Analysis of nociceptin-induced spontaneous transient outward currents and their physiological function in the CNS

伤害感受肽诱导的自发瞬时外向电流及其在中枢神经系统中的生理功能分析

• 批准号: 11680811
• 负责人: SHIRASAKI Tetsuya
• 金额: $ 2.3万
• 依托单位: Kumamoto University (2000-2001)Kansai Medical University (1999)
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1999
• 资助国家: 日本
• 起止时间: 1999 至 2001
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11680811/
• 关键词: Nociceptin; STOCs; Intracellular Ca^<2+>; Hippocampus; Dentate Gyrus; ORL1; Ca^<2+> Sparks; Ca^<2+> Quarks; Ca^<2+>; SMOCs; SMDCs; ORLI

Spontaneous transient outward currents (STOCs) have been found in peripheral neurons and smooth muscle cells, but rarely in central neurons. Using a nystatin-perforated patch clamp technique, we succeeded in recording STOCs in mouse dentate gyrus granule cells. Nociceptin increased the amplitude and frequency of STOCs. We consider modulation of STOCs to be a new means to regulate cell activity in central neurons, and studied their characteristics and mechanism of augmentation. The whole-cell current-voltage relationship showed outward rectification and the reversal potential was close to the equilibrium potential for K The frequency of STOCs increased at depolarized potentials. Tetraethylammonium, iberiotoxin and a Ca^<2+> chelator BAPTA-AM inhibited STOCs. These results suggest the involvement of large-conductance Ca^<2+>-activated K^+ channels. Single-channel recordings in the inside-out configuration revealed Ca^<2+>-activated K^+ channels with a conductance ranging from 82 to 352 p … More S. The augmenting effect of nociceptin was cancelled by [Phe^1Ψ(CH -NH)Gly^2]Nociceptin(1-13)NH. Cd^<2+> did not affect the transient outward currents or augmentation by nociceptin. Whereas nociceptin, theophylline and cyclic ADP ribose induced transient outward currents with short duration observed under control conditions, inositol 1, 4, 5-trisphosphate induced transient outward currents with long duration, in addition to those with short duration. Ryanodine inhibited nociceptin from augmenting STOCs. Our data suggest that Ca^<2+> sparks, not Ca^<2+> quarks, transiently activate large-conductance Ca -activated K^+ channels to induce transient outward currents Nociceptin probably sensitizes ryanodine receptors and increases transient outward currents to reduce cell excitability. Nociceptin-induced increase in the amplitude and frequency of STOCs was observed even in the nociceptin receptor knockout mice, suggesting the presence of receptor subtype. In this study, we first revealed the presence and the characteristics of STOCs in the CNS and the modulation of STOCs by G protein coupled receptor. Less

自发瞬时外向电流（STOCs）在周围神经元和平滑肌细胞中发现，但在中枢神经元中很少发现。利用制氨抑素穿孔膜片钳技术，我们成功地记录了小鼠齿状回颗粒细胞的STOCs。诺西西汀增加了STOCs的振幅和频率。我们认为stos调控是调节中枢神经元细胞活性的一种新手段，并对其特点和增强机制进行了研究。全细胞电流-电压关系表现为向外整流，反转电位接近K的平衡电位，去极化电位下stos频率增加。四乙基铵、iberiotoxin和Ca^<2+>螯合剂BAPTA-AM抑制STOCs。这些结果表明参与了大电导Ca^<2+>激活的K^+通道。单通道记录显示Ca^<2+>激活的K^+通道电导范围为82 ~ 352 p . More S. nociceptin的增强作用被[Phe^1Ψ（CH -NH）Gly^2] nociceptin (1-13)NH所抵消。Cd^<2+>不影响瞬时外向电流或痛觉肽的增强。在对照条件下，痛觉肽、茶碱和环ADP核糖诱导的瞬时外向电流持续时间短，而肌醇1,4,5 -三磷酸诱导的瞬时外向电流除了持续时间短外，还持续时间长。Ryanodine抑制nociceptin增加STOCs。我们的数据表明，Ca^<2+>火花，而不是Ca^<2+>夸克，瞬间激活大电导Ca激活的K^+通道，以诱导瞬态向外电流。即使在伤害肽受体敲除小鼠中，也观察到伤害肽诱导的STOCs幅度和频率的增加，表明受体亚型的存在。在这项研究中，我们首次揭示了stos在中枢神经系统中的存在和特征，以及G蛋白偶联受体对stos的调节。少

项目成果

T Shirasaki, T Houtani, T Sugimoto and H Matsuda: "Spontaneous transient outward currents : modulation by nociceptin in murine dentate gyrus granule cells"Brain Research. 917. 191-205 (2001)

T Shirasaki、T Houtani、T Sugimoto 和 H Matsuda：“自发瞬时外向电流：小鼠齿状回颗粒细胞中伤害感受素的调节”脑研究。

Shirasaki T, Houtani T, Sugimoto T, Matsuda H: "Spontaneous transient outward currents : modulation by nociceptin in murine dentate gyrus granule cells"Brain Research. 917. 191-205 (2001)

Shirasaki T、Houtani T、Sugimoto T、Matsuda H：“自发瞬时外向电流：小鼠齿状回颗粒细胞中伤害感受素的调节”脑研究。