■γ-氨基丁酸(GABA)A型受体(GABAAR)是配体门控的Cl通道,可介导成熟CNS中大量的抑制性神经传递,并且是许多药物的靶标。在皮质发育过程中,GABAAR介导的信号通过改变Cl-转运蛋白的亚基组成和表达而被显着调节,这是发育过程和早期网络活动的一部分。迄今为止,这种发展演变仍未得到充分研究,特别是在皮质层特异性变化的水平。在这项研究中,我们表征了从胚胎发育到断奶后成熟的小鼠体感皮层中9个主要GABAAR亚基和K-Cl转运蛋白2(KCC2)的表达。
■我们使用免疫组织化学和蛋白质印迹技术评估了α1-5,β2-3,γ2和δGABAAR亚基的表达,和使用免疫组织化学在E13.5至P25小鼠的皮质中KCC2的表达。
■我们发现胚胎皮质主要表达α3,α5,β3和γ2,而α1,α2,α4,β2,δ,KCC2在开发的后期开始;然而,在特定的薄层中可以找到许多细微的表达模式,皮质区域,细胞和结构。
■虽然每个亚基和KCC2的表达模式与以前的研究相似,我们发现了一些独特的时间,区域,和以前未知的层状模式。这些发现为GABAAR组成和KCC2表达的复杂发育进化提供了急需的知识,以适应过渡到成熟神经传递的发育信号。
UNASSIGNED: γ-Aminobutyric acid (GABA) type A receptors (GABAARs) are ligand-gated Cl-channels that mediate the bulk of inhibitory neurotransmission in the mature CNS and are targets of many drugs. During cortical development, GABAAR-mediated signals are significantly modulated by changing subunit composition and expression of Cl-transporters as part of developmental processes and early network activity. To date, this developmental evolution has remained understudied, particularly at the level of cortical layer-specific changes. In this study, we characterized the expression of nine major GABAAR subunits and K-Cl transporter 2 (KCC2) in mouse somatosensory cortex from embryonic development to postweaning maturity.
UNASSIGNED: We evaluated expression of α1-5, β2-3, γ2, and δ GABAAR subunits using immunohistochemistry and Western blot techniques, and expression of KCC2 using immunohistochemistry in cortices from E13.5 to P25 mice.
UNASSIGNED: We found that embryonic cortex expresses mainly α3, α5, β3, and γ2, while expression of α1, α2, α4, β2, δ, and KCC2 begins at later points in development; however, many patterns of nuanced expression can be found in specific lamina, cortical regions, and cells and structures.
UNASSIGNED: While the general pattern of expression of each subunit and KCC2 is similar to previous studies, we found a number of unique temporal, regional, and laminar patterns that were previously unknown. These findings provide much needed knowledge of the intricate developmental evolution in GABAAR composition and KCC2 expression to accommodate developmental signals that transition to mature neurotransmission.