Tsumori T, Ando A, Yasui Y
Department of Anatomy, Schimane Medical University, Izumo, Japan.
Anat Embryol (Berl). 1996 Dec;194(6):559-68. doi: 10.1007/BF00187469.
The topographical distribution of the preganglionic neurons sending projection fibers to the tongue, and the connections between their fibers and the intralingual ganglion cells, were examined in the rat. When horseradish peroxidase injections were made into the anterior two-thirds of the tongue, labeled neuronal cell bodies were distributed mainly in the lateral reticular formation at the level between the rostral part of the facial nucleus and the caudal part of the superior olivary complex. On the other hand, after horseradish peroxidase injections into the posterior one-third of the tongue, labeled neuronal cell bodies were found mainly in the rostromedial part of the nucleus of the solitary tract, and additionally in the lateral reticular formation just ventral to the rostral part of the nucleus of the solitary tract. In both cases, labeled neuronal cell bodies were always found in the hypoglossal nucleus. The anterograde tracing study with Phaseolus vulgaris-leucoagglutinin or Fluoro-ruby confirmed the topographical organization suggested by the retrograde tracing study; when the tracer injections were centered on the lateral reticular formation at the level of the rostral part of the facial nucleus or on the rostral part of the nucleus of the solitary tract, labeled fibers distributed mainly in the anterior or posterior part of the tongue, respectively. It was also shown that the axon terminals of the preganglionic fibers labeled with Fluoro-ruby made close contacts with the intralingual ganglion cells immunopositive for neuron specific enolase. The electron microscopy combined with the anterograde tracing method with biotinylated dextran amine further indicated that the preganglionic fibers made synaptic contacts with the soma and dendritic processes of the intralingual ganglion cells.
在大鼠中，研究了向舌部发出投射纤维的节前神经元的拓扑分布，以及它们的纤维与舌内神经节细胞之间的连接。当将辣根过氧化物酶注射到舌前三分之二时，标记的神经元细胞体主要分布在面神经核嘴侧部分与上橄榄复合体尾侧部分之间水平的外侧网状结构中。另一方面，在将辣根过氧化物酶注射到舌后三分之一后，标记的神经元细胞体主要见于孤束核嘴内侧部分，另外在孤束核嘴侧部分腹侧的外侧网状结构中也有发现。在这两种情况下，标记的神经元细胞体总是在舌下神经核中被发现。用菜豆白细胞凝集素或荧光红宝石进行的顺行示踪研究证实了逆行示踪研究所提示的拓扑组织；当示踪剂注射集中在面神经核嘴侧部分水平的外侧网状结构或孤束核嘴侧部分时，标记的纤维分别主要分布在舌的前部或后部。还表明，用荧光红宝石标记的节前纤维的轴突终末与对神经元特异性烯醇化酶呈免疫阳性的舌内神经节细胞紧密接触。结合生物素化葡聚糖胺顺行示踪法的电子显微镜进一步表明，节前纤维与舌内神经节细胞的胞体和树突形成突触联系。
