Musculotopic organization of the facial motor nucleus in Macaca fascicularis: a morphometric and retrograde tracing study with cholera toxin B-HRP.
Musculotopic organization of the facial motor nucleus in Macaca fascicularis: a morphometric and retrograde tracing study with cholera toxin B-HRP.
复制标题
食蟹猴面部运动核的肌肉组织：霍乱毒素 B-HRP 的形态测量和逆行追踪研究。
DOI：
10.1002/cne.902910409
复制
发表时间：
1990
期刊：
影响因子：
--
通讯作者：
Abbs,JH
中科院分区：
文献类型：
--
作者：
Welt,C;Abbs,JH
采用形态测量和逆行追踪方法确定了支配食蟹猴个体面部肌肉的运动神经元的位置和数量。肌内注射霍乱毒素B亚基-辣根过氧化物酶结合物在同侧面神经运动核中产生离散的标记模式，胞体及其突起具有良好的定义。面神经核在脑桥中向吻尾方向延伸约2 mm，沿此轴的形状和横截面积沿着变化。运动神经元在亚核内成簇分布，但边界不清晰，不被纤维束分隔。各亚核的长度、数量和面积随吻尾侧位置的不同而不同。逆行标记模式显示，单个肌肉由运动神经元纵列支配，每个肌肉区域在其纵列的所有吻尾侧水平上都有代表。列开始在不同的rostrocaudal水平和长度不同。列密切相关的肌肉，如口轮匝肌和颏的下唇，往往重叠，而列不同的肌肉，如口周和眶，没有重叠。大多数运动神经元的树突状突起在几个不同的柱或亚核之间广泛分支。部分树突伸出核外，进入周围的被盖区，索马体直径（10.4 - 42.2 μm）呈单峰分布，反映了面肌中γ运动神经元的缺失和肌梭的缺乏。大，小运动神经元被发现在核的所有区域，但最大的位于尾侧和支配肌肉的上唇和下唇。口周肌也有更多的神经元，更长的列，和较低的细胞密度比其他肌肉群检查。这些特征可能反映了口周肌在面部表情和发声中的功能。
Morphometric and retrograde tracing methods were used to determine the location and number of motoneurons innervating individual facial muscles inMacaca fascicularis. Intramuscular injections of the cholera toxin B subunit‐horseradish peroxidase conjugate produced discrete labeling patterns in the ipsilateral facial motor nucleus with good definition of somata and their processes. The facial nucleus extended rostrocaudally in the pons for about 2 mm, varying in shape and cross‐sectional area along this axis. Motoneurons were clustered in subnuclei, but their boundaries were not sharp and they were not segregated by fiber bundles. The length, number, and area of subnuclei varied with rostrocaudal location.Retrograde labeling patterns revealed that individual muscles were innervated by longitudinal columns of motoneurons with each muscle region represented at all rostrocaudal levels of its column. The columns began at different rostrocaudal levels and varied in length. Columns for closely related muscles, such as the orbicularis oris and mentalis of the lower lip, tended to overlap, whereas columns for disparate muscles, such as the perioral and orbital, did not overlap. The dendritic processes of most motoneurons branched extensively among several different columns or subnuclei. Some dendrites extended outside of the nucleus into the surrounding tegmentum.Mean soma diameter (10.4‐42.2 μm) was distributed unimodally, reflecting the absence of gamma motoneurons and lack of muscle spindles in the facial muscles. Large and small motoneurons were found in all regions of the nucleus, but the largest ones were located caudally and innervated muscles of the upper and lower lip. The perioral muscles also had more neurons, longer columns, and a lower cell density than the other muscle groups examined. These features may reflect the functions of the perioral muscles in facial expression and vocalization.