Belknap D B, McCrea R A
Department of Pharmacological and Physiological Sciences, University of Chicago, Illinois 60637.
J Comp Neurol. 1988 Feb 1;268(1):13-28. doi: 10.1002/cne.902680103.
The primary goal of this investigation was to identify the areas of the brainstem and cerebellum that provide afferent projections to the nucleus prepositus hypoglossi in primates. After horseradish peroxidase conjugated to wheat germ agglutinin (WGA-HRP) was injected into the prepositus in squirrel monkeys (Saimiri sciureus), the largest populations of retrogradely labeled neurons were found in the vestibular nuclei, the contralateral perihypoglossal nuclei, and the medullary and pontine reticular formation. Unlike the cat, the prepositus in Saimiri received substantial projections from the nucleus raphe dorsalis and the central mesencephalic reticular formation, whereas few or no labeled cells were found in the cerebellar cortex, the superior colliculus, or the nucleus reticularis tegmenti pontis. By comparing the afferents to the prepositus with those to the abducens nucleus, we found that all regions projecting to the abducens also projected to the prepositus, without exception. Anterogradely transported WGA-HRP showed that the major brainstem recipients of prepositus efferents were the vestibular and perihypoglossal nuclei, the inferior olive, the medullary reticular formation, and the extraocular motor nuclei. In the cerebellar cortex, the prepositus projected to restricted regions of crura I and II as well as the caudal vermis and vestibulocerebellum. The many parts of the oculomotor system receiving input from the prepositus and the parallel innervation of the prepositus and the abducens by a large number of premotor centers lend support to the hypothesis that the prepositus may distribute an efference copy of motor activity, and may also play an important role in the process of neural integration.
本研究的主要目的是确定灵长类动物中向舌下前置核提供传入投射的脑干和小脑区域。将与小麦胚凝集素结合的辣根过氧化物酶（WGA-HRP）注入松鼠猴（Saimiri sciureus）的前置核后，在前庭核、对侧舌下周围核以及延髓和脑桥网状结构中发现了数量最多的逆行标记神经元。与猫不同，松鼠猴的前置核接受来自中缝背核和中脑中央网状结构的大量投射，而在小脑皮质、上丘或脑桥被盖网状核中发现的标记细胞很少或没有。通过比较投射到前置核和展神经核的传入纤维，我们发现所有投射到展神经核的区域也无一例外地投射到了前置核。顺行运输的WGA-HRP显示，前置核传出纤维的主要脑干接受者是前庭核和舌下周围核、下橄榄核、延髓网状结构和眼外肌运动核。在小脑皮质中，前置核投射到小脑脚I和II的受限区域以及尾状蚓部和前庭小脑。动眼系统的许多部分接受来自前置核的输入，并且大量运动前中枢对前置核和展神经进行平行支配，这支持了前置核可能分布运动活动的传出拷贝，并且可能在神经整合过程中发挥重要作用的假说。
