行为小鼠海马空间受限振荡的记录
Summary
该协议描述了用多柄线性硅探针记录局部场电位的情况。利用电流源密度分析转换信号, 可以重建小鼠海马区的局部电活动。利用这种技术, 可以在自由运动小鼠中研究空间限制的脑振荡。
Abstract
局部场电位 (LFP) 是通过神经膜的离子运动而产生的。由于 LFP 电极所记录的电压反映了大量脑组织的电场, 提取有关当地活动的信息具有挑战性。然而, 研究神经元集成电路需要对真正的局部事件和来自遥远脑区的体积传导信号进行可靠的区分。电流源密度 (CSD) 分析通过提供有关电极附近的电流汇和源的信息, 为这个问题提供了解决方案。在具有层流细胞构筑的脑区, 如海马, 可通过估计 LFP 的第二空间导数来获得一维 CSD。在这里, 我们描述了一个方法, 记录 multilaminar LFPs 使用线性硅探针植入到背海马。惩教署的踪迹沿探头的个别柄计算。该协议描述了一种解决自由移动小鼠海马空间受限神经元网络振荡的方法。
Introduction
LFP 中的振荡在神经回路的信息处理中有重要的介入。它们涵盖了广泛的频率范围, 从慢波 (1 赫兹) 到快速脉动振荡 (~ 200 赫兹)1。不同频段与认知功能相关, 包括记忆、情感处理和导航2、3、4、5、6、7。电流在神经元膜上的流动构成了 LFP 信号8的最大部分。阳离子进入细胞 (例如通过激活谷氨酸兴奋突触) 代表一个活跃的电流接收器 (电荷离开胞外培养基)。相比之下, 正电荷对胞外介质的净流量, 例如通过激活 GABAergic 抑制突触, 描述了该位置的活动电流源。在神经元偶极子中, 电流汇与被动源成对, 反之亦然, 因为补偿电流影响到远处的膜电荷。
由远程神经过程产生的电场也可能导致记录电极上的电压偏转相当大, 因此可能被错误地认为是局部事件。这种体积传导对 LFP 信号的解释构成了严重的挑战。惩教署的分析提供有关本地电流汇和 LFP 信号来源的资料, 因此包括减少体积传导8的影响的方法。在层状结构, 如海马体, 一维的 CSD 信号可以获得的第二空间导数的 LFP 记录从等距电极安排垂直于层流平面9。商用线性硅探针的问世使研究人员得以利用 CSD 方法研究海马区的局部振荡活动。例如, 已经证明, 不同的伽玛振荡在 CA1 区10中以特定层的方式出现。此外, 惩教署的分析已确定的独立热点的伽玛活动在主细胞层的齿状回11。重要的是, 这些发现只在当地的惩教署, 而不是 LFP 的信号中可见。因此, 惩教署的分析提供了一个强有力的工具, 以获得洞察的电路操作海马。
在本协议中, 我们提供了一个全面的指南, 以获得一维的 CSD 信号与硅探针。这些方法将使用户能够调查行为小鼠海马区内的局部振荡事件。
Protocol
Representative Results
Discussion
增加的证据表明, 海马神经元电路的脑振荡发生在离散空间域10,11,16。CSD 分析大大降低了容积传导的影响, 是研究局部振荡事件的重要前提。通过这个视频, 我们提供了一个指南, 以植入小鼠海马的硅探针, 以分析惩教署的数据。我们展示了 CA1 中尖锐波波纹和齿状回局部伽玛振荡信号的代表性例子。然而, 这个协议也可以用来研?…
Declarações
The authors have nothing to disclose.
Acknowledgements
我们感谢凯琳温特哈尔特和 Kerstin Semmler 的技术援助。这项工作得到了德国研究基金会 BrainLinks-BrainTools (激动 1086) 的杰出群体的支持。
Materials
| Crocodile clamp with stand | Reichelt Elektronik | HALTER ZD-10D | |
| Silicon probe | Cambridge Neurotech | P-series 32 | |
| Stereoscope | Olympus | SZ51 | |
| Varnish-insulated copper wire | Bürklin Elektronik | 89 F 232 | |
| Ground screws | Screws & More GmbH (screwsandmore.de) | DIN 84 A2 M1x2 | |
| Flux | Stannol | 114018 | |
| Ceramic-tipped forceps | Fine Science Tools | 11210-60 | |
| Paraffine Wax | Sigma-Aldrich | 327204 | |
| Cauterizer | Fine Science Tools | 18010-00 | |
| Soldering iron | Kurtz Ersa | OIC1300 | |
| Multimeter | Uni-T | UT61C | |
| Ethanol | Carl Roth | 9065.1 | |
| Pasteur pipettes | Carl Roth | EA65.1 | |
| Heat sterilizer | Fine Science Tools | 18000-45 | |
| Stereotaxic frame | David Kopf | Model 1900 | |
| Stereotaxic electrode holder | David Kopf | Model 1900 | |
| Isoflurane | Abbvie | B506 | |
| Oxygen concentrator | Respironix | 1020007 | |
| Buprenorphine | Indivior UK Limited | ||
| Electrical shaver | Tondeo | Eco-XS | |
| Heating pad | Thermolux | 463265/-67 | |
| Surgical clamps | Fine Science Tools | 18050-28 | |
| Hydrogen peroxide | Sigma-Aldrich | H1009 | |
| Sterile cotton wipes | Carl Roth | EH12.1 | |
| Drill | Proxxon | Micromot 230/E | |
| 21G injection needle | B. Braun | 4657527 | |
| Phosphate buffer/phosphate buffered saline | |||
| Stereotaxic atlas | Elsevier | 9.78012E+12 | |
| Surgical scissors | Fine Science Tools | 14094-11 | |
| Surgical forceps | Fine Science Tools | 11272-40 | |
| 27G injection needles | B. Braun | 4657705 | |
| Vaseline | |||
| Dental cement | Sun Medical | SuperBond T&M | |
| Carprofen | Zoetis | Rimadyl 50mg/ml | |
| Recording amplifier | Intan Technologies | C3323 | |
| USB acquisition board | Intan Technologies | C3004 | |
| Recording cables | Intan Technologies | C3216 | |
| Electrical commutator | Doric lenses | HRJ-OE_FC_12_HARW | |
| Acquisition software | OpenEphys (www.open-ephys.org) | GUI | allows platform-independent data acquisition |
| Computer for data acquisition | |||
| Analysis environment | Python (www.python.org) | allows platform-independent data analysis | |
| Urethane | Sigma-Aldrich | ||
| Vibratome | Leica | VT1000 | |
| Microscope slides | Carl Roth | H868.1 | |
| Cover slips | Carl Roth | H878.2 | |
| Embedding medium | Sigma-Aldrich | 81381-50G | |
| Distilled water | Millipore | Milli Q | Table-top machine for the production of distilled water |
| Tergazyme | Alconox | Tergazyme |
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