The modulation of two motor behaviors by persistent sodium currents in Xenopus laevis tadpoles.
The modulation of two motor behaviors by persistent sodium currents in Xenopus laevis tadpoles.
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DOI：
10.1152/jn.00755.2016
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发表时间：
2017-07-01
影响因子：
2.5
通讯作者：
Li WC
中科院分区：
文献类型：
--
作者：
Svensson E;Jeffreys H;Li WC
我们的特点是持续性钠电流在三组脊髓神经元和它们的作用，在非洲爪蟾蝌蚪的尖峰活动的塑造。然后，我们试图通过使用低浓度的持续性钠电流拮抗剂利鲁唑来评估持续性钠电流在调节蝌蚪游泳和挣扎运动输出中的作用。持续性钠电流（INaP）在神经元回路中很常见，并与肌萎缩侧索硬化（ALS）和癫痫等多种疾病有关。然而，INaP在特定行为调节中的作用仍然知之甚少。在这项研究中，我们的特点INaP和研究其在非洲爪蟾蝌蚪的游泳和挣扎行为的作用。INaP在三组神经元中被鉴定，即感觉Rohon-Beard神经元（RB神经元）、下行中间神经元（dIN）和非dIN（在游泳中节律性活跃的神经元）。所有组的神经元表达INaP，但电流的衰减时间常数，振幅和膜电位INaP峰值不同。低浓度（1 µM）的INaP阻断剂利鲁唑阻断了约30%的INaP，并降低了三个神经元组的兴奋性，而不影响尖峰幅度或细胞输入电阻。阿曲唑减少dIN的反弹尖峰的数量，并抑制RB神经元和非dIN的重复放电。在行为水平上，1 µM利鲁唑缩短了虚构的游泳事件。它还减少了每个挣扎周期中激发的动作电位神经元的数量。结果表明，INaP可能在运动行为中起重要的调节作用。新&值得注意的是，我们已经确定了三组脊髓神经元中持续钠电流的特征，以及它们在非洲爪蟾蝌蚪中形成尖峰活动中的作用。然后，我们试图通过使用低浓度的持续性钠电流拮抗剂利鲁唑来评估持续性钠电流在调节蝌蚪游泳和挣扎运动输出中的作用。
We have characterized persistent sodium currents in three groups of spinal neurons and their role in shaping spiking activity in the Xenopus tadpole. We then attempted to evaluate the role of persistent sodium currents in regulating tadpole swimming and struggling motor outputs by using low concentrations of the persistent sodium current antagonist riluzole. Persistent sodium currents (INaP) are common in neuronal circuitries and have been implicated in several diseases, such as amyotrophic lateral sclerosis (ALS) and epilepsy. However, the role of INaP in the regulation of specific behaviors is still poorly understood. In this study we have characterized INaP and investigated its role in the swimming and struggling behavior of Xenopus tadpoles. INaP was identified in three groups of neurons, namely, sensory Rohon-Beard neurons (RB neurons), descending interneurons (dINs), and non-dINs (neurons rhythmically active in swimming). All groups of neurons expressed INaP, but the currents differed in decay time constants, amplitudes, and the membrane potential at which INaP peaked. Low concentrations (1 µM) of the INaP blocker riluzole blocked INaP ~30% and decreased the excitability of the three neuron groups without affecting spike amplitudes or cellular input resistances. Riluzole reduced the number of rebound spikes in dINs and depressed repetitive firing in RB neurons and non-dINs. At the behavior level, riluzole at 1 µM shortened fictive swimming episodes. It also reduced the number of action potentials neurons fired on each struggling cycle. The results show that INaP may play important modulatory roles in motor behaviors. NEW & NOTEWORTHY We have characterized persistent sodium currents in three groups of spinal neurons and their role in shaping spiking activity in the Xenopus tadpole. We then attempted to evaluate the role of persistent sodium currents in regulating tadpole swimming and struggling motor outputs by using low concentrations of the persistent sodium current antagonist riluzole.