de Graaf F, van Raamsdonk W, van Asselt E, Diegenbach P C
Department of Experimental Zoology, University of Amsterdam, The Netherlands.
Anat Embryol (Berl). 1990;182(1):93-102. doi: 10.1007/BF00187531.
We investigated the location and size distribution of motoneurons that innervate red, intermediate and white muscle fibers in the axial musculature of the zebrafish (Brachydanio rerio). Motoneurons were identified by retrograde labeling from the respective myotomal compartments with horseradish peroxidase applied either in small polyacrylamide gel fragments or as pure crystals. We found a spatial relationship between the three myotomal muscle fiber types and the corresponding motoneurons. The white motoneurons are grouped in the dorsal part of the motorcolumn, near the central canal. Motoneurons of the red and intermediate muscle are clustered in the ventral part of the motorcolumn. The average position of the red motoneurons is ventral to that of the intermediate motoneurons. Some sizes are distributed over wide overlapping ranges, spanning from 41 to 352 microns 2 for red and intermediate and from 56 to 894 microns 2 for white motoneurons. These data are discussed in relation to the recruitment order of myotomal muscle fibers of different types as revealed by electromyographic recordings in fish, and the so called "size principle" for motoneuron recruitment.
我们研究了斑马鱼（Brachydanio rerio）轴肌中支配红色、中间型和白色肌纤维的运动神经元的位置和大小分布。通过在小聚丙烯酰胺凝胶片段中或作为纯晶体应用辣根过氧化物酶，从各自的肌节隔室进行逆行标记来识别运动神经元。我们发现了三种肌节肌纤维类型与相应运动神经元之间的空间关系。白色运动神经元聚集在运动柱的背侧部分，靠近中央管。红色和中间型肌肉的运动神经元聚集在运动柱的腹侧部分。红色运动神经元的平均位置在中间型运动神经元的腹侧。一些大小分布在广泛重叠的范围内，红色和中间型运动神经元的范围为41至352平方微米，白色运动神经元的范围为56至894平方微米。结合鱼类肌电图记录所揭示的不同类型肌节肌纤维的募集顺序以及运动神经元募集的所谓“大小原则”，对这些数据进行了讨论。
