A synaptic memory trace for cortical receptive field plasticity
A synaptic memory trace for cortical receptive field plasticity
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DOI：
10.1038/nature06289
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发表时间：
2007-11-15
期刊：
影响因子：
64.8
通讯作者：
Schreiner, Christoph E.
中科院分区：
文献类型：
--
作者：
Froemke, Robert C.;Merzenich, Michael M.;Schreiner, Christoph E.
感觉皮层神经元的感受野是可塑性的，会随着神经活动或感觉体验的改变而改变（1-12）。通过这种方式，感觉环境的皮层表征可以包含关于世界的新信息，这取决于特定刺激的相关性或价值（1，6，9）。皮质可塑性需要神经调节，但尚不确定皮质下神经调节系统（如胆碱能基底核）如何与皮质回路相互作用并改善皮质回路（13-24）。在这里，我们使用体内全细胞记录来确定成人初级听觉皮质（也称为AI）中突触感受野可塑性的动态变化。配对感觉刺激与基底核激活转移皮层神经元的首选刺激诱导突触抑制在几秒钟内迅速减少，其次是一个大的兴奋增加，这两个特定的配对刺激。虽然基底核只刺激了几分钟，突触调谐曲线的重组进展了几个小时之后：抑制缓慢增加的活动依赖性的方式重新平衡的持续增强的兴奋，导致一个重新调整的感受野与新的偏好配对刺激。这段限制性的去抑制期可能是感受野可塑性的一个基本机制，并且可以作为获得新的行为意义的刺激或事件的记忆痕迹（9，25）。
Receptive fields of sensory cortical neurons are plastic, changing in response to alterations of neural activity or sensory experience(1-12). In this way, cortical representations of the sensory environment can incorporate new information about the world, depending on the relevance or value of particular stimuli(1,6,9). Neuromodulation is required for cortical plasticity, but it is uncertain how subcortical neuromodulatory systems, such as the cholinergic nucleus basalis, interact with and refine cortical circuits(13-24). Here we determine the dynamics of synaptic receptive field plasticity in the adult primary auditory cortex ( also known as AI) using in vivo whole-cell recording. Pairing sensory stimulation with nucleus basalis activation shifted the preferred stimuli of cortical neurons by inducing a rapid reduction of synaptic inhibition within seconds, which was followed by a large increase in excitation, both specific to the paired stimulus. Although nucleus basalis was stimulated only for a few minutes, reorganization of synaptic tuning curves progressed for hours thereafter: inhibition slowly increased in an activity-dependent manner to rebalance the persistent enhancement of excitation, leading to a retuned receptive field with new preference for the paired stimulus. This restricted period of disinhibition may be a fundamental mechanism for receptive field plasticity, and could serve as a memory trace(9,25) for stimuli or episodes that have acquired new behavioural significance.