Analysis for the cycle variation of [Cl^-]_i in supraoptic chiasma nucreus neuron

视上交叉核神经元[Cl^-]_i周期变化分析

• 批准号: 14570056
• 负责人: OKABE Akihito
• 金额: $ 2.37万
• 依托单位: HAMAMATSU UNIVERSITY SCHOOL OF MEDICINE
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2002
• 资助国家: 日本
• 起止时间: 2002 至 2003
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-14570056/
• 关键词: 6-methoxy-N-ethylquinolinium iodide (MEQ); suprachiasmatic nucleus (SCN); Cl^-transporter; Cl^-imaging; [Cl^-]_i; GABA; NKCC1; KCC2; 視交叉上核; 外側膝状体; 大脳皮質視覚野; Cl^-ホメオスタシス; Cl^-イメージング; 6-methoxy-N-ethylquinolinium iodide(MEQ); Cl^-imaging; リズム

GABA is the most principal inhibitory neurotransmitter in the brain. However, in the regulation of circadian rhythm, it is suggested that GABA shows the excitatory effect and plays an important role. In a living organism, physiological and behavioral parameters are known to be controlled by endogenous oscillators and to show a daily rhysmicity with a period of about 24h. The seat of the oscillator differs from species to species. In mammals, the suprachiasmatic nucleus (SCN) is widely accepted as the seat of the oscillator. In the visual system, it has been reported that GABA shows the excitatory effects on immature neurons in the retina and the visual cortex, hence inducing calcium influx. Thus, GABA is expected to have some trophic action in the process of the neuronal development. In this study, using optical imaging of [Cl]_i with 6-methoxy-N-ethylquinolinium iodide (MEQ) fluorescence, we have compared the effects of GABA on neuronal [Cl]_i changes in the SCN, the dorsal lateral geniculate nucleus (DLG), and the visual cortex (VC). In addition, we consider that differential regulational process of neuronal Cl^-homeostasis in those regions. Therefore, we examined the expession changes of cation-Cl^-cotransporters, e.g., outwardly directed K^+-Cl^-cotransporter KCC2 and inwardly directed Na^+,K^+-2Cl^-cotransporter NKCC1, in SCN, DLG and VC. The [Cl]_i and expression of NKCC1 mRNA of SCN neurons was higher in daytime than in nighttime. The application of vasopressin tended to downregulate [Cl]_i in daytime. And only in the immature VC, application of GABA elicited an increase in, indicating a decrease in [Cl]_i. In the P0 DLQ the expression of KCC2 mRNA signals were higher than that in VC. This suggests that extrusion of Cl^-from neuron is higher in the DLG than in the VC, so that GABAergic excitatory effect were not observed in DLG because of more negative equilibrium potential for Cl^-.

GABA是大脑中最主要的抑制性神经递质。但在昼夜节律的调节中，GABA表现出兴奋作用，起着重要作用。在生物体中，生理和行为参数都是由内源性振荡器控制的，并且表现出约24小时的日节律性。振子的位置因物种而异。在哺乳动物中，视交叉上核（SCN）被广泛认为是振荡器的所在地。在视觉系统中，据报道GABA对视网膜和视皮层中的未成熟神经元显示兴奋作用，从而诱导钙内流。因此，GABA在神经元发育过程中具有一定的营养作用。本研究采用碘化6-甲氧基-N-乙基喹啉（MEQ）荧光光学成像技术，比较了GABA对SCN、外侧膝状体背核（DLG）和视皮层（VC）神经元[Cl] i变化的影响。此外，我们还考虑了这些区域神经元Cl^-稳态的差异调节过程。因此，我们检测了阳离子-Cl ^-共转运蛋白的表达变化，例如，SCN、DLG和VC中的外向K^+-Cl^-共转运蛋白KCC 2和内向Na^+，K^+-2Cl ^-共转运蛋白NKCC 1。SCN神经元的[Cl] i和NKCC 1 mRNA表达在白天高于夜间。加压素的应用有降低[Cl] i的趋势。GABA处理仅引起未成熟VC的[Cl]_i增加，表明[Cl]_i降低。在P0 DLQ中KCC 2 mRNA信号的表达高于VC。这表明DLG中Cl^-的排出量高于VC，因此DLG中Cl^-的负平衡电位更高，因此未观察到GABA能兴奋效应。

项目成果

Okabe, A., et al.: "Amygdala kindling induces upregulation of mRNA for NKCC1, a Na^+, K^+-2Cl^-cotransporter, in the rat piriform cortex."Neurosci.Res.. 44. 223-227 (2002)

Okabe, A., 等人：“杏仁核点燃诱导大鼠梨状皮质中 NKCC1（一种 Na^ 、 K^ -2Cl^-协同转运蛋白） mRNA 的上调。”Neurosci.Res.. 44. 223-227 (2002

Shibata, S., Kakazu, Y., Okabe, A.et al.: "Experience-dependent changes in intracellular Cl^-regulation in developing auditory neurons."Neurosci.Res.. 48. 211-220 (2004)

Shibata, S.、Kakazu, Y.、Okabe, A.等人：“发育中的听觉神经元中细胞内 Cl^ 调节的经验依赖性变化。”Neurosci.Res.. 48. 211-220 (2004)

Okabe, A. et al.: "Homogenous glycine receptor expression in cortical plate neurons and Cajal-Retzius cells of neonatal rat cerebral cortex."Neuroscience. 123. 715-724 (2004)

Okabe, A. 等人：“新生大鼠大脑皮层的皮质板神经元和 Cajal-Retzius 细胞中的同质甘氨酸受体表达。”神经科学。

Oka T, Akisada M, Okabe A, et al.: "Extracellular serine protease neuropsin (KLK8) modulates neurite outgrowth and fasciculation of mouse hippocampal neurons in culture."Neuroscience Letters. 321. 141-144 (2002)

Oka T、Akisada M、Okabe A 等人：“细胞外丝氨酸蛋白酶神经蛋白酶 (KLK8) 调节培养物中小鼠海马神经元的神经突生长和束颤。”《神经科学快报》。

Ikeda, M., Toyoda, H., Yamada, J., Okabe, A., et al.: "Differential development of cation-chloride cotransporters and Cl^-homeostasis contributes to differential GABAergic actions between developing rat visual cortex and dorsal lateral geniculate nucleus.

Ikeda, M.、Toyoda, H.、Yamada, J.、Okabe, A. 等人：“阳离子-氯化物协同转运蛋白和 Cl^-稳态的差异发育有助于发育中的大鼠视觉皮层和背侧外侧之间的 GABA 能作用的差异