The ability to directly measure acetylcholine (ACh) release is an essential step toward understanding its physiological function. Here we optimized the GRAB_ACh (GPCR-activation-based ACh) sensor to achieve substantially improved sensitivity in ACh detection, as well as reduced downstream coupling to intracellular pathways. The improved version of the ACh sensor retains the subsecond response kinetics, physiologically relevant affinity and precise molecular specificity for ACh of its predecessor. Using this sensor, we revealed compartmental ACh signals in the olfactory center of transgenic flies in response to external stimuli including odor and body shock. Using fiber photometry recording and two-photon imaging, our ACh sensor also enabled sensitive detection of single-trial ACh dynamics in multiple brain regions in mice performing a variety of behaviors.

直接测量乙酰胆碱 (ACh) 释放的能力是了解其生理功能的重要一步。在这里我们优化了 GRAB _ACh（基于 GPCR 激活的 ACh）传感器可显着提高 ACh 检测的灵敏度，并减少下游与细胞内通路的耦合。ACh 传感器的改进版本保留了其前身 ACh 的亚秒级响应动力学、生理学相关的亲和力和精确的分子特异性。使用该传感器，我们揭示了转基因果蝇嗅觉中心的区室 ACh 信号，以响应包括气味和身体休克在内的外部刺激。使用光纤光度记录和双光子成像，我们的 ACh 传感器还能够灵敏检测执行各种行为的小鼠多个大脑区域的单次试验 ACh 动力学。