FUNCTIONAL ORGANIZATION OF THE NERVUS TERMINALIS

终神经（NT）是神经节化的脑神经， 连接着大脑和周围的嗅觉结构 的 NT存在于大多数脊椎动物中，包括成年人 而且，虽然用各种技术反复研究， NT仍然是唯一的脑神经，其功能是 在人类或任何物种中完全未知。 基于 NT中神经的连接和细胞的形态 神经节，解剖学家认为，神经可能是一个 结合了感觉和自主神经功能 可能某个 最近关于NT的最重要的发现是， 神经中的神经元含有高水平的促黄体激素， 释放激素（LHRH）免疫反应性。 其中一些 LHRH免疫反应性细胞投射到涉及LHRH的脑区。 有些似乎与生殖有直接联系， 血管 NT中LHRH免疫反应性的存在 神经元以及神经的中枢和外周连接 导致一些研究人员认为NT可能是 对信息素化学敏感并参与生殖 在鱼类和哺乳动物中发挥作用，可能是通过释放LHRH 直接进入血液。 然而，没有 电生理学证据表明，无论是化学感觉或 神经内分泌功能的NT，它是不知道，如果 NT神经节的电路与这些建议是兼容的 功能协调发展的 生理和形态组织的调查 NT神经节将提供一个更知情的地面计划 NT功能研究。 板鳃类将用于这些 研究，因为只有在这些动物中，NT是分开的 从大脑中直接进入电生理学 实验 本文提出的实验包括：1） 电生理学、药理学和形态学 NT神经节细胞的研究，这将提供关于 生理性的传入和/或传出投射 特征化的细胞; 2）组合的电生理学、染料填充和 免疫细胞化学将研究肽的功能 包含细胞，包括这种细胞 构成神经的传入或传出成分; 3） 所有实验数据的整合将提供第一个 NT神经节神经元回路的连贯图片， 包括突触内元件之间的相互作用， 神经节

The nervus terminalis (NT) is a ganglionated cranial nerve which connects the brain and the peripheral olfactory structures. The NT has been found in most vertebrates, including adult humans and, although studied repeatedly with a variety of techniques, the NT remains the only cranial nerve for which the function is completely unknown in humans or in any species. Based on the connections of the nerve and the morphology of cells in the NT ganglion, anatomists have suggested that the nerve may serve a combined sensory and autonomic function. Perhaps one of the most significant recent findings concerning the NT is that some neurons in the nerve contain high levels of luteinizing hormone- releasing hormone (LHRH) immunoreactivity. Some of these LHRH-immunoreactive cells project to brain areas involved with reproduction and some appear to have direct connections with blood vessels. The presence of LHRH-immunoreactivity in the NT neurons and the central and peripheral connections of the nerve has led some researchers to suggest that the NT may be chemosensitive to pheromones and involved in reproductive functions in fish and mammals, possibly by releasing LHRH directly into the blood. However, there has been no electrophysiological evidence for either a chemosensory or a neuroendocrine function for the NT and it is not known if the circuitry of the NT ganglion is compatible with these suggested functions. Investigation of the physiological and morphological organization of the NT ganglion will provide a ground-plan for a more informed investigation of NT function. Elasmobranchs will be used in these studies, because it is only in these animals that the NT is separate from the brain and directly accessible for electrophysiological experiments. Experiments proposed here include: 1) electrophysiological, pharmacological and morphological investigations of NT ganglion cells, which will provide data on the afferent and/or efferent projections of physiologically characterized cells; 2) combined electrophysiology, dye-fills and immunocytochemistry will investigate the function(s) of peptide containing cells, including the possibility that such cells constitute the afferent or efferent component of the nerve; 3) integration of data from all experiments will provide the first coherent picture of the neuronal circuitry of the NT ganglion, including the synaptic interactions between elements within the ganglion.