From the Department of Cellular and Molecular Physiology, Yale University, New Haven, Connecticut 06520-8026.
From the Department of Cellular and Molecular Physiology, Yale University, New Haven, Connecticut 06520-8026
J Biol Chem. 2014 May 30;289(22):15441-8. doi: 10.1074/jbc.M114.550012. Epub 2014 Apr 11.
Protons activate acid-sensing ion channel 1a (ASIC1a) in the central nervous system (CNS) although the impact of such activation on brain outputs remains elusive. Progress elucidating the functional roles of ASIC1a in the CNS has been hindered by technical difficulties of achieving acidification with spatial and temporal precision. We have implemented a method to control optically the opening of ASIC1a in brain slices and also in awake animals. The light-driven H(+) pump ArchT was expressed in astrocytes of mouse cortex by injection of adenoviral vectors containing a strong and astrocyte-specific promoter. Illumination with amber light acidified the surrounding interstitium and led to activation of endogenous ASIC1a channels and firing of action potentials in neurons localized in close proximity to ArchT-expressing astrocytes. We conclude that this optogenetic method offers a minimally invasive approach that enables examining the biological consequences of ASIC1a currents in any structure of the CNS and in the modulation of animal behaviors.
质子在中枢神经系统 (CNS) 中激活酸感应离子通道 1a（ASIC1a），尽管这种激活对大脑输出的影响仍不清楚。阐明 ASIC1a 在中枢神经系统中的功能作用的进展受到实现酸精确时空酸化的技术困难的阻碍。我们已经实施了一种方法来控制脑切片和清醒动物中 ASIC1a 的光学打开。通过注射含有强和星形胶质细胞特异性启动子的腺病毒载体，在小鼠皮层中的星形胶质细胞中表达光驱动 H(+)泵 ArchT。用琥珀光照射使周围间质酸化，导致内源性 ASIC1a 通道激活，并导致位于与表达 ArchT 的星形胶质细胞紧密接近的神经元中产生动作电位。我们得出结论，这种光遗传学方法提供了一种微创方法，可用于研究 CNS 中任何结构中 ASIC1a 电流的生物学后果以及动物行为的调节。
