Intra- and intersegmental influences among central pattern generating networks in the walking system of the stick insect
Intra- and intersegmental influences among central pattern generating networks in the walking system of the stick insect
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DOI：
10.1152/jn.00321.2017
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发表时间：
2017-10-01
影响因子：
2.5
通讯作者：
Bueschges, Ansgar
中科院分区：
文献类型：
--
作者：
Mantziaris, Charalampos;Bockemuehl, Till;Bueschges, Ansgar
为了有效地移动，动物需要协调四肢。腿部运动背后的神经网络之间适当的、上下文相关的耦合对于产生节间协调是必要的。在慢行竹节虫中，局部感觉信息对形成协调非常重要。然而，片段中心模式发生器（cpg）之间的中心耦合机制也可能有助于此。在这里，我们分析了对侧网络之间的相互作用，驱动腿的降粗隆肌在孤立和相互连接的脱神经胸椎节的节约虫应用匹罗卡平，一种毒菌碱乙酰胆碱受体激动剂。我们的研究结果表明，抑制CPG活性在所有片段之间仅弱耦合。三个孤立的神经节之间的节段内相关系不同，当神经节相互连接时，它们被修改和稳定。然而，出现的协调模式与走路时观察到的不一样。我们的发现与最近的研究一致，并强调了感觉输入对缓慢行走昆虫协调的影响。最后，由于无法观察到抑制CPG网络与对侧运动神经元之间的直接相互作用，我们假设耦合是基于CPG中间神经元水平的相互作用。当动物在变化的环境中运动时，维持功能性腿间协调是至关重要的。在这个过程中，中枢机制和感觉反馈的相对重要性还没有得到很好的理解。我们分析了在缺乏相位感觉反馈的竹节虫准备中产生腿部运动的神经网络之间的协调。在这些条件下，控制不同腿的网络只是弱耦合的。因此，在竹节虫中，仅靠中央连接不足以产生行为上观察到的腿部协调。
To efficiently move around, animals need to coordinate their limbs. Proper, context-dependent coupling among the neural networks underlying leg movement is necessary for generating intersegmental coordination. In the slow-walking stick insect, local sensory information is very important for shaping coordination. However, central coupling mechanisms among segmental central pattern generators (CPGs) may also contribute to this. Here, we analyzed the interactions between contralateral networks that drive the depressor trochanteris muscle of the legs in both isolated and interconnected deafferented thoracic ganglia of the stick insect on application of pilocarpine, a muscarinic acetylcholine receptor agonist. Our results show that depressor CPG activity is only weakly coupled between all segments. Intrasegmental phase relationships differ between the three isolated ganglia, and they are modified and stabilized when ganglia are interconnected. However, the coordination patterns that emerge do not resemble those observed during walking. Our findings are in line with recent studies and highlight the influence of sensory input on coordination in slowly walking insects. Finally, as a direct interaction between depressor CPG networks and contralateral motoneurons could not be observed, we hypothesize that coupling is based on interactions at the level of CPG interneurons.NEW & NOTEWORTHY Maintaining functional interleg coordination is vitally important as animals locomote through changing environments. The relative importance of central mechanisms vs. sensory feedback in this process is not well understood. We analyzed coordination among the neural networks generating leg movements in stick insect preparations lacking phasic sensory feedback. Under these conditions, the networks governing different legs were only weakly coupled. In stick insect, central connections alone are thus insufficient to produce the leg coordination observed behaviorally.