Distinct mechanosensitive properties of capsaicin-sensitive and -insensitive sensory neurons
Distinct mechanosensitive properties of capsaicin-sensitive and -insensitive sensory neurons
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DOI：
10.1523/jneurosci.22-12-j0001.2002
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发表时间：
2002-06-15
影响因子：
5.3
通讯作者：
Cesare, P
中科院分区：
文献类型：
--
作者：
Drew, LJ;Wood, JN;Cesare, P
机械刺激培养的新生大鼠背根神经节(DRG)神经元的胞体可诱发内向阳离子电流，这种电流在不同的细胞亚群之间表现出不同的特性。由辣椒素敏感性定义的伤害性感受器群体，表现出比其他机械敏感神经元更高的内向电流诱导阈值和更低的峰值电流。一部分辣椒素敏感的IB4阳性感觉神经元对机械刺激不敏感。所有的机械激活电流都被Gd(IC(50)类似于8um)和Ru红(IC(50)类似于3um)所阻断。急性应用10微米细胞松弛素B破坏肌动蛋白细胞骨架抑制辣椒素不敏感神经元的电流(61%)比辣椒素敏感神经元(20%)更有效。细胞外钙也减弱机械敏感电流，在辣椒素不敏感神经元中的作用比辣椒素敏感神经元更大。这些数据表明，不同类型培养的感觉神经元的体细胞具有不同的机械敏感表型，这些表型保留了与体内神经末梢机械传感器相关的特性。
Mechanical stimulation of the somata of cultured neonatal rat dorsal root ganglia (DRG) neurons evoked inward cationic currents that displayed distinct properties between different subsets of cells. The presumptive nociceptor population, defined by capsaicin sensitivity, showed higher thresholds for the induction of an inward current and lower peak currents than other mechanosensitive neurons. A subset of capsaicin-sensitive IB4-positive sensory neurons was refractory to mechanical stimulation. All mechanically activated currents were blocked by gadolinium (IC(50) similar to8 muM) and ruthenium red (IC(50) similar to3 muM). Disruption of the actin cytoskeleton by acute application of 10 muM cytochalasin B inhibited currents much more effectively in capsaicin-insensitive (61%) than capsaicin-sensitive neurons (20%). Extracellular calcium also attenuated mechanosensitive currents and to a greater degree in capsaicin-insensitive neurons than capsaicin-sensitive neurons. These data demonstrate that the somata of different types of cultured sensory neurons have distinct mechanosensitive phenotypes that retain properties associated with nerve terminal mechanosensors in vivo.