Morphological analysis of the cerebrospinal-fluid-(CSF)-contacting neuron in the lateral septum of avian species

我们证明了日本鹌鹑侧隔中的免疫反应小神经元簇与视蛋白样免疫反应神经元和vip样免疫反应神经元具有相似的形态学特征。核周聚积于双侧脑室腹壁的室管膜下区。标记的神经元呈多极或双极，胞体呈梨状或梭形。免疫反应性脑脊液接触神经元通过穿透室管膜的过程与脑脊液接触，最终形成单个结节状肿胀。扫描电镜显示心室突起。球状体（直径约2 μm）在室间隔内侧壁高度限定的区域内发现。这些结构分布在约1000 μm的正尾向内，被认为是接触csf神经元的室突。利用血管活性肠多肽（VIP）、VIP受体（VIPR）和视蛋白抗体对日本鹌鹑视交叉上核（mSCN）神经元成分进行免疫电镜分析。VIP元素分为两类。大约40%的VIP神经元元素属于突触类型。另一种是曲张型，在该节中没有突触特化。VIPR的免疫反应性是在突起的膜上发现的一种模糊物质，它似乎与突触连接相对应。视蛋白ir元素含有免疫反应性小颗粒。这个神经元成分可能是神经纤维的静脉曲张。在一些鸟类物种中，VIP和视蛋白共存于脑深部光感受器中。视蛋白末端的存在表明，视蛋白位于侧隔的脑深部光感受器支配着日本鹌鹑的中核神经。

We demonstrated clusters of immunoreactive small neurons in the lateral septum of the Japanese quail Opsin-like immunoreactive neurons and VIP-like immunoreactive neurons have similar morphological features. Their perikarya accumulate in the subependymal regions of the ventromedial walls of both lateral ventricles. The labelled neurons are multipolar or bipolar with pyriform or spindle-shaped cell bodies. Immunoreactive CSF-contacting neurons contact the CSF via a process that penetrates the ependyma and terminates in a single knob-like swelling. Scanning electron microscopic study revealed ventricular processes. Spherical bodies (about 2 μm in diameter) are found in a highly circumscribed region of the lateral ventricular wall of the medial lateral septum. These structures are distributed within about 1000 μm in rostro-caudal direction This structure is considerd as the venticular process of the CSF-contacting neuron. We examined immunoelectron microscopic analyses of neuronal elements in the suprachiasmtic nucleus (mSCN) of the Japanese quail using antibodies of vasoactive intestinal polypeptide (VIP), VIP receptor (VIPR) and an opsin. VIP ir elements are classified in two groups. About 40% of VIP ir neuronal elements are a synapse type. Another is a varicose type, which shows no synaptic specialization in the section. VIPR immunoreactivity is found as a fuzzy material on the membrane of the process, which seems to correspond to a synaptic junction. Opsin ir elements contain immunoreactive small granules. This neuronal element is probably a varicose of neuronal fiber. In several avian species, VIP and opsin co-exist in the deep brain photoreceptor. The presence of opsin ir terminals suggests that opsin ir deep brain photoreceptors of the lateral septum innervate the mSCN of the Japanese quail.