作者要感谢马蒂·S.海迈莱伊宁，Zöllei里拉和审稿人的宝贵意见。资金来源:R00DC010196（AKCL）; T32DC000018（EDL）; T32DC005361（RKM）。

1。解剖数​​据采集与处理<ol><li>收购磁化准备快速梯度回波（MPRAGE）MRI扫描的主题。这可能需要5-10分钟，这取决于使用特定扫描协议。 </li><li>如果EEG数据用于逆成像分析，FLASH序列提供不同的组织从的标准MPRAGE序列1的对比度，获得两个额外的快速低角度拍摄（FLASH）MRI扫描（翻转角= 5°〜30°）。 </li><li> （见表）使用FreeSurfer软件2，3，重建皮质表面，并成立单独的M /脑电偶极子源空间。 <ol><li>这个源空间被约束为灰/白质边界分割从MPRAGE扫描。每个半球包含大约10万个潜在的顶点，间距为1毫米。偶极估计（见下文），使用的栅格间距为7毫米，产生〜3000元每半球的偶极子。 </li></ol></li><li>重建皮肤，外的头骨和内颅骨表面MNE（见表），FreeSurfer从MPRAGE和FLASH图像。使用这些表面上以产生一个三层的边界元模型（BEM）。 </li></ol> 2。 M / EEG数据采集<ol><li>准备主题M / EEG记录。 <ol><li>电图和参考电极的制备以及数字化主体的基准标志性建筑，头部位置指示器线圈（HPI）和脑电图电极的详细信息，请参阅刘等 4。 </li></ol></li><li>一旦问题被放置在MEG，测量头的位置，使用HPI线圈的。 </li><li>开始记录。开始呈现的听觉和视觉刺激。 <ol><li>许多硬件和软件解决方案，可用来进行刺激呈现（ 例如 ，演示，E-总理）。我们使用了的塔克-戴维斯技术RZ6的听觉刺激呈现和触发冲压，5 Psychtoolbox的视觉小号timulus介绍，通过MATLAB控制。测试的听觉和视觉延迟使用麦克风和光电二极管连接到屏幕上，随后又确保有没有可观察到的抖动（这可能需要设置演示文稿投影机的原始分辨率）之前的实验，有助于确保时序的完整性。 </li></ol></li><li>主题通过光按钮盒的听觉和视觉刺激，而执行行为的任务。 </li><li>所有的刺激，实验参数和数据文件保存为离线分析。 </li></ol> 3。 M / EEG与MRI扫描和数据处理有限公司登记<ol><li>使用的MNE软件，加载数字化仪的数据和对象的重建MRI头部模型。选择基准的地标，启动共登记过程中，继续使用自动校准程序来完成坐标变换（ 图2）。 </li><li>与每个偶极子的位置在源SP王牌与每个传感器的位置，结合记录的HPI数据（见2.2）来计算的正向与三层BEM溶液（见1.4） </li><li>检查所有记录的M / EEG数据，并确定有非常高的变异，或者是完全平坦的通道。设置这些坏信道的渠道。 </li><li>使用信号空间投影6或其他降低噪声的技术（如信号空间分离7）突出或分离出空间场模式源于周围的环境领域的污染或其它不希望的生理信号，如那些与眼睛闪烁和心脏工件（ 图3）。 <ol><li>应用时域神器去除（ 例如 。时代，删除含有异常高振幅信号，由于扣球的通道）和频域神器去除（ 例如 ，带50或60 Hz线路频率的陷波滤波），以进一步提高信号 - 噪声比。 </li></ol></li><li>确定一个基准期的主题不执行任何任务（ 例如 ，200毫秒内每个试验开始之前）。生成这些基线历元的平均值，以获得（也被称为协方差矩阵）的噪声估计。 </li><li>确定时代的兴趣（ 例如 ，仅收集的时代，正确的行为反应），实验对比（ 例如 ，时代主题切换的听觉注意力到对面的视野时，最初线索- "开关"状态-与主题相关的定义条件维持原来的视野时的注意 - "保留"状态）。为每个定义的条件生成的平均响应。 <ol><li>这些平均可基线校正或不依赖于实验参数（见图8），这里显示的数据是基线校正。 </li></ol></li><li>合并的协方差矩阵（3.5）和（3.2）计算的正解，以获得分布式皮层约束的最低标准，涉及的传感器测量偶极目前的估计，在源空间的逆算子。 <ol><li>您可以约限制或固定偶极子定位于大脑皮质的正常方向9。 </li></ol></li><li>生成一个"脑电影"分布式偶极子的每个实验条件下（ 图4）的估计值（ 即 ，时间在每个偶极子的位置在源空间中的当前估计值）。 <ol><li>根据你的实验设计的时间特性，你可以BIN你的数据在目前的估计，使用非重叠的时间窗平均时间。 </li></ol></li></ol> 4。统计推断的基础上的共同表面的坐标系<ol><li>变形的"大脑为每个主题的电影"到一个共同的（平均）皮质空间的基础上的表面为基础的坐标系统，最佳对齐个人的脑沟，GYRAL模式3。这使我们能够比较或所有科目的平均皮质活动。 （ 图5）。 </li><li>有许多不同的统计推断方法。我们将突出三个可能的方法。方法没有被实施的软件包，可以用自定义软件在我们的例子中，我们使用MATLAB进行非参数的时空集中排列测试。尽管这些数据的高维（空间x时间x的主题），所有这些方法都可以使用标准的现代桌面电脑硬件秒（投资回报率4.3的方法）小时（非参数聚类; 4.5）。 </li><li> 地区的利益（投资回报率）的方法 <ol><li>您可以定义ROI解剖结构（ 例如 ，定义自动地块划分算法1）和/或功能（ 例如 ，通过记录功能定位的任务，如一个的Go / No转到扫视任务确定oculomotoŕ地区）。 </li><li>您可以进一步限制您的分析，以一个特定的时间的利益，是适合您的实验范式（ 例如 ，前一段时间在发病后的声音刺激）。您也可以使用其他的时间序列分析与统计推断。 </li></ol></li><li> 全的大脑邦费罗尼或虚假发现率（FDR）校正 <ol><li>采用的Bonferroni法或FDR修正的，如果你需要全脑，全时间的分析。 </li><li>生成统计在每个偶极子的位置的地图，并使用适当的检验统计量，如t-检验或受试者内方差分析为约常分布式数据的每个时间点。例如，z分数从动态统计参数映射的MNE估计固定偶极源10时，可以使用的校正中的估计的相关性（例如作为保守了Greenhouse-Geisser校正）配对。 </li><li>对于邦费罗尼校正，取得显着的空间的时间点，在显着性水平为0.05的比较次数（乘以时间点的数目的偶极子数）除以通过阈值。对于一个较保守的方法，使用FDR p值修正11。 </li></ol></li><li> 非参数时空聚类 <ol><li>使用此方法基于一个简单的扩展12地区的大，一致的空间和时间激活，而更小的保守Bonferroni校正，且不容易键入我的统计误差控制家庭明智的错误率比FDR 。 <ol><li>由于这种方法使用置换或蒙特卡洛重采样技术，它不依赖于数据的正常性的假设，并只假定的条件的标签的零假设下是可交换的。虽然这是比前两种方法计算密集的，它仍然可以执行在时间上的一个单台机器使用的现代桌面计算机硬件。 </li></ol></li><li>生成统计地图在每个偶极子的位置和每个时间点，使用适当的检验统计量，如t-检验。 </li><li>本地图一个初步的意义阈值阈值， 例如 ，P &lt;0.05。 </li><li>这些假定的重要点集群时空接近的基础上， 例如 。 5毫秒和5毫米的测地距离的另一个重要点内，在同一个集群。得分每个群集使用超体积或总价值（ 例如，T-集群中的得分点的总和）。 </li><li>执行标准的置换重采样（或蒙地卡罗更大的数据集， 例如重采样数学科N&gt; 10，，节省计算）测试的最大统计（排列测试的例子参见图12）。简单地说，对于一个随机子集的主题（选择从0到N个对象），重新标记的条件被克，比之前获得的统计图，进行聚类新的统计图，并获得最大的集群得分，重贴标签。执行此过程长达2 N排列新的随机relabelings上获得的最大统计量的分布;执行所有N个可能的relabelings产生的排列测试，并利用不到2 N relabelings蒙地卡罗（或随机产生的随机子集）置换测试。 </li><li>获得一个给定的原始簇（从原来的标签）确定的时间比例最大的簇大小大于原来的集群的意义， 例如 。大于95％的最大统计集群的集群，可以被宣布重大。 <ol><li> MEG分布式源成像的统计推断了深入的讨论，请参阅13。 </li></ol></li></ol></li><li>由此产生的数据文件可以是vi<html> sualized在许多方面，包括利用跨国公司软件的使用本地存储的时空皮质估计，即STC文件的格式。 ，旁边的标签，可以产生相应的重大地区，可以使用MATLAB和Python的跨国公司工具箱提供。 </li></ol> 5。代表性的成果 图6示出了一组有代表性的结果，使用在图4中所概述的行为范式。使用非参数的的时空聚类程序（4.5）中，右侧的FEF被发现时是显着的被摄体相比，一个标准的任务（ 图6左侧）进行重新调整任务。使用的ROI的方法（4.3），右FEF的时间过程被示出，随着的时间段，这两个条件是显着不同的。 p_upload/4262/4262fig1.jpg"/&gt; 图1。工作流程产生一个"大脑电影"使用皮质约束的最低标准偶极子的估算（ 参见 图1刘等人，2010）。 <img alt="图2" src="/files/ftp_upload/4262/4262fig2.jpg" /> 图2。跨国公司使用的软件，方便的EEG渠道和HPI地点共同注册到一个主题的MRI统筹空间。 <img alt="图3" src="/files/ftp_upload/4262/4262fig3.jpg" /> 图3。MEG数据之前和之后的使用SSP取出心脏（以橙色突出显示）和眼睛闪烁（蓝绿色突出显示），以删除线频率的文物和低通滤波。 <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/4262/4262fig3large.jpg" target="_blank">点击此处查看大图</a> 。 <p="jove_content"佛:保持together.within"页面="总是"&gt; <img alt="图4" src="/files/ftp_upload/4262/4262fig4.jpg" /> 图4。主体的本地皮质空间和时间的的视听演示（在600毫秒的视觉刺激在-600毫秒的听觉刺激）在一个实验范式（注:这将是A"大脑电影"在最后的影片剪辑的电影） <img alt="图5" src="/files/ftp_upload/4262/4262fig5.jpg" /> 图5。主体的本地皮质空间映射到一个假设的投资回报率，后演变到一个共同的皮质空间之间的比较。 <img alt="图6" src="/files/ftp_upload/4262/4262fig6.jpg" /> 图6。写照时空群集与两个实验条件和时间进程蒸发散测试。

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没有利益冲突的声明。

为了估计偶极子从收购MEG / EEG数据上皮层的激活，我们需要解决的一个反问题，没有唯一稳定的解决方案，除非适当的解剖和生理健全的约束应用于。使用的解剖收购个别科目使用MRI和采用的最低标准作为我们的估计准则的约束，我们可以得出逆皮层电流源的估计，同意传感器的测量。这种方法已被证明是有用的研究，不仅听觉处理14，但也有其他领域，如视觉15和语言处理16。 还有许多其他的逆的方法。然而，所有这些方法可归纳为两类:本地化（ 例如 ，等效电流偶极子模型）或影像（ 例如 ，跨国公司，波束赋形技术）。此外，每个逆方法都有其TRAdeoff（见17了深入的讨论）。例如，这里介绍的方法使用的当前估计值必须在空间分布的，由于其最小范数约束。这最低标准估算方法非常适合为皮质的分布式网络招聘的任务。映射的早期反应刺激，唤起重点源的活动，如在试听的双边和听觉皮层（ 例如 ，N1M和意识相关负18），被认为是本地化的，也可以提高使用功能磁共振成像约束14。 谱域分析， 例如 ，调查的作用不同皮层节律参与在注意力，横跨皮层也可使用任何上述的逆技术之后进行。此外，这种类型的分析可以很容易地扩展到地址有关的问题，不同的区域之间的功能连接，在brAIN。

<table border="1"><tbody><tr><td> 设备/软件名称 </td><td> 公司/源 </td><td></td><td></td></tr><tr><td> 306通道Vectorview MEG系统</td><td> Eleka Neuromag有限公司， </td><td></td><td></td></tr><tr><td> 1.5-T的Avanto MRI扫描仪</td><td>西门子医疗解决方案</td><td></td><td></td></tr><tr><td> FreeSurfer </td><td></td><td></td><td> <a href="http://freesurfer.net/" target="_blank">http://freesurfer.net/</a> </td></tr><tr><td>跨国公司软件</td><td></td><td></td><td> <a href="http://www.nmr.mgh.harvard.edu/martinos/userInfo/data/sofMNE.php" target="_blank">http://www.nmr.mgh.harvard.edu/martinos/userInfo/data/sofMNE.php</a> </td></tr><tr><td>脑电图电极</td><td>脑，采集卡有限公司</td><td></td><td></td></tr><tr><td> 3SPACE的FasTrak系统</td><td> Polhemus公司</td><td></td><td></td></tr><tr><td>光按钮盒（FIU-932） </td><td>目前的设计</td><td></td><td></td></tr></tbody></table>

mapping cortical dynamics using simultaneous meg/eeg and anatomically-constrained minimum-norm estimates: an auditory attention example

磁和脑电图（MEG / EEG）的神经影像学技术，提供高时间分辨率，特别适合动态感知和认知能力的任务，如参加一个鸡尾酒会不同的声音在参与调查的皮质神经元网络。许多过去的研究只采用的传感器记录的数据， 即 ，记录外，在头皮上的磁场或电势，并通常集中在活动时间锁定的刺激呈现。这种类型的事件相关领域的/潜在的分析是非常有用的，只有少数不同的偶极模式，可以在时间和空间的分离和鉴定。另外，通过利用解剖信息，这些不同领域的模式可以被本地化为电流源上皮层。然而，对于一个更持久的反应，可能没有时间锁定到一个特定的刺激（ 如 ，准备听之一的两个同时出现的口语线索的听觉特性的基础上的数字），或者可以被分布在多个空间位置未知的先验 ，招募的一个分布式皮质网络可能不会被充分地通过使用有限数量的捕获焦点来源。 在这里，我们描述一个过程，采用个别解剖MRI数据建立的传感器信息和偶极子上皮层的激活，通过使用最小模估计（MNE）之间的关系。这种逆成像方法为我们提供了分布式信源分析工具。为了便于说明，我们将介绍使用FreeSurfer和跨国公司的软件，不管是免费的所有程序。我们将总结MRI序列和分析所需的步骤，以产生正向模型，使我们能够与预期的场模式到M / EEG传感器所造成的偶极子分布在皮层。 NEXT，我们会加强有利于我们在去噪的环境和生理污染物的传感器数据，通过必要的程序。然后，我们将概述的程序，用于组合和的MEG / EEG传感器数据映射到皮层的空间，从而产生皮质偶极激活在脑表面（或"大脑电影"）有关的每个实验条件下的时间序列的家庭。最后，我们将重点介绍一些统计技术，使我们能够在一个受人口（ 即 ，执行组级别分析）基于一个共同的皮质坐标空间科学推断。

Watch this Scientific Journal Video about Mapping Cortical Dynamics Using Simultaneous MEG/EEG and Anatomically-constrained Minimum-norm Estimates: an Auditory Attention Example at JoVE.com

Mapping Cortical Dynamics Using Simultaneous MEG/EEG and Anatomically-constrained Minimum-norm Estimates: an Auditory Attention Example

我们使用磁和脑电图（MEG / EEG），磁共振成像（MRI）拍摄的解剖信息相结合，与听觉注意力的皮质网络的动态映射。

同时MEG / EEG和解剖约束的最小模估计皮质动态映射:听觉注意示例

Magneto- and electroencephalography (MEG/EEG) are neuroimaging techniques that provide a high temporal resolution particularly suitable to investigate the ...

mapping-cortical-dynamics-using-simultaneous-megeeg-anatomically

Nanyang Technological University

Research

JoVE Journal

Neuroscience

14.6K 次观看.  University of Washington. 我们使用磁和脑电图（MEG / EEG），磁共振成像（MRI）拍摄的解剖信息相结合，与听觉注意力的皮质网络的动态映射。

视频: Mapping Cortical Dynamics Using Simultaneous MEG/EEG and Anatomically-constrained Minimum-norm Estimates: an Auditory Attention Example

Functional Mapping with Simultaneous MEG and EEG

We use magnetoencephalography (MEG) and electroencephalography (EEG) to locate and determine the temporal evolution in brain areas involved in the processing of simple sensory stimuli. We will use somatosensory stimuli to locate the hand somatosensory areas, auditory stimuli to locate the auditory cortices, visual stimuli in four quadrants of the visual field to locate the early visual areas. These type of experiments are used for functional mapping in epileptic and brain tumor patients to locate eloquent cortices. In basic neuroscience similar experimental protocols are used to study the orchestration of cortical activity. The acquisition protocol includes quality assurance procedures, subject preparation for the combined MEG/EEG study, and acquisition of evoked-response data with somatosensory, auditory, and visual stimuli. We also demonstrate analysis of the data using the equivalent current dipole model and cortically-constrained minimum-norm estimates. Anatomical MRI data are employed in the analysis for visualization and for deriving boundaries of tissue boundaries for forward modeling and cortical location and orientation constraints for the minimum-norm estimates.

We use magnetoencephalography (MEG) and electroencephalography (EEG) to map brain areas involved in the processing of simple sensory stimuli.

同时脑磁图和脑电图的功能映射

We use magnetoencephalography (MEG) and electroencephalography (EEG) to locate and determine the temporal evolution in brain areas involved in the ...

科研

神经科学

Preparation and Culture of Chicken Auditory Brainstem Slices

The chicken auditory brainstem is a well-established model system that has been widely used to study the anatomy and physiology of auditory processing at discreet periods of development 1-4 as well as mechanisms for temporal coding in the central nervous system 5-7.
Here we present a method to prepare chicken auditory brainstem slices that can be used for acute experimental procedures or to culture organotypic slices for long-term experimental manipulations.
The chicken auditory brainstem is composed of nucleus angularis, magnocellularis, laminaris and superior olive. These nuclei are responsible for binaural sound processing and single coronal slice preparations preserve the entire circuitry. Ultimately, organotypic slice cultures can provide the opportunity to manipulate several developmental parameters such as synaptic activity, expression of pre and postsynaptic components, expression of aspects controlling excitability and differential gene expression
This approach can be used to broaden general knowledge about neural circuit development, refinement and maturation.

The chicken auditory brainstem is comprised of nuclei responsible for binaural sound processing. A single coronal slice preparation maintains the entire circuitry while the cultured approach provides a unique preparation to study the development of neuronal structure and auditory function at the molecular, cellular and network levels.

鸡脑干切片的制备及文化

The chicken auditory brainstem is a well-established model system that has been widely used to study the anatomy and physiology of auditory processing at ...

Recording Human Electrocorticographic (ECoG) Signals for Neuroscientific Research and Real-time Functional Cortical Mapping

Neuroimaging studies of human cognitive, sensory, and motor processes are usually based on noninvasive techniques such as electroencephalography (EEG), magnetoencephalography or functional magnetic-resonance imaging. These techniques have either inherently low temporal or low spatial resolution, and suffer from low signal-to-noise ratio and/or poor high-frequency sensitivity. Thus, they are suboptimal for exploring the short-lived spatio-temporal dynamics of many of the underlying brain processes. In contrast, the invasive technique of electrocorticography (ECoG) provides brain signals that have an exceptionally high signal-to-noise ratio, less susceptibility to artifacts than EEG, and a high spatial and temporal resolution (i.e., &lt;1 cm/&lt;1 millisecond, respectively). ECoG involves measurement of electrical brain signals using electrodes that are implanted subdurally on the surface of the brain. Recent studies have shown that ECoG amplitudes in certain frequency bands carry substantial information about task-related activity, such as motor execution and planning1, auditory processing2 and visual-spatial attention3. Most of this information is captured in the high gamma range (around 70-110 Hz). Thus, gamma activity has been proposed as a robust and general indicator of local cortical function1-5. ECoG can also reveal functional connectivity and resolve finer task-related spatial-temporal dynamics, thereby advancing our understanding of large-scale cortical processes. It has especially proven useful for advancing brain-computer interfacing (BCI) technology for decoding a user's intentions to enhance or improve communication6 and control7. Nevertheless, human ECoG data are often hard to obtain because of the risks and limitations of the invasive procedures involved, and the need to record within the constraints of clinical settings. Still, clinical monitoring to localize epileptic foci offers a unique and valuable opportunity to collect human ECoG data. We describe our methods for collecting recording ECoG, and demonstrate how to use these signals for important real-time applications such as clinical mapping and brain-computer interfacing. Our example uses the BCI2000 software platform8,9 and the SIGFRIED10 method, an application for real-time mapping of brain functions. This procedure yields information that clinicians can subsequently use to guide the complex and laborious process of functional mapping by electrical stimulation.
Prerequisites and Planning:
Patients with drug-resistant partial epilepsy may be candidates for resective surgery of an epileptic focus to minimize the frequency of seizures. Prior to resection, the patients undergo monitoring using subdural electrodes for two purposes: first, to localize the epileptic focus, and second, to identify nearby critical brain areas (i.e., eloquent cortex) where resection could result in long-term functional deficits. To implant electrodes, a craniotomy is performed to open the skull. Then, electrode grids and/or strips are placed on the cortex, usually beneath the dura. A typical grid has a set of 8 x 8 platinum-iridium electrodes of 4 mm diameter (2.3 mm exposed surface) embedded in silicon with an inter-electrode distance of 1cm. A strip typically contains 4 or 6 such electrodes in a single line. The locations for these grids/strips are planned by a team of neurologists and neurosurgeons, and are based on previous EEG monitoring, on a structural MRI of the patient's brain, and on relevant factors of the patient's history. Continuous recording over a period of 5-12 days serves to localize epileptic foci, and electrical stimulation via the implanted electrodes allows clinicians to map eloquent cortex. At the end of the monitoring period, explantation of the electrodes and therapeutic resection are performed together in one procedure.
In addition to its primary clinical purpose, invasive monitoring also provides a unique opportunity to acquire human ECoG data for neuroscientific research. The decision to include a prospective patient in the research is based on the planned location of their electrodes, on the patient's performance scores on neuropsychological assessments, and on their informed consent, which is predicated on their understanding that participation in research is optional and is not related to their treatment. As with all research involving human subjects, the research protocol must be approved by the hospital's institutional review board. The decision to perform individual experimental tasks is made day-by-day, and is contingent on the patient's endurance and willingness to participate. Some or all of the experiments may be prevented by problems with the clinical state of the patient, such as post-operative facial swelling, temporary aphasia, frequent seizures, post-ictal fatigue and confusion, and more general pain or discomfort.
At the Epilepsy Monitoring Unit at Albany Medical Center in Albany, New York, clinical monitoring is implemented around the clock using a 192-channel Nihon-Kohden Neurofax monitoring system. Research recordings are made in collaboration with the Wadsworth Center of the New York State Department of Health in Albany. Signals from the ECoG electrodes are fed simultaneously to the research and the clinical systems via splitter connectors. To ensure that the clinical and research systems do not interfere with each other, the two systems typically use separate grounds. In fact, an epidural strip of electrodes is sometimes implanted to provide a ground for the clinical system. Whether research or clinical recording system, the grounding electrode is chosen to be distant from the predicted epileptic focus and from cortical areas of interest for the research. Our research system consists of eight synchronized 16-channel g.USBamp amplifier/digitizer units (g.tec, Graz, Austria). These were chosen because they are safety-rated and FDA-approved for invasive recordings, they have a very low noise-floor in the high-frequency range in which the signals of interest are found, and they come with an SDK that allows them to be integrated with custom-written research software. In order to capture the high-gamma signal accurately, we acquire signals at 1200Hz sampling rate-considerably higher than that of the typical EEG experiment or that of many clinical monitoring systems. A built-in low-pass filter automatically prevents aliasing of signals higher than the digitizer can capture. The patient's eye gaze is tracked using a monitor with a built-in Tobii T-60 eye-tracking system (Tobii Tech., Stockholm, Sweden). Additional accessories such as joystick, bluetooth Wiimote (Nintendo Co.), data-glove (5th Dimension Technologies), keyboard, microphone, headphones, or video camera are connected depending on the requirements of the particular experiment.
Data collection, stimulus presentation, synchronization with the different input/output accessories, and real-time analysis and visualization are accomplished using our BCI2000 software8,9. BCI2000 is a freely available general-purpose software system for real-time biosignal data acquisition, processing and feedback. It includes an array of pre-built modules that can be flexibly configured for many different purposes, and that can be extended by researchers' own code in C++, MATLAB or Python. BCI2000 consists of four modules that communicate with each other via a network-capable protocol: a Source module that handles the acquisition of brain signals from one of 19 different hardware systems from different manufacturers; a Signal Processing module that extracts relevant ECoG features and translates them into output signals; an Application module that delivers stimuli and feedback to the subject; and the Operator module that provides a graphical interface to the investigator.
A number of different experiments may be conducted with any given patient. The priority of experiments will be determined by the location of the particular patient's electrodes. However, we usually begin our experimentation using the SIGFRIED (SIGnal modeling For Realtime Identification and Event Detection) mapping method, which detects and displays significant task-related activity in real time. The resulting functional map allows us to further tailor subsequent experimental protocols and may also prove as a useful starting point for traditional mapping by electrocortical stimulation (ECS).
Although ECS mapping remains the gold standard for predicting the clinical outcome of resection, the process of ECS mapping is time consuming and also has other problems, such as after-discharges or seizures. Thus, a passive functional mapping technique may prove valuable in providing an initial estimate of the locus of eloquent cortex, which may then be confirmed and refined by ECS. The results from our passive SIGFRIED mapping technique have been shown to exhibit substantial concurrence with the results derived using ECS mapping10.
The protocol described in this paper establishes a general methodology for gathering human ECoG data, before proceeding to illustrate how experiments can be initiated using the BCI2000 software platform. Finally, as a specific example, we describe how to perform passive functional mapping using the BCI2000-based SIGFRIED system.

Recording Human Electrocorticographic ECoG Signals for Neuroscientific Research and Real-time Functional Cortical Mapping

We present a method for collecting electrocorticographic signals for research purposes from humans who are undergoing invasive epilepsy monitoring. We show how to use the BCI2000 software platform for data collection, signal processing and stimulus presentation. Specifically, we demonstrate SIGFRIED, a BCI2000-based tool for real-time functional brain mapping.

神经科学的研究和实时功能皮层映射记录人力Electrocorticographic（ECOG）信号

Neuroimaging studies of human cognitive, sensory, and motor processes are usually based on noninvasive techniques such as electroencephalography (EEG), ...

Functional Imaging of Auditory Cortex in Adult Cats using High-field fMRI

Current knowledge of sensory processing in the mammalian auditory system is mainly derived from electrophysiological studies in a variety of animal models, including monkeys, ferrets, bats, rodents, and cats. In order to draw suitable parallels between human and animal models of auditory function, it is important to establish a bridge between human functional imaging studies and animal electrophysiological studies. Functional magnetic resonance imaging (fMRI) is an established, minimally invasive method of measuring broad patterns of hemodynamic activity across different regions of the cerebral cortex. This technique is widely used to probe sensory function in the human brain, is a useful tool in linking studies of auditory processing in both humans and animals and has been successfully used to investigate auditory function in monkeys and rodents. The following protocol describes an experimental procedure for investigating auditory function in anesthetized adult cats by measuring stimulus-evoked hemodynamic changes in auditory cortex using fMRI. This method facilitates comparison of the hemodynamic responses across different models of auditory function thus leading to a better understanding of species-independent features of the mammalian auditory cortex.

Functional studies of the auditory system in mammals have traditionally been conducted using spatially-focused techniques such as electrophysiological recordings. The following protocol describes a method of visualizing large-scale patterns of evoked hemodynamic activity in the cat auditory cortex using functional magnetic resonance imaging.

听觉皮层在成年猫用高场磁共振成像功能成像

Current knowledge of sensory processing in the mammalian auditory system is mainly derived from electrophysiological studies in a variety of animal ...

Optogenetic Stimulation of the Auditory Nerve

Direct electrical stimulation of spiral ganglion neurons (SGNs) by cochlear implants (CIs) enables open speech comprehension in the majority of implanted deaf subjects1-6. Nonetheless, sound coding with current CIs has poor frequency and intensity resolution due to broad current spread from each electrode contact activating a large number of SGNs along the tonotopic axis of the cochlea7-9. Optical stimulation is proposed as an alternative to electrical stimulation that promises spatially more confined activation of SGNs and, hence, higher frequency resolution of coding. In recent years, direct infrared illumination of&#160;the cochlea has been used to evoke responses in the auditory nerve10. Nevertheless it requires higher energies than electrical stimulation10,11 and uncertainty remains as to the underlying mechanism12. Here we describe a method based on optogenetics to stimulate SGNs with low intensity blue light, using transgenic mice with neuronal expression of channelrhodopsin 2 (ChR2)13 or virus-mediated expression of the ChR2-variant CatCh14. We used micro-light emitting diodes (&#181;LEDs) and fiber-coupled lasers to stimulate ChR2-expressing SGNs through a small artificial opening (cochleostomy) or the round window. We assayed the responses by scalp recordings of light-evoked potentials (optogenetic auditory brainstem response: oABR) or by microelectrode recordings from the auditory pathway and compared them with acoustic and electrical stimulation.

Cochlear implants (CIs) enable hearing by direct electrical stimulation of the auditory nerve. However, poor frequency and intensity resolution limits the quality of hearing with CIs. Here we describe optogenetic stimulation of the auditory nerve in mice as an alternative strategy for auditory research and developing future CIs.

听觉神经的光遗传学刺激

Direct electrical stimulation of spiral ganglion neurons (SGNs) by cochlear implants (CIs) enables open speech comprehension in the majority of implanted ...

Real-time Electrophysiology: Using Closed-loop Protocols to Probe Neuronal Dynamics and Beyond

Experimental neuroscience is witnessing an increased interest in the development and application of novel and often complex, closed-loop protocols, where the stimulus applied depends in real-time on the response of the system. Recent applications range from the implementation of virtual reality systems for studying motor responses both in mice1 and in zebrafish2, to control of seizures following cortical stroke using optogenetics3. A key advantage of closed-loop techniques resides in the capability of probing higher dimensional properties that are not directly accessible or that depend on multiple variables, such as neuronal excitability4 and reliability, while at the same time maximizing the experimental throughput. In this contribution and in the context of cellular electrophysiology, we describe how to apply a variety of closed-loop protocols to the study of the response properties of pyramidal cortical neurons, recorded intracellularly with the patch clamp technique in acute brain slices from the somatosensory cortex of juvenile rats. As no commercially available or open source software provides all the features required for efficiently performing the experiments described here, a new software toolbox called LCG5 was developed, whose modular structure maximizes reuse of computer code and facilitates the implementation of novel experimental paradigms. Stimulation waveforms are specified using a compact meta-description and full experimental protocols are described in text-based configuration files. Additionally, LCG has a command-line interface that is suited for repetition of trials and automation of experimental protocols.

Closed-loop protocols are becoming increasingly widespread in modern day electrophysiology. We present a simple, versatile and inexpensive way to perform complex electrophysiological protocols in cortical pyramidal neurons in vitro, using a desktop computer and a digital acquisition board.

实时电:采用闭环协议来探测神经动力学和超越

Experimental neuroscience is witnessing an increased interest in the development and application of novel and often complex, closed-loop protocols, where ...

Touchscreen Sustained Attention Task (SAT) for Rats

Sustained attention is the ability to monitor intermittent and unpredictable events over a prolonged period of time. This attentional process subserves other aspects of cognition and is disrupted in certain neurodevelopmental, neuropsychiatric, and neurodegenerative disorders. Thus, it is clinically important to identify mechanisms that impair and improve sustained attention. Such mechanisms are often first discovered using rodent models. Therefore, several behavior procedures for testing aspects of sustained attention have been developed for rodents. One, first described by McGaughy and Sarter (1995), called the sustained attention task (SAT), trains rats to distinguish between signal (i.e., brief light presentation) and non-signal trials. The signals are short and thus require careful attention to be perceived. Attentional demands can be increased further by introducing a distractor (e.g., flashing houselight). We have modified this task for touchscreen operant chambers, which are configured with a touchscreen on one wall that can present stimuli and record responses. Here we detail our protocol for SAT in touchscreen chambers. Additionally, we present standard measures of performance in male and female Sprague-Dawley rats. Comparable performance on this task in both sexes highlights its use for attention studies, especially as more researchers are including female rodents in their experimental design. Moreover, the easy implementation of SAT for the increasingly popular touchscreen chambers increases its utility.

Touchscreen Sustained Attention Task SAT for Rats

Sustained attention, or continuously monitoring situations for intermittent and unpredictable events, is a critical aspect of cognition. Here we detail how to test sustained attention in rats using touchscreen operant chambers. We demonstrate comparable performance in male and female rats, making this task useful for studying attention in both sexes.

触摸屏持续注意任务 (SAT) 大鼠

Sustained attention is the ability to monitor intermittent and unpredictable events over a prolonged period of time. This attentional process subserves ...

Simultaneous Recordings of Cortical Local Field Potentials, Electrocardiogram, Electromyogram, and Breathing Rhythm from a Freely Moving Rat

Monitoring the physiological dynamics of the brain and peripheral tissues is necessary for addressing a number of questions about how the brain controls body functions and internal organ rhythms when animals are exposed to emotional challenges and changes in their living environments. In general experiments, signals from different organs, such as the brain and the heart, are recorded by independent recording systems that require multiple recording devices and different procedures for processing the data files. This study describes a new method that can simultaneously monitor electrical biosignals, including tens of local field potentials in multiple brain regions, electrocardiograms that represent the cardiac rhythm, electromyograms that represent awake/sleep-related muscle contraction, and breathing signals, in a freely moving rat. The recording configuration of this method is based on a conventional micro-drive array for cortical local field potential recordings in which tens of electrodes are accommodated, and the signals obtained from these electrodes are integrated into a single electrical board mounted on the animal's head. Here, this recording system was improved so that signals from the peripheral organs are also transferred to an electrical interface board. In a single surgery, electrodes are first separately implanted into the appropriate body parts and the target brain areas. The open ends of all of these electrodes are then soldered to individual channels of the electrical board above the animal's head so that all of the signals can be integrated into the single electrical board. Connecting this board to a recording device allows for the collection of all of the signals into a single device, which reduces experimental costs and simplifies data processing, because all data can be handled in the same data file. This technique will aid the understanding of the neurophysiological correlates of the associations between central and peripheral organs.

This study introduces a method for the simultaneous recording of local field potentials in the brain, electrocardiograms, electromyograms, and breathing signals of a freely moving rat. This technique, which reduces experimental costs and simplifies data analysis, will contribute to the understanding of the interactions between the brain and peripheral organs.

自由运动大鼠皮质局部电位、心电图、肌电图和呼吸节律的同步记录

Monitoring the physiological dynamics of the brain and peripheral tissues is necessary for addressing a number of questions about how the brain controls ...

Visualization of Motor Axon Navigation and Quantification of Axon Arborization In Mouse Embryos Using Light Sheet Fluorescence Microscopy

Spinal motor neurons (MNs) extend their axons to communicate with their innervating targets, thereby controlling movement and complex tasks in vertebrates. Thus, it is critical to uncover the molecular mechanisms of how motor axons navigate to, arborize, and innervate their peripheral muscle targets during development and degeneration. Although transgenic Hb9::GFP mouse lines have long served to visualize motor axon trajectories during embryonic development, detailed descriptions of the full spectrum of axon terminal arborization remain incomplete due to the pattern complexity and limitations of current optical microscopy. Here, we describe an improved protocol that combines light sheet fluorescence microscopy (LSFM) and robust image analysis to qualitatively and quantitatively visualize developing motor axons. This system can be easily adopted to cross genetic mutants or MN disease models with Hb9::GFP lines, revealing novel molecular mechanisms that lead to defects in motor axon navigation and arborization.

Here, we describe a protocol for visualizing motor neuron projection and axon arborization in transgenic Hb9::GFP mouse embryos. After immunostaining for motor neurons, we used light sheet fluorescence microscopy to image embryos for subsequent quantitative analysis. This protocol is applicable to other neuron navigation processes in the central nervous system.

用光片荧光显微镜观察运动轴突导航和小鼠胚轴突树枝状的定量化

Spinal motor neurons (MNs) extend their axons to communicate with their innervating targets, thereby controlling movement and complex tasks in ...

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, ...