作者承认澳大利亚研究理事会通过卓越的Electromaterials科学中心的支持。

该协议已获得拉筹伯大学（09-28P）和RMIT大学动物伦理委员会（1315）。 1。 体外测试电极的制备及初步<ol><li>制备电极涂层沉积的解决方案;例如10mM的3,4 -乙烯二氧噻吩（EDOT）和0.1M钠对 -甲苯磺酸盐（钠2点 ），以形成聚-3,4 -亚乙二氧基-PTS（PEDOT-PTS）。 </li><li>电极阵列连接到恒电位仪。 </li><li>小心地将电极阵列成沉积溶液并夹紧到位。 </li><li>放置一个铂网状反电极和Ag / AgCl参比电极浸入沉积溶液，并连接到恒电位仪。 </li><li>使用恒电位仪，存款涂料到所需的电极。沉积条件（电位，电流和时间）将取决于所期望的涂层而变化。对于PEDOT-PTS涂层，外加POTE1 V为15，30，45，或60秒微分方程边值问题已被使用。在阵列上的四个电极，应涂覆有涂层以交错构造（ 图1）。 </li><li>从沉积溶液中取出电极阵列，并与去离子水轻轻冲洗。 </li><li>随意与其它材料重复该涂层过程。 </li><li>准备在体外测试溶液（0.3M的二磷酸钠（ 磷酸氢二钠），在去离子水中）。 </li><li>电极阵列连接到恒电位仪。 </li><li>小心地将电极阵列到测试解决方案并夹紧到位。 </li><li>放置一个铂网状反电极和Ag / AgCl参比电极浸入测试溶液中并连接到恒电位仪。 </li><li>使用恒电位仪，进行连续的电化学阻抗谱（EIS）（潜在的偏移量为0 V，振幅10毫伏，频率范围10〜100,000 Hz）和循环伏安法（1个周期，电位范围00.8到-0.8 V，扫描速率100毫伏/秒）上的所有电极。未经测试的电极保持在开路电位和1秒的安静时间是用来测试每​​一个之间。所有32个电极与1小时的全面测试环节的溶液接触。 </li><li>从试验溶液中取出电极阵列，并与去离子水轻轻冲洗。 </li><li>执行任何其他所需的分析，例如光学显微镜。 </li><li>店铺探针在干燥的保护容器，防止电极表面的损伤和劣化。 </li></ol> 2。电极植入<ol><li>称量大鼠。 </li><li>注入聚氨酯（20％w / v的蒸馏水，1.3克/千克IP）为nonrecovery麻醉。 </li><li>通过测试的脚趾捏撤回反射确保麻醉起效。如果麻醉不充分，补充剂量的氨基甲酸乙酯，应给予（0.4克/千克IP）。 </li><li>敷眼部润滑剂，然后剃了头进制。 </li><li>将动物在一个恒温动物板俯卧位和插入直肠探头（37.5℃）。 </li><li>将一只耳朵扎入约预计最终位置的立体框架内，然后调整动物放置在外耳道耳吧。 </li><li>第二耳杆对齐到对侧外耳道。转移动物的耳棒，使之与牙齿保持器。 </li><li>用鼠齿钳，打开动物的下颚，勾上门牙在牙支架和夹鼻到位。 </li><li>在头部的皮肤上创建一个切口，大约1mm到中线的右侧，从10毫米喙的λ为10毫米尾。 </li><li>缩回的皮肤和肌肉横向切口以暴露顶叶及interparietal骨头用20％过氧化氢溶液和纱布垫擦洗裸露骨的表面上。 </li><li>钻一个孔约3厘的interparietal骨接近的lambda和中线，尽量去除骨栓。用无菌生理盐水，冲洗孔，以消除任何骨粉或片段，可能会损坏电极。 </li><li>用钝钝的剪刀，解剖颈背下方，形成空腔。紧裹的Ag / AgCl丝在药棉，用盐水饱和，然后插入参比电极到空腔中。 </li><li>用针的尖端使在矢状面硬脑膜切开。 </li><li>装上电极阵列电极操纵器，并调整其在开口位置与19°rostro-尾角。手动插入电极大约为2毫米到对下丘脑。 </li><li>连接扬声器的左侧空心穗条。 </li><li>确保放大器已开启。然后密封录音室之前，验证动物麻醉。 </li></ol> 3。体内试验<ol><li>提供白噪声阵阵，（高斯分布的噪声，1-44千赫; 10毫秒，上升和下降时间），并监控每个电极上的活动。在这阵阵应交付的最大速率是一个突发每200毫秒。 </li><li>使用电动微型硬盘，慢慢插入电极阵列，直到声驱动的活动被记录在每个柄的3最远端电极（电极记录活动的数量和位置可能会与电极放置或电极设计有所不同）。 </li><li>执行使用300重复50毫秒白噪声脉冲（高斯分布的噪声，1-44千赫; 10毫秒，上升和下降时间）的声刺激协议与1秒的重复率在70分贝，在记录每个电极的多组活动（ 24.4 kHz的采样率）。 </li><li>慢慢地插入电极阵列的另一个200μ米到IC在大致相同的位置上，从日较远端的电极定位每个电极Ë初始记录的位置。 </li><li>重复的声刺激和神经录制协议。 </li><li>继续插入电极阵列在200μm步和表演，直到所有电极都来自至少3个位置（通常为8-12电极整体位置）记录声驱动的活动声刺激和神经录制协议。 </li><li>收回电极阵列在200μm步，继续执行声刺激神经 ​​记录的协议，直到最初的电极阵列位置的实现。 </li><li>小心手动回缩电极阵列。 </li><li>注入的戊巴比妥钠过量（Lethobarb; 200毫克/千克IP）安乐死的动物。 </li><li>轻轻冲洗电极阵列用蒸馏水冲洗。然后在干燥的保护容器店铺探针以防止电极表面的损伤和劣化。 </li></ol> 4。植入后的维生素RO测试<ol><li>轻轻冲洗电极阵列用蒸馏水以除去任何污染。 </li><li>电极阵列连接到恒电位仪。 </li><li>小心地将电极阵列到测试解决方案并夹紧到位。 </li><li>放置一个铂网状反电极和Ag / AgCl参比电极浸入测试溶液中，并连接到恒电位仪。 </li><li>使用恒电位仪，进行连续的电化学阻抗谱（EIS）（潜在的偏移量为0 V，振幅10毫伏，频率范围10〜100,000 Hz）和循环伏安法（1个周期，电位范围0.8〜-0.8 V，扫描速率100毫伏/秒）上的所有电极。未经测试的电极保持在开路电位和1秒的安静时间是用来测试每​​一个之间。所有32个电极与1小时的全面测试环节的溶液接触。 </li><li>从试验溶液中取出电极阵列，并与去离子水轻轻冲洗。 </li><li> P花边电极阵列为24小时酶清洗液。 </li><li>从溶液中取出电极阵列和用蒸馏水冲洗。 </li><li>电极阵列连接到恒电位仪。 </li><li>小心地将电极阵列到测试解决方案并夹紧到位。 </li><li>放置一个铂网状反电极和Ag / AgCl参比电极浸入测试溶液中，并连接到恒电位仪。 </li><li>使用恒电位仪，进行连续的电化学阻抗谱（EIS）（潜在的偏移量为0 V，振幅10毫伏，频率范围10〜100,000 Hz）和循环伏安法（1个周期，电位范围0.8〜-0.8 V，扫描速率100毫伏/秒）上的所有电极。未经测试的电极保持在开路电位和1秒的安静时间是用来测试每​​一个之间。所有32个电极与1小时的全面测试环节的溶液接触。 </li><li>从测试溶液中取出电极阵列和轻轻地用去离子水冲洗。 </li><li>店铺探针在干燥的保护容器，防止电极表面的损伤和劣化。 </li></ol>

<ol>
	<li>Oluigbo, C. O., Rezai, A. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Addressing+Neurological+Disorders+With+Neuromodulation.">Addressing Neurological Disorders With Neuromodulation.</a> IEEE Trans. Biomed. Eng. 58, 1907-1917 (2011).</li><li>Shivdasani, M. N., Mauger, S. J., Rathbone, G. D., Paolini, A. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Inferior+Colliculus+Responses+to+Multichannel+Microstimulation+of+the+Ventral+Cochlear+Nucleus:+Implications+for+Auditory+Brain+Stem+Implants.">Inferior Colliculus Responses to Multichannel Microstimulation of the Ventral Cochlear Nucleus: Implications for Auditory Brain Stem Implants.</a> J. Neurophysiol. 99, 1-13 (2008).</li><li>Perlmutter, J. S., Mink, J. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Deep+Brain+Stimulation.">Deep Brain Stimulation.</a> Ann. Rev. Neurosci. 29, 229 (2006).</li><li>Weaver, F. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bilateral+Deep+Brain+Stimulation+vs+Best+Medical+Therapy+for+Patients+With+Advanced+Parkinson+Disease.">Bilateral Deep Brain Stimulation vs Best Medical Therapy for Patients With Advanced Parkinson Disease.</a> J. Am. Med. Assoc. 301, 63-73 (2009).</li><li>Biran, R., Martin, D. C., Tresco, P. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Neuronal+cell+loss+accompanies+the+brain+tissue+response+to+chronically+implanted+silicon+microelectrode+arrays.">Neuronal cell loss accompanies the brain tissue response to chronically implanted silicon microelectrode arrays.</a> Exp. Neurol. 195, 115-126 (2005).</li><li>McConnell, G. C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Implanted+neural+electrodes+cause+chronic,+local+inflammation+that+is+correlated+with+local+neurodegeneration.">Implanted neural electrodes cause chronic, local inflammation that is correlated with local neurodegeneration.</a> J. Neural Eng. 6, (2009).</li><li>Liu, X., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Stability+of+the+interface+between+neural+tissue+and+chronically+implanted+intracortical+microelectrodes.">Stability of the interface between neural tissue and chronically implanted intracortical microelectrodes.</a> IEEE Trans. Rehab. Eng. 7, 315-326 (1999).</li><li>Rousche, P. J., Normann, R. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chronic+recording+capability+of+the+Utah+Intracortical+Electrode+Array+in+cat+sensory+cortex.">Chronic recording capability of the Utah Intracortical Electrode Array in cat sensory cortex.</a> J. Neurosci. Methods. 82, 1-15 (1998).</li><li>Williams, J. C., Rennaker, R. L., Kipke, D. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Long-term+neural+recording+characteristics+of+wire+microelectrode+arrays+implanted+in+cerebral+cortex.">Long-term neural recording characteristics of wire microelectrode arrays implanted in cerebral cortex.</a> Brain Res. Protoc. 4, 303-313 (1999).</li><li>Harris, A. R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Conducting+polymer+coated+neural+recording+electrodes.">Conducting polymer coated neural recording electrodes.</a> J. Neural Eng. 10, (2013).</li><li>Bard, A. J., Faulkner, L. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Electrochemical Methods. , (2001).</li><li>Ludwig, K. A., Uram, J. D., Yang, J., Martin, D. C., Kipke, D. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chronic+neural+recordings+using+silicon+microelectrode+arrays+electrochemically+deposited+with+a+poly(3,4-ethylenedioxythiophene)+(PEDOT)+film.">Chronic neural recordings using silicon microelectrode arrays electrochemically deposited with a poly(3,4-ethylenedioxythiophene) (PEDOT) film.</a> J. Neural Eng. 3, 59 (2006).</li></ol>

该协议规定了在一个动物的神经比较记录电极涂层的方法。使用的电极的设计非常适合植入大鼠下丘（IC），具有类似规模的大小。该电极的变体如柄部之间的空间会阻止所有柄在大鼠集成电路是在同一时间，而较长的柄部和电极之间具有较大的间距增加的风险，该柄部的提示将要与颅骨的基极接触在插入。较小的电极间距从一个电极相邻的电极接触增加了涂层的风险。电极面积会影响神经记录?...

神经植入物被越来越多地用于研究，控制假肢和治疗疾病，如帕金森氏病，癫痫，和感觉丧失1,2。测量和/或控制了化学和大脑的电组合物的基础是所有神经植入物。然而，它管理一个治疗只有当神经组织是在异常状态下，以减少副作用3是非常重要的。例如，脑深部电刺激治疗癫痫的治疗应只适用于电脉冲到大脑中癫痫发作。有些副作用可能是肌张力障碍，记忆力，定向力障碍，认知功能受损，诱发幻觉，抑郁或抗抑郁3,4损失。在许多器件中，构成一个闭环系统，因此有必要记录的电活动与触发刺激检测到异常状态时。记录电极也用于控制亲sthetic设备。关键是要具有尽可能高的信号 - 噪声比，以获得最准确的触发和设备控制记录目标的神经活动。一个大的信号 - 噪声比也是用于研究应用中是非常理想的，因为更可靠的数据能够获得，从而减少所需的测试对象。这也将让参与神经刺激和记录的机制和途径更深入的了解。 后一个神经植入物已被放置入脑，免疫应答被触发5,6。响应的时间过程一般分为急性和慢性阶段，每个阶段由不同的生物过程7。免疫应答可以对植入物的性能显着影响，如从由包封在目标神经元中的神经胶质瘢痕的植入材料8的或化学降解的电极隔离。这可以减少一个记录电极的信号-噪声比和功率输出的激励电极，并且引线与电极失效9。谨慎选择植入物的设计和材料是必要的，以防止故障在植入物的使用寿命。 许多不同的材料和植入物的设计近来已经开发来改善信号噪声比和植入物的稳定性为神经记录。电极材料包括铂，铱，钨，氧化铱，氧化钽，氧化石墨烯，碳纳米管，掺杂的导电聚合物，以及最近的水凝胶。测试的基体材料还包括硅，氧化硅，氮化硅，丝，聚四氟乙烯，聚酰亚胺和聚硅氧烷。各个电极的修改也进行了研究，使用涂料如层粘连蛋白，神经营养因子，或自组装采用电化学，等离子体和光学技术的单层和治疗。假体设计竟可以是1 - ，2 - 或3 - 维与电极通常在绝缘探针的末端或沿着柄部为贯通电极或在一个2维数组为皮质表面植入物的边缘。无论电极设计或材料的，以前的文献中通常表现出新的植入物在不参考其他植入物构建体的性能。这可以防止他们的财产进行了系统评价。 这个协议提供了经由各种分析和电生理技术比较不同电极材料的方法。它是基于最近发表的文章相比，其中4种不同掺杂的导电聚合物涂层（聚吡咯（PPY）和聚-3,4 -亚乙二氧基（PEDOT）掺有硫酸（SO 4）或对 -甲苯磺酸盐（PTS））和4不同的涂层厚度10。这篇文章发现一种材料，PEDOT-PTS有45秒的沉积时间，具有最高信号噪声比和穗计数具有最小背景噪声，并且这些参数都依赖于电极的阻抗。相比其他掺杂导电聚合物和裸铱电极PEDOT-PTS也显示优异的生物稳定性急。该协议允许的临界参数，用于控制所述信号的信噪比和稳定性，以确定并用于进一步改善神经记录电极的性能。

<table border="0" cellpadding="0" cellspacing="0" width="1217">
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	</colgroup>
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:244px;">Programmable Attenuator</td>
			<td style="width:195px;">TDT</td>
			<td style="width:179px;">PA5</td>
			<td style="width:600px;">Controls the amplitude of the acoustic signal across frequencies</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:244px;">Electrostatic speaker driver</td>
			<td style="width:195px;">TDT</td>
			<td style="width:179px;">ED1</td>
			<td>Drives the electrostatic speakers (EC1)</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:244px;">Coupled electrostatic speaker</td>
			<td style="width:195px;">TDT</td>
			<td style="width:179px;">EC1</td>
			<td>Delivers sound to the animal</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:244px;">Processing base station</td>
			<td style="width:195px;">TDT</td>
			<td style="width:179px;">RZ2</td>
			<td>Records neural activity from electrode array (using PZ2 preamplifier)</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:244px;">Preamplifier</td>
			<td style="width:195px;">TDT</td>
			<td style="width:179px;">PZ2-256</td>
			<td>256-channel high impedance preamplifier</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:244px;">Multifunction Processor</td>
			<td style="width:195px;">TDT</td>
			<td style="width:179px;">RX6</td>
			<td>Used to generate acoustic stimuli</td>
		</tr>
		<tr height="24">
			<td height="24" style="height:24px;width:244px;">Multichannel electrode</td>
			<td style="width:195px;">NeuroNexus Technologies</td>
			<td style="width:179px;">A4 &#215; 8&#8211;5mm-200-200-413</td>
			<td>4-shank 32-channel electrode array</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:244px;">Potentiostat</td>
			<td style="width:195px;">CH Instruments</td>
			<td style="width:179px;">CHI660B</td>
			<td>Deposits electrode coatings and performs cyclic voltammetry and EIS (used with CHI684)</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:244px;">Multiplexer</td>
			<td style="width:195px;">CH Instruments</td>
			<td style="width:179px;">CHI684</td>
			<td>Switches between electrodes on the potentiostat</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:244px;">di-sodium phosphate</td>
			<td style="width:195px;">Fluka</td>
			<td style="width:179px;">71644</td>
			<td>Used in the test solution</td>
		</tr>
		<tr height="24">
			<td height="24" style="height:24px;width:244px;">3,4-ethylenedioxythiophene (EDOT)</td>
			<td style="width:195px;">Sigma Aldrich</td>
			<td style="width:179px;">483028</td>
			<td>An electrode coating material</td>
		</tr>
		<tr height="25">
			<td height="25" style="height:25px;width:244px;">para-toluene sulfonate (Na2pTS)</td>
			<td style="width:195px;">Sigma Aldrich</td>
			<td style="width:179px;">152536</td>
			<td>An electrode coating material</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:244px;">Urethane</td>
			<td style="width:195px;">Sigma Aldrich</td>
			<td style="width:179px;">U2500</td>
			<td>Used to anaesthetise the animal</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:244px;">Silver/Silver chloride electrode</td>
			<td style="width:195px;">CH Instruments</td>
			<td style="width:179px;">CHI111</td>
			<td>Used for testing the electrode in vitro</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:244px;">Platinum electrode</td>
			<td style="width:195px;">CH Instruments</td>
			<td style="width:179px;">MW4130</td>
			<td>Used for testing the electrode in vitro</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:244px;">Motorized microdrive</td>
			<td style="width:195px;">Sutter Instruments</td>
			<td style="width:179px;">DR1000</td>
			<td>To control the electrode array position during surgery</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:244px;">Enzymatic cleaner</td>
			<td style="width:195px;">Advanced Medical Optics</td>
			<td style="width:179px;">Ultrazyme</td>
			<td>Cleans the protein off the electrode array after implantation</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:244px;">Acoustic enclosure</td>
			<td style="width:195px;">TMC Ametek</td>
			<td style="width:179px;">83-501</td>
			<td>Isolates the animal from acoustic and electrical noise</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:244px;">Stereotaxic frame</td>
			<td style="width:195px;">David Kopf Instruments</td>
			<td style="width:179px;">1430</td>
			<td>Secures and positions the animal</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:244px;">Temperature controller</td>
			<td style="width:195px;">World Precision Instruments</td>
			<td style="width:179px;">ATC1000</td>
			<td>Controls the animal temperature</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:244px;">Bone drill</td>
			<td style="width:195px;">KaVo Dental</td>
			<td style="width:179px;">K5Plus</td>
			<td>Used to perform the craniectomy</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:244px;">Aspirator</td>
			<td style="width:195px;">Flaem</td>
			<td style="width:179px;">Suction pro</td>
			<td>Used to perform the craniectomy</td>
		</tr>
	</tbody>
</table>

a method for systematic electrochemical and electrophysiological evaluation of neural recording electrodes

新的材料和用于神经假体的设计通常被单独测试，与性能的示范，但不参考其他植入物的特性。这排除了一个合理的选择一个特定的植入体作为最适合于特定的应用程序，并基于该最重要的性能参数的新材料的开发。本文开发了一个协议，用于在体外和神经记录电极的体内试验。电化学和电生理检测推荐参数记录与讨论的关键步骤和潜在的问题。这种方法消除或减少存在于简单的活体测试范例，在电极/神经元的距离和动物模型之间的差异尤其是许多系统误差的影响。其结果是在体外和体内反应，如阻抗和Si的临界之间有很强的相关性GNAL噪比。这个协议可以很容易地适用于测试其它电极材料和设计。的体外技术可扩展到任何其他非破坏性方法来确定进一步重要的性能指标。用于在听觉通道的外科手术方法的原理也可以被修改为其它的神经区域或组织。

用于此实验的协议典型的电极阵列， 如图1所示。上有4柄与413μ 平方公尺名义几何面积和200μ米间距32铱电极。在阵列上的每个第二电极被涂覆有四种不同的电极涂层，标记为1-4 1。涂层材料都经过精心选择了他们的化学，机械和电化学性能。如前面10所提到的，增加沉积时间将增大电极面积和涂层厚度，而较大的施加电流或电势也可以增加沉积速率，可?...

Watch this Scientific Journal Video about A Method for Systematic Electrochemical and Electrophysiological Evaluation of Neural Recording Electrodes at JoVE.com

A Method for Systematic Electrochemical and Electrophysiological Evaluation of Neural Recording Electrodes

不同电极涂层通过改变电化学，化学和机械性能影响神经的记录性能。 在体外电极比较是比较简单的，但是在体内响应的比较通常是并发的变化极/神经元的距离与动物之间。本文提供了一个可靠的方法来比较神经记录电极。

对于系统电化学神经记录电极和电生理评价方法

New materials and designs for neural implants are typically tested separately, with a demonstration of performance but without reference to other implant ...

a-method-for-systematic-electrochemical-electrophysiological

Research

JoVE Journal

Neuroscience

13.3K 次观看.  La Trobe University. 不同电极涂层通过改变电化学，化学和机械性能影响神经的记录性能。 在体外电极比较是比较简单的，但是在体内响应的比较通常是并发的变化极/神经元的距离与动物之间。本文提供了一个可靠的方法来比较神经记录电极。 

视频: A Method for Systematic Electrochemical and Electrophysiological Evaluation of Neural Recording Electrodes

Surgical Implantation of Chronic Neural Electrodes for Recording Single Unit Activity and Electrocorticographic Signals

The success of long-term electrophysiological recordings often depends on the quality of the implantation surgery. Here we provide useful information for surgeons who are learning the process of implanting electrode systems. We demonstrate the implantation procedure of both a penetrating and a surface electrode. The surgical process is described from start to finish, including detailed descriptions of each step throughout the procedure. It should also be noted that this video guide is focused towards procedures conducted in rodent models and other small animal models. Modifications of the described procedures are feasible for other animal models.

We provide useful information for surgeons who are learning the process of implanting chronic neural recording electrodes. Techniques for both penetrating and surface electrode systems are described in a rodent animal model.

用于记录单机活动和Electrocorticographic信号的慢性神经电极植入手术

The success of long-term electrophysiological recordings often depends on the quality of the implantation surgery.  Here we provide useful information for ...

科研

神经科学

Reproducible Mouse Sciatic Nerve Crush and Subsequent Assessment of Regeneration by Whole Mount Muscle Analysis

Regeneration in the peripheral nervous system (PNS) is widely studied both for its relevance to human disease and to understand the robust regenerative response mounted by PNS neurons thereby possibly illuminating the failures of CNS regeneration1. Sciatic nerve crush (axonotmesis) is one of the most common models of peripheral nerve injury in rodents2. Crushing interrupts all axons but Schwann cell basal laminae are preserved so that regeneration is optimal3,4. This allows the investigator to study precisely the ability of a growing axon to interact with both the Schwann cell and basal laminae4. Rats have generally been the preferred animal models for experimental nerve crush. They are widely available and their lesioned sciatic nerve provides a reasonable approximation of human nerve lesions5,4. Though smaller in size than rat nerve, the mouse nerve has many similar qualities. Most importantly though, mouse models are increasingly valuable because of the wide availability of transgenic lines now allows for a detailed dissection of the individual molecules critical for nerve regeneration6, 7. Prior investigators have used multiple methods to produce a nerve crush or injury including simple angled forceps, chilled forceps, hemostatic forceps, vascular clamps, and investigator-designed clamps8,9,10,11,12. Investigators have also used various methods of marking the injury site including suture, carbon particles and fluorescent beads13,14,1. We describe our method to obtain a reproducibly complete sciatic nerve crush with accurate and persistent marking of the crush-site using a fine hemostatic forceps and subsequent carbon crush-site marking. As part of our description of the sciatic nerve crush procedure we have also included a relatively simple method of muscle whole mount we use to subsequently quantify regeneration.

In this report we describe a method to crush mouse sciatic nerve. This method uses readily available hemostatic forceps and easily and reproducibly produces complete sciatic nerve crush. In addition, we describe a method to prepare muscle whole mounts suitable for analysis of nerve regeneration after sciatic nerve crush.

重复性小鼠坐骨神经挤压和再生的后续评估整装肌肉分析

Regeneration in the peripheral nervous system (PNS) is widely studied both for its relevance to human disease and to understand the robust regenerative ...

Preparation of an Awake Mouse for Recording Neural Responses and Injecting Tracers

It is well known that anesthesia alters neural response properties in various regions of the brain.13. In the auditory system, fundamental response properties of brainstem neurons including threshold, frequency specificity, and inhibitory sidebands are altered in significant ways under anesthesia1-2. These observations prompted physiologists to seek ways to record from single neurons without the contaminating effects of anesthesia. One result was a decerebrate preparation, where the brainstem was completely transected at the level of the midbrain4. The drawbacks of this preparation are a formidable surgery, the elimination of descending projections from the forebrain, and an inability to use sensory stimulation to examine structures above the midbrain. A different strategy has been to implant electrode arrays chronically to record from single neurons and multiunit clusters while the animal is awake and/or behaving5,6. These techniques however are not compatible with injecting tracer dyes after first electrophysiologically characterizing a brain structure. To avoid altering neural response properties with anesthetics while recording electrophysiological response properties from single neurons, we have adapted a head restraint technique long used in bats7-9 to mouse10-12. Using this method, we are able to conduct electrophysiological recordings over several days in the unanesthetized mouse. At the end of the recording sessions, we can then inject a dye to reconstruct electrode positions and recording sites or inject a tracer so that pathways to and from the recording loci can be determined. This method allows for well isolated single neuron recordings over multiple days without the use anesthetics.

Electrophysiological characterization of neuronal responses is important for understanding brain function and for guiding the placement of dyes for pathway tracing. However, many studies are performed in anesthetized animals. To understand brain function without anesthetics, we developed a method to record neuronal response properties and inject dyes in awake mouse.

记录神经反应和注射示踪剂一个清醒小鼠的制备

It is well known that anesthesia alters neural response properties in various regions of the brain.13.  In the auditory system, fundamental response ...

Forebrain Electrophysiological Recording in Larval Zebrafish

Epilepsy affects nearly 3 million people in the United States and up to 50 million people worldwide. Defined as the occurrence of spontaneous unprovoked seizures, epilepsy can be acquired as a result of an insult to the brain or a genetic mutation. Efforts to model seizures in animals have primarily utilized acquired insults (convulsant drugs, stimulation or brain injury) and genetic manipulations (antisense knockdown, homologous recombination or transgenesis) in rodents. Zebrafish are a vertebrate model system1-3 that could provide a valuable alternative to rodent-based epilepsy research. Zebrafish are used extensively in the study of vertebrate genetics or development, exhibit a high degree of genetic similarity to mammals and express homologs for ~85% of known human single-gene epilepsy mutations. Because of their small size (4-6 mm in length), zebrafish larvae can be maintained in fluid volumes as low as 100 &mu;l during early development and arrayed in multi-well plates. Reagents can be added directly to the solution in which embryos develop, simplifying drug administration and enabling rapid in vivo screening of test compounds4. Synthetic oligonucleotides (morpholinos), mutagenesis, zinc finger nuclease and transgenic approaches can be used to rapidly generate gene knockdown or mutation in zebrafish5-7. These properties afford zebrafish studies an unprecedented statistical power analysis advantage over rodents in the study of neurological disorders such as epilepsy. Because the "gold standard" for epilepsy research is to monitor and analyze the abnormal electrical discharges that originate in a central brain structure (i.e., seizures), a method to efficiently record brain activity in larval zebrafish is described here. This method is an adaptation of conventional extracellular recording techniques and allows for stable long-term monitoring of brain activity in intact zebrafish larvae. Sample recordings are shown for acute seizures induced by bath application of convulsant drugs and spontaneous seizures recorded in a genetically modified fish.

A simple method to record extracellular field potentials in the larval zebrafish forebrain is described. The method provides a robust in vivo read-out of seizure-like activity. This technique can be used with genetically modified zebrafish larvae carrying epilepsy-related genes or seizures evoked by administration of convulsant drugs.

斑马鱼幼虫的前脑的电生理记录

Epilepsy affects nearly 3 million people in the United States and up to 50 million people worldwide. Defined as the occurrence of spontaneous unprovoked ...

Simultaneous Electrophysiological Recording and Calcium Imaging of Suprachiasmatic Nucleus Neurons

Simultaneous electrophysiological and fluorescent imaging recording methods were used to study the role of changes of membrane potential or current in regulating the intracellular calcium concentration. Changing environmental conditions, such as the light-dark cycle, can modify neuronal and neural network activity and the expression of a family of circadian clock genes within the suprachiasmatic nucleus (SCN), the location of the master circadian clock in the mammalian brain. Excitatory synaptic transmission leads to an increase in the postsynaptic Ca2+ concentration that is believed to activate the signaling pathways that shifts the rhythmic expression of circadian clock genes. Hypothalamic slices containing the SCN were patch clamped using microelectrodes filled with an internal solution containing the calcium indicator bis-fura-2. After a seal was formed between the microelectrode and the SCN neuronal membrane, the membrane was ruptured using gentle suction and the calcium probe diffused into the neuron filling both the soma and dendrites. Quantitative ratiometric measurements of the intracellular calcium concentration were recorded simultaneously with membrane potential or current. Using these methods it is possible to study the role of changes of the intracellular calcium concentration produced by synaptic activity and action potential firing of individual neurons. In this presentation we demonstrate the methods to simultaneously record electrophysiological activity along with intracellular calcium from individual SCN neurons maintained in brain slices.

Procedures are described to perform simultaneous recordings of membrane potential or current and changes of intracellular calcium concentration. Suprachiasmatic nucleus neurons are filled with the calcium indicator bis-fura-2 using a patch clamp electrode in the whole cell patch clamp configuration.

Simultaneous electrophysiological and fluorescent imaging recording methods were used to study the role of changes of membrane potential or current in ...

Electrophysiological Recording in the Brain of Intact Adult Zebrafish

Previously, electrophysiological studies in adult zebrafish have been limited to slice preparations or to eye cup preparations and electrorentinogram recordings. This paper describes how an adult zebrafish can be immobilized, intubated, and used for in vivo electrophysiological experiments, allowing recording of neural activity. Immobilization of the adult requires a mechanism to deliver dissolved oxygen to the gills in lieu of buccal and opercular movement. With our technique, animals are immobilized and perfused with habitat water to fulfill this requirement. A craniotomy is performed under tricaine methanesulfonate (MS-222; tricaine) anesthesia to provide access to the brain. The primary electrode is then positioned within the craniotomy window to record extracellular brain activity. Through the use of a multitube perfusion system, a variety of pharmacological compounds can be administered to the adult fish and any alterations in the neural activity can be observed. The methodology not only allows for observations to be made regarding changes in neurological activity, but it also allows for comparisons to be made between larval and adult zebrafish. This gives researchers the ability to identify the alterations in neurological activity due to the introduction of various compounds at different life stages.

This paper describes how an adult zebrafish can be immobilized, intubated, and used for in vivo electrophysiological experiments to allow recordings and manipulation of neural activity in an intact animal.

在完整的成年斑马鱼大脑电生理记录

Previously, electrophysiological studies in adult zebrafish have been limited to slice preparations or to eye cup preparations and electrorentinogram ...

Extracellular Recording of Neuronal Activity Combined with Microiontophoretic Application of Neuroactive Substances in Awake Mice

Differences in the activity of neurotransmitters and neuromodulators, and consequently different neural responses, can be found between anesthetized and awake animals. Therefore, methods allowing the manipulation of synaptic systems in awake animals are required in order to determine the contribution of synaptic inputs to neuronal processing unaffected by anesthetics. Here, we present methodology for the construction of electrodes to simultaneously record extracellular neural activity and release multiple neuroactive substances at the vicinity of the recording sites in awake mice. By combining these procedures, we performed microiontophoretic injections of gabazine to selectively block GABAA receptors in neurons of the inferior colliculus of head-restrained mice. Gabazine successfully modified neural response properties such as the frequency response area and stimulus-specific adaptation. Thus, we demonstrate that our methods are suitable for recording single-unit activity and for dissecting the role of specific neurotransmitter receptors in auditory processing.
The main limitation of the described procedure is the relatively short recording time (~3 hr), which is determined by the level of habituation of the animal to the recording sessions. On the other hand, multiple recording sessions can be performed in the same animal. The advantage of this technique over other experimental procedures used to manipulate the level of neurotransmission or neuromodulation (such as systemic injections or the use of optogenetic models), is that the drug effect is confined to the local synaptic inputs to the target neuron. In addition, the custom-manufacture of electrodes allows adjustment of specific parameters according to the neural structure and type of neuron of interest (such as the tip resistance for improving the signal-to-noise ratio of the recordings).

We present methods for the construction of electrodes to simultaneously record extracellular neural activity and release multiple neuroactive substances at the vicinity of the recording sites in awake mice. This technique allows the detailed analysis of putative local synaptic inputs to the neuron of interest.

神经元电活动外记录与神经活性物质在清醒小鼠微电泳应用相结合

Differences in the activity of neurotransmitters and neuromodulators, and consequently different neural responses, can be found between anesthetized and ...

Electrophysiological Method for Recording Intracellular Voltage Responses of Drosophila Photoreceptors and Interneurons to Light Stimuli In Vivo

Voltage responses of insect photoreceptors and visual interneurons can be accurately recorded with conventional sharp microelectrodes. The method described here enables the investigator to measure long-lasting (from minutes to hours) high-quality intracellular responses from single Drosophila R1-R6 photoreceptors and Large Monopolar Cells (LMCs) to light stimuli. Because the recording system has low noise, it can be used to study variability among individual cells in the fly eye, and how their outputs reflect the physical properties of the visual environment. We outline all key steps in performing this technique. The basic steps in constructing an appropriate electrophysiology set-up for recording, such as design and selection of the experimental equipment are described. We also explain how to prepare for recording by making appropriate (sharp) recording and (blunt) reference electrodes. Details are given on how to fix an intact fly in a bespoke fly-holder, prepare a small window in its eye and insert a recording electrode through this hole with minimal damage. We explain how to localize the center of a cell's receptive field, dark- or light-adapt the studied cell, and to record its voltage responses to dynamic light stimuli. Finally, we describe the criteria for stable normal recordings, show characteristic high-quality voltage responses of individual cells to different light stimuli, and briefly define how to quantify their signaling performance. Many aspects of the method are technically challenging and require practice and patience to master. But once learned and optimized for the investigator's experimental objectives, it grants outstanding in vivo neurophysiological data.

Electrophysiological Method for Recording Intracellular Voltage Responses of Drosophila Photoreceptors and Interneurons to Light Stimuli In Vivo

Sharp microelectrodes enable accurate electrophysiological characterization of photoreceptor and visual interneuron output in living Drosophila. Here we show how to use this method to record high-quality voltage responses of individual cells to controlled light stimulation. This method is ideal for studying neural information processing in insect compound eyes.

为记录细胞内电压响应电法<em&gt;果蝇</em&gt;光感受器和中间对光刺激<em&gt;在体内</em

Voltage responses of insect photoreceptors and visual interneurons can be accurately recorded with conventional sharp microelectrodes. The method ...

Fabrication of High Contact-Density, Flat-Interface Nerve Electrodes for Recording and Stimulation Applications

Many attempts have been made to manufacture multi-contact nerve cuff electrodes that are safe, robust and reliable for long term neuroprosthetic applications. This protocol describes a fabrication technique of a modified cylindrical nerve cuff electrode to meet these criteria. Minimum computer-aided design and manufacturing (CAD and CAM) skills are necessary to consistently produce cuffs with high precision (contact placement 0.51 &#177; 0.04 mm) and various cuff sizes. The precision in spatially distributing the contacts and the ability to retain a predefined geometry accomplished with this design are two criteria essential to optimize the cuff&#39;s interface for selective recording and stimulation. The presented design also maximizes the flexibility in the longitudinal direction while maintaining sufficient rigidity in the transverse direction to reshape the nerve by using materials with different elasticities. The expansion of the cuff&#39;s cross sectional area as a result of increasing the pressure inside the cuff was observed to be 25% at 67 mm Hg. This test demonstrates the flexibility of the cuff and its response to nerve swelling post-implant. The stability of the contacts&#39; interface and recording quality were also examined with contacts&#39; impedance and signal-to-noise ratio metrics from a chronically implanted cuff (7.5 months), and observed to be 2.55 &#177; 0.25 k&#8486; and 5.10 &#177; 0.81 dB respectively.

This article provides a detailed description on the fabrication process of a high contact-density flat interface nerve electrode (FINE). This electrode is optimized for recording and stimulating neural activity selectively within peripheral nerves.

高接触密度的制作，平面接口神经电极用于记录和刺激的应用

Many attempts have been made to manufacture multi-contact nerve cuff electrodes that are safe, robust and reliable for long term neuroprosthetic ...

A Micro-CT-based Method for Characterizing Lesions and Locating Electrodes in Small Animal Brains

Lesion and electrode location verification are traditionally done via histological examination of stained brain slices, a time-consuming procedure that requires manual estimation. Here, we describe a simple, straightforward method for quantifying lesions and locating electrodes in the brain that is less laborious and yields more detailed results. Whole brains are stained with osmium tetroxide, embedded in resin, and imaged with a micro-CT scanner. The scans result in 3D digital volumes of the brains with resolutions and virtual section thicknesses dependent on the sample size (12&#8211;15 and 5&#8211;6 &#181;m&#160;per voxel for rat and zebra finch brains, respectively). Surface and deep lesions can be characterized, and single tetrodes, tetrode arrays, electrolytic lesions, and silicon probes can also be localized. Free and proprietary software allows experimenters to examine the sample volume from any plane and segment the volume manually or automatically. Because this method generates whole brain volume, lesions and electrodes can be quantified to a much higher degree than in current methods, which will help standardize comparisons within and across studies.

This article describes a straightforward method to prepare small animal brains for micro-CT imaging, in which lesions can be quantified and electrodes located with high precision in the context of the whole brain.

一种基于微 ct 的小动物脑损伤和定位电极表征方法

Lesion and electrode location verification are traditionally done via histological examination of stained brain slices, a time-consuming procedure that ...