MORPHOLOGY AND SYNAPTIC CONNECTIONS OF SLOWLY ADAPTING PERIODONTAL AFFERENT TERMINALS IN THE TRIGEMINAL SUBNUCLEI PRINCIPALIS AND ORALIS OF THE CAT
MORPHOLOGY AND SYNAPTIC CONNECTIONS OF SLOWLY ADAPTING PERIODONTAL AFFERENT TERMINALS IN THE TRIGEMINAL SUBNUCLEI PRINCIPALIS AND ORALIS OF THE CAT
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DOI：
10.1002/cne.903480107
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发表时间：
1994-10-01
影响因子：
2.5
通讯作者：
SHIGENAGA, Y
中科院分区：
文献类型：
--
作者：
BAE, YC;NAKAGAWA, S;SHIGENAGA, Y
先前的研究表明，来自初级传入纤维的感觉信息在三叉神经感觉核复合体的各个亚核中以独特的方式进行处理。本研究通过使用辣根过氧化物酶的轴突内标记来检查轴突末端的超微结构和突触组织，从而解决了这个问题，这些轴突末端来自主肌腹侧细分（Vpv）和口背内侧部分（Vo.r）的缓慢适应（SA）牙周传入神经。我们的观察基于 Vpv 中的 139 个突触按钮和 Vo.r 中的 105 个突触按钮的完整或接近完整重建。所有标记的按钮都包含透明的球形突触囊泡，并且位于未标记树突的突触前，并且它们经常位于包含多形性突触囊泡（P 结尾）的未标记轴突末端的突触后。 P 末端经常在树突上形成轴突突触，树突接收来自标记的纽扣（突触三联体）的轴突突触。根据接触的数量，与标记的按钮相关的突触排列可以分为简单（一个或两个接触）、中间（三个或四个接触）和复杂（五个或更多接触）类型。贴有标签的纽扣形状多样，从圆形到细长形，轮廓从光滑到更不规则或扇形。具有扇形轮廓的纽扣在复杂类型中更为常见。中间型的突触明显小于复杂型，大于简单型。SA牙周传入末梢参与了Vpv中的各类型突触排列，但在Vo.r中以简单型突触排列为主。 Vpv 中标记的按钮大小明显大于 Vo.r。 Vpv 中每个标记 bouton 的轴突和轴突接触总数显着高于 Vo.r。另一个区别是 Vpv 中的突触三联体比 Vo.r 中更频繁地出现。这些观察结果提供了证据，表明来自初级传入纤维的感觉信息在两个亚核中以不同的方式处理。 (C) 1994 年 Wiley-Liss 公司
Previous studies suggest that sensory information from primary afferent fibers is processed in a distinct manner in the individual subnuclei of trigeminal sensory nuclear complex. The present study has addressed this issue by using intra-axonal labeling with horseradish peroxidase to examine the ultrastructure and synaptic organization of axon terminals from slowly adapting (SA) periodontal afferents in the ventral subdivision (Vpv) of principalis and the rostro-dorsomedial part (Vo.r) of oralis. Our observations are based on complete or near-complete reconstructions of 139 synaptic boutons in Vpv and 105 in Vo.r.All the labeled boutons contained clear, spherical, synaptic vesicles and were presynaptic to unlabeled dendrites, and they were frequently postsynaptic to unlabeled axon terminals containing pleomorphic synaptic vesicles (P-endings). The P-endings frequently formed axodendritic synapses on dendrites which received axodendritic synapses from labeled boutons (synaptic triads). On the basis of the number of contacts, synaptic arrangements associated with the labeled boutons could be subgrouped into simple (one or two contacts), intermediate (three or four contacts), and complex (five or more contacts) types. The labeled boutons varied from round to elongated forms with smooth to more irregular or scalloped contours. The boutons with scalloped contour were much more frequent in the complex type. The boutons of the intermediate type were significantly smaller than the complex type and larger than the simple type.The SA periodontal afferent terminals participated in each type of synaptic arrangements in Vpv, but were mostly of the simple type in Vo.r. The size of labeled boutons was significantly larger in Vpv than in Vo.r. The total number of axodendritic and axoaxonic contacts per labeled bouton was significantly higher in Vpv than in Vo.r. Another difference was the more frequent occurrence of synaptic triads in Vpv than in Vo.r.These observations provide evidence that sensory information from primary afferent fibers is processed in a different manner in the two subnuclei. (C) 1994 Wiley-Liss, Inc.