Neuronal plasticity affects correlation between the size of dendritic spine and its postsynaptic density
Neuronal plasticity affects correlation between the size of dendritic spine and its postsynaptic density
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DOI：
10.1038/s41598-018-38412-7
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发表时间：
2019-02-08
影响因子：
4.6
通讯作者：
Radwanska, Kasia
中科院分区：
文献类型：
--
作者：
Borczyk, Malgorzata;Sliwinska, Malgorzata Alicja;Radwanska, Kasia
树突棘的结构可塑性被认为是记忆形成的基础。树突棘的大小被认为与其突触后密度(PSD)、谷氨酸受体的数量和突触强度成正比。然而，这种相关性是否适用于所有树突棘体积，并在突触可塑性期间保持稳定，在很大程度上尚不清楚。在这项研究中，我们利用三维电子显微镜，从器官型海马脑片CA1区的放射层重建了PSD的树突和核心。我们观察到，在中等大小的范围内，大约1/3的树突棘体积与PSD表面积或PSD核心体积之间未能达到显著的相关性。在NMDA受体依赖的化学长时程增强(NMDAR-cLTP)过程中，树突棘及其PSD不仅生长，而且PSD面积和PSD核心体积与脊椎体积的比率增大，两者的大小之间的相关性变得更加紧密。进一步的分析表明，在cLTP过程中，只有含有光滑内质网(SER)的脊柱才会生长，而PSD核心的生长与脊柱中SERR的存在无关。有SER的树突与无SER的树突相比，体积参数的相关性也更高，而且这种相关性在cLTP过程中只在含有SER的棘中进一步增强。总体而言，我们发现PSD表面积和脊柱体积之间的相关性在所有脊柱体积中并不一致，在突触可塑性过程中被修改和收紧，并受到SER的调节。
Structural plasticity of dendritic spines is thought to underlie memory formation. Size of a dendritic spine is considered proportional to the size of its postsynaptic density (PSD), number of glutamate receptors and synaptic strength. However, whether this correlation is true for all dendritic spine volumes, and remains stable during synaptic plasticity, is largely unknown. In this study, we take advantage of 3D electron microscopy and reconstruct dendritic spines and cores of PSDs from the stratum radiatum of the area CA1 of organotypic hippocampal slices. We observe that approximately 1/3 of dendritic spines, in a range of medium sizes, fail to reach significant correlation between dendritic spine volume and PSD surface area or PSD-core volume. During NMDA receptor-dependent chemical long-term potentiation (NMDAR-cLTP) dendritic spines and their PSD not only grow, but also PSD area and PSD-core volume to spine volume ratio is increased, and the correlation between the sizes of these two is tightened. Further analysis specified that only spines that contain smooth endoplasmic reticulum (SER) grow during cLTP, while PSD-cores grow irrespectively of the presence of SER in the spine. Dendritic spines with SER also show higher correlation of the volumetric parameters than spines without SER, and this correlation is further increased during cLTP only in the spines that contain SER. Overall, we found that correlation between PSD surface area and spine volume is not consistent across all spine volumes, is modified and tightened during synaptic plasticity and regulated by SER.