Inagaki N, Toda K, Taniuchi I, Panula P, Yamatodani A, Tohyama M, Watanabe T, Wada H
Department of Pharmacology II, Faculty of Medicine, Osaka University, Japan.
Exp Brain Res. 1990;80(2):374-80. doi: 10.1007/BF00228164.
The efferent projections of the five histaminergic neuronal subgroups in the tuberomammillary nucleus to the medial preoptic area (MPO) and inferior colliculus (IC) were examined by immunocytochemistry with antihistidine decarboxylase (HDC) antibodies combined with retrograde axonal tracing with Fast Blue (FB). The term "E groups" were used for the histaminergic neuronal subgroups. About 10% of the HDC-immunoreactive (HDCI) neurons were retrogradely labeled after FB injection into the MPO. The labeled neurons were not concentrated in any particular area, but were diffusely distributed bilaterally in all the subgroups. About two-thirds of the labeled neurons were observed on the side ipsilateral to the injection site and one-third on the contralateral side. The percentages of labeled neurons (double-labeled neurons/HDCI neurons) in the five subgroups were not significantly different with each other. The percentages in group E1 and E2 were particularly close, while that in group E4 resembled that in group E5. About 4% of the HDCI neurons were retrogradely labeled after the dye injections into the IC, and about half of the labeled neurons were detected on the ipsilateral side. The percentage of the double-labeled neurons in the five groups were not significantly different. Furthermore, those in E1 and E2, and in E4 and E5 were almost identical, respectively, to the situation following injection of FB into the MPO. These results indicate that each subgroup of histaminergic neurons in the tuberomammillary nucleus has similar efferent projections to the MPO and IC.
采用抗组氨酸脱羧酶（HDC）抗体免疫细胞化学结合Fast Blue（FB）逆行轴突示踪技术，研究了结节乳头核中五个组胺能神经元亚群向内侧视前区（MPO）和下丘（IC）的传出投射。组胺能神经元亚群用“E组”表示。将FB注入MPO后，约10%的HDC免疫反应性（HDCI）神经元被逆行标记。标记的神经元并不集中在任何特定区域，而是双侧分散分布于所有亚群中。约三分之二的标记神经元出现在注射部位同侧，三分之一出现在对侧。五个亚群中标记神经元的百分比（双标记神经元/HDCI神经元）彼此之间无显著差异。E1组和E2组的百分比特别接近，而E4组的百分比与E5组相似。将染料注入IC后，约4%的HDCI神经元被逆行标记，约一半的标记神经元在同侧被检测到。五组中双标记神经元的百分比无显著差异。此外，E1组和E2组以及E4组和E5组中的情况分别与将FB注入MPO后的情况几乎相同。这些结果表明，结节乳头核中组胺能神经元的每个亚群向MPO和IC发出的传出投射相似。
