Do Michael Tri H, Bean Bruce P
Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA.
Neuron. 2003 Jul 3;39(1):109-20. doi: 10.1016/s0896-6273(03)00360-x.
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.
丘脑底核（STN）的神经元具有自发活动。通过电压钳制分离的具有自身放电模式的大鼠STN神经元，我们发现节律性放电由两种阈下钠电流驱动：一种稳态的“持续性”钠电流和一种动态的“复苏性”钠电流，后者在动作电位后立即流动，促进快速放电。这些电流受到在生理放电频率下活跃的缓慢失活过程的强烈调节。起搏钠电流的缓慢失活在面对输入的小而稳定的变化时促进了强直性放电的恒定频率，并构成了单细胞水平上的一种适应形式。以高频率（75Hz）驱动细胞会使复苏性、持续性和瞬态钠电流成分出现明显的缓慢失活（60%-70%）。这种失活可能有助于临床深部脑刺激对STN兴奋性的影响。
