Takemura M, Nagase Y, Yoshida A, Yasuda K, Kitamura S, Shigenaga Y, Matano S
Second Department of Oral Anatomy, Osaka University Faculty of Dentistry, Japan.
Somatosens Mot Res. 1993;10(2):217-27. doi: 10.3109/08990229309028833.
Transganglionic transport of horseradish peroxidase conjugated to wheatgerm agglutinin (HRP:WGA) entrapped in hypoallergenic polyacrylamide gel was used to study the patterns of termination of primary afferents that innervate the upper and lower tooth pulps within the trigeminal sensory nuclear complex (TSNC) of the monkey. HRP:WGA injections were also made into the lower incisors and molars, in order to examine the topographic arrangement of pulpal afferent projections. HRP-labeled pulpal afferents innervating lower and upper teeth projected ipsilaterally to the rostral subnucleus dorsalis (Vpd) and caudal subnucleus ventralis (Vpv) of the nucleus principalis (Vp); the rostrodorsomedial (Vo.r) and dorsomedial (Vo.dm) subdivisions of the nucleus oralis (Vo); the dorsomedial subdivision of the nucleus interpolaris (Vi); and laminae I-II and/or V of the nucleus caudalis (Vc) at its rostralmost level. The HRP-labeled terminals from upper and lower pulpal afferents formed a rostrocaudal column from the midlevel of Vp to the rostral tip of Vc. The label in Vp and Vo was considerably dense, but the column of terminals was interrupted at the Vpd-Vpv transition. The label in Vi and Vc was much less dense compared to that in the rostral nuclei, and the column of terminals was interrupted frequently. The representation of the upper and lower teeth in TSNC was organized in a somatotopic fashion that varied from one subdivision to the next, though their terminal zones overlapped within Vpd. The upper and lower teeth were represented in Vpv, Vo.r, Vo.dm, Vi, and Vc in a ventrodorsal, dorsoventral, lateromedial, lateromedial, and lateromedial sequence, respectively. Topographic arrangement was also noticed for the projections of pulpal afferents from the lower incisors and molars: The representations of the lower incisors and molars in Vpv, Vo.r, Vo.dm, Vi, and Vc were organized in a lateromedial, dorsoventral, ventrodorsal, ventrodorsal, and lateromedial sequence, respectively. The present results indicating sparse projections from pulpal afferents in the monkey's Vc are in good correspondence with a clinical report that trigeminal tractotomy just rostral to the obex has no significant effect on dental pain perception in patients. Furthermore, the present study indicates that projection patterns of pulpal afferents--which include the termination sites, the density of terminations between nuclei, and topographic arrangement--differ among animal species.
将包裹在低变应原性聚丙烯酰胺凝胶中的与麦胚凝集素结合的辣根过氧化物酶（HRP:WGA）进行跨神经节运输，用于研究支配猕猴三叉神经感觉核复合体（TSNC）内上下牙髓的初级传入神经的终止模式。还将HRP:WGA注射到下切牙和磨牙中，以检查牙髓传入投射的拓扑排列。支配上下牙齿的HRP标记的牙髓传入神经同侧投射到主核（Vp）的吻侧背侧亚核（Vpd）和尾侧腹侧亚核（Vpv）；口核（Vo）的吻背内侧（Vo.r）和背内侧（Vo.dm）亚区；极间核（Vi）的背内侧亚区；以及尾侧核（Vc）最吻侧水平的I-II层和/或V层。来自上下牙髓传入神经的HRP标记终末从Vp的中间水平到Vc的吻端形成一个头尾柱。Vp和Vo中的标记相当密集，但终末柱在Vpd-Vpv过渡处中断。与吻侧核相比，Vi和Vc中的标记要稀疏得多，终末柱也经常中断。TSNC中上下牙齿的代表以躯体定位的方式组织，不同亚区有所不同，尽管它们的终末区在Vpd内重叠。上下牙齿在Vpv、Vo.r、Vo.dm、Vi和Vc中的代表分别以腹背、背腹、内外、内外和内外顺序排列。还注意到来自下切牙和磨牙的牙髓传入投射的拓扑排列：下切牙和磨牙在Vpv、Vo.r、Vo.dm、Vi和Vc中的代表分别以内外、背腹、腹背、腹背和内外顺序排列。目前的结果表明猕猴Vc中牙髓传入神经的投射稀疏，这与一项临床报告相符，该报告指出在闩前方的三叉神经束切断术对患者的牙痛感知没有显著影响。此外，本研究表明，牙髓传入神经的投射模式——包括终末部位、核间终末密度和拓扑排列——在不同动物物种之间存在差异。
