In vivo light-induced activation of neural circuitry in transgenic mice expressing channelrhodopsin-2
In vivo light-induced activation of neural circuitry in transgenic mice expressing channelrhodopsin-2
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DOI：
10.1016/j.neuron.2007.03.005
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发表时间：
2007-04-19
期刊：
影响因子：
16.2
通讯作者：
Feng, Guoping
中科院分区：
文献类型：
--
作者：
Arenkiel, Benjamin R.;Peca, Joao;Feng, Guoping
视紫红质-2（ChR 2）是从莱氏衣藻（Chlamyeliumreinhardtii）的绿色藻类中分离的一种光门控阳离子选择性离子通道。在这里，我们报告的一代转基因小鼠表达的ChR 2-YFP融合蛋白在中枢神经系统的体内激活和映射的神经回路。使用大脑皮层和嗅球的局部照明，我们证明了一个高度可重复的，光依赖性的神经元激活和精确控制的放电频率在体内。为了测试映射神经回路的可行性，我们利用麻醉小鼠的嗅球和梨状皮质之间形成的回路。在嗅球，个别二尖瓣细胞发射动作电位响应光，其发射率不受共刺激肾小球。然而，在梨状皮质中，当灯泡的较大区域被照亮以招募更多的肾小球时，靶神经元的活性增加。这些结果支持了一个模型的嗅觉处理，是依赖于二尖瓣细胞的收敛和整合到皮层细胞。更广泛地说，这些发现证明了一个系统，用于精确操纵神经活动在完整的哺乳动物大脑与光，并说明了使用ChR 2小鼠在探索功能连接的复杂神经回路在体内。
Channelrhodopsin-2 (ChR2) is a light-gated, cation-selective ion channel isolated from the green algae Chlamydomonas reinhardtii. Here, we report the generation of transgenic mice that express a ChR2-YFP fusion protein in the CNS for in vivo activation and mapping of neural circuits. Using focal illumination of the cerebral cortex and olfactory bulb, we demonstrate a highly reproducible, light-dependent activation of neurons and precise control of firing frequency in vivo. To test the feasibility of mapping neural circuits, we exploited the circuitry formed between the olfactory bulb and the piriform cortex in anesthetized mice. In the olfactory bulb, individual mitral cells fired action potentials in response to light, and their firing rate was not influenced by costimulated glomeruli. However, in piriform cortex, the activity of target neurons increased as larger areas of the bulb were illuminated to recruit additional glomeruli. These results support a model of olfactory processing that is dependent upon mitral cell convergence and integration onto cortical cells. More broadly, these findings demonstrate a system for precise manipulation of neural activity in the intact mammalian brain with light and illustrate the use of ChR2 mice in exploring functional connectivity of complex neural circuits in vivo.