Van Bockstaele E J, Pieribone V A, Aston-Jones G
Department of Mental Health Sciences, Hahnemann University, Philadelphia, Pennsylvania 19102-1192.
J Comp Neurol. 1989 Dec 22;290(4):561-84. doi: 10.1002/cne.902900410.
The nucleus paragigantocellularis in the ventrolateral medulla has been implicated in cardiovascular, pain, and analgesic functions; and it has also been found to be a major afferent to the pontine nucleus locus coeruleus. In the present study, afferents to the nucleus paragigantocellularis were identified in the rat by means of the retrograde tracers wheat germ agglutinin-conjugated horseradish peroxidase or Fluoro-Gold. Projections to the nucleus paragigantocellularis arise from a wide variety of nuclei with autonomic, visceral, and sensory-related functions. Major afferents with consistent and robust retrograde labeling include most laminae of the spinal cord, the caudal lateral medulla, the contralateral paragigantocellularis, the nucleus of the solitary tract, the A1 area, the lateral parabrachialis, the Kölliker-Fuse nucleus, the periaqueductal gray, and a preoculomotor nucleus in the ventral central gray, the supraoculomotor nucleus. Other notable afferents, seen only after large caudal injections into the nucleus paragigantocellularis, include the lateral hypothalamus, the paraventricular nucleus of the hypothalamus, and the medial prefrontal cortex. Minor afferents include the gigantocellular nucleus, the area postrema, the caudal raphe groups, the inferior colliculus, the A5 area, and the locus coeruleus. The projection from the supraoculomotor nucleus, not previously reported as an afferent to the ventrolateral medulla, was confirmed with anterograde tracing by means of Phaseolus vulgaris-leucoagglutinin. Iontophoretic deposits of Phaseolus vulgaris-leucoagglutinin into the nucleus of the solitary tract (commissuralis level) or into the periaqueductal gray also yielded terminal fiber labeling in the nucleus paragigantocellularis. Fibers from the supraoculomotor nucleus and the nucleus of the solitary tract were densest in the lateral aspect of the nucleus paragigantocellularis (corresponding to the rostroventrolateral reticular nucleus), while fibers from the periaqueductal gray were more medially located. Previous studies have defined inputs to the rostral ventrolateral medulla from the cochlear nucleus as well as from the colliculi. In the present study, deposits of wheat germ agglutinin-conjugated horseradish peroxidase or Phaseolus vulgaris-leucoagglutinin into the cochlear nucleus or the superior colliculus yielded only sparse anterograde labeling in the nucleus paragigantocellularis, but heavily labeled adjacent areas. The inferior collicular injections yielded strong but restricted anterograde labeling in the rostromedial paragigantocellularis, medial to the facial nucleus. These results indicate that the paragigantocellularis area receives inputs from diverse brain structures. Neurons in the nucleus paragigantocellularis afferent to the locus coeruleus, being distributed throughout this region, may provide a channel where several types of information are integrated and transmitted to the extensive locus coeruleus noradrenergic efferent network...
延髓腹外侧的巨细胞旁核与心血管、疼痛及镇痛功能有关；还发现它是蓝斑核的主要传入神经。在本研究中，通过逆行示踪剂麦胚凝集素结合辣根过氧化物酶或荧光金，在大鼠中确定了到巨细胞旁核的传入神经。到巨细胞旁核的投射来自具有自主、内脏和感觉相关功能的多种核团。具有一致且强烈逆行标记的主要传入神经包括脊髓的大多数板层、延髓尾外侧部、对侧巨细胞旁核、孤束核、A1区、外侧臂旁核、 Kölliker-Fuse核、导水管周围灰质以及腹侧中央灰质中的动眼神经前核、动眼神经上核。其他值得注意的传入神经，仅在向巨细胞旁核进行大剂量尾侧注射后才能看到，包括外侧下丘脑、下丘脑室旁核和内侧前额叶皮质。次要传入神经包括巨细胞网状核、最后区、尾侧中缝核群、下丘、A5区和蓝斑核。动眼神经上核的投射此前未被报道为延髓腹外侧的传入神经，通过菜豆凝集素顺行追踪得到了证实。将菜豆凝集素离子电渗沉积到孤束核（连合部水平）或导水管周围灰质中，也在巨细胞旁核产生了终末纤维标记。来自动眼神经上核和孤束核的纤维在巨细胞旁核的外侧最密集（对应于嘴侧腹外侧网状核），而来自导水管周围灰质的纤维位置更偏内侧。先前的研究已经确定了来自耳蜗核以及上丘到嘴侧延髓腹外侧的输入。在本研究中，将麦胚凝集素结合辣根过氧化物酶或菜豆凝集素沉积到耳蜗核或上丘中，仅在巨细胞旁核产生了稀疏的顺行标记，但相邻区域标记明显。在下丘注射则在面神经核内侧的嘴侧内侧巨细胞旁核产生了强烈但局限的顺行标记。这些结果表明，巨细胞旁核区域接收来自不同脑结构的输入。巨细胞旁核中传入蓝斑核的神经元分布在整个该区域，可能提供了一个整合多种信息并将其传递到广泛的蓝斑去甲肾上腺素能传出网络的通道……
