LUMBAR MOTONEURONS OF MAN .2. NUMBER AND DIAMETER DISTRIBUTION OF LARGE-DIAMETER AND INTERMEDIATE-DIAMETER CYTONS IN MOTONEURON COLUMNS OF SPINAL-CORD OF MAN
LUMBAR MOTONEURONS OF MAN .2. NUMBER AND DIAMETER DISTRIBUTION OF LARGE-DIAMETER AND INTERMEDIATE-DIAMETER CYTONS IN MOTONEURON COLUMNS OF SPINAL-CORD OF MAN
复制标题
DOI：
10.1097/00005072-197709000-00010
复制
发表时间：
1977-01-01
影响因子：
3.2
通讯作者：
DYCK, PJ
中科院分区：
文献类型：
--
作者：
KAWAMURA, Y;OBRIEN, P;DYCK, PJ
本文采用校正分裂细胞误差和校正核仁直径与胞体直径线性关系的方法，半自动计数和测量，程序计算和绘图，对18例正常人（年龄17-82岁）脊髓L-3、L-4和L-5运动神经元柱的胞体数目和直径直方图进行了评价。L-3、L-4和L-5腹侧脊根（VSR）的有髓纤维的直径的数量和频率分布（直径直方图）在先前的研究中作为对照被确定，以验证α的估计数量。和γ本研究中确定的运动神经元细胞来自同一脊髓节段。运动神经元柱细胞直径直方图一致地包含3个离散峰：大直径峰（CL）、中直径峰（CI）和小直径峰（CS）。举例来说，平均而言，有4874 .+-。585个大细胞和1700 . ±. 564.rarw.脊髓L5节段的中间细胞。发现脊髓节段的大细胞平均数与腹侧脊神经根（VSR）的大直径有髓纤维数之间存在合理的密切一致性（L3、L4和L5脊髓节段和腹侧脊神经根分别为0.91、0.94和0.98）。对于中间细胞数与中间轴突数的比值，一致性不太好（L3、L4和L5节段分别为0.77、0.85和1.14）。假设一个细胞仅向VSR提供1个轴突，从这些研究中推断大多数大直径细胞是α的细胞是合理的。运动神经元和大多数中等直径的细胞是γ细胞。运动神经元对于中等直径组，轴突的数量大于细胞的数量可能来自于小直径轴突（可能是神经节前自主神经纤维）与中等直径组的虚假包含。平均而言，运动神经元柱中大直径细胞群的直径范围为33-59 μ m，中等直径细胞群的直径范围为24-33 μ m。每个L3、L4和L5节段的细胞总数以约0.5的速率下降。分别为260、175和200/十年。
Using a methodology which corrects for split cell error and for the linear relationship between diameter of nucleolus and of cell body (cyton), semi-automatic methods of counting and sizing and programmed calculation and plotting, the number and diameter histograms of cytons of L-3, L-4, and L-5 motoneuron columns of 18 reference spinal cords of man (ages 17-82 yr) were evaluated. The number and frequency distribution of diameters (diameter histograms) of myelinated fibers of L-3, L-4 and L-5 ventral spinal roots (VSR) was determined in a preceding study as a control to validate the estimated number of .alpha. and .gamma. motoneuron cytons determined in this study from the same segment of spinal cord. The diameter histograms of cytons of motoneuron columns consistently contained 3 discrete peaks: a large-diameter peak (CL), an intermediate-diameter (CI) and small-diameter peak (CS). To illustrate, on the average, there were 4874 .+-. 585 large cytons and 1700 .+-. 564 .rarw. intermediate cytons in the L5 segment of spinal cord. A reasonably close concordance was found between the average number of large cytons of spinal cord segments and the number of large-diameter myelinated fibers of ventral spinal roots (VSR) (0.91, 0.94, and 0.98 for L3, L4 and L5 spinal cord segments and ventral spinal roots, respectively). For the ratio of the number of intermediate cytons to the number of intermediate axons the concordance was not as good (0.77, 0.85, and 1.14 for L3, L4 and L5 segments, respectively). Assuming that a cyton provided only 1 axon to VSR it was reasonable to infer from these studies that most large-diameter cytons are those of .alpha. motoneurons and that most of the intermediate-diameter cytons were those of .gamma. motor neurons. The greater number of axons than of cytons for the intermediate diameter group may be from a spurious inclusion of small-diameter axons (possibly pre-ganglionic autonomic fibers) with the intermediate-diameter group. On the average, the range of diameters of large-diameter cyton population n motoneuron columns was 33-59 .mu.m and for intermediate-diameter cytons was 24-33 .mu.m. The total number of cytons per L3, L4 and L5 segments fell at a rate of .apprx. 260, 175 and 200/decade, respectively.