Separation of hemodynamic signals from GCaMP fluorescence measured with wide-field imaging
Separation of hemodynamic signals from GCaMP fluorescence measured with wide-field imaging
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DOI：
10.1152/jn.00304.2019
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发表时间：
2020-01-01
影响因子：
2.5
通讯作者：
Reimers, M.
中科院分区：
文献类型：
--
作者：
Valley, M. T.;Moore, M. G.;Reimers, M.
宽视野钙成像通常用于测量行为小鼠的脑动力学。凭借大视野和高采样率，宽场成像可以同时监测几个遥远的皮层区域的活动，揭示皮层的相互作用。然而，由于血红蛋白对光的吸收，宽视场图像的解释是复杂的，这可以显著地影响所测量的荧光。分离血流动力学和钙信号的一种方法是使用多波长反向散射记录来测量血红蛋白的光吸收。根据这种方法，我们开发了一种基于空间详细回归的方法来估计血液动力学。该空间模型基于Beer-Lambert关系的线性形式，但适合图像中的每个像素，并且不依赖于物理参数的估计。在清醒的三个转基因系小鼠中，空间模型提供了改善的血流动力学和GCaMP荧光变化的分离。这种改善是显着的血管附近，并与比尔-兰伯特方程，可以删除血管伪影沿着矢状中线，并在一般情况下允许更准确的基于荧光的确定神经元的活动在整个cortex.NEW & NOTEWORTHY本文讨论了一个众所周知的和强大的污染源在宽场钙成像数据：血流动力学。为了指导研究人员找到将钙信号与血流动力学分离的最佳方法，我们在三种常用的小鼠品系中比较了几种方法的性能，并提出了一种新的回归模型，该模型优于我们考虑的其他技术。
Wide-field calcium imaging is often used to measure brain dynamics in behaving mice. With a large field of view and a high sampling rate, wide-field imaging can monitor activity from several distant cortical areas simultaneously, revealing cortical interactions. Interpretation of wide-field images is complicated, however, by the absorption of light by hemoglobin, which can substantially affect the measured fluorescence. One approach to separating hemodynamics and calcium signals is to use multiwavelength backscatter recordings to measure light absorption by hemoglobin. Following this approach, we develop a spatially detailed regression-based method to estimate hemodynamics. This Spatial Model is based on a linear form of the Beer-Lambert relationship but is fit at every pixel in the image and does not rely on the estimation of physical parameters. In awake mice of three transgenic lines, the Spatial Model offers improved separation of hemodynamics and changes in GCaMP fluorescence. The improvement is pronounced near blood vessels and, in contrast with the Beer-Lambert equations, can remove vascular artifacts along the sagittal midline and in general permits more accurate fluorescence-based determination of neuronal activity across the cortex.NEW & NOTEWORTHY This paper addresses a well-known and strong source of contamination in wide-field calcium-imaging data: hemodynamics. To guide researchers toward the best method to separate calcium signals from hemodynamics, we compare the performance of several methods in three commonly used mouse lines and present a novel regression model that outperforms the other techniques we consider.