PERIPHERAL INNERVATION PATTERNS OF VESTIBULAR NERVE AFFERENTS IN THE BULLFROG UTRICULUS
PERIPHERAL INNERVATION PATTERNS OF VESTIBULAR NERVE AFFERENTS IN THE BULLFROG UTRICULUS
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DOI：
10.1002/cne.903420210
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发表时间：
1994-04-08
影响因子：
2.5
通讯作者：
SCHUFF, NR
中科院分区：
文献类型：
--
作者：
BAIRD, RA;SCHUFF, NR
支配牛蛙椭圆体的前庭神经传入具有不同的反应动力学和对自然刺激的敏感性。它们还提供在毛束形态上明显不同的毛细胞。为了更深入地观察单个椭圆形传入神经的周围神经支配模式，将前庭神经切断至Scarpa神经节内侧，用细胞外注射辣根过氧化物酶(HRP)的方法标记传入纤维，以允许交感和传出纤维变性。然后，单个传入神经的外周分支与它们的父轴突的直径、它们所支配的黄斑区域以及它们所提供的毛细胞的数量和类型相关。根据其所属轴突的上皮性入路和终末野的位置，将丘脑传入神经分为纹状体或纹状体外传入。总体而言，纹状体传入神经元比纹状体外区域的传入神经元具有更厚的母轴突、更少的上皮下分叉、更大的终末和更多的突触终末。与内侧纹状体相邻的纹状体旁区域的传入神经具有介于纹状体和纹外内侧更多周边部之间的神经支配模式。大多数传入神经只支配单一的黄斑区。前人根据毛束形态将牛蛙椭圆体中的毛细胞分为四种类型(Lewis和Li：Brain Res.83：35-50,1975)。纹状体外区和纹状体旁区的传入神经主要或完全支配B型毛细胞，B型毛细胞是椭圆形黄斑中的主要毛细胞类型。纹状体传入神经供应四种毛细胞类型的混合体，但主要接触B型和C型毛细胞，尤其是内侧纹状体外侧的毛细胞。提供更多中央纹状体区域的传入神经支配较少的B型毛细胞和较多数量的E型和F型毛细胞。在纹状体最内侧的E型毛细胞中，纹状体传入的细小轴突主要供应带有球状动丝的E型毛细胞。(C)1994年Wiley-Liss，Inc.
Vestibular nerve afferents innervating the bullfrog utriculus differ in their response dynamics and sensitivity to natural stimulation. They also supply hair cells that differ markedly in hair bundle morphology. To examine the peripheral innervation patterns of individual utricular afferents more closely, afferent fibers were labeled by the extracellular injection of horseradish peroxidase (HRP) into the vestibular nerve after sectioning the vestibular nerve medial to Scarpa's ganglion to allow the degeneration of sympathetic and efferent fibers. The peripheral arborizations of individual afferents were then correlated with the diameters of their parent axons, the regions of the macula they innervate, and the number and type of hair cells they supply.The utriculus is divided by the striola, a narrow zone of distinctive morphology, into medial and lateral parts. Utricular afferents were classified as striolar or extrastriolar according to the epithelial entrance of their parent axons and the location of their terminal fields. In general, striolar afferents had thicker parent axons, fewer subepithelial bifurcations, larger terminal fields, and more synaptic endings than afferents in extrastriolar regions. Afferents in a juxtastriolar zone, immediately adjacent to the medial striola, had innervation patterns transitional between those in the striola and more peripheral parts of the medial extrastriola. Most afferents innervated only a single macular zone. The terminal fields of striolar afferents, with the notable exception of a few afferents with thin parent axons, were generally confined to one side of the striola.Hair cells in the bullfrog utriculus have previously been classified into four types based on hair bundle morphology (Lewis and Li: Brain Res. 83:35-50, 1975). Afferents in the extrastriolar and juxtastriolar zones largely or exclusively innervated Type B hair cells, the predominant hair cell type in the utricular macula. Striolar afferents supplied a mixture of four hair cell types, but largely contacted Type B and Type C hair cells, particularly on the outer rows of the medial striola. Afferents supplying more central striolar regions innervated fewer Type B and larger numbers of Type E and Type F hair cells. Striolar afferents with thin parent axons largely supplied Type E hair cells with bulbed kinocilia in the innermost striolar rows. (C) 1994 Wiley-Liss, Inc.