Gilly W F, Preuss T, McFarlane M B
Department of biological Sciences, Hopkins Marine Station of Stanford University, Pacific Grove, California 93950, USA.
Biol Bull. 1996 Dec;191(3):337-40. doi: 10.2307/1543006.
Motor function in squid (Loligo) mantle reflects the highly coordinated activity of two motor pathways associated with giant and non-giant motor axons that respectively produce all-or-none and graded contractions in mantle muscle. Whereas both types of axons innervate circular mantle muscle fibers, precise nerve-muscle relationships remain unclear. Are squid like most invertebrates, in which single muscle fibers receive dual innervation from giant and non-giant motor axons, or is squid mantle configured more like vertebrates, in which parallel motor axon systems innervate distinct fast and slow muscle fibers? In this report, we describe giant and nongiant motor pathways that appear to control different pools of circular muscle fibers in squid. A subset of circular muscle fibers possesses large Na currents, and these fibers are proposed to employ Na-dependent action potentials to produce fast, all-or-none muscle twitches associated with giant axon stimulation.
鱿鱼（枪乌贼属）外套膜的运动功能反映了与巨轴突和非巨轴突相关的两条运动通路的高度协调活动，这两条通路分别在外套膜肌肉中产生全或无收缩和分级收缩。虽然这两种类型的轴突都支配环形外套膜肌纤维，但精确的神经-肌肉关系仍不清楚。鱿鱼是像大多数无脊椎动物一样，单个肌纤维接受来自巨轴突和非巨轴突的双重神经支配，还是鱿鱼的外套膜结构更类似于脊椎动物，其中平行的运动轴突系统支配不同的快肌纤维和慢肌纤维？在本报告中，我们描述了似乎控制鱿鱼环形肌纤维不同群体的巨轴突和非巨轴突运动通路。一部分环形肌纤维具有大的钠电流，并且这些纤维被认为利用依赖钠的动作电位来产生与巨轴突刺激相关的快速、全或无的肌肉抽搐。
