Vornov J J, Sutin J
J Comp Neurol. 1983 Feb 20;214(2):198-208. doi: 10.1002/cne.902140207.
The noradrenergic innervation of the trigeminal motor nucleus of the rat can be increased severalfold by neonatal treatment with the neurotoxin, 6-hydroxydopamine. The brainstem projections to the nucleus were studied by injecting HRP into the nucleus of normal and noradrenergically hyperinnervated rats. In order to identify the source of the noradrenergic innervation, the fluorescent dye, True Blue, was used as a retrograde tracer in combination with the glyoxylic acid histofluorescence method for catecholamines. In both control and neonatally treated rats, the noradrenergic innervation of the motor nucleus was shown to arise from an ipsilateral group of cells located among the fibers of the lateral lemniscus just rostral to the motor nucleus. Our results confirmed the high degree of specificity of noradrenergic innervation, which arises exclusively from this lateral tegmental noradrenergic cell group. During the process of sprouting, this specificity is maintained since only those noradrenergic cells normally innervating the nucleus were retrogradely labeled in neonatally treated animals. Other noradrenergic projections which are also increased in these animals, such as the nearby locus ceruleus innervation of the main sensory trigeminal nucleus, do not spread to the motor trigeminal nucleus. HRP-labeled nonadrenergic cells were concentrated dorsally, with scattered cells surrounding the nucleus. A similar distribution was observed contralateral to the injection site. The mesencephalic trigeminal nucleus was labeled only ipsilateral to the injection. The motor nucleus also receives an extensive bilateral input from the pontine and medullary reticular formation. The medial reticular formation nuclei, including nucleus pontis caudalis, nucleus gigantocellularis, and nucleus reticularis ventralis contained large labeled cells, which were especially numerous in the retrotrigeminal area. Smaller, lateral reticular formation neurons were concentrated rostrally and ipsilaterally in the nucleus pontis lateralis. HRP retrograde labeling revealed no obvious change in the overall pattern of cells innervating the trigeminal motor nucleus following noradrenergic hyperinnervation.
通过用神经毒素6-羟基多巴胺对新生大鼠进行处理，大鼠三叉神经运动核的去甲肾上腺素能神经支配可增加数倍。通过将辣根过氧化物酶（HRP）注入正常和去甲肾上腺素能神经支配过度的大鼠的该核，研究了脑干向该核的投射。为了确定去甲肾上腺素能神经支配的来源，将荧光染料真蓝用作逆行示踪剂，并结合用于儿茶酚胺的乙醛酸组织荧光法。在对照大鼠和新生处理的大鼠中，运动核的去甲肾上腺素能神经支配均显示来自位于运动核前方、外侧丘系纤维之间的同侧细胞群。我们的结果证实了去甲肾上腺素能神经支配的高度特异性，其仅源自该外侧被盖去甲肾上腺素能细胞群。在发芽过程中，这种特异性得以维持，因为在新生处理的动物中，只有那些正常支配该核的去甲肾上腺素能细胞被逆行标记。这些动物中同样增加的其他去甲肾上腺素能投射，如主要感觉三叉神经核附近的蓝斑神经支配，不会扩散到运动三叉神经核。HRP标记的去甲肾上腺素能细胞集中在背侧，核周围有散在的细胞。在注射部位的对侧观察到类似的分布。中脑三叉神经核仅在注射同侧被标记。运动核还从脑桥和延髓网状结构接受广泛的双侧输入。内侧网状结构核，包括脑桥尾侧核、巨细胞网状核和腹侧网状核，含有大量标记细胞，在三叉神经后区尤其众多。较小的外侧网状结构神经元集中在脑桥外侧核的前方和同侧。HRP逆行标记显示，去甲肾上腺素能神经支配过度后，支配三叉神经运动核的细胞总体模式没有明显变化。
