Eflects of ions onthe stimulation-induced changas in transmitten veleace at the frog neuromusculan junction.

离子对青蛙神经肌肉接头处传导纤维刺激诱导的变化的影响。

• 批准号: 04640679
• 负责人: TANABE Noriko
• 金额: $ 1.54万
• 依托单位: Daiichi Hoiku Junior College
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1992
• 资助国家: 日本
• 起止时间: 1992 至 1994
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-04640679/
• 关键词: neurotransmitter; calcium; magnesium; augmentation; potentiation; facilitation; neuromuscular junction; divalent cation; ポテンシエイション; 2価陽イオン; augmentation; potentiation; カルシウムイオン; マグネシウムイオン; オウグメンティション

Four components of stimulation-induced changes in neurotransmitter release are known as the synaptic plasticity at the frog neuromuscular junction. These are : fast and slow facilitation, augmentation and potentiation, classified by their decay time constants after repetitive nerve stimulation. Most experiments support the view that fast facilitation is caused by residual Ca^<2+>. However, the causes of the other three components are not clear. I have studied electrophysiologically the effect of Mg^<2+>and other divalent cations on these three components. Transmitter release was estimated by the amplitudes of endplate potential (EPP) and by the frequencies of miniature endplate potential (MEPP). The increase in the transmitter release by nerve stimulation is described as the product of four components. The magnitude of potentiation of MEPP frequencies after a tetanic nerve stimulation (100Hz, 5000times) increased markedly in high Mg^<2+>concentrations. Conversely, the magnitude of augmentation (MEPP frequencies and EPP amplitude) decreased in the higher Mg^<2+>Ringer solution. Ni^<2+> promoted the amplitude of potentiation and Sr^<2+> enhanced slow facilitation.

刺激引起的神经递质释放变化的四个组成部分被称为青蛙神经肌肉接头的突触可塑性。这些是：快速和缓慢的促进，增强和增强，根据重复神经刺激后的衰减时间常数分类。大多数实验支持快速易化是由残余Ca^<2+>引起的观点。但是，其他三个组成部分的原因尚不清楚。我研究了Mg^<2+>和其他二价阳离子对这三种成分的电生理作用。通过终板电位（EPP）的振幅和微型终板电位（MEPP）的频率估计递质释放。神经刺激引起的递质释放的增加被描述为四个分量的乘积。在高浓度Mg^<2+>时，强直刺激（100 Hz，5000次）后MEPP频率的增强幅度显著增加。相反，在高Mg^<2+>林格氏液中，增强幅度（MEPP频率和EPP振幅）降低。Ni^<2+>促进增强幅度，Sr^<2+>增强慢易化.

项目成果

Tanabe, N.& Kijima, H.: "BAPTA identifies Ca-dependent and independent components of transmitter release at the frog neuromuscular junction" J.Physiol.455. 271-289 (1992)

田边，N.

木島博正 田辺憲子: "神経伝達物質放出の調節機構" 生物物理. 32. 18-24 (1992)

Hiromasa Kijima 和 Noriko Tanabe：“神经递质释放的调节机制”生物物理学 32. 18-24 (1992)。

Tanabe, N., Morota, A.& Kijima, H.: "Effects of Mg on the stimulation-induced changes in transmitter release at the frog neuromuscular junction" Zoo.Sci.(in press).

田边，N.，莫田，A.

Kijima,H.Tanabe,N.,Sato J.& Kijima S.: "Ca-independent regulation transmitter release at the frog NMJ" Abstracts of Annals of the New York Academy of Sciences. 707. 443-446 (1993)

木岛H.田边N.佐藤J.

Tanabe, N.: "The study of chelating effects of some Ca-chelators at the frog neuromuscular junction" Res.Bull.Daichi Hoiku Junior Coll. 11. 29-36 (1994)

Tanabe, N.：“青蛙神经肌肉接头处某些钙螯合剂的螯合作用的研究”Res.Bull.Daichi Hoiku Junior Coll。