Konakci Kadriye Zeynep, Streicher Johannes, Hoetzenecker Wolfram, Blumer Michael Josef Franz, Lukas Julius-Robert, Blumer Roland
Center of Anatomy and Cell Biology, Integrative Morphology Group, Vienna, Austria.
Invest Ophthalmol Vis Sci. 2005 Jan;46(1):155-65. doi: 10.1167/iovs.04-1087.
To analyze palisade endings in cat extraocular muscles (EOMs) and to clarify whether these EOM-specific organs are sensory or motor.
Twelve cats aged between 1 and 16 years were analyzed. Whole EOM tendons were immunostained using four different combinations of triple fluorescence labeling. Triple labeling included antibodies against choline acetyltransferase (ChAT), neurofilament, synaptophysin, and alpha-bungarotoxin. Preparations were examined by confocal laser scanning microscopy. ChAT-labeled EOMs were also analyzed by immunoelectron microscopy. Three-dimensional reconstructions were made of palisade endings.
Palisade endings were found in the distal and proximal myotendinous regions of cat EOMs. These endings arose from thin nerve fibers coming from the muscle and extending into the tendon. There, the nerve fibers turned back 180 degrees to divide into terminal branches around the muscle fiber tips. Terminal branches established numerous contacts with the tendon attached to the muscle fiber tip and only a few contacts with the muscle fiber. Often, nerve fibers forming palisade endings on muscle fiber tips were observed to establish multiple motor contacts on muscle fibers outside palisade endings. Three-dimensional reconstructions depicted the complex morphology of the palisade endings. All nerve fibers supplying palisade endings stained positively for ChAT and neurofilament. All nerve terminals in palisade endings were ChAT and synaptophysin positive. Only neuromuscular contacts in palisade endings were positive for alpha-bungarotoxin, as well.
This study provides evidence that palisade endings in cat EOMs have effector function. The findings may be of significance for strabismus surgery because palisade endings are also found in human EOMs.
分析猫眼外肌（EOMs）中的栅栏状末梢，并阐明这些眼外肌特异性器官是感觉性还是运动性的。
对12只年龄在1至16岁之间的猫进行分析。使用四种不同的三重荧光标记组合对整个眼外肌肌腱进行免疫染色。三重标记包括针对胆碱乙酰转移酶（ChAT）、神经丝、突触素和α-银环蛇毒素的抗体。通过共聚焦激光扫描显微镜检查标本。对ChAT标记的眼外肌也进行了免疫电子显微镜分析。对栅栏状末梢进行三维重建。
在猫眼外肌的远端和近端肌腱区域发现了栅栏状末梢。这些末梢起源于来自肌肉并延伸到肌腱的细神经纤维。在那里，神经纤维向后转180度，在肌纤维末端周围分成终末分支。终末分支与附着在肌纤维末端的肌腱建立了许多接触，而与肌纤维的接触较少。经常观察到在肌纤维末端形成栅栏状末梢的神经纤维在栅栏状末梢外的肌纤维上建立多个运动接触。三维重建描绘了栅栏状末梢的复杂形态。所有供应栅栏状末梢的神经纤维对ChAT和神经丝染色均呈阳性。栅栏状末梢中的所有神经末梢ChAT和突触素均呈阳性。栅栏状末梢中只有神经肌肉接触对α-银环蛇毒素也呈阳性。
本研究提供了证据表明猫眼外肌中的栅栏状末梢具有效应器功能。这些发现可能对视斜视手术具有重要意义，因为在人类眼外肌中也发现了栅栏状末梢。
