Expression and Localization of the Calmodulin-Binding Protein Neurogranin in the Adult Mouse Olfactory Bulb
Expression and Localization of the Calmodulin-Binding Protein Neurogranin in the Adult Mouse Olfactory Bulb
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DOI：
10.1002/cne.22177
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发表时间：
2009-12-10
影响因子：
2.5
通讯作者：
De Marchis, S.
中科院分区：
文献类型：
--
作者：
Gribaudo, S.;Bovetti, S.;De Marchis, S.
Neurogranin (Ng) 是一种大脑特异性突触后蛋白，通过调节神经元中 Ca(2+)/钙调蛋白 (CaM) 依赖性信号转导来参与活动依赖性突触可塑性。在这项研究中，我们使用生化和免疫组织化学方法，证明了成年小鼠嗅球（OB）中的 Ng 表达，嗅球是气味信息处理的第一个中继站。我们发现 Ng 主要与颗粒细胞层 (GCL) 有关，颗粒细胞层由颗粒细胞抑制性中间神经元组成。这种细胞类型在成年期间不断更新，在 OB 回路中发挥关键作用，整合和调节二尖瓣/簇状细胞的活性。我们的结果表明，Ng 定位于成熟 GABA 能颗粒细胞的特定亚群的体细胞和树突中，富含 GCL 的深部。 Ng免疫阳性细胞主要共表达Ca(+)/CaM依赖性激酶IV (CaMKIV)，CaM信号级联的下游蛋白，而Ng和钙结合蛋白钙结合蛋白之间没有观察到共定位。最后，我们证明成体神经发生有助于 Ng 表达群体，更多新生成的 Ng 阳性细胞整合到深层 GCL 中。总之，这些结果提供了一种新的特异性神经化学标记物来识别嗅粒细胞亚群，并提示 Ng 在 OB 可塑性机制中可能的功能意义。 J.Comp。内罗尔。 517:683-694, 2009。(C) 2009 Wiley-Liss, Inc.
Neurogranin (Ng) is a brain-specific postsynaptic protein involved in activity-dependent synaptic plasticity through modulation of Ca(2+)/calmodulin (CaM)-dependent signal transduction in neurons. In this study, using biochemical and immunohistochemical approaches, we demonstrate Ng expression in the adult mouse olfactory bulb (OB), the first relay station in odor information processing. We show that Ng is principally associated with the granule cell layer (GCL), which is composed of granule cell inhibitory interneurons. This cell type is continuously renewed during adult life and plays a key role in OB circuits, integrating and modulating the activity of mitral/tufted cells. Our results indicate that Ng localizes in the soma and dendrites of a defined subpopulation of mature GABAergic granule cells, enriched in the deep portion of the GCL. Ng-immunopositive cells largely coexpress the Ca(+)/CaM-dependent kinase IV (CaMKIV), a downstream protein of CaM signaling cascade, whereas no colocalization was observed between Ng and the calcium-binding protein calretinin. Finally, we demonstrate that adult neurogenesis contributes to the Ng-expressing population, with more newly generated Ng-positive cells integrated in the deep GCL. Together, these results provide a new specific neurochernical marker to identify a subpopulation of olfactory granule cells and suggest possible functional implications for Ng in OB plasticity mechanisms. J. Comp. Neurol. 517:683-694, 2009. (C) 2009 Wiley-Liss, Inc.