BKCa currents are enriched in a subpopulation of adult rat cutaneous nociceptive dorsal root ganglion neurons.
BKCa currents are enriched in a subpopulation of adult rat cutaneous nociceptive dorsal root ganglion neurons.
复制标题
BKCa 电流在成年大鼠皮肤伤害性背根神经节神经元亚群中丰富。
DOI：
10.1111/j.1460-9568.2009.07060.x
复制
发表时间：
2010-02
期刊：
影响因子：
--
通讯作者：
Gold MS
中科院分区：
文献类型：
--
作者：
Zhang XL;Mok LP;Katz EJ;Gold MS
用全细胞膜片钳技术研究了急性分离的成年大鼠皮肤感觉神经元亚群的电压依赖性钙调节钾电流(BKCa)的生物物理特性和分布。用黄连毒素、轮藻毒素或帕西林从总K+电流中分离BKCa电流。BKCa电流的生物物理性质有相当大的变异性。BKCa电流在皮肤背根节神经元亚群中的分布也存在差异。虽然存在于由细胞体大小、IB4结合或辣椒素敏感性定义的每个亚群中，但BKCa电流存在于绝大多数(>；90%)小直径Ib4+神经元中，但仅存在于由其他标准(即小直径Ib4−)定义的亚群中的少数神经元。电流钳分析表明，在IB4+神经元中，BKCa电流参与了动作电位的复极化和对持续膜去极化的适应，而对动作电位阈值的确定几乎没有作用。逆转录-聚合酶链式反应分析显示，BKCa通道α亚基、RSLO和所有4个辅助β亚基存在多种剪接变体，这表明BKCa电流在皮肤神经元中的生物物理和药理特性的异质性至少部分地反映了剪接变体和/或β亚基的不同分布。由于BKCa电流的微小下降似乎对兴奋性有显著的影响，这一电流的调节可能有助于组织损伤后观察到的伤害性传入的敏化。
The biophysical properties and distribution of voltage-dependent, Ca2+-modulated K+ (BKCa) currents among subpopulations of acutely dissociated DiI labeled cutaneous sensory neurons from the adult rat were characterized with whole cell patch clamp techniques. BKCa currents were isolated from total K+ current with iberiotoxin, charybdotoxin, or paxilline. There was considerable variability in biophysical properties of BKCa currents. There was also variability in the distribution of BKCa current among subpopulations of cutaneous DRG neurons. While present in each of the subpopulations defined by cell body size, IB4 binding or capsaicin sensitivity, BKCa current was present in vast majority (>90%) of small diameter IB4+ neurons but was present in only a minority of neurons in subpopulations defined by other criteria (i.e., small diameter IB4−). Current clamp analysis indicated that in IB4+ neurons, BKCa currents contribute to the repolarization of the action potential and adaptation in response to sustained membrane depolarization, while playing little role in the determination of action potential threshold. RT-PCR analysis of mRNA collected from whole DRG revealed the presence of multiple splice variants of the BKCa channel α-subunit, rslo and all 4 of the accessory β subunits, suggesting that heterogeneity in the biophysical and pharmacological properties of BKCa current in cutaneous neurons, reflects, at least in part, the differential distribution of splice variants and/or β subunits. Because even a small decrease in BKCa current appears to have a dramatic influence on excitability, modulation of this current may contribute to sensitization of nociceptive afferents observed following tissue injury.
登录
查看更多内容
影响因子：
2.5
作者：
Abdulla, FA;Smith, PA
通讯作者：
Smith, PA
影响因子：
5.3
作者：
Hu, H;Shao, LR;Storm, JF
通讯作者：
Storm, JF
影响因子：
--
作者：
Djouhri, L;Lawson, SN
通讯作者：
Lawson, SN
影响因子：
4.8
作者：
Brenner, R;Jegla, TJ;Aldrich, RW
通讯作者：
Aldrich, RW
影响因子：
5.5
作者：
Hicks, GA;Marrion, NV
通讯作者：
Marrion, NV