Identification of excitatory premotor interneurons which regulate local muscle contraction during Drosophila larval locomotion.
Identification of excitatory premotor interneurons which regulate local muscle contraction during Drosophila larval locomotion.
复制标题
识别兴奋性前神经元，这些神经元在果蝇幼虫运动过程中调节局部肌肉收缩。
DOI：
10.1038/srep30806
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发表时间：
2016-07-29
影响因子：
4.6
通讯作者：
Nose A
中科院分区：
文献类型：
--
作者：
Hasegawa E;Truman JW;Nose A
我们以果蝇幼虫运动为模型来阐明运动回路的工作原理。幼虫的运动是由体壁肌肉从后节到前节的有节奏和顺序的收缩产生的，而这种收缩又由相应神经粒中的运动神经元调节。众所周知，运动神经元同时接受兴奋性和抑制性输入，它们的联合作用可能调节运动过程中的运动活动。虽然最近的研究确定了候选的抑制性前运动中间神经元，但在运动过程中为运动神经元提供兴奋驱动的前运动中间神经元的身份仍然未知。在这项研究中，我们在该系统中寻找并鉴定了两个假定的兴奋性运动前中间神经元，称为CLI1和CLI2（胆碱能外侧中间神经元1和2）。这些神经元被节段排列，并在蠕动过程中从后节到前节依次激活。与它们是兴奋性运动前中间神经元一致，CLIs与运动神经元形成了GRASP-和chat -阳性的假定突触，并且在运动神经元放电之前在每个节段都是活跃的。此外，局部激活的CLI1s诱导相应身体节段的肌肉收缩。综上所述，我们的研究结果表明，在幼虫运动过程中，cli直接沿着节段顺序激活运动神经元。
We use Drosophila larval locomotion as a model to elucidate the working principles of motor circuits. Larval locomotion is generated by rhythmic and sequential contractions of body-wall muscles from the posterior to anterior segments, which in turn are regulated by motor neurons present in the corresponding neuromeres. Motor neurons are known to receive both excitatory and inhibitory inputs, combined action of which likely regulates patterned motor activity during locomotion. Although recent studies identified candidate inhibitory premotor interneurons, the identity of premotor interneurons that provide excitatory drive to motor neurons during locomotion remains unknown. In this study, we searched for and identified two putative excitatory premotor interneurons in this system, termed CLI1 and CLI2 (cholinergic lateral interneuron 1 and 2). These neurons were segmentally arrayed and activated sequentially from the posterior to anterior segments during peristalsis. Consistent with their being excitatory premotor interneurons, the CLIs formed GRASP- and ChAT-positive putative synapses with motoneurons and were active just prior to motoneuronal firing in each segment. Moreover, local activation of CLI1s induced contraction of muscles in the corresponding body segments. Taken together, our results suggest that the CLIs directly activate motoneurons sequentially along the segments during larval locomotion.