We employ transcranial wide-field single-photon imaging to compare genetically encoded calcium sensors under transgenic or viral vector expression strategies. Awake, head-fixed animals and brief visual flash stimuli are used to assess function. The use of awake transcranial imaging may reduce confounds attributed to cranial window implantation or anesthesia states. We report differences in wide-field epifluorescence brightness and peak Δ F / F 0 response to visual stimulation between expression strategies. Other metrics for indicator performance include fluctuation analysis (standard deviation) and regional correlation maps made from spontaneous activity. We suggest that multiple measures, such as stimulus-evoked signal-to-noise ratio, brightness, and averaged visual Δ F / F 0 response, may be necessary to characterize indicator sensitivity and methods of expression. Furthermore, we show that strategies using blood brain barrier-permeable viruses, such as PHP.eB, yield comparable expression and function as those derived from transgenic mice. We suggest that testing of new genetically engineered activity sensors could employ a single-photon, wide-field imaging pipeline involving visual stimulation in awake mice that have been intravenously injected with PHP.eB.

中文翻译：

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使用脑活动的体内广域功能成像比较转基因和AAV-PHP.eB介导的GCaMP6s表达。

我们采用经颅大视野单光子成像技术来比较转基因或病毒载体表达策略下的遗传编码钙传感器。清醒，固定头部的动物和短暂的视觉闪光刺激用于评估功能。清醒的经颅影像学检查可减少因颅窗植入或麻醉状态引起的混淆。我们报告表达策略之间的视觉刺激在宽视野落射荧光亮度和峰值ΔF / F 0的差异。指标绩效的其他指标包括波动分析（标准差）和由自发活动绘制的区域相关图。我们建议采用多种措施，例如刺激诱发的信噪比，亮度和平均视觉ΔF / F 0响应，表征指标敏感性和表达方法可能是必要的。此外，我们表明使用血脑屏障可渗透病毒（例如PHP.eB）的策略产生的表达和功能与衍生自转基因小鼠的表达和功能相当。我们建议对新的基因工程活动传感器的测试可以采用单光子，广域成像管道，其中涉及在静脉内注射PHP.eB的清醒小鼠中的视觉刺激。