González A, Meredith G E, Roberts B L
Department of Cell Biology, Faculty of Biology, Complutense University, Madrid, Spain.
J Comp Neurol. 1993 Jun 8;332(2):258-68. doi: 10.1002/cne.903320209.
The goal of the present study was to investigate aspects of the central organization of the neurons belonging to the octavolateralis efferent system of amphibians. The perikarya of three genera, Pleurodeles, Xenopus, and Discoglossus, were located in the brainstem by applying retrograde tracers to the appropriate cranial nerves and choline acetyltransferase immunohistochemistry was used to identify cholinergic neurons. The efferent neurons supplying lateral line (Pleurodeles, Xenopus) and labyrinthine (Pleurodeles, Xenopus, and Discoglossus) end organs were found to intermingle in a single octavolateralis efferent nucleus. The neurons lie bilateral to the labelled nerves in Pleurodeles and ipsilateral in Xenopus and Discoglossus. Separate labelling of the anterior and posterior octavus rami provided no evidence for distinct groupings of efferent neurons that could be associated with auditory and vestibular end organs. In all three species many if not all octavolateral efferent neurons displayed immunoreactivity for choline acetyltransferase. They could be distinguished from the cholinergic facial motoneurons, with which they sometimes intermingle, on the basis of either their distinctive size and shape (Pleurodeles, Xenopus) or their location (Discoglossus). Double labelling in Xenopus confirmed the cholinergic nature of the efferent neurons.
本研究的目的是探究两栖动物八侧线传出系统所属神经元的中枢组织情况。通过向适当的颅神经应用逆行示踪剂，确定了三个属（肋突螈属、非洲爪蟾属和盘舌蟾属）的神经元胞体位于脑干，并使用胆碱乙酰转移酶免疫组织化学来识别胆碱能神经元。发现供应侧线（肋突螈属、非洲爪蟾属）和迷路（肋突螈属、非洲爪蟾属和盘舌蟾属）终器的传出神经元在单个八侧线传出核中相互交织。在肋突螈属中，神经元位于标记神经的两侧，而在非洲爪蟾属和盘舌蟾属中则位于同侧。对前、后听神经支进行单独标记，未发现可与听觉和前庭终器相关的传出神经元有明显分组的证据。在所有三个物种中，许多（如果不是全部）八侧线传出神经元都显示出胆碱乙酰转移酶免疫反应性。根据其独特的大小和形状（肋突螈属、非洲爪蟾属）或位置（盘舌蟾属），它们可以与有时与之交织的胆碱能面神经运动神经元区分开来。在非洲爪蟾属中的双重标记证实了传出神经元的胆碱能性质。
