Soulé Jonathan, Penke Zsuzsa, Kanhema Tambudzai, Alme Maria Nordheim, Laroche Serge, Bramham Clive R
Department of Biomedicine and Bergen Mental Health Research Center, University of Bergen, Bergen, Norway.
Neural Plast. 2008;2008:269097. doi: 10.1155/2008/269097. Epub 2009 Jan 26.
Long-term recognition memory requires protein synthesis, but little is known about the coordinate regulation of specific genes. Here, we examined expression of the plasticity-associated immediate early genes (Arc, Zif268, and Narp) in the dentate gyrus following long-term object-place recognition learning in rats. RT-PCR analysis from dentate gyrus tissue collected shortly after training did not reveal learning-specific changes in Arc mRNA expression. In situ hybridization and immunohistochemistry were therefore used to assess possible sparse effects on gene expression. Learning about objects increased the density of granule cells expressing Arc, and to a lesser extent Narp, specifically in the dorsal blade of the dentate gyrus, while Zif268 expression was elevated across both blades. Thus, object-place recognition triggers rapid, blade-specific upregulation of plasticity-associated immediate early genes. Furthermore, Western blot analysis of dentate gyrus homogenates demonstrated concomitant upregulation of three postsynaptic density proteins (Arc, PSD-95, and alpha-CaMKII) with key roles in long-term synaptic plasticity and long-term memory.
长期识别记忆需要蛋白质合成，但对于特定基因的协同调控却知之甚少。在此，我们检测了大鼠在进行长期物体-位置识别学习后，齿状回中与可塑性相关的即刻早期基因（Arc、Zif268和Narp）的表达情况。对训练后不久采集的齿状回组织进行的RT-PCR分析未发现Arc mRNA表达存在学习特异性变化。因此，采用原位杂交和免疫组织化学方法来评估对基因表达可能产生的稀疏效应。对物体的学习增加了表达Arc的颗粒细胞的密度，在较小程度上也增加了表达Narp的颗粒细胞的密度，特别是在齿状回的背侧叶片中，而Zif268的表达在两个叶片中均升高。因此，物体-位置识别触发了与可塑性相关的即刻早期基因的快速、叶片特异性上调。此外，对齿状回匀浆的蛋白质印迹分析表明，三种在长期突触可塑性和长期记忆中起关键作用的突触后致密蛋白（Arc、PSD-95和α-CaMKII）也同时上调。
