Complexity of Contacts Between Synaptic Boutons and Dendritic Spines in Adult Rat Hippocampus: Three-Dimensional Reconstructions From Serial Ultrathin Sections In Vivo
Complexity of Contacts Between Synaptic Boutons and Dendritic Spines in Adult Rat Hippocampus: Three-Dimensional Reconstructions From Serial Ultrathin Sections In Vivo
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DOI：
10.1002/syn.20613
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发表时间：
2009-05-01
期刊：
影响因子：
2.3
通讯作者：
Stewart, Michael G.
中科院分区：
文献类型：
--
作者：
Popov, Victor I.;Stewart, Michael G.
突触与树突棘之间的形态关系是突触功能的重要决定因素，在电子显微镜下已被广泛研究。这表明，每个脊椎有一个突触的普遍观点不再成立；树突棘有时可以形成具有两个或更多轴突钮扣的突触。为了阐明成年大鼠齿状回分子层中棘及其突触接触的详细结构和关系，利用轴突和树突突触前和突触后的连续超薄切片（每组多达150个切片）进行了三维重建研究。我们发现所有检查的无髓鞘轴突的突触都是在传递的，尽管突触和脊柱之间的大多数接触是一对一的，但所有检查的重建都包含多突触轴突段和多突触棘。在齿状回中，3.48%的蘑菇棘为多突触，与两个以上的轴突突触，占突触总数的0.46%。虽然这些值看起来很小，但它们实际上包含了每立方毫米组织的数百万次接触。轴突静脉曲张可以接触来自不同树突分支的三个以上的树突棘，而棘可以有多达三个头，棘头可以接受两个或更多的突触接触。我们的数据证实了脊柱和突触之间关系的复杂性，并表明突触和脊柱之间的一对一关系不能自动假设。中文信息学报（英文版），2009。(C) 2009 Wiley-Liss, Inc。
The morphological relationship between a synapse and dendritic spine is an important determinant of synaptic function, and has been studied extensively with the electron microscope. This has revealed that the universal idea of one synapse per spine is no longer tenable; dendritic spines may on occasions form synapses with two or more axonal boutons. To elucidate the detailed structure and relationship of spines and their synaptic contacts in the molecular layers of the dentate gyrus of the adult rat, a study using 3-dimensional (M) reconstructions was made from serial ultrathin sections (up to 150 sections per series), of both pre- and postsynaptic segments of axons and dendrites. We found that synapses from all unmyelinated axons examined were en passant and although most contacts between synapse and spine are one-to-one, all reconstructions examined contained both multisynaptic axonal segments, and multisynaptic spines. In the dentate gyrus, 3.48% mushroom spines were multisynaptic, synapsing with more than two axons, and 0.46% of the total population of synapses were multisynaptic. Although these values appear small, they actually comprise millions of contacts per cubic millimeter of tissue. Axonal varicosities can contact more than three dendritic spines originating from different dendritic branches while spines may branch with up to three heads, and spine heads may receive two or more synaptic contacts. Our data confirm the complexity of relationships between spines and synapses and show that a one-one relationship between synapse and spine cannot be assumed automatically. Synapse 63:369-377, 2009. (C) 2009 Wiley-Liss, Inc.