The calcium sensor synaptotagmin 1 is expressed and regulated in hippocampal postsynaptic spines
The calcium sensor synaptotagmin 1 is expressed and regulated in hippocampal postsynaptic spines
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DOI：
10.1002/hipo.22761
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发表时间：
2017-11-01
期刊：
影响因子：
3.5
通讯作者：
Davanger, Svend
中科院分区：
文献类型：
--
作者：
Hussain, Suleman;Egbenya, Daniel Lawer;Davanger, Svend
突触结合蛋白1是突触前钙离子传感器，调节SNARE介导的囊泡胞吐递质。越来越多的证据表明SNARE蛋白在突触后谷氨酸受体运输中的作用。然而，突触结合蛋白1可能的突触后表达尚未得到证实。在这里，我们使用postembedding免疫金电子显微镜，以确定突触结合蛋白1在大鼠海马CA1 Schaffer侧支突触的突触下定位。我们报告的第一次，synaptotagmin 1是目前在大鼠海马突触后棘，无论是在细胞质囊泡和突触后密度。我们进一步研究了突触后突触结合蛋白1是否在突触可塑性过程中受到调节。在慢性颞叶癫痫的大鼠模型中，我们发现与对照动物相比，突触前和突触后蛋白质浓度降低。这种下调可能是一种适应性措施，以减少突触前和突触后的兴奋性毒性条件下的钙敏感性。
Synaptotagmin 1 is a presynaptic calcium sensor, regulating SNARE-mediated vesicle exocytosis of transmitter. Increasing evidence indicate roles of SNARE proteins in postsynaptic glutamate receptor trafficking. However, a possible postsynaptic expression of synaptotagmin 1 has not been demonstrated previously. Here, we used postembedding immunogold electron microscopy to determine the subsynaptic localization of synaptotagmin 1 in rat hippocampal CA1 Schaffer collateral synapses. We report for the first time that synaptotagmin 1 is present in rat hippocampal postsynaptic spines, both on cytoplasmic vesicles and at the postsynaptic density. We further investigated whether postsynaptic synaptotagmin 1 is regulated during synaptic plasticity. In a rat model of chronic temporal lobe epilepsy, we found that presynaptic and postsynaptic concentrations of the protein are reduced compared to control animals. This downregulation may possibly be an adaptive measure to decrease both presynaptic and postsynaptic calcium sensitivity in excitotoxic conditions.