Subthreshold sodium currents and pacemaking of subthalamic neurons: Modulation by slow inactivation
Subthreshold sodium currents and pacemaking of subthalamic neurons: Modulation by slow inactivation
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DOI：
10.1016/s0896-6273(03)00360-x
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发表时间：
2003-07-03
期刊：
影响因子：
16.2
通讯作者：
Bean, BP
中科院分区：
文献类型：
--
作者：
Do, MTH;Bean, BP
丘脑底核（subthalamic nucleus，简称丘脑底核）的神经元是自发活动的。通过电压钳位分离的具有自身放电模式的大鼠海马神经元，我们发现起搏由两种阈下钠电流驱动：稳态的“持续性”钠电流和动态的“复苏性”钠电流，其通过在锋电位后立即流动来促进快速放电。这些电流受到在生理放电频率下激活的缓慢失活过程的强烈调节。起搏钠电流的缓慢失活促进了在面对输入的小而稳定的变化时的恒定频率的紧张性放电，并且构成了单细胞水平上的一种适应形式。以高速率（75 Hz）驱动细胞产生明显的缓慢失活（60%-70%）的复苏，持续和短暂的成分钠电流。这种失活可能有助于临床脑深部电刺激对脑兴奋性的影响。
Neurons of the subthalamic nucleus (STN) are spontaneously active. By voltage clamping dissociated rat STN neurons with their own firing patterns, we found that pacemaking is driven by two kinds of subthreshold sodium current: a steady-state "persistent" sodium current and a dynamic "resurgent" sodium current, which promotes rapid firing by flowing immediately after a spike. These currents are strongly regulated by a process of slow inactivation that is active at physiological firing frequencies. Slow inactivation of the pacemaking sodium currents promotes a constant frequency of tonic firing in the face of small, steady changes in input and constitutes a form of adaptation at the single-cell level. Driving cells at a high rate (75 Hz) produced pronounced slow inactivation (60%-70%) of resurgent, persistent, and transient components of sodium current. This inactivation is likely to contribute to effects of clinical deep-brain stimulation on STN excitability.