Siaud P, Denoroy L, Assenmacher I, Alonso G
Laboratoire de Neurobiologie Endocrinologique, URA 1197 CNRS, Université de Montpellier II, France.
J Comp Neurol. 1989 Dec 15;290(3):323-35. doi: 10.1002/cne.902900302.
Light and electron microscopic immunocytochemistry was used to study the fine structural organization of the catecholaminergic and hypothalamic peptidergic innervation of the dorsal vagal complex of the medulla oblongata in the rat and guinea pig, the latter of which is known to lack central adrenergic neurons. In the rat, adrenergic fibers immunoreactive to phenylethanolamine-N-methyltransferase were concentrated in the dorsal motor nucleus of the vagus, where they established frequent symmetric synapses with dendrites and perikarya. On the other hand, the density of both oxytocin- and corticotropin-immunoreactive fibers appeared far lower in this nucleus than in the dorsal regions of the nucleus of the tractus solitarius, where they formed asymmetric synapses with small dendrites. In tissue treated for the dual labeling of two neuronal antigens, oxytocin- or corticotropin-reactive fibers were in close contact with adrenergic neurons in this dorsal medullary region. In the guinea pig, unlike the rat, the dorsal motor nucleus of the vagus contained large amounts of oxytocin- and corticotropin-reactive fibers, which formed many symmetric synapses with perikarya and dendrites. Taken together, these data suggest that the control of vagal preganglionic neurons by hypothalamic peptidergic neurons involves a bisynaptic neuronal pathway including adrenergic medullary neurons in the rat, whereas it is direct in the guinea pig, which lacks this adrenergic relay.
采用光镜和电镜免疫细胞化学方法，研究大鼠和豚鼠延髓背迷走复合体中儿茶酚胺能和下丘脑肽能神经支配的精细结构组织，已知豚鼠缺乏中枢肾上腺素能神经元。在大鼠中，对苯乙醇胺 - N - 甲基转移酶免疫反应阳性的肾上腺素能纤维集中在迷走神经背运动核，在那里它们与树突和胞体频繁形成对称突触。另一方面，催产素和促肾上腺皮质激素免疫反应阳性纤维在该核中的密度似乎远低于孤束核背侧区域，在孤束核背侧区域它们与小树突形成不对称突触。在对两种神经元抗原进行双重标记处理的组织中，催产素或促肾上腺皮质激素反应性纤维在这个延髓背侧区域与肾上腺素能神经元紧密接触。与大鼠不同，在豚鼠中，迷走神经背运动核含有大量催产素和促肾上腺皮质激素反应性纤维，它们与胞体和树突形成许多对称突触。综上所述，这些数据表明，下丘脑肽能神经元对迷走神经节前神经元的控制在大鼠中涉及一条双突触神经元通路，包括延髓肾上腺素能神经元，而在缺乏这种肾上腺素能中继的豚鼠中则是直接控制。
