Yogesh Baba, Heindorf Matthias, Jordan Rebecca, Keller Georg B
Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland.
Faculty of Natural Sciences, University of Basel, Basel, Switzerland.
Elife. 2025 May 28;14:RP104914. doi: 10.7554/eLife.104914.
The last few years have seen an explosion in the number of tools available to measure neuronal activity using fluorescence imaging (Chen et al., 2013; Feng et al., 2019; Jing et al., 2019; Sun et al., 2018; Wan et al., 2021). When performed in vivo, these measurements are invariably contaminated by hemodynamic occlusion artifacts. In widefield calcium imaging, this problem is well recognized. For two-photon imaging, however, the effects of hemodynamic occlusion have only been sparsely characterized. Here, we perform a quantification of hemodynamic occlusion effects using measurements of fluorescence changes observed with GFP expression using both widefield and two-photon imaging in mouse cortex. We find that in many instances the magnitude of signal changes attributable to hemodynamic occlusion is comparable to that observed with activity sensors. Moreover, we find that hemodynamic occlusion effects were spatially heterogeneous, both over cortical regions and across cortical depth, and exhibited a complex relationship with behavior. Thus, hemodynamic occlusion is an important caveat to consider when analyzing and interpreting not just widefield but also two-photon imaging data.
在过去几年中，利用荧光成像来测量神经元活动的工具数量呈爆发式增长（Chen等人，2013年；Feng等人，2019年；Jing等人，2019年；Sun等人，2018年；Wan等人，2021年）。在活体中进行这些测量时，这些测量结果总是会受到血流动力学阻塞伪影的干扰。在宽场钙成像中，这个问题已得到充分认识。然而，对于双光子成像，血流动力学阻塞的影响仅得到了很少的表征。在这里，我们通过在小鼠皮层中使用宽场和双光子成像对绿色荧光蛋白（GFP）表达所观察到的荧光变化进行测量，来量化血流动力学阻塞的影响。我们发现，在许多情况下，由血流动力学阻塞引起的信号变化幅度与活动传感器所观察到的相当。此外，我们发现血流动力学阻塞效应在空间上是异质的，无论是在皮层区域还是在皮层深度上都是如此，并且与行为表现出复杂的关系。因此，在分析和解释不仅是宽场而且还有双光子成像数据时，血流动力学阻塞都是一个需要考虑的重要注意事项。
