Arango V, Ruggiero D A, Callaway J L, Anwar M, Mann J J, Reis D J
Department of Psychiatry, Cornell University Medical College, New York, New York 10021.
J Comp Neurol. 1988 Jul 8;273(2):224-40. doi: 10.1002/cne.902730207.
Catecholaminergic neurons in the ventrolateral medulla (VLM) and nucleus of the solitary tract (NTS) are important because of their presumed roles in autonomic regulation, including the tonic and reflex control of arterial pressure, neuroendocrine functions, and the chemosensitivity associated with the ventral medullary surface. However, little is known about the connections of these neurons in the human brain. As a first step in analyzing the functional biochemical anatomy of catecholamine neurons in the human, we used antisera against tyrosine hydroxylase (TH) and phenylethanolamine N-methyltransferase (PNMT) to localize medullary catecholamine-containing neurons and processes in the VLM and the NTS. Cells staining for TH were located throughout the VLM. Most cells staining for TH and PNMT, which are therefore adrenergic, occurred in an area of the VLM probably corresponding to the rostroventrolateral reticular nucleus. Axons of TH-immunoreactive neurons in the VLM projected (1) dorsally, in a series of parallel transtegmental trajectories, toward the dorsomedial reticular formation, the NTS, and vagal motor nucleus, (2) longitudinally, through the central tegmental field, as fascicles running parallel to the neuraxis, (3) ventrolaterally toward the ventral surface (VS) of the rostral VLM where they appeared to terminate, and (4) medially into the raphe, where they arborized. Similar systems of fibers were labeled for PNMT; the longitudinal bundles of PNMT-labeled axons were limited to the principal tegmental bundle and concentrated dorsally. Fibers containing PNMT were also identified in the medullary raphe, on the medullary ventral surface, and contacting intraparenchymal blood vessels. In the NTS, neurons exhibited immunoreactivity to both TH and PNMT: Four principal subgroups of TH-immunoreactive neurons were seen: a ventral, an intermediate, a medial, and a dorsal group. Perikarya containing PNMT were restricted to the dorsolateral aspect of the NTS. Processes containing TH and PNMT immunoreactivity were identified in the medial and dorsolateral NTS; others appeared to project between the NTS and the VLM and within the solitary tract. The presence of catecholaminergic fibers of the VLM interconnecting with the NTS, raphe, intraparenchymal microvessels, VS, and possibly the spinal cord suggests that the autonomic and chemoreceptor functions attributed to these neurons also may apply to the human.
延髓腹外侧区（VLM）和孤束核（NTS）中的儿茶酚胺能神经元很重要，因为它们在自主神经调节中可能发挥作用，包括对动脉血压的紧张性和反射性控制、神经内分泌功能以及与延髓腹侧面相关的化学敏感性。然而，对于这些神经元在人脑中的连接情况知之甚少。作为分析人类儿茶酚胺能神经元功能生化解剖学的第一步，我们使用抗酪氨酸羟化酶（TH）和苯乙醇胺N-甲基转移酶（PNMT）的抗血清来定位VLM和NTS中含儿茶酚胺的神经元和突起。TH染色阳性的细胞遍布VLM。大多数TH和PNMT染色阳性的细胞，即肾上腺素能细胞，位于VLM中一个可能对应于嘴侧腹外侧网状核的区域。VLM中TH免疫反应性神经元的轴突投射方向如下：（1）背侧，通过一系列平行的跨被盖轨迹，朝向背内侧网状结构、NTS和迷走运动核；（2）纵向，穿过中央被盖区，呈与神经轴平行的束状；（3）腹外侧，朝向嘴侧VLM的腹侧面（VS），似乎在此处终止；（4）内侧，进入中缝，在那里分支。PNMT也标记了类似的纤维系统；PNMT标记的轴突纵向束仅限于主要被盖束，并集中在背侧。在延髓中缝、延髓腹侧面以及与实质内血管接触处也发现了含PNMT的纤维。在NTS中，神经元对TH和PNMT均表现出免疫反应性：可见四个主要的TH免疫反应性神经元亚群：腹侧、中间、内侧和背侧组。含PNMT的胞体局限于NTS的背外侧。在NTS的内侧和背外侧发现了含TH和PNMT免疫反应性的突起；其他突起似乎在NTS和VLM之间以及孤束内投射。VLM的儿茶酚胺能纤维与NTS、中缝、实质内微血管、VS以及可能与脊髓相互连接，这表明归因于这些神经元的自主神经和化学感受器功能也可能适用于人类。
