In vivo visualization of single-unit recording sites using MRI-detectable elgiloy deposit marking
In vivo visualization of single-unit recording sites using MRI-detectable elgiloy deposit marking
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DOI：
10.1152/jn.00358.2010
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发表时间：
2011-03-01
影响因子：
2.5
通讯作者：
Miyashita, Yasushi
中科院分区：
文献类型：
--
作者：
Koyano, Kenji W.;Machino, Akinori;Miyashita, Yasushi
Koyano KW，Machino A，Takeda M，Matsui T，Fujimichi R，Ohashi Y，Miyashita Y。使用MRI可检测的Elgiloy沉积标记对单一单元记录位置的活体可视化。神经生理学杂志105：1380-1392,2011。2010年12月1日首次出版；DOI：10.1152/jn.00358.2010。-对单个神经元活动的精确定位阐明了灵长类大脑皮质的功能结构，与垂直堆叠的层和水平排列的柱相关。传统的定位记录神经元的“金标准”方法是对记录部位的电解性损伤标记进行组织学检查。虽然这种方法可以通过精细的神经解剖学定位记录的神经元，但由于需要进行死后分析，因此不能用于长期的慢性实验。为了定位记录到的单个神经元在体内的位置，我们引入了MRI可检测的Elgiloy沉积标记，它可以通过电解Elgiloy微电极尖端产生并在高对比度磁共振(MR)图像上可视化。组织学分析证实，沉积标记中心可以相对于活体神经解剖学以单像素精度定位，平面分辨率为200微米。为了展示该技术的实际应用，我们记录了执行认知任务的猴子的单个神经元活动，并使用沉积标记在体内进行定位(沉积：2 mA，3分钟；扫描：快速自旋回波序列，分辨率为0.15 x 0.15 x 0.8 mm(3)，回声时间/重复时间为120/4,500 ms，回声序列长度为8)，通常使用电解损伤标记的传统尸检方法进行。两种定位方法被证明：1)微电极轨迹内的沉积标记被用来直接在MR图像上重建沿该轨迹记录的12个神经元位置；2)结合X射线成像可以在MR图像上估计数百个神经元位置。这种新的体内方法对于非人类灵长类动物的慢性实验是可行的，能够分析认知过程背后的大脑皮层的功能结构。
Koyano KW, Machino A, Takeda M, Matsui T, Fujimichi R, Ohashi Y, Miyashita Y. In vivo visualization of single-unit recording sites using MRI-detectable elgiloy deposit marking. J Neurophysiol 105: 1380-1392, 2011. First published December 1, 2010; doi:10.1152/jn.00358.2010.-Precise localization of single-neuron activity has elucidated functional architectures of the primate cerebral cortex, related to vertically stacked layers and horizontally aligned columns. The traditional "gold standard" method for localizing recorded neuron is histological examination of electrolytic lesion marks at recording sites. Although this method can localize recorded neurons with fine neuroanatomy, the necessity for postmortem analysis prohibits its use in long-term chronic experiments. To localize recorded single-neuron positions in vivo, we introduced MRI-detectable elgiloy deposit marks, which can be created by electrolysis of an elgiloy microelectrode tip and visualized on highly contrasted magnetic resonance (MR) images. Histological analysis validated that the deposit mark centers could be localized relative to neuroanatomy in vivo with single-voxel accuracy, at an in-plane resolution of 200 mu m. To demonstrate practical applications of the technique, we recorded single-neuron activity from a monkey performing a cognitive task and localized it in vivo using deposit marks (deposition: 2 mu A for 3 min; scanning: fast-spin-echo sequence with 0.15 x 0.15 x 0.8 mm(3) resolution, 120/4,500 ms of echo-time/repetition-time and 8 echo-train-length), as is usually performed with conventional postmortem methods using electrolytic lesion marks. Two localization procedures were demonstrated: 1) deposit marks within a microelectrode track were used to reconstruct a dozen recorded neuron positions along the track directly on MR images; 2) combination with X-ray imaging allowed estimation of hundreds of neuron positions on MR images. This new in vivo method is feasible for chronic experiments with nonhuman primates, enabling analysis of the functional architecture of the cerebral cortex underlying cognitive processes.