Characterization of six voltage-gated K+ currents in adult rat sensory neurons
Characterization of six voltage-gated K+ currents in adult rat sensory neurons
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DOI：
10.1152/jn.1996.75.6.2629
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发表时间：
1996-06-01
影响因子：
2.5
通讯作者：
Levine, JD
中科院分区：
文献类型：
--
作者：
Gold, MS;Shuster, MJ;Levine, JD
1.以前三个电压门控的K+电流被描述在哺乳动物感觉神经节的神经元：两个短暂的和一个持续的。由于这三种电流的门控特性存在相当大的变异性，我们研究了这种变异性反映感觉神经元中存在额外电流的可能性。采用全细胞膜片钳技术，在培养的成年大鼠背根神经节（DRG）神经元上观察到6种电压门控性K+电流。根据不同的生物物理和药理学特性鉴定了六种电流;三种电流是瞬时的（I-Af，I-Aht和I-As），三种是持续的（I-Ki，I-Kit和I-Kn）。除了具有不同的生物物理和药理学特性，四个电流的DRG神经元的亚群之间的差异表达。I-Aht在小直径神经元中选择性表达。I-Ki在具有动作电位肩的神经元中更频繁地表达，并且I-Aht和I-As在对致痛剂辣椒素有反应的神经元中选择性地共表达。I-Af在大直径神经元中选择性表达，是唯一在无动作电位肩的神经元中表达频率更高的电流.这是可能的，在脊椎动物感觉神经元的三个电压门控K+电流的属性的明显的变化可以占本报告中描述的至少三个额外的电压门控K+电流的存在。
1. Previously three voltage-gated K+ currents were described in neurons from mammalian sensory ganglia: two transient and one sustained. Because there is considerable variability in the gating properties of these three currents, we have investigated the possibility that this variability reflects the presence of additional currents in sensory neurons.2. Using whole cell patch-clamp techniques, we provide evidence for the existence of six voltage-gated K+ currents in cultured dorsal root ganglion (DRG) neurons from the adult rat. The six currents were identified on the basis of distinct biophysical and pharmacological properties; three currents are transient (I-Af, I-Aht, and I-As), and three are sustained (I-Ki, I-Kit, and I-Kn).3. In addition to possessing distinct biophysical and pharmacological properties, four of the six currents are differentially expressed among subpopulations of DRG neurons. I-Aht is selectively expressed in small-diameter neurons. I-Ki is expressed more frequently in neurons with an action-potential shoulder, and both I-Aht and I-As are selectively coexpressed in neurons that respond to the algogenic agent capsaicin. I-Af is selectively expressed in large-diameter neurons and is the only current expressed more frequently in neurons without an action-potential shoulder.4. It is likely that much of apparent variability in the properties of the three voltage-gated K+ currents reported previously in vertebrate sensory neurons can be accounted for by the existence of at least three additional voltage-gated K+ currents described in this report.