The elucidation of developmental synaptic elimination mechanisms using in vivo patch-clamp methods and two-photon imaging

使用体内膜片钳方法和双光子成像阐明发育突触消除机制

• 批准号: 21700428
• 负责人: KAWAMURA Yoshinobu
• 金额: $ 2.75万
• 依托单位: The University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Young Scientists (B)
• 财政年份: 2009
• 资助国家: 日本
• 起止时间: 2009 至 2010
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-21700428/
• 关键词: 神経科学; 脳・神経; 小脳; プルキンエ細胞; 登上線維; 発達; シナプス; in vivo

Development of functional neuronal circuits involves initial formation of supernumerary synaptic connections followed by strengthening of necessary synapses and elimination of redundant ones in early postnatal life. How neuronal activity contributes to this developmental process still remains unknown. We examined activities of Climbing-fiber(CF)-Purkinje cell(PC) synapses in intact cerebellum of developing rat by in vivo whole-cell recordings and two-photon Ca^<2+> imaging. We found that burst spiking (BS) of immature PC required summation of multiple CF inputs. Importantly the CF-EPSP just before the BS onset was selectively strengthened during postnatal development. Since BS elicited Ca^<2+> transients in PCs, the CF-EPSP synchronous to the BS-induced Ca^<2+> rise appeared to be potentiated. Thus, spike timing-dependent mechanisms involving synchronous CF inputs and postsynaptic Ca^<2+> elevation appear to underlie the selection of single CFs and the establishment of mature CF-PC connections in individual PCs.

功能性神经元回路的发育包括额外突触连接的初步形成，随后是必要突触的加强和出生后早期多余突触的消除。神经元活动如何促进这一发育过程仍然是未知的。本研究采用在体全细胞记录和双光子Ca ^2+成像技术，观察了发育中大鼠小脑爬行纤维（CF）-浦肯野细胞（PC）突触的活动。我们发现不成熟PC的爆发尖峰（BS）需要多个CF输入的总和。重要的是，在出生后发育过程中，BS发作前的CF-EPSP选择性地增强。由于BS引起了PC中的Ca ^<2 +>瞬变，与BS诱导的Ca ^<2 +>升高同步的CF-EPSP似乎被增强。因此，包括同步CF输入和突触后Ca ^2+升高的锋电位时间依赖性机制似乎是单个CF选择和单个PC中成熟CF-PC连接建立的基础。

项目成果

Analysis of climbing fiber inputs to Purkinje cells in the developing rat cerebellum in vivo.

分析体内发育中的大鼠小脑中浦肯野细胞的攀爬纤维输入。

• 发表时间: 2009
• 作者: K.Yamamoto;J.Ando;Kawamura Y
• 通讯作者: Kawamura Y