Structural stabilization of CNS synapses during postnatal development in rat cortex.
Structural stabilization of CNS synapses during postnatal development in rat cortex.
复制标题
大鼠皮层出生后发育过程中中枢神经系统突触的结构稳定性。
DOI：
10.1111/j.1471-4159.2006.03898.x
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发表时间：
2006
期刊：
影响因子：
--
通讯作者：
Phillips,GregR
中科院分区：
文献类型：
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作者：
Khaing,ZinZ;Fidler,Lazar;Nandy,Nina;Phillips,GregR
CNS突触在突触前和突触后募集时迅速产生。然而，已知它们的组成在发育过程中会发生变化，我们推断这可能反映在突触的总生化特性中。我们发现突触结构在成人皮质突触体是抵抗消化与胰蛋白酶的存在和不存在的钙离子，与以前的观察。我们评估了二价阳离子依赖性和胰蛋白酶敏感性的突触使用不同发育阶段的突触体。与成年突触相反，在出生后第10天（P），EDTA处理消除了约60%的突触，胰蛋白酶和EDTA一起消除了所有连接。在钙存在下的胰蛋白酶消化在P10消除了约60%的连接。到P35时，所有突触都不依赖钙，而直到P49才达到完全的胰蛋白酶抵抗。为了比较成人大脑另一区域突触的钙依赖性和胰蛋白酶敏感性，我们检测了成人（P50）海马的突触。成人海马保持了一个人口的突触，类似于P35皮层。我们的研究结果表明，突触修改了很长一段时间在发展中的皮层。我们提出了一个模型，其中添加协同的钙依赖性和非依赖性粘附系统稳定突触。
CNS synapses are produced rapidly upon pre‐ and post‐synaptic recruitment. However, their composition is known to change during development and we reasoned that this may be reflected in the gross biochemical properties of synapses. We found synaptic structure in adult cortical synaptosomes to be resistant to digestion with trypsin in the presence and absence of calcium ions, contrasting with previous observations. We evaluated the divalent cation dependence and trypsin sensitivities of synapses using synaptosomes from different developmental stages. In contrast to adult synapses, at postnatal day (P) 10 EDTA treatment eliminated ∼60% of the synapses, and trypsin and EDTA, together, eliminated all junctions. Trypsinization in the presence of calcium eliminated ∼60% of the junctions at P10. By P35, all synapses were calcium independent, whereas full trypsin resistance was not attained until P49. To compare the calcium dependence and trypsin sensitivity of synapses in another region of the adult brain, we examined synapses from adult (P50) hippocampus. Adult hippocampus maintained a population of synapses that resembled that of P35 cortex. Our results show that synapses are modified over a long time period in the developing cortex. We propose a model in which the addition of synergistic calcium‐dependent and ‐independent adhesive systems stabilize synapses.