Abstract：
Norepinephrine (NE) is an essential biogenic monoamine neurotransmitter. The first-generation NE sensor makes in vivo, real-time, cell-type-specific and region-specific NE detection possible, but its low NE sensitivity limits its utility. Here, we developed the second-generation GPCR-activation-based NE sensors (GRABNE2m and GRABNE2h) with a superior response and high sensitivity and selectivity to NE both in vitro and in vivo. Notably, these sensors can detect NE release triggered by either optogenetic or behavioral stimuli in freely moving mice, producing robust signals in the locus coeruleus and hypothalamus. With the development of a novel transgenic mouse line, we recorded both NE release and calcium dynamics with dual-color fiber photometry throughout the sleep-wake cycle; moreover, dual-color mesoscopic imaging revealed cell-type-specific spatiotemporal dynamics of NE and calcium during sensory processing and locomotion. Thus, these new GRABNE sensors are valuable tools for monitoring the precise spatiotemporal release of NE in vivo, providing new insights into the physiological and pathophysiological roles of NE.
摘要：
去甲肾上腺素(NE)是一种必需的生物单胺神经递质。第一代NE传感器使体内，实时,细胞类型特异性和区域特异性NE检测可能，但它的低NE灵敏度限制了它的实用性。这里,我们开发了第二代基于GPCR激活的NE传感器（GRABNE2m和GRABNE2h），在体外和体内均具有出色的响应性以及对NE的高灵敏度和选择性。值得注意的是,这些传感器可以检测由光遗传学或行为刺激在自由移动的小鼠中触发的NE释放，在蓝斑和下丘脑产生强大的信号。随着新型转基因小鼠品系的发展,我们用双色纤维光度法记录了整个睡眠-觉醒周期的NE释放和钙动力学；双色介观成像显示了感觉处理和运动过程中NE和钙的细胞类型特异性时空动力学。因此，这些新的GRABNE传感器是监测NE在体内的精确时空释放的有价值的工具，为NE的生理和病理生理作用提供新的见解。
