Inward rectification in rat nucleus accumbens neurons.
Inward rectification in rat nucleus accumbens neurons.
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大鼠伏隔核神经元的内向整流。
DOI：
10.1152/jn.1989.62.6.1280
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发表时间：
1989
影响因子：
2.5
通讯作者：
North,RA
中科院分区：
文献类型：
--
作者：
Uchimura,N;Cherubini,E;North,RA
1.细胞内记录是从大鼠延髓隔核切片中的神经元进行的。用单电极电压钳放大器在-50至-140 mV的电位范围内测量膜电流。2.在对照条件（2.5 mM钾）下，神经元的静息膜电位为-83.4 +/- 1.1（SE）mV（n = 157）。稳态膜电导是电压依赖性的，在-100 mV时为34.8 +/- 1.7 nS（n = 25），在-60 mV时为8.0 +/- 0.7 nS（n = 25）。3.钡（1 μ M）显著减少内向整流，并在静息电位下引起小的内向电流（40.6 +/- 8.7 pA，n = 8）。随着钡浓度的增加，这些效应变得更大，并且在100 μ M钡中，电流-电压关系是直线的。4.钡（-130 mV）对内向电流的阻断呈指数时间过程; 1 μ M钡的时间常数约为1 s，100 μ M钡的时间常数小于90 ms。锶的效果与钡相似，但需要高出1000倍的浓度。氯化铯（2 mM）和氯化铷（2 mM）也阻断了内向整流;它们的作用在50 ms内达到稳态。它的结论是，延髓核神经元具有典型的内向整流器的许多功能的钾电导，这有助于钾电导在静息电位。
1. Intracellular recordings were made from neurons in slices cut from the rat nucleus accumbens septi. Membrane currents were measured with a single-electrode voltage-clamp amplifier in the potential range -50 to -140 mV. 2. In control conditions (2.5 mM potassium), the resting membrane potential of the neurons was -83.4 +/- 1.1 (SE) mV (n = 157). Steady state membrane conductance was voltage dependent, being 34.8 +/- 1.7 nS (n = 25) at -100 mV and 8.0 +/- 0.7 nS (n = 25) at -60 mV. 3. Barium (1 microM) markedly reduced the inward rectification and caused a small inward current (40.6 +/- 8.7 pA, n = 8) at the resting potential. These effects became larger with higher barium concentrations, and, in 100 microM barium, the current-voltage relation was straight. 4. The block of the inward current by barium (at -130 mV) occurred with an exponential time course; the time constant was approximately 1 s at 1 microM barium and less than 90 ms with 100 microM. Strontium had effects similar to those of barium, but 1000-fold higher concentrations were required. Cesium chloride (2 mM) and rubidium chloride (2 mM) also blocked the inward rectification; their action reached steady state within 50 ms. 5. It is concluded that the nucleus accumbens neurons have a potassium conductance with many features of a typical inward rectifier and that this contributes to the potassium conductance at the resting potential.