In actio optophysiological analyses reveal functional diversification of dopaminergic neurons in the nematode C. elegans.
In actio optophysiological analyses reveal functional diversification of dopaminergic neurons in the nematode C. elegans.
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DOI：
10.1038/srep26297
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发表时间：
2016-05-19
影响因子：
4.6
通讯作者：
Kimura KD
中科院分区：
文献类型：
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作者：
Tanimoto Y;Zheng YG;Fei X;Fujie Y;Hashimoto K;Kimura KD
许多神经元群，如多巴胺释放(多巴胺能)神经元，在功能上是不同的，尽管这种不同的细节还不是很清楚。线虫线虫体内的多巴胺调节各种神经功能，并由四对左右的神经元释放。这些多巴胺能神经元的终末身份由相同的遗传程序调节，以前的研究表明它们在功能上是多余的。然而，在这项研究中，我们发现线虫的多巴胺能神经元内存在功能分化。由于动物的多巴胺能神经元在进入它们的食物细菌的草坪时被机械刺激激活，我们开发了一种新型的集成显微镜系统，可以自动跟踪自由移动的线虫，以单独监测和刺激多个神经元的神经元活动。我们发现，只有头部-背侧的多巴胺能神经元(CEPD)对，而不是头部-腹侧或后部的对，在食物进入时优先被激活。此外，仅CEPD神经元的光遗传激活就表现出与食物进入时观察到的类似的效果。因此，我们的结果显示了遗传相似的多巴胺能神经元的功能差异，这可能为理解神经元的功能多样性提供了一个新的切入点，而不仅仅是遗传终末识别。
Many neuronal groups such as dopamine-releasing (dopaminergic) neurons are functionally divergent, although the details of such divergence are not well understood. Dopamine in the nematode Caenorhabditis elegans modulates various neural functions and is released from four left-right pairs of neurons. The terminal identities of these dopaminergic neurons are regulated by the same genetic program, and previous studies have suggested that they are functionally redundant. In this study, however, we show functional divergence within the dopaminergic neurons of C. elegans. Because dopaminergic neurons of the animals were supposedly activated by mechanical stimulus upon entry into a lawn of their food bacteria, we developed a novel integrated microscope system that can auto-track a freely-moving (in actio) C. elegans to individually monitor and stimulate the neuronal activities of multiple neurons. We found that only head-dorsal pair of dopaminergic neurons (CEPD), but not head-ventral or posterior pairs, were preferentially activated upon food entry. In addition, the optogenetic activation of CEPD neurons alone exhibited effects similar to those observed upon food entry. Thus, our results demonstrated functional divergence in the genetically similar dopaminergic neurons, which may provide a new entry point toward understanding functional diversity of neurons beyond genetic terminal identification.