically accessible model systems, the desired promoter may be unknown or genetically homogenous neurons may have varying projection patterns. Similarly, viral vectors have been used to label specific subgroups of projection neurons7, but use of this method is limited by toxicity and lack of trans-synaptic specificity. Thus, additional techniques that offer specific pre-visualization to record from identified single neurons in vivo are needed. Pre-visualization of the target neuron is particularly useful for challenging recording conditions, for which classical single-cell recordings are often prohibitively difficult8-11. The novel technique described in this paper uses retrograde transport of a fluorescent dye applied using tungsten needles to rapidly and selectively label a specific subset of cells within a particular brain region based on their unique axonal projections, thereby providing a visual cue to obtain targeted electrophysiological recordings from identified neurons in an intact circuit within a vertebrate CNS.
The most significant novel advancement of our method is the use of fluorescent labeling to target specific cell types in a non-genetically accessible model system. Weakly electric fish are an excellent model system for studying neural circuits in awake, behaving animals12. We utilized this technique to study sensory processing by "small cells" in the anterior exterolateral nucleus (ELa) of weakly electric mormyrid fish. "Small cells" are hypothesized to be time comparator neurons important for detecting submillisecond differences in the arrival times of presynaptic spikes13. However, anatomical features such as dense myelin, engulfing synapses, and small cell bodies have made it extremely difficult to record from these cells using traditional methods11, 14. Here we demonstrate that our novel method selectively labels these cells in 28% of preparations, allowing for reliable, robust recordings and characterization of responses to electrosensory stimulation.

Retrograde Fluorescent Labeling Allows for Targeted Extracellular Single-unit Recording from Identified Neurons In vivo

Retrograde transport of fluorescent dye labels a sub-population of neurons based on anatomical projection. Labeled axons can be visually targeted in vivo, permitting extracellular recording from identified axons. This technique facilitates recording when neurons cannot be labeled through genetic manipulation or are difficult to isolate using 'blind' in vivo approaches.

逆行荧光染料标记允许有针对性的外单细胞记录技术鉴定神经元<em&gt;在体内</em

The overall goal of this method is to record single-unit responses from an identified population of neurons. In vivo electrophysiological recordings from ...

Retrograde Loading of Nerves, Tracts, and Spinal Roots with Fluorescent Dyes

Retrograde labeling of neurons is a standard anatomical method1,2 that has also been used to load calcium and voltage-sensitive dyes into neurons3-6. Generally, the dyes are applied as solid crystals or by local pressure injection using glass pipettes. However, this can result in dilution of the dye and reduced labeling intensity, particularly when several hours are required for dye diffusion. Here we demonstrate a simple and low-cost technique for introducing fluorescent and ion-sensitive dyes into neurons using a polyethylene suction pipette filled with the dye solution. This method offers a reliable way for maintaining a high concentration of the dye in contact with axons throughout the loading procedure.

We describe a simple and low cost technique for introducing high concentration of fluorescent and calcium-sensitive dyes into neurons or any neuronal tract using a polyethylene suction pipette.

逆行神经，大港，并用荧光染料的神经根装载

Retrograde labeling of neurons is a standard anatomical method1,2 that has also been used to load calcium and voltage-sensitive dyes into neurons3-6. ...

Genetic Study of Axon Regeneration with Cultured Adult Dorsal Root Ganglion Neurons

It is well known that mature neurons in the central nervous system (CNS) cannot regenerate their axons after injuries due to diminished intrinsic ability to support axon growth and a hostile environment in the mature CNS1,2. In contrast, mature neurons in the peripheral nervous system (PNS) regenerate readily after injuries3. Adult dorsal root ganglion (DRG) neurons are well known to regenerate robustly after peripheral nerve injuries. Each DRG neuron grows one axon from the cell soma, which branches into two axonal branches: a peripheral branch innervating peripheral targets and a central branch extending into the spinal cord. Injury of the DRG peripheral axons results in substantial axon regeneration, whereas central axons in the spinal cord regenerate poorly after the injury. However, if the peripheral axonal injury occurs prior to the spinal cord injury (a process called the conditioning lesion), regeneration of central axons is greatly improved4. Moreover, the central axons of DRG neurons share the same hostile environment as descending corticospinal axons in the spinal cord. Together, it is hypothesized that the molecular mechanisms controlling axon regeneration of adult DRG neurons can be harnessed to enhance CNS axon regeneration. As a result, adult DRG neurons are now widely used as a model system to study regenerative axon growth5-7.
Here we describe a method of adult DRG neuron culture that can be used for genetic study of axon regeneration in vitro. In this model adult DRG neurons are genetically manipulated via electroporation-mediated gene transfection6,8. By transfecting neurons with DNA plasmid or si/shRNA, this approach enables both gain- and loss-of-function experiments to investigate the role of any gene-of-interest in axon growth from adult DRG neurons. When neurons are transfected with si/shRNA, the targeted endogenous protein is usually depleted after 3-4 days in culture, during which time robust axon growth has already occurred, making the loss-of-function studies less effective. To solve this problem, the method described here includes a re-suspension and re-plating step after transfection, which allows axons to re-grow from neurons in the absence of the targeted protein. Finally, we provide an example of using this in vitro model to study the role of an axon regeneration-associated gene, c-Jun, in mediating axon growth from adult DRG neurons9.

An in vitro model for genetic study of axon regeneration using cultured adult mouse dorsal root ganglion neurons is described. The method includes a re-suspension/re-plating step to allow axon re-growth from neurons undergoing genetic manipulation. This approach is especially useful for loss-of-function studies of axon regeneration using RNAi-based protein knockdown.

培养成年的背根神经节神经元轴突再生的遗传研究

It is well known that mature neurons in the central nervous system (CNS) cannot regenerate their axons after injuries due to diminished intrinsic ability ...

Implementing Dynamic Clamp with Synaptic and Artificial Conductances in Mouse Retinal Ganglion Cells

Ganglion cells are the output neurons of the retina and their activity reflects the integration of multiple synaptic inputs arising from specific neural circuits. Patch clamp techniques, in voltage clamp and current clamp configurations, are commonly used to study the physiological properties of neurons and to characterize their synaptic inputs. Although the application of these techniques is highly informative, they pose various limitations. For example, it is difficult to quantify how the precise interactions of excitatory and inhibitory inputs determine response output. To address this issue, we used a modified current clamp technique, dynamic clamp, also called conductance clamp 1, 2, 3 and examined the impact of excitatory and inhibitory synaptic inputs on neuronal excitability. This technique requires the injection of current into the cell and is dependent on the real-time feedback of its membrane potential at that time. The injected current is calculated from predetermined excitatory and inhibitory synaptic conductances, their reversal potentials and the cell's instantaneous membrane potential. Details on the experimental procedures, patch clamping cells to achieve a whole-cell configuration and employment of the dynamic clamp technique are illustrated in this video article. Here, we show the responses of mouse retinal ganglion cells to various conductance waveforms obtained from physiological experiments in control conditions or in the presence of drugs. Furthermore, we show the use of artificial excitatory and inhibitory conductances generated using alpha functions to investigate the responses of the cells.

This video article illustrates the set-up, the procedures to patch cell bodies and how to implement dynamic clamp recordings from ganglion cells in whole-mount mouse retinae. This technique allows the investigation of the precise contribution of excitatory and inhibitory synaptic inputs, and their relative magnitude and timing to neuronal spiking.

在小鼠视网膜神经细胞，实现动态夹具与突触和人工电导

Ganglion cells are the output neurons of the  retina and their activity reflects the integration of multiple synaptic inputs  arising from specific neural ...

A Novel Light Damage Paradigm for Use in Retinal Regeneration Studies in Adult Zebrafish

Light-induced retinal degeneration (LIRD) is commonly used in both rodents and zebrafish to damage rod and cone photoreceptors. In adult zebrafish, photoreceptor degeneration triggers M&#252;ller glial cells to re-enter the cell cycle and produce transient-amplifying progenitors. These progenitors continue to proliferate as they migrate to the damaged area, where they ultimately give rise to new photoreceptors. Currently, there are two widely-used LIRD paradigms, each of which results in varying degrees of photoreceptor loss and corresponding differences in the regeneration response. As more genetic and pharmacological tools are available to test the role of individual genes of interest during regeneration, there is a need to develop a robust LIRD paradigm. Here we describe a LIRD protocol that results in widespread and consistent loss of both rod and cone photoreceptors in which we have combined the use of two previously established LIRD techniques. Furthermore, this protocol can be extended for use in pigmented animals, which eliminates the need to maintain transgenic lines of interest on the albino background for LIRD studies.

Multiple light damage protocols have been described to damage photoreceptors and consequently induce a retinal regeneration response in adult zebrafish. This protocol describes an improved method that can be used in pigmented animals and that damages the vast majority of rod and cone photoreceptors across the entire retina.

成年斑马鱼视网膜再生研究中使用的一种新型的光损伤范式

Light-induced retinal degeneration (LIRD) is commonly used in both rodents and zebrafish to damage rod and cone photoreceptors. In adult zebrafish, ...

Single-cell RNA-Seq of Defined Subsets of Retinal Ganglion Cells

The discovery of cell type-specific markers can provide insight into cellular function and the origins of cellular heterogeneity. With a recent push for the improved understanding of neuronal diversity, it is important to identify genes whose expression defines various subpopulations of cells. The retina serves as an excellent model for the study of central nervous system diversity, as it is composed of multiple major cell types. The study of each major class of cells has yielded genetic markers that facilitate the identification of these populations. However, multiple subtypes of cells exist within each of these major retinal cell classes, and few of these subtypes have known genetic markers, although many have been characterized by morphology or function. A knowledge of genetic markers for individual retinal subtypes would allow for the study and mapping of brain targets related to specific visual functions and may also lend insight into the gene networks that maintain cellular diversity. Current avenues used to identify the genetic markers of subtypes possess drawbacks, such as the classification of cell types following sequencing. This presents a challenge for data analysis and requires rigorous validation methods to ensure that clusters contain cells of the same function. We propose a technique for identifying the morphology and functionality of a cell prior to isolation and sequencing, which will allow for the easier identification of subtype-specific markers. This technique may be extended to non-neuronal cell types, as well as to rare populations of cells with minor variations. This protocol yields excellent-quality data, as many of the libraries have provided read depths greater than 20 million reads for single cells. This methodology overcomes many of the hurdles presented by Single-cell RNA-Seq and may be suitable for researchers aiming to profile cell types in a straightforward and highly efficient manner.

Here, we present a combinatorial approach for classifying neuronal cell types prior to isolation and for the subsequent characterization of single-cell transcriptomes. This protocol optimizes the preparation of samples for successful RNA Sequencing (RNA-Seq) and describes a methodology designed specifically for the enhanced understanding of cellular diversity.

视网膜神经节细胞定义子集的单细胞RNA-Seq

The discovery of cell type-specific markers can provide insight into cellular function and the origins of cellular heterogeneity. With a recent push for ...