Synaptic up-and down-regulation by changes in intracellular calcium concentrations

细胞内钙浓度变化引起的突触上调和下调

• 批准号: 04670072
• 负责人: KATO Nobuo
• 金额: $ 0.26万
• 依托单位: KYOTO UNIVERSITY
• 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 1993
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-04670072/
• 关键词: Synaptic plasticity; LTP; LTD; Calcium; Cortex

Glutamate is the major excitatory neurotransmitter in the cerebral cortex. After blockade of NMDA and non-NMDA ionotropic glutamate receptors, tetanization to presynaptic fibers were induced long-term depression. Further experiments with agonists and antagonists suggested that some G protein-linked, inositol-1,4,5-trisphosphate (IP3)-coupled types of metabotropic glutamate receptors (mGluRs) are involved in induction of this long-term depression. Intracellular injection of the G-protein inhibitor GDPbetaS or the IP3 receptor inhibitor heparin prevented long-term depression but allowed long-term potentiation induction. Also Ca^<2+> chelation by EGTA prevented long-term depression. These experiments suggest that Ca^<2+> released from cytosolic stores resulted in long-term depression, whereas Ca^<2+> influxes lead to long-term potentiation. It thus seems that Ca^<2+> source may determine the whole fate of synaptic regulation.

谷氨酸是大脑皮层中主要的兴奋性神经递质。阻断 NMDA 和非 NMDA 离子型谷氨酸受体后，突触前纤维的强直作用会导致长期抑制。进一步的激动剂和拮抗剂实验表明，一些 G 蛋白连接的、1,4,5-三磷酸肌醇 (IP3) 偶联类型的代谢型谷氨酸受体 (mGluR) 参与了这种长期抑郁症的诱导。细胞内注射 G 蛋白抑制剂 GDPbetaS 或 IP3 受体抑制剂肝素可以防止长期抑制，但可以诱导长期增强。 EGTA 的Ca 2+ 螯合也预防了长期抑郁。这些实验表明，从胞质储存中释放的Ca 2+ 导致长期抑制，而Ca 2+ 流入导致长期增强。因此看来Ca^2+来源可能决定突触调节的整个命运。

项目成果

Kato,N.: "Mechanisms of β-adrenergic facilitation of LTP in rat visual cortex." Neuroreport. 4. 1087-1090 (1993)

Kato, N.：“大鼠视觉皮层中 β-肾上腺素能促进 LTP 的机制”，Neuroreport 4. 1087-1090 (1993)。

Kato N and Yoshimura H: "Tetanization during GABA-A activation induces long-term depression in visual cortex slices." Neuropharmacology. 32. 511-513 (1993)

Kato N 和 Yoshimura H：“GABA-A 激活过程中的强直作用会导致视觉皮层切片的长期抑制。”

Kato,N.,and Yoshimura,H.: "Tetanization during GABA-A activation induces long-term depression in visual cortex slices." Neuropharmacology. 32. 511-513 (1993)

Kato,N. 和 Yoshimura,H.：“GABA-A 激活过程中的强直作用会导致视觉皮层切片的长期抑制。”

Kato N, Yoshimura H: "Reduced Mg^<2+>block of N-methyl-D-aspartate receptor-mediated synaptic potentials in developing visual cortex." Proc Natl Acad Sci USA.90. 7114-7118 (1993)

Kato N，Yoshimura H：“在发育中的视觉皮层中减少 Mg^2 对 N-甲基-D-天冬氨酸受体介导的突触电位的阻断。”

Kato,N.,and Yoshimura,H.: "Reduced Mg^<2+> block of N-methyl-D-aspartate receptor-mediated synaptic potentials in developing visual cortex" Proc.Natl.Acad.Sci USA. 90. 7114-7118 (1993)

Kato,N.和Yoshimura,H.：“在发育中的视觉皮层中减少N-甲基-D-天冬氨酸受体介导的突触电位的Mg^2阻断”Proc.Natl.Acad.Sci USA。