Rapid structural remodeling of thalamocortical synapses parallels experience-dependent functional plasticity in mouse primary visual cortex.
Rapid structural remodeling of thalamocortical synapses parallels experience-dependent functional plasticity in mouse primary visual cortex.
复制标题
丘脑皮质突触的快速结构重塑使小鼠初级视觉皮层的经验依赖性功能可塑性。
DOI：
10.1523/jneurosci.1248-10.2010
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发表时间：
2010-07-21
期刊：
影响因子：
--
通讯作者：
Bear MF
中科院分区：
文献类型：
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作者：
Coleman JE;Nahmani M;Gavornik JP;Haslinger R;Heynen AJ;Erisir A;Bear MF
单眼眼睑闭合(MC)引起初级视皮层(V1)神经元眼优势(OD)的显著改变。猫和小鼠V1的解剖学研究表明，对MC的反应，眼睛特异的丘脑皮质(TC)轴突的大规模结构重排发生得比OD变化慢得多。因此，对于将相互竞争的视觉信息从每只眼睛传递到V1的TC突触的可塑性是否有助于MC的早期功能后果，还是仅仅是长期剥夺的特征，一直存在着相当大的争论。在这里，我们使用定量免疫电子显微镜来检测TC突触的改变发生得足够快以影响短暂MC后OD的可能性。本文观察了短期剥夺对雄性C57BL/6小鼠MC和单眼视网膜灭活(MI)3d和7d后TC突触结构的影响。结果表明，3d的MC足以诱导TC突触的实质性重塑。相反，3d的MI改变了TC的活性，但不改变OD，对TC突触的结构没有显著的影响。我们的结果支持这一假设，即TC突触的快速可塑性是视皮层OD变化的一系列事件中的关键一步。
Monocular lid closure (MC) causes a profound shift in the ocular dominance (OD) of neurons in primary visual cortex (V1). Anatomical studies in both cat and mouse V1 suggest that large-scale structural rearrangements of eye-specific thalamocortical (TC) axons in response to MC occur much more slowly than the shift in OD. Consequently, there has been considerable debate as to whether the plasticity of TC synapses, which transmit competing visual information from each eye to V1, contributes to the early functional consequences of MC or is simply a feature of long-term deprivation. Here, we used quantitative immuno-electron microscopy to examine the possibility that alterations of TC synapses occur rapidly enough to impact OD after brief MC. The effect of short-term deprivation on TC synaptic structure was examined in male C57BL/6 mice that underwent 3 and 7 d of MC or monocular retinal inactivation (MI) with tetrodotoxin. The data show that 3 d of MC is sufficient to induce substantial remodeling of TC synapses. In contrast, 3 d of MI, which alters TC activity but does not shift OD, does not significantly affect the structure of TC synapses. Our results support the hypothesis that the rapid plasticity of TC synapses is a key step in the sequence of events that shift OD in visual cortex.