Chabbert C, Chambard J M, Valmier J, Sans A, Desmadryl G
INSERM U432, UM2 cp 089, place E. Bataillon, 34095 Montpellier, Cedex 5, France.
Neuroreport. 2001 Aug 28;12(12):2701-4. doi: 10.1097/00001756-200108280-00022.
The presence of a hyperpolarization-activated inward current (Ih) was investigated in mouse vestibular primary neurons using the whole-cell patch-clamp technique. In current-clamp configuration, injection of hyperpolarizing currents induced variations of membrane voltage with prominent time-dependent rectification increasing with current amplitudes. This effect was abolished by 2 mM Cs+ or 100 microM ZD7288. In voltage-clamp configuration, hyperpolarization pulses from -60 mV to -140 mV triggered a slow activating and non inactivating inward current that was sensitive to the two blockers, but insensitive to 5 mM Ba2+. Changing Na+ and K+ concentrations demonstrated that Ih current is carried by both these monovalent cations. This is the first demonstration of a Ih current in vestibular primary neurons.
采用全细胞膜片钳技术，研究了小鼠前庭初级神经元中是否存在超极化激活内向电流（Ih）。在电流钳模式下，注入超极化电流会引起膜电压变化，且随着电流幅度增加，呈现出明显的时间依赖性整流。2 mM Cs⁺ 或 100 μM ZD7288可消除这种效应。在电压钳模式下，从 -60 mV 到 -140 mV 的超极化脉冲会触发一种缓慢激活且不衰减的内向电流，该电流对上述两种阻滞剂敏感，但对 5 mM Ba²⁺ 不敏感。改变 Na⁺ 和 K⁺ 浓度表明，Ih 电流由这两种单价阳离子携带。这是首次在前庭初级神经元中证实存在 Ih 电流。
