Stefani A, Calabresi P, Mercuri N B, Bernardi G
Clinica Neurologica, II Università degli Studi di Roma Tor Vergata, Italy.
Neurosci Lett. 1992 Sep 14;144(1-2):4-8. doi: 10.1016/0304-3940(92)90703-a.
Globus pallidus neurons were dissociated from adult rats and recorded in whole-cell voltage-clamp mode. In tetrodotoxin- and cadmium-added bath, outward potassium conductances were evaluated. Depolarization activated large and predominantly sustained currents, with little inactivation. The transient outward current was isolated through its voltage-dependency, kinetics and pharmacology. A-like current activated around -45 mV and decayed exponentially with a time-constant of about 50 ms at 0 mV. Steady-state half-inactivation voltage was about -60 mV, suggesting that A-current was not fully inactivated at rest. 4-Aminopyridine sensitivity of the transient outward current was in the low millimolar range. A-current might play a relevant role in shaping firing properties of pallidal neurons.
从成年大鼠中分离出苍白球神经元，并在全细胞电压钳模式下进行记录。在添加了河豚毒素和镉的浴液中，评估外向钾电导。去极化激活了大的且主要是持续的电流，几乎没有失活。通过其电压依赖性、动力学和药理学特性分离出瞬时外向电流。A样电流在约-45 mV时激活，在0 mV时以约50 ms的时间常数呈指数衰减。稳态半失活电压约为-60 mV，表明A电流在静息时未完全失活。瞬时外向电流对4-氨基吡啶的敏感性处于低毫摩尔范围内。A电流可能在塑造苍白球神经元的放电特性中发挥相关作用。
