Department of Brain & Cognitive Sciences and Division of Life & Pharmaceutical Sciences, Ewha Womans University, 11-1 Daehyun-dong, Seodaemun-Gu, Seoul 120-750, Republic of Korea.
Neurosci Res. 2010 May;67(1):95-7. doi: 10.1016/j.neures.2010.01.008. Epub 2010 Feb 1.
Although zinc ion (Zn2+) reduced the low-threshold T-type Ca2+ current of a rat thalamic relay neuron (TRN), we observed that Zn2+ increased a bursting activity of TRN by altering the generation and maintenance of low-threshold spike (LTS). Interestingly and importantly, Zn2+ shifted dramatically the voltage-dependence of both steady-state inactivation and activation of the transient A-type K+ current (I(A)) to a depolarizing direction. As I(A) is one of the main factors in shaping thalamic LTS, such alterations of gating properties of I(A) would contribute to the enhancement of TRN excitability under Zn2+.
虽然锌离子 (Zn2+) 降低了大鼠丘脑中继神经元 (TRN) 的低阈值 T 型钙电流，但我们观察到，锌离子通过改变低阈值 spikes (LTS) 的产生和维持，增加了 TRN 的爆发活动。有趣的是，重要的是，锌离子显著地将稳态失活和瞬态 A 型钾电流 (I(A)) 的激活的电压依赖性向去极化方向移动。由于 I(A) 是塑造丘脑 LTS 的主要因素之一，因此 I(A) 的门控特性的这种改变将有助于在 Zn2+ 下增强 TRN 的兴奋性。
