Oscillatory membrane potential activity in the soma of a primary afferent neuron.
Oscillatory membrane potential activity in the soma of a primary afferent neuron.
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DOI：
10.1152/jn.1999.82.3.1465
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发表时间：
1999-09
影响因子：
2.5
通讯作者：
C. Pedroarena;I. Pose;J. Yamuy;M. Chase;F. Morales
中科院分区：
文献类型：
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作者：
C. Pedroarena;I. Pose;J. Yamuy;M. Chase;F. Morales
在本报告中，我们提供的证据表明，中脑三叉神经（Mes-V）感觉神经元，一种特殊类型的初级传入细胞，其细胞体位于中枢神经系统内，可能会在不同的功能模式，这取决于其膜极化的程度。使用细胞内记录技术在切片制备的成年大鼠脑干，我们证明，当这些神经元去极化，他们表现出持续的，高频率的，调幅的膜电位振荡。在这些条件下，细胞会释放出高频率的尖峰信号。振荡发生在去极化超过-53 +/- 2.3 mV（平均值+/- SD）的膜电位水平。这些振荡的幅度随着膜去极化水平的增加而增加。当细胞去极化至接近重复放电阈值的水平时，这些波的峰间振幅约为3 mV。振荡的频率在不同的神经元中是相似的（108.9 +/- 15.5 Hz），并且在任何单个神经元中都没有被膜电位水平的变化所改变。这些振荡被超极化和TTX消除，而电压依赖性K+电流的阻断剂减慢振荡的频率，但不消除活性。这些数据表明，振荡产生的激活内向Na+电流/s和形状的电压依赖性K+外向电流。振荡活动不修改灌注低钙，高镁，或含钴的解决方案，也不是在镉或Apamin的存在下修改。这些结果表明，钙依赖性K+电流不发挥重要作用，在这一活动。我们假设，在Mes-V神经元的膜振荡活动是同步的相邻的电紧张耦合细胞，这种活动可能是调制的行为动物突触的影响。
In the present report, we provide evidence that mesencephalic trigeminal (Mes-V) sensory neurons, a peculiar type of primary afferent cell with its cell body located within the CNS, may operate in different functional modes depending on the degree of their membrane polarization. Using intracellular recording techniques in the slice preparation of the adult rat brain stem, we demonstrate that when these neurons are depolarized, they exhibit sustained, high-frequency, amplitude-modulated membrane potential oscillations. Under these conditions, the cells discharge high-frequency trains of spikes. Oscillations occur at membrane potential levels more depolarized than -53 +/- 2.3 mV (mean +/- SD). The amplitude of these oscillations increases with increasing levels of membrane depolarization. The peak-to-peak amplitude of these waves is approximately 3 mV when the cells are depolarized to levels near threshold for repetitive firing. The frequency of oscillations is similar in different neurons (108.9 +/- 15.5 Hz) and was not modified, in any individual neuron, by changes in the membrane potential level. These oscillations are abolished by hyperpolarization and by TTX, whereas blockers of voltage-dependent K+ currents slow the frequency of oscillations but do not abolish the activity. These data indicate that the oscillations are generated by the activation of inward Na+ current/s and shaped by voltage-dependent K+ outward currents. The oscillatory activity is not modified by perfusion with low-calcium, high-magnesium, or cobalt-containing solutions nor is it modified in the presence of cadmium or Apamin. These results indicate that a calcium-dependent K+ current does not play a significant role in this activity. We postulate that the membrane oscillatory activity in Mes-V neurons is synchronized in adjoining electrotonically coupled cells and that this activity may be modulated in the behaving animal by synaptic influences.