Role of Immediate-Early Genes in Synaptic Plasticity and Neuronal Ensembles Underlying the Memory Trace.
Role of Immediate-Early Genes in Synaptic Plasticity and Neuronal Ensembles Underlying the Memory Trace.
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DOI：
10.3389/fnmol.2015.00078
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发表时间：
2015
影响因子：
4.8
通讯作者：
Okuno H
中科院分区：
文献类型：
--
作者：
Minatohara K;Akiyoshi M;Okuno H
在脑中，神经元基因表达响应于神经元活动而动态变化。特别是，在与学习和记忆形成相关的特定脑区的神经元亚群中，立即早期基因（IEG）（如EST-I、c-fos和Arc）的表达迅速且选择性地上调。IEG的表达因此被广泛用作神经元群体的分子标记，这些神经元群体经历长期记忆形成的潜在可塑性变化。近年来，对表达c-fos或Arc的神经元的光遗传学和药物遗传学研究表明，在学习过程中，IEG阳性神经元编码和储存记忆回忆所需的信息，这表明它们可能参与记忆痕迹的形成。然而，尽管越来越多的证据表明IEGs在突触可塑性中的作用，但与此过程相关的分子和细胞机制仍不清楚。在这篇综述中，我们首先总结了最近的文献有关的作用，IEG表达的神经元合奏组织的记忆痕迹。然后，我们专注于IEGs，特别是弧，在突触可塑性的生理意义，并描述了我们的假设的重要性，弧表达在各种类型的输入特定的电路重组。最后，我们提供了Arc功能的观点，揭示了在海马和其他脑区记忆痕迹形成中表达IEG的神经元的作用。
In the brain, neuronal gene expression is dynamically changed in response to neuronal activity. In particular, the expression of immediate-early genes (IEGs) such as egr-1, c-fos, and Arc is rapidly and selectively upregulated in subsets of neurons in specific brain regions associated with learning and memory formation. IEG expression has therefore been widely used as a molecular marker for neuronal populations that undergo plastic changes underlying formation of long-term memory. In recent years, optogenetic and pharmacogenetic studies of neurons expressing c-fos or Arc have revealed that, during learning, IEG-positive neurons encode and store information that is required for memory recall, suggesting that they may be involved in formation of the memory trace. However, despite accumulating evidence for the role of IEGs in synaptic plasticity, the molecular and cellular mechanisms associated with this process remain unclear. In this review, we first summarize recent literature concerning the role of IEG-expressing neuronal ensembles in organizing the memory trace. We then focus on the physiological significance of IEGs, especially Arc, in synaptic plasticity, and describe our hypotheses about the importance of Arc expression in various types of input-specific circuit reorganization. Finally, we offer perspectives on Arc function that would unveil the role of IEG-expressing neurons in the formation of memory traces in the hippocampus and other brain areas.