Circadian gating of neuronal functionality: a basis for iterative metaplasticity.
Circadian gating of neuronal functionality: a basis for iterative metaplasticity.
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DOI：
10.3389/fnsys.2014.00164
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发表时间：
2014
影响因子：
3
通讯作者：
Gillette MU
中科院分区：
文献类型：
--
作者：
Iyer R;Wang TA;Gillette MU
大脑可塑性是神经系统编码经验的能力，是一个导致持久结构和功能变化的调节过程。显着的经历会引起海马体神经元的可塑性变化，这是记忆形成和回忆的基础。在视交叉上核 (SCN) 中，即中央昼夜节律（~24 小时）时钟，夜间的光照体验会引起神经元状态的变化，从而导致昼夜节律可塑性。 SCN 的内源性约 24 小时时间发生器包含一系列动态功能状态，可控制塑性反应。这限制了光引起的 SCN 状态动态变化和夜间输出。内源性产生的昼夜节律振荡器协调兴奋性和细胞内信号分子的循环状态，从而启动 SCN 对可塑性信号的感受性，产生夜间易感性窗口。我们认为，这构成了约 24 小时迭代化塑性的范例，即对神经元可塑性诱导的敏感性的重复、模式化发生。我们详细介绍了允许可塑性循环敏感性的效应器。我们考虑了 SCN 昼夜节律可塑性和海马长时程增强 (LTP) 中可塑性的细胞内和膜机制的相似性。海马生物钟的日益突出也表明了该组织的迭代化塑性。探索这些联系对于理解突触可塑性、学习和记忆的昼夜节律塑造有着巨大的希望。
Brain plasticity, the ability of the nervous system to encode experience, is a modulatory process leading to long-lasting structural and functional changes. Salient experiences induce plastic changes in neurons of the hippocampus, the basis of memory formation and recall. In the suprachiasmatic nucleus (SCN), the central circadian (~24-h) clock, experience with light at night induces changes in neuronal state, leading to circadian plasticity. The SCN's endogenous ~24-h time-generator comprises a dynamic series of functional states, which gate plastic responses. This restricts light-induced alteration in SCN state-dynamics and outputs to the nighttime. Endogenously generated circadian oscillators coordinate the cyclic states of excitability and intracellular signaling molecules that prime SCN receptivity to plasticity signals, generating nightly windows of susceptibility. We propose that this constitutes a paradigm of ~24-h iterative metaplasticity, the repeated, patterned occurrence of susceptibility to induction of neuronal plasticity. We detail effectors permissive for the cyclic susceptibility to plasticity. We consider similarities of intracellular and membrane mechanisms underlying plasticity in SCN circadian plasticity and in hippocampal long-term potentiation (LTP). The emerging prominence of the hippocampal circadian clock points to iterative metaplasticity in that tissue as well. Exploring these links holds great promise for understanding circadian shaping of synaptic plasticity, learning, and memory.