Dawydow Alexej, Gueta Ronnie, Ljaschenko Dmitrij, Ullrich Sybille, Hermann Moritz, Ehmann Nadine, Gao Shiqiang, Fiala André, Langenhan Tobias, Nagel Georg, Kittel Robert J
Department of Neurophysiology, Institute of Physiology, Julius-Maximilians-University of Würzburg, D-97070 Würzburg, Germany;
Institute for Molecular Plant Physiology and Biophysics, Biocenter, Julius-Maximilians-University of Würzburg, D-97082 Würzburg, Germany; and.
Proc Natl Acad Sci U S A. 2014 Sep 23;111(38):13972-7. doi: 10.1073/pnas.1408269111. Epub 2014 Sep 8.
Channelrhodopsin-2 (ChR2) has provided a breakthrough for the optogenetic control of neuronal activity. In adult Drosophila melanogaster, however, its applications are severely constrained. This limitation in a powerful model system has curtailed unfolding the full potential of ChR2 for behavioral neuroscience. Here, we describe the D156C mutant, termed ChR2-XXL (extra high expression and long open state), which displays increased expression, improved subcellular localization, elevated retinal affinity, an extended open-state lifetime, and photocurrent amplitudes greatly exceeding those of all heretofore published ChR variants. As a result, neuronal activity could be efficiently evoked with ambient light and even without retinal supplementation. We validated the benefits of the variant in intact flies by eliciting simple and complex behaviors. We demonstrate efficient and prolonged photostimulation of monosynaptic transmission at the neuromuscular junction and reliable activation of a gustatory reflex pathway. Innate male courtship was triggered in male and female flies, and olfactory memories were written through light-induced associative training.
通道视紫红质-2（ChR2）为神经元活动的光遗传学控制带来了突破。然而，在成年黑腹果蝇中，其应用受到严重限制。在这个强大的模型系统中的这一局限性，限制了ChR2在行为神经科学中充分发挥其潜力。在这里，我们描述了D156C突变体，称为ChR2-XXL（超高表达和长开放状态），它表现出表达增加、亚细胞定位改善、视网膜亲和力提高、开放状态寿命延长以及光电流幅度大大超过迄今所有已发表的ChR变体。因此，即使在没有视网膜补充的情况下，也可以用环境光有效诱发神经元活动。我们通过引发简单和复杂行为，在完整果蝇中验证了该变体的优势。我们证明了在神经肌肉接头处对单突触传递进行高效且持久的光刺激，以及对味觉反射通路的可靠激活。在雄性和雌性果蝇中引发了先天性求偶行为，并通过光诱导的联想训练写入了嗅觉记忆。
