Roles of presynaptic calcium stores at hipporampal mossy fiber synapse

海马苔藓纤维突触突触前钙储存的作用

• 批准号: 15500284
• 负责人: KAMIYA Haruyuki
• 金额: $ 2.43万
• 依托单位: HOKKAIDO UNIVERSITY (2004)Kobe University (2003)
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2003
• 资助国家: 日本
• 起止时间: 2003 至 2004
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-15500284/
• 关键词: HIPPOCAMPUS; SYNAPTIC TRANSMISSION; CALCIUM; CALCIUM ION; カルシウムストア

Ryanodine receptors mediate Ca^<2+> release from intracellular stores and regulate various functions of neuronal and non-neuronal cells. To investigate the roles of ryanodine receptors in activity-dependent modulation of presynaptic Ca^<2+> dynamics, we adopted optical methods to selectively monitor Ca^<2+> concentrations in the presynaptic terminals of mossy fiber-CA3 synapse in the hippocampus. Fluorescent Ca^<2+> indicator rhod-2 AM was locally injected into the axon bundles mossy fibers at stratum lucidum of CA3 region, resulting in selective labeling of the mossy fibers. Fluorescence intencity at the synaptic sites was monitored to assess the Ca^<2+> levels in the presynaptic terminals. Application of ryanodine receptor blacker TMB-8 selectively suppressed the presynaptic Ca^<2+> transient evoked by high frequency stimulation of the mossy fibers. We also investigated the effect of caffeine, which induces Ca^<2+> release from intracellular store through ryanodine receptors, on the synaptic transmission at mossy fiber-CA3 synapse. Application of caffeine caused robust enhancement of the field EPSPs, and this synaptic enhancement was accompanied by a marked reduction of paired-pulse facilitation. These results suggested that ryanodine receptors are present in the presynaptic terminals of the hippocampal mossy fiber synapses, and Ca^<2+> release from the intracellular stores plays a pivotal role in regulation of presynaptic Ca^<2+> dynamics as well as synaptic plasticity at this synapse.

Ryanodine受体介导细胞内储存的Ca 2+ 释放并调节神经元和非神经元细胞的各种功能。为了研究兰尼碱受体在突触前Ca^2+动力学的活性依赖性调节中的作用，我们采用光学方法选择性监测海马苔藓纤维-CA3突触突触前末端的Ca^2+浓度。将荧光Ca 2+ 指示剂rhod-2 AM局部注射到CA3区透明层的轴突束苔藓纤维中，导致苔藓纤维的选择性标记。监测突触位点的荧光强度以评估突触前末端的Ca 2+ 水平。兰尼碱受体黑TMB-8的应用选择性地抑制了由苔藓纤维的高频刺激引起的突触前Ca 2+ 瞬态。我们还研究了咖啡因对苔藓纤维-CA3突触处突触传递的影响，咖啡因通过兰尼碱受体诱导细胞内储存的Ca 2+ 释放。咖啡因的应用引起场 EPSP 的强烈增强，并且这种突触增强伴随着配对脉冲促进的显着减少。这些结果表明，兰尼碱受体存在于海马苔藓纤维突触的突触前末端，并且细胞内存储的Ca ^ 2+ 释放在调节突触前Ca ^ 2+ 动力学以及该突触的突触可塑性中起着关键作用。

项目成果

Specification of the retinal fate of mouse embryonic stem cells by ectopic expression of Rx/rax, a homeobox gene

通过同源盒基因 Rx/rax 的异位表达来规范小鼠胚胎干细胞的视网膜命运

• 发表时间: 2004
• 期刊: Mol. Cell. Biol. 24
• 作者: Tabata;Y.
• 通讯作者: Y.

Y.Tabata: "Retinal fate specification of mouse embryonic stem cells by ectopic expression of Rx/rax, a homeobox gene"Molecular and Cellular Biology. (印刷中).

Y.Tabata：“通过同源框基因 Rx/rax 的异位表达来确定小鼠胚胎干细胞的视网膜命运”《分子和细胞生物学》（正在出版）。

Defective function of GABA-containing synaptic vesicles in mice lacking the AP-3B clathrin adaptor.

缺乏AP-3B网格蛋白适配器的小鼠中含GABA的突触囊泡的功能不良。

• DOI: 10.1083/jcb.200405032
• 发表时间: 2004-10-25
• 期刊: JOURNAL OF CELL BIOLOGY
• 影响因子: 7.8
• 作者: Nakatsu, Fubito;Okada, Motohiro;Mori, Fumiaki;Kumazawa, Noriko;Iwasa, Hiroto;Zhu, Gang;Kasagi, Yasufumi;Kamiya, Haruyuki;Harada, Akihiro;Nishimura, Kazuhiro;Takeuchi, Arata;Miyazaki, Taisuke;Watanabe, Masahiko;Yuasa, Shigeki;Manabe, Toshiya;Wakabayashi, Koichi;Kaneko, Sunao;Saito, Takashi;Ohno, Hiroshi
• 通讯作者: Ohno, Hiroshi

Specification of the retinal fate of mouse embryonic stem cells by ectopic expression of Rx/tax, a homeobox gene.

通过同源盒基因 Rx/tax 的异位表达来规范小鼠胚胎干细胞的视网膜命运。

• 发表时间: 2004
• 期刊: Mol Cell Biol 24(10)
• 作者: Saitoh K;Isa T;Takakusaki K.;Y.Tabata et al.
• 通讯作者: Y.Tabata et al.