Indirect pathway to pectoral fin motor neurons from nucleus ruber in the Nile tilapia Oreochromis niloticus
Indirect pathway to pectoral fin motor neurons from nucleus ruber in the Nile tilapia Oreochromis niloticus
复制标题
尼罗罗非鱼 Oreochromis niloticus 红核到胸鳍运动神经元的间接途径
DOI：
10.1002/cne.24578
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
Yamamoto N
中科院分区：
文献类型：
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作者：
Nakayama T;Nishino H;Narita J;Abe H;Yamamoto N
硬骨鱼胸鳍棘上运动控制系统尚不清楚。Goldstein （1905; NRg）的橡胶核可能是四足动物橡胶核的同源物，是具有这种功能的候选结构。在本研究中，我们通过尼罗罗非鱼（oreochromis niloticus）的通道追踪实验，探讨了NRg可能参与控制胸鳍运动的机制。向NRg注射示踪剂显示了红脊髓束的纤维路线。红脊纤维在中脑水平穿过中线，经被盖下降，在脊髓交界处腹侧靠近背角的区域终止，但未到达胸鳍运动神经元存在的腹角。在背角区域注射示踪剂的实验结果显示，在假定的胸鳍运动神经元附近有标记的终末。向背角注射示踪剂的实验结果显示逆行标记的神经元位于背角的腹侧，在那里注射后检测到标记的终末。这些解剖分析表明，放光鳍鱼的NRg通过背角中间神经元间接参与胸鳍运动神经元的控制。
Supraspinal motor control systems of pectoral fins remain unclear in teleosts. Nucleus ruber of Goldstein (1905; NRg), which has been identified as the probable homologue of nucleus ruber of tetrapods, is a candidate structure serving for such functions. In the present study, we investigated possible involvement of the NRg in the control of pectoral fin movement by tract‐tracing experiments in the Nile tilapiaOreochromis niloticus. Tracer injections into the NRg revealed the fiber course of rubrospinal tract. Rubrospinal fibers crossed the midline at the level of midbrain, descended through the tegmentum, and terminated in a region ventrally adjacent to the dorsal horn at the spinomedullary junction, without reaching the ventral horn where pectoral fin motor neurons are present. Tracer injection experiments into the dorsal horn region resulted in labeled terminals in proximities of presumed pectoral fin motor neurons in the ventral horn. Tracer injection experiments into the ventral horn resulted in retrogradely labeled neurons ventrally adjacent to the dorsal horn, where labeled terminals were detected following rubral injections. These anatomical analyses suggest that the NRg of actinopterygians is involved in the control of pectoral fin motor neurons through an indirect pathway via interneurons in the dorsal horn.