Iwase M, Shioda S, Nakai Y, Homma I
Department of Physiology, School of Medicine, Showa University, Tokyo, Japan.
Brain Res Bull. 1991 Jan;26(1):49-57. doi: 10.1016/0361-9230(91)90191-l.
The distribution and ultrastructure of thyrotropin-releasing hormone-like immunoreactive (TRH-LI) neurons were examined in rabbit medulla oblongata. TRH-LI cell bodies were located in the ventral region of the medulla oblongata: in the paraolivary and parapyramidal regions, regions in and around the pyramidal tract, the dorsolateral region of the lateral reticular nucleus, and the raphe nuclei. The paraolivary and parapyramidal regions contained most of the TRH-LI cell bodies in the medulla oblongata. TRH-LI neurons processes were densely distributed in the dorsal vagal complex and the area postrema. Electron-microscopic immunocytochemical studies revealed TRH-LI neurons at the obex level in the paraolivary region of rabbits. TRH-like immunoreactivity was localized in larger granular vesicles. TRH-LI somata and dendrites received synaptic inputs from both TRH-LI and unlabeled axon terminals. More than half of the TRH-LI axon terminals made synapses with somata or processes of TRH-LI neurons. These observations, together with previous reports that TRH causes respiratory facilitation, suggest that TRH-LI neurons in the paraolivary region in rabbits may be involved in respiratory functions.
对兔延髓中促甲状腺激素释放激素样免疫反应性（TRH-LI）神经元的分布和超微结构进行了研究。TRH-LI细胞体位于延髓腹侧区域：在橄榄旁和锥体旁区域、锥体束内及周围区域、外侧网状核背外侧区域和中缝核。橄榄旁和锥体旁区域包含了延髓中大部分的TRH-LI细胞体。TRH-LI神经元的突起密集分布于迷走神经背侧复合体和最后区。电子显微镜免疫细胞化学研究显示，在兔橄榄旁区域的闩平面存在TRH-LI神经元。TRH样免疫反应性定位于较大的颗粒小泡中。TRH-LI胞体和树突接受来自TRH-LI和未标记轴突终末的突触输入。超过一半的TRH-LI轴突终末与TRH-LI神经元的胞体或突起形成突触。这些观察结果，连同先前关于TRH引起呼吸促进作用的报道，提示兔橄榄旁区域的TRH-LI神经元可能参与呼吸功能。
