Light activation of channelrhodopsin-2 in excitable cells of Caenorhabditis elegans triggers rapid Behavioral responses
Light activation of channelrhodopsin-2 in excitable cells of Caenorhabditis elegans triggers rapid Behavioral responses
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DOI：
10.1016/j.cub.2005.11.032
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发表时间：
2005-12-20
期刊：
影响因子：
9.2
通讯作者：
Gottschalk, A
中科院分区：
文献类型：
--
作者：
Nagel, G;Brauner, M;Gottschalk, A
为了研究特定神经元在其原生回路中的功能，需要精确控制它们的活动。这通常需要解剖以实现精确的电刺激[1]或神经递质施加[2]，因此在活体动物中，特别是在小型模式生物中，这本身就很困难。在此，我们在线虫秀丽隐杆线虫的可兴奋细胞中使用了来自绿藻莱茵衣藻的光敏感通道蛋白 - 2（ChR2），仅通过光照就能触发特定行为。光敏感通道蛋白[3,4]是一种7次跨膜螺旋蛋白，类似于光驱动质子泵细菌视紫红质[5]，它们也利用生色团全反式视黄醛，但用于打开一个内在的阳离子通道。在肌肉细胞中，光激活的ChR2引发强烈的同步收缩，在突变的L型电压门控Ca²⁺通道（VGCCs）和兰尼碱受体（RyRs）的背景下收缩减弱。电生理分析表明，只要有光照就会持续存在快速的内向电流。当ChR2在机械感觉神经元中表达时，光照会引发通常由机械刺激引起的退缩行为。此外，在缺乏MEC - 4/MEC - 10机械感觉离子通道[6]的突变体中，ChR2使这些神经元能够活动。因此，在活体且有行为的动物以及解剖后的动物中，表达ChR2的特定神经元或肌肉可以通过光照快速且可逆地被激活。
For studying the function of specific neurons in their native circuitry, it is desired to precisely control their activity. This often requires dissection to allow accurate electrical stimulation [1] or neurotransmitter application [2], and it is thus inherently difficult in live animals, especially in small model organisms. Here, we employed channelrhodopsin-2 (ChR2), a directly light-gated cation channel from the green alga Chlamydomonas reinhardtii [3], in excitable cells of the nematode Caenorhabditis elegans, to trigger specific behaviors, simply by illumination. Channelrhodopsins [3, 4] are 7-transmembrane-helix proteins that resemble the light-driven proton pump bacteriorhodopsin [5], and they also utilize the chromophore all-trans retinal, but to open an intrinsic cation pore. In muscle cells, light-activated ChR2 evoked strong, simultaneous contractions, which were reduced in the background of mutated L-type, voltage-gated Ca2+-channels (VGCCs) and ryanodine receptors (RyRs). Electrophysiological analysis demonstrated rapid inward currents that persisted as long as the illumination. When ChR2 was expressed in mechanosensory neurons, light evoked withdrawal behaviors that are normally elicited by mechanical stimulation. Furthermore, ChR2 enabled activity of these neurons in mutants lacking the MEC-4/MEC-10 mechanosensory ion channel [6]. Thus, specific neurons or muscles expressing ChR2 can be quickly and reversibly activated by light in live and behaving, as well as dissected, animals.