Large and Small Dendritic Spines Serve Different Interacting Functions in Hippocampal Synaptic Plasticity and Homeostasis.
Large and Small Dendritic Spines Serve Different Interacting Functions in Hippocampal Synaptic Plasticity and Homeostasis.
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DOI：
10.1155/2016/6170509
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发表时间：
2016
影响因子：
3.1
通讯作者：
Edwards FA
中科院分区：
文献类型：
--
作者：
Paulin JJ;Haslehurst P;Fellows AD;Liu W;Jackson JD;Joel Z;Cummings DM;Edwards FA
记忆的形成需要强烈的刺激，导致突触强度的特定变化和树突棘大小的相应变化。强烈的刺激也可能是病理性的，引起稳态反应，抑制和收缩突触，以防止过多的Ca2+内流造成损害。但是，所有类型的树突棘都具有这两种明显相反的功能吗？在海马神经元中表达绿色荧光蛋白的小鼠的器官型切片中使用共聚焦显微镜，已经跟踪了响应于四乙基铵的应用的树突沿着部分的单个棘的大小。这种强烈的刺激预计会引起保护性稳态反应和长时程增强。我们报告这些功能的分离，不同大小的棘对相同的强刺激有不同的反应。大棘的立即收缩表明在潜在危险期间的自我平衡保护反应。在CA1中，小棘的持久生长随后发生巩固长时程增强，但只有在大棘恢复到其原始大小之后。与此相反，小棘不改变齿状回的增强不发生。这些变化在时间上的分离允许不同大小的棘的明确的功能分化。
The laying down of memory requires strong stimulation resulting in specific changes in synaptic strength and corresponding changes in size of dendritic spines. Strong stimuli can also be pathological, causing a homeostatic response, depressing and shrinking the synapse to prevent damage from too much Ca2+ influx. But do all types of dendritic spines serve both of these apparently opposite functions? Using confocal microscopy in organotypic slices from mice expressing green fluorescent protein in hippocampal neurones, the size of individual spines along sections of dendrite has been tracked in response to application of tetraethylammonium. This strong stimulus would be expected to cause both a protective homeostatic response and long-term potentiation. We report separation of these functions, with spines of different sizes reacting differently to the same strong stimulus. The immediate shrinkage of large spines suggests a homeostatic protective response during the period of potential danger. In CA1, long-lasting growth of small spines subsequently occurs consolidating long-term potentiation but only after the large spines return to their original size. In contrast, small spines do not change in dentate gyrus where potentiation does not occur. The separation in time of these changes allows clear functional differentiation of spines of different sizes.