Drebrin a content correlates with spine head size in the adult mouse cerebral cortex
Drebrin a content correlates with spine head size in the adult mouse cerebral cortex
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DOI：
10.1002/cne.21408
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发表时间：
2007-08-10
影响因子：
2.5
通讯作者：
Shirao, Tomoaki
中科院分区：
文献类型：
--
作者：
Kobayashi, Chiho;Aoki, Chiye;Shirao, Tomoaki
突触活动改变轴棘连接处的突触强度，这种变化通常伴随着突触后棘大小的变化。我们一直在探索这样的想法：drebrin A（一种位于兴奋性突触突触后侧的神经元特异性肌动蛋白结合蛋白）可能是将突触活动与棘的形状和内容联系起来的分子。在这里，我们使用非扩散金标记进行了电子显微镜免疫细胞化学，以探讨成年小鼠大脑中 N-甲基-D-天冬氨酸受体 NR2A 亚基 Drebrin A 的水平与成年小鼠大脑鼻周皮层棘大小之间的关系。与新生棘中的膜定位相反，drebrin A 的大多数免疫金颗粒定位于成熟棘中棘的细胞质核心区域。这种分布表明，除了已知的新生儿脊柱形成中的作用之外，成人脊柱中的树突蛋白可能会重组脊柱核心的 F-肌动蛋白网络。与drebrin A 免疫阴性(DIN) 棘相比，Drebrin A 免疫阳性(DIP) 棘表现出更大的棘头面积和更长的突触后密度(PSD) (P < 0.001)。此外，脊柱头部面积和 PSD 长度与 drebrin A 水平呈正相关（r = 0.47 和 0.40）。 DIP 棘突中的突触 NR2A 免疫标记数量也高于 DIN 棘突，而 PSD 每单位长度的密度没有显着差异。 DIP 和 DIN 棘突之间的这些差异表明，成熟大脑的棘突大小和突触蛋白组成至少部分受到 drebrin A 水平的调节。
Synaptic activities alter synaptic strengths at the axospinous junctions, and such changes are often accompanied by changes in the size of the postsynaptic spines. We have been exploring the idea that drebrin A, a neuron-specific actin-binding protein localized on the postsynaptic side of excitatory synapses, may be a molecule that links synaptic activity to the shape and content of spines. Here, we performed electron microscopic immunocytochemistry with the nondiffusible gold label to explore the relationship among levels of drebrin A, the NR2A subunit of N-methyl-D-aspartate receptors, and the size of spines in the perirhinal cortex of adult mouse brains. In contrast to the membranous localization within neonatal spines, most immunogold particles for drebrin A were localized to the cytoplasmic core region of spines in mature spines. This distribution suggests that drebrin within adult spines may reorganize the F-actin network at the spine core, in addition to its known neonatal role in spine formation. Drebrin A-immunopositive (DIP) spines exhibited larger spine head areas and longer postsynaptic densities (PSDs) than drebrin A-immunonegative (DIN) spines (P < 0.001). Furthermore, spine head area and PSD lengths correlated positively with drebrin A levels (r = 0.47 and 0.40). The number of synaptic NR2A immunolabels was also higher in DIP spines than in DIN spines, whereas their densities per unit lengths of PSD were not significantly different. These differences between the DIP and the DIN spines indicate that spine sizes and synaptic protein composition of mature brains are regulated, at least in part, by drebrin A levels.