The need for speed. I. Fast reactions and myelinated axons in copepods
The need for speed. I. Fast reactions and myelinated axons in copepods
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对速度的需要。
DOI：
--
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发表时间：
2000
期刊：
影响因子：
--
通讯作者：
A. Davis
中科院分区：
文献类型：
--
作者：
Petra H. Lenz;D. Hartline;A. Davis
摘要快速而有力的逃逸反应降低了浮游桡足类的捕食风险。甲鱼类桡足类对微小而短暂的水动力干扰很敏感：它们对振动的球体做出多个神经冲动的反应。一些物种，如翼乳亚种和小唇角亚目，以非常大的尖峰(1-4 mV)响应，而其他物种的最大尖峰高度较小一个数量级，如普通乌贼和细小新卡兰斯。对逃逸反应的比较研究表明，所有物种在启动流体动力刺激后的10 ms内都有反应。然而，普通U和N.gracilis的反应时间(最小反应时间分别为1.5 ms和1.6 ms)明显短于另外两种：剑尾藻(6.6 ms)和马杜里乳杆菌(3.1 ms)。用透射电子显微镜检查第一触角和中枢神经系统发现，这两个物种的感觉和运动轴突髓鞘广泛，反应时间较短。另外两个物种的轴突类似于典型的甲壳类无髓纤维。一项对20个鱿鱼的调查显示，在两个更古老的超级家族中，没有一个物种具有髓鞘，但来自三个较新进化的超级家族的物种中存在髓鞘。
Abstract A rapid and powerful escape response decreases predation risk in planktonic copepods. Calanoid copepods are sensitive to small and brief hydrodynamic disturbances: they respond with multiple nerve impulses to a vibrating sphere. Some species, such as Pleuromamma xiphias and Labidocera madurae, respond with very large spikes (1–4 mV), whereas maximum spike heights are an order of magnitude smaller in others, such as Undinula vulgaris and Neocalanus gracilis. A comparative study of the escape responses showed that all species reacted within 10 ms of the initiation of a hydrodynamic stimulus. However, U. vulgaris and N. gracilis had significantly shorter reaction times (minimum reaction times: 1.5 ms and 1.6 ms) than the other two, P. xiphias (6.6 ms) and L. madurae (3.1 ms). Examination of the first antenna and the central nervous system using transmission electron microscopy revealed extensive myelination of sensory and motor axons in the two species with the shorter reaction times. Axons of the other two species resembled typical crustacean unmyelinated fibers. A survey of 20 calanoids revealed that none of the species in two of the more ancient superfamilies possessed myelin, but myelination was present in the species from three more recently-evolved superfamilies.
节段巨人：小龙虾逃逸系统中命令神经元和运动神经元之间存在驱动神经元的证据。
影响因子：
2.5
作者：
Roberts,A;Krasne,FB;Hagiwara,G;Wine,JJ;Kramer,AP
通讯作者：
Kramer,AP