PHYSIOLOGICAL ROLE OF NEURONAL-GRIAL INTERACTION

神经元-颗粒相互作用的生理作用

• 批准号: 10680744
• 负责人: INOUE Isao
• 金额: $ 2.11万
• 依托单位: The University of Tokushima
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10680744/
• 关键词: NEURON; SQUID GAINT AXON; SHWANN CELL; SIGNALING; POTASSIUM CHANNEL; CALCIUM CHANNEL; GLUTAMIC ACID; INTRACELLULAR CALCIUMION; 神経系; 神経細胞; グリア細胞; カリウムホメオスタシス; 不活性化

Schwann cells were enzymatically isolated from squid giant axons. Macroscopic ionic currents were recorded using whole cell clamp and single channel currents using patch clamp. Two types of ionic currents were found with whole cell voltage clamp. One is voltage gated L-type calcium current sensitive to externally applied nifedipine or CoィイD12+ィエD1. This current is activated at >-40 mV. The other current is outwardly rectified potassium current. This current is blocked by externally applied nifedipine or COィイD12+ィエD1, but insensitive to externally applied caffeine, ryanodine or L-glutamate. Single potassium channel currents with a conductance of 40 pS were recorded from excised inside-out patches. The open probability (Po) was 0.05 at 3x10ィイD1-7ィエD1 M CaィイD12+ィエD1, increased transiently to 0.4 when the CaィイD12+ィエD1 concentration was elevated to 1×10ィイD1-6ィエD1 M, then ran down spontaneously at this CaィイD12+ィエD1 concentration. The channel activity was insensitive to externally applied L-glutamate, internally applied acetylcholine (ACh), or ATP. The results suggest that the calcium activated potassium channels play an essential role in generation of the Schwann cell membrane potential of -40 mV, and the membrane potential is controlled by the intracellular CaィイD12+ィエD1 level. Schwann cells were loaded fluo-3, a CaィイD12+ィエD1-sensitive dye. Externally applied K+ induced an increase in the internal CaィイD12+ィエD1 level only when external solution contained CaィイD12+ィエD1. Externally applied L-glutamate, ACh, and caffeine induced no detectable change in the internal CaィイD12+ィエD1level.

用酶法从鱿鱼巨轴突中分离出雪旺细胞。宏观离子电流用全细胞钳记录，单通道电流用膜片钳记录。在全电池电压钳上观察到两种离子电流。一种是电压门控型L钙电流，对外用硝苯地平或复方ィイD12+ィエD1敏感。该电流在&gt；-40 mV时激活。另一种电流是外向整流钾电流。该电流可被外用硝苯地平或COィイD12+ィエD1阻断，但对外用咖啡因、兰尼定或L-谷氨酸不敏感。从内向外记录单个钾通道电流，其电导为40pS。开放概率(Po)在3×10ィイd1-7ィエd1 M CaィイD12+ィエd1时为0.0 5，当CaィイD12+ィエd1浓度增加到1×10ィイd1-6ィエd1 M时，一过性增加到0.4，然后在该浓度下自发下降。通道活动对外用L-谷氨酸、内用乙酰胆碱或三磷酸腺苷不敏感。结果提示，钙激活钾通道在雪旺细胞膜电位-40 mV的产生中起重要作用，膜电位受细胞内钙ィイD12+ィエD1水平的控制。雪旺细胞负载钙ィイD12+ィエD1敏感染料Fluo-3。外加K+只有在外液中含有CaィイD12+ィエD1时，才能引起细胞内CaィイD12+ィエD1水平的升高。外用L-谷氨酸、乙酰胆碱和咖啡因对内钙ィイD12+ィエD1无明显影响。

项目成果

Inoue, I.: "Evolution of L-type CaィイD12+ィエD1 channel as a voltage sensor in striated muscle."In "CaィイD12+ィエD1 channels, Structure and Phylogeny" Society of Experimental Biology Seminar Series, Cambridge Univ. Press. (in press).

Inoue, I.：“L 型 CaiD12+D1 通道作为横纹肌电压传感器的进化”，《CaiD12+D1 通道、结构和系统发育》实验生物学学会研讨会系列，剑桥大学出版社。 ）。

Inoue,I.: "The locomotor muscle sheet of Chelophyes and other calycophoran siphonophores:muscle fibres without any sarcoplasmic reticulum but with a T-system analogue"J.mar biol Ass.UK. 79. 1111-1116 (1999)

Inoue,I.：“Chelophyes 和其他管水动物的运动肌片：没有任何肌浆网但具有 T 系统类似物的肌肉纤维”J.mar biol Ass.UK。

Inoue,I.et al: "Effect of lipophilic ions on the intramembrane charge movement and intracellular Ca release in fetal mouse skeletal muscle cells" Jap.J.Physiol.47. 567-570 (1997)

Inoue,I.et al：“亲脂性离子对胎儿小鼠骨骼肌细胞膜内电荷运动和细胞内 Ca 释放的影响”Jap.J.Physiol.47。

Tsutsui, I., Inoue, I., Carre, C. & Bone, Q.: "Activation of locomotor and grasping spine muscle fibres in chaetognaths ; a curious paradox. J."Muscle Res. Cell Motl.. (in press). (2000)

筒井，I.，井上，I.，卡雷，C.

Tsutsui,I.: "Activation of locomotor and grasping spine muscle fibres in chaetognaths;a curious paradox"J.Muscle Res.Cell Motl.. (in press). (2000)

Tsutsui,I.：“毛颌动物运动和抓握脊柱肌肉纤维的激活；一个奇怪的悖论”J.Muscle Res.Cell Motl..（出版中）。