Matsushima T A, Satou M, Ueda K
Brain Res. 1986 Feb 12;365(1):198-203. doi: 10.1016/0006-8993(86)90740-7.
Anuran tongue-muscle motoneurons receive excitatory inputs both from the glossopharyngeal nerve afferents and from the optic tectum. As a step toward elucidating the neural bases for controlling the tongue movements, we searched intracellularly for the neuronal pathways from the glossopharyngeal afferents to the tongue-muscle motoneurons in paralyzed Japanese toads. The electrical stimuli applied to the glossopharyngeal nerve (ipsilateral lingual branch) evoked polysynaptic excitatory postsynaptic potentials (EPSPs) in tongue-protractor motoneurons and mixed mono- and polysynaptic EPSPs in tongue-retractor motoneurons. Furthermore, we investigated the mode of the convergency of the excitatory inputs from the glossopharyngeal nerve and those from the optic tectum. A spatial facilitation was observed between the tectal EPSPs and the glossopharyngeal EPSPs in some motoneurons tested. These results suggest the existence of common excitatory premotor interneurons, on which the tectal descending volleys and the glossopharyngeal afferent volleys converge.
无尾两栖类动物的舌肌运动神经元既接受来自舌咽神经传入纤维的兴奋性输入，也接受来自视顶盖的兴奋性输入。作为阐明控制舌运动神经基础的第一步，我们在麻痹的日本蟾蜍中，通过细胞内记录寻找从舌咽神经传入纤维到舌肌运动神经元的神经通路。施加于舌咽神经（同侧舌支）的电刺激在舌前伸运动神经元中诱发多突触兴奋性突触后电位（EPSP），在舌后缩运动神经元中诱发单突触和多突触混合的EPSP。此外，我们研究了来自舌咽神经的兴奋性输入与来自视顶盖的兴奋性输入的汇聚方式。在一些被测试的运动神经元中，观察到视顶盖EPSP与舌咽神经EPSP之间存在空间易化现象。这些结果表明存在共同的兴奋性运动前中间神经元，视顶盖下行冲动和舌咽神经传入冲动在其上汇聚。
