Environmental influences on cortical development and plasticity via Cl^-homeostasis modulation

环境通过 Cl^-稳态调节对皮质发育和可塑性的影响

基本信息

批准号：
16390058
负责人：
FUKUDA Atsuo
金额：
$ 9.22万
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 (B)
财政年份：
2004
资助国家：
日本
起止时间：
2004 至 2006
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-16390058/
关键词：
Cl^- transporter cortical plate cell Cajal-Retzius cell cell migration GABA taurine maternal stress Germany 国際情報交換

项目摘要

The aim of this study is to examine a validity of the hypothesis that a programmed Cl^- homeostasis of the developmental period renders GABA excitatory and promotes corticogenesis by cell migration, and that its change by environmental stimulation influence the neural circuit formation and plasticity. We established a method to distinguish between radially-migrating glutamate cells and tangentially-migrating GABA cells in living slices, by means of transfection of the HcRed gene into a GAD67-GFP knock-in mouse embryo brain in vivo. Taurine, abundantly contained in embryo brains, might act as autocrine endogenous agonist of GABA_A receptors for radial migration, and might also act as paracrine agonist for a signal to tangential migration. As for transfected ectopic KCC2, it was suggested that it did not function in vivo during radial migration. Therefore, we have designed the base sequence which was most suitable for shRNA which interfere a transcription process of a Cl^- transporter, a … More nd constructed an expression plasmid vector encoding it. Regarding the communication within the marginal zone containing the Cajal-Retzius cells which play an important role in radial migration, GABA and taurine worked as endogenous agonists of GABA_A and glycine receptors, respectively, that promoted a spread of excitation within the marginal zone. GABA_A and the glycine receptors, that were originally inhibitory, increased an excitability due to high [Cl^-]_i what was maintained by NKCC1. However, glutamate receptors which are originally excitatory did not participate. Considering maternal stress as environmental stimulation for embryos, we developed a mouse model of restriction stress to a mother, which were confined in a cylinder of 3cm diameter and 9cm in length for six hours/day from 8th to 17th gestational days. Both the body weight and the brain weight of embryos at day 18th were significantly decreased in comparison with control, indicating an influence to the embryonic brain development by maternal stress. Less

本研究的目的是检验以下假设的有效性：发育期的程序化 Cl^- 稳态使 GABA 兴奋并通过细胞迁移促进皮质生成，并且我们建立了环境影响刺激神经回路形成和可塑性的变化。一种通过将 HcRed 基因转染到活切片中区分径向迁移的谷氨酸细胞和切向迁移的 GABA 细胞的方法体内 GAD67-GFP 敲入小鼠胚胎脑中，胚胎脑中富含牛磺酸，可能充当径向迁移的 GABA_A 受体的自分泌内源激动剂，也可能充当切向迁移信号的旁分泌激动剂。异位KCC2，表明它在径向迁移过程中在体内不起作用，因此，我们设计了最适合干扰shRNA的碱基序列。 Cl^-转运蛋白的转录过程，构建了编码它的表达质粒载体，关于包含在径向迁移中发挥重要作用的Cajal-Retzius细胞的边缘区域内的通讯，GABA和牛磺酸作为内源性发挥作用。 GABA_A 和甘氨酸受体的激动剂分别促进边缘区内兴奋的扩散，而最初具有抑制性的甘氨酸受体则增加了兴奋性。 NKCC1维持高[Cl^-]_i，但是，最初具有兴奋性的谷氨酸受体不参与其中，考虑到母体应激是对胚胎的环境刺激，我们开发了一种对母体产生限制性应激的小鼠模型。直径3厘米、长度9厘米的圆柱体，从妊娠第8天到第17天，每天6小时，第18天胚胎的体重和脑重量与对照相比显着下降，表明母亲压力对胚胎大脑发育的影响较小。