Neuromuscular effects of impulse pattern in a crustacean motoneuron.
Neuromuscular effects of impulse pattern in a crustacean motoneuron.
复制标题
甲壳动物运动神经元脉冲模式的神经肌肉效应。
DOI：
10.1152/jn.1969.32.4.607
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发表时间：
1969
影响因子：
2.5
通讯作者：
D. Kennedy
中科院分区：
文献类型：
--
作者：
H. L. Gillary;D. Kennedy
材料和方法按前#年第(4)号文件所述进行了制备。刺激和记录神经节2、3或4两侧第三根的浅支，电极的顶径大致等于神经干的直径。在神经进入浅屈肌之前，将记录电极连接到神经的远端。信号被引导到一个低电平电容耦合前置放大器，然后显示在示波器上，以监测神经中的脉冲活动。在神经中枢端插入第二个吸电极，用电子刺激器发出的短脉冲(0.1毫秒)方波进行刺激。这里感兴趣的运动神经元有六个在神经干中运行的最大的轴突，因为它的阈值通常是最低的，所以可以有选择地进行刺激。在实验开始时，这种运动神经元的活动是由自然刺激引起的。它的幅度随后被用来验证一次诱发的离心式截击是否只包含来自最大运动神经元的脉冲。这也可以通过测量传导速度来证实。然后在脊髓的出口处挤压神经，以阻止较小的紧张性运动神经元的自发传出冲动。使用阻抗约为15兆欧姆的氯化钾填充玻璃微电极记录外侧浅屈肌纤维的连接电位。信号被引入高阻抗直流放大器(Bio Electric Instruments，Inc.)然后连接到一个多道示波器。用RCA5734探头测量肌肉收缩。管子的移动阳极连接到一对钳子上，钳子抓住浅屈肌纤维附着点附近的软外骨骼。产量大约是
MATERIALS AND METHODSCrayfish were prepared as described in the previous# paper (4). The superficial branch of the third root on either side of ganglion 2, 3, or 4 was stimulated and recorded from with suction electrodes having tip diameters approximately equal to the diameter of the nerve trunk. A recording electrode was attached to the distal portion of the nerve before it entered the superficial flexor muscle. The signal was led to a low-level capacitance-coupled preamplifier and then displayed on an oscilloscope in order to monitor impulse activity in the nerve. A second suction electrode was nlacedon the central end of the nerve for stimulation by brief (0.1 msec) square pulses from an electronic stimulator. The motoneuron of interest here has the largest axon of the six which run in the nerve trunk, and since it often had the lowest threshold it could be stimulated selectively. At the beginning of an experiment, activity in this motoneuron was evoked by natural stimulation. Its amplitude was then used to verify that an evoked centrifugal volley contained only impulses from the largest motoneuron. This could also be confirmed bv conduction-velocity measurements. The nerve was then crushed at its exit point from the cord to block spontaneous efferent impulses in the smaller, tonic motoneurons. Junctional potentials were recorded from lateral superficial flexor muscle fibers using KCl-filled glass microelectrodes of about 15 megohms impedance. Signals were led to a high-impedance dc amplifier(Bioelectric Instruments, Inc.) and then to a multitrace oscilloscope. Contraction of the muscle was measured with an RCA 5734 transducer. The moving anode of the tube was connected to a pair of forceps which gripped the soft exoskeleton near one point of attachment of the superficial flexor fibers. The output was approximately