THE VESTIBULAR NERVE OF THE CHINCHILLA .1. PERIPHERAL INNERVATION PATTERNS IN THE HORIZONTAL AND SUPERIOR SEMICIRCULAR CANALS
THE VESTIBULAR NERVE OF THE CHINCHILLA .1. PERIPHERAL INNERVATION PATTERNS IN THE HORIZONTAL AND SUPERIOR SEMICIRCULAR CANALS
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DOI：
10.1152/jn.1988.60.1.167
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发表时间：
1988-07-01
影响因子：
2.5
通讯作者：
GOLDBERG, JM
中科院分区：
文献类型：
--
作者：
FERNANDEZ, C;BAIRD, RA;GOLDBERG, JM
1.用辣根过氧化物酶（HRP）标记了供应灰鼠水平半规管和上级半规管的传入纤维。从嵴的连续切片重建感觉上皮内标记纤维的分支。2.嵴的感觉上皮可分为中央区、中间区和周边区，其面积大致相等。这三个区域可以在正常材料中通过毛细胞的密度和萼末端的形态来区分。3.标记纤维供应嵴的小管侧或椭圆囊侧。轴突很少在基底膜下分叉，它们开始几乎在进入感觉上皮后立即分裂成末端分支。树枝状结构是紧凑的，很少从母体轴突延伸超过50 μ m。4.花萼和终末都被标记。花萼可以是简单的或复杂的。简单的肾盏支配单个的毛细胞，而复杂的肾盏供应两到三个相邻的毛细胞。复杂的花萼通常只在中央区域发现。单盏和终扣位于上皮的所有区域。花萼从母轴突或其粗枝上长出。终扣，无论是在途中或终端，总是位于薄进程。5.纤维被归类为花萼bouton，或二型。第一种类型只有花萼末端，第二种只有端扣末端，第三种同时具有两种末端。二形单位约占标记纤维的70%，钮扣单位约占20%，花萼单位约占10%。这三种纤维类型在它们的亲本轴突的直径和它们供应的嵴的区域上不同。轴直径最大的花萼单位和最小的bouton单位。花萼单位集中在嵴的中心区，而端扣单位主要局限于外围区。在整个感觉上皮中可见二形单位。6.花萼单位几乎总是不分枝的，末端为简单的花萼，或者，不太常见，为复杂的花萼。终末枝由15-80个终末的细突起组成。二形单位的复杂性不同，从单花萼和少数终扣的纤维到具有1至4个花萼和50个以上终扣的纤维。7.结果强调了双形单位的重要性，这是最多的传入纤维标记在这项研究中的类型，是唯一的单位发现，支配所有区域的感觉上皮。二形单位提供的主要传入神经支配II型毛细胞在中央区，I型毛细胞在周边区，和两种毛细胞在中间区。8.试图重建嵴的传入神经支配。本研究的数据与先前发表的豚鼠毛细胞计数一起使用（18，28）。计算结果表明，大多数的运河传入神经支配的边缘区的嵴，而一个相对较小的数量供应的中央区。
1. Afferent fibers supplying the horizontal and superior semicircular canals of the chinchilla were labeled by extracellular injections of horseradish peroxidase (HRP) into the vestibular nerve. The arborizations of labeled fibers within the sensory epithelium were reconstructed from serial sections of the crista. 2. The sensory epithelium of the crista can be divided into central, intermediate, and peripheral zones of approximately equal areas. The three zones can be distinguished in normal material by the density of hair cells and by the morphology of calyx endings. 3. Labeled fibers supply either the canalicular or the utricular side of the crista. Axons seldom bifurcate below the basement membrane and they begin dividing into their terminal arborizations almost immediately upon entering the sensory epithelium. The arborizations are compact, seldom extending more than 50 .mu.m from the parent axon. 4. Both calyx and bouton endings were labeled. Calyces can be simple or complex. Simple calyces innervate individual hair cells, whereas complex calyces supply two to three adjacent hair cells. Complex calyces are commonly found only in the central zone. Simple calyces and boutons are located in all regions of the epithelium. Calyces emerge from the parent axon or one of its thick branches. Boutons, whether en passant or terminal, are always located on thin processes. 5. Fibers were classified as calyx bouton, or dimorphic. The first type only has calyx endings, the second only has bouton endings, and the third has both kinds of endings. Dimorphic units make up some 70% of the labeled fibers, bouton units some 20%, and calyx units some 10%. The three fiber types differ in the diameters of their parent axons and in regions of the crista they supply. Axon diameters are largest for calyx units and smallest for bouton units. Calyx units are concentrated in the central zone of the crista, whereas bouton units are largely confined to the peripheral zone. Dimorphic units are seen throughout the sensory epithelium. 6. Calyx units are almost always unbranched and end as simple calyces or, less often, as complex calyces. The terminal arbors of bouton units consist of fine processes containing 15-80 endings. Dimorphic units vary in complexity from fibers with a single calyx and a few boutons to those with one to four calyces and more than 50 boutons. 7. The results emphasize the importance of dimorphic units, which were the most numerous types of afferent fiber labeled in this study and were the only units found to innervate all regions of the sensory epithelium. Dimorphic units provide the major afferent innervation to type II hair cells in the central zone, to type I hair cells in the peripheral zone, and to both kinds of hair cells in the intermediate zone. 8. An attempt was made to reconstruct the afferent innervation of the crista. Data from the present study were used together with previously published hair cell counts in the guinea pig (18, 28). The calculations indicate that the majority of canal afferents innervate the peripheral zone of the crista, whereas a relatively small number supply the central zone.