Temporal Dynamics of Neuronal Activation by Channelrhodopsin-2 and TRPA1 Determine Behavioral Output in Drosophila Larvae
Temporal Dynamics of Neuronal Activation by Channelrhodopsin-2 and TRPA1 Determine Behavioral Output in Drosophila Larvae
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DOI：
10.1152/jn.00071.2009
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发表时间：
2009-06-01
影响因子：
2.5
通讯作者：
Griffith, Leslie C.
中科院分区：
文献类型：
--
作者：
Pulver, Stefan R.;Pashkovski, Stanislav L.;Griffith, Leslie C.
首页--期刊主要分类--期刊细介绍--期刊题录与文摘--期刊详细文摘内容通道视紫红质-2和TRPA1激活神经元的时间动力学决定了果蝇幼虫的行为输出。神经生理学杂志101：3075-3088,2009。2009年4月1日首次出版；DOI：10.1152/jn.00071.2009。近年来，已经有许多工具可以远程激活果蝇的神经回路。尽管这些工具被广泛使用并在不断增长，但在准确描述这些工具如何影响已识别的苍蝇神经元活动方面所做的工作很少。利用GAL4-UAS系统，我们在果蝇三龄运动回路的运动神经元和感觉神经元中表达了蓝光门控通道视紫红质-2(ChR2)和突变形式的ChR2(H134R-ChR2)。与表达ChR2的神经元相比，表达H134R-ChR2的神经元对蓝光脉冲的反应增强，对尖峰频率的适应较弱。尽管H134R-ChR2在操纵行为方面比ChR2更有效，但在感觉神经元和运动神经元中，放电频率适应的行为后果是不同的。为了进行比较，我们研究了温度激活的阳离子通道果蝇TRPA1(DTRPA1)的异位表达的影响。当dTRPA1在幼虫运动神经元中表达时，从21摄氏度到27摄氏度的热坡度引起类似于25摄氏度的紧张性尖峰，在许多分钟内几乎没有表现出适应。与ChR2变体相比，dTRPA1激活对行为的影响更强、更持久。这些结果表明，dTRPA1对于有兴趣在长时间尺度上激活苍蝇神经回路的研究人员可能特别有用。总体而言，这项工作表明，了解这些遗传工具的细胞效应及其时间动力学对于设计和解释行为实验很重要。
Pulver SR, Pashkovski SL, Hornstein NJ, Garrity PA, Griffith LC. Temporal dynamics of neuronal activation by Channelrhodopsin-2 and TRPA1 determine behavioral output in Drosophila larvae. J Neurophysiol 101: 3075-3088, 2009. First published April 1, 2009; doi:10.1152/jn.00071.2009. In recent years, a number of tools have become available for remotely activating neural circuits in Drosophila. Despite widespread and growing use, very little work has been done to characterize exactly how these tools affect activity in identified fly neurons. Using the GAL4-UAS system, we expressed blue light-gated Channelrhodopsin-2 (ChR2) and a mutated form of ChR2 (H134R-ChR2) in motor and sensory neurons of the Drosophila third-instar locomotor circuit. Neurons expressing H134R-ChR2 show enhanced responses to blue light pulses and less spike frequency adaptation than neurons expressing ChR2. Although H134R-ChR2 was more effective at manipulating behavior than ChR2, the behavioral consequences of firing rate adaptation were different in sensory and motor neurons. For comparison, we examined the effects of ectopic expression of the warmth-activated cation channel Drosophila TRPA1 (dTRPA1). When dTRPA1 was expressed in larval motor neurons, heat ramps from 21 to 27 degrees C evoked tonic spiking at similar to 25 degrees C that showed little adaptation over many minutes. dTRPA1 activation had stronger and longer-lasting effects on behavior than ChR2 variants. These results suggest that dTRPA1 may be particularly useful for researchers interested in activating fly neural circuits over long time scales. Overall, this work suggests that understanding the cellular effects of these genetic tools and their temporal dynamics is important for the design and interpretation of behavioral experiments.