Essential role of a fast persistent inward current in action potential initiation and control of rhythmic firing
Essential role of a fast persistent inward current in action potential initiation and control of rhythmic firing
复制标题
DOI：
10.1152/jn.2001.85.1.472
复制
发表时间：
2001-01-01
影响因子：
2.5
通讯作者：
Heckman, CJ
中科院分区：
文献类型：
--
作者：
Lee, RH;Heckman, CJ
在脊髓运动神经元在体内制备，我们研究了一个快速的持续性内向电流位于或附近的索马和这些细胞的能力，有节奏地发射之间的关系。延长去极化时间可显著降低快持续电流。适度的减少导致频率-电流关系的斜率发生深刻变化。在更大的减少水平，节律性放电失败，不能通过增加注入电流恢复。然而，完全形成的尖峰仍然发生在一个缓慢的，不协调的方式，这表明快速失活的Na+电流产生的尖峰本身保持不变。因此，快速持续的内向电流，这可能主要是由持久的Na+通道产生的，似乎是必不可少的启动尖峰在有节奏的射击。此外，快速持续电流似乎在设置频率-电流增益方面起主要作用。
In spinal motoneurons in an in vivo preparation, we investigated the relationship between a fast persistent inward current located in or near the soma and the capacity of these cells to fire rhythmically. The fast persistent current could be markedly reduced by prolonged depolarization. Modest reductions resulted in profound changes in the slope of the frequency-current relationship. At greater reduction levels, rhythmic firing failed and could not be restored by increasing injected current. However, fully formed spikes still occurred in a slow, uncoordinated fashion, suggesting that the fast inactivating Na+ currents that generate the spike itself remained unchanged. Consequently, the fast persistent inward current, which may be primarily generated by persistent Na+ channels, appears to be essential for initiation of spikes during rhythmic firing. Additionally, it appears that the fast persistent current plays a major role in setting the frequency-current gain.