Assessing functional connectivity across 3D tissue engineered axonal tracts using calcium fluorescence imaging.
Assessing functional connectivity across 3D tissue engineered axonal tracts using calcium fluorescence imaging.
复制标题
DOI：
10.1088/1741-2552/aac96d
复制
发表时间：
2018-10
影响因子：
4
通讯作者：
Cullen DK
中科院分区：
文献类型：
--
作者：
Dhobale AV;Adewole DO;Chan AHW;Marinov T;Serruya MD;Kraft RH;Cullen DK
微组织工程神经网络(Micro-Tenns)是一种受解剖学启发的结构，旨在从结构和功能上模拟大脑中的白质通路。这些三维神经网络的特点是长轴索横跨管状水凝胶中包含的离散神经元群体，正在被开发用于重建大脑中受损的轴突路径，以及作为与生理相关的体外实验平台。当前研究的目标是描述这些神经元和轴突网络的功能特性。双向微TEN被转导来表达遗传编码的钙指示物，并使用实时显微镜在20赫兹下记录神经元群体中特定感兴趣区域的自发荧光活动。然后，使用统计学和信息论中的各种技术，包括皮尔逊互相关、相位同步矩阵、功率谱分析、定向传递函数和传递熵，来评估轴突束上的网络活动模式和功能连通性。皮尔逊互相关、相位同步矩阵和功率谱分析表明，通过轴索连接的空间分离的神经元簇之间具有很高的相关性和同步性。具体地说，相位同步显示感兴趣的微Tenn区域之间的>；0.8高度同步。归一化有向传递函数和传递熵矩阵表明，在2-5赫兹的频率上，神经元群体之间存在着稳健的信息流。时变功率谱分析揭示了不同频率下信息传播的强度。在优势的Delta(1-4 HZ)和Theta(4-8 HZ)频段，信号功率强度在峰值升高时可见，而在较高频率时逐渐减弱。这些信号功率强度结果与归一化直接传递函数分析非常匹配，其中在2至5赫兹的频率之间检测到接近同步的信息流。据我们所知，这是首次使用基于荧光钙活性的定向传递函数和传递熵方法，通过长投射的三维轴突束来估计不同神经元群体的功能连通性。这些功能数据将进一步改进可植入神经网络的设计和优化，最终可用于重建神经系统，以治疗神经疾病和损伤。
Micro-Tissue Engineered Neural Networks (micro-TENNs) are anatomically-inspired constructs designed to structurally and functionally emulate white matter pathways in the brain. These three-dimensional neural networks feature long axonal tracts spanning discrete neuronal populations contained within a tubular hydrogel, and are being developed to reconstruct damaged axonal pathways in the brain as well as to serve as physiologically-relevant in vitro experimental platforms. The goal of the current study was to characterize the functional properties of these neuronal and axonal networks. Bidirectional micro-TENNs were transduced to express genetically-encoded calcium indicators, and spontaneous fluorescence activity was recorded using real-time microscopy at 20 Hz from specific regions-of-interest in the neuronal populations. Network activity patterns and functional connectivity across the axonal tracts were then assessed using various techniques from statistics and information theory including Pearson cross-correlation, phase synchronization matrices, power spectral analysis, directed transfer function, and transfer entropy. Pearson cross-correlation, phase synchronization matrices, and power spectral analysis revealed high values of correlation and synchronicity between the spatially segregated neuronal clusters connected by axonal tracts. Specifically, phase synchronization revealed high synchronicity of >0.8 between micro-TENN regions of interest. Normalized directed transfer function and transfer entropy matrices suggested robust information flow between the neuronal populations over frequencies of 2–5 Hz. Time varying power spectrum analysis revealed the strength of information propagation at various frequencies. Signal power strength was visible at elevated peak levels for dominant delta (1–4Hz) and theta (4–8Hz) frequency bands and progressively weakened at higher frequencies. These signal power strength results closely matched normalized directed transfer function analysis where near synchronous information flow was detected between frequencies of 2 to 5Hz. To our knowledge, this is the first report using directed transfer function and transfer entropy methods based on fluorescent calcium activity to estimate functional connectivity of distinct neuronal populations via long-projecting, three-dimensional axonal tracts. These functional data will further improve the design and optimization of implantable neural networks that could ultimately be deployed to reconstruct the nervous system to treat neurological disease and injury.
登录
查看更多内容
影响因子：
9.2
作者：
Dai, Ji;Brooks, Daniel I.;Sheinberg, David L.
通讯作者：
Sheinberg, David L.
影响因子：
--
作者：
Adewole DO;Serruya MD;Harris JP;Burrell JC;Petrov D;Chen HI;Wolf JA;Cullen DK
通讯作者：
Cullen DK
影响因子：
3
作者：
Bastos AM;Schoffelen JM
通讯作者：
Schoffelen JM
DOI：
10.1109/tnsre.2014.2341632
发表时间：
2015-05-01
影响因子：
4.9
作者：
Fallani, Fabrizio De Vico;Corazzol, Martina;Chavez, Mario
通讯作者：
Chavez, Mario
影响因子：
16.2
作者：
Grienberger, Christine;Konnerth, Arthur
通讯作者：
Konnerth, Arthur