Morphological changes of the soleus motoneuron pool in chronic midthoracic contused rats
Morphological changes of the soleus motoneuron pool in chronic midthoracic contused rats
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DOI：
10.1016/j.expneurol.2004.08.028
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发表时间：
2005-01-01
影响因子：
5.3
通讯作者：
Thompson, FJ
中科院分区：
文献类型：
--
作者：
Bose, P;Parmer, R;Thompson, FJ
本研究观察了慢性(4个月)、中度胸部(T-8)挫伤大鼠比目鱼肌运动神经元池的形态特征。用非结合霍乱毒素B(CTB)亚单位溶液逆行标记10例挫伤患者和6例年龄、性别匹配的正常对照组比目鱼肌中的运动神经元。形态计量学研究比较了胞体面积、周长。正常和挫伤后动物标记细胞的直径、树突长度和大小分布。在正常动物中，脊髓注射毒素侧(左侧)的运动神经元平均为110.4+/-5.2.相比之下，慢性脊髓损伤动物的标记细胞数平均为93.00+/-8.4%(减少16%，P=0.006)。在被标记的比目鱼肌运动神经元池中，与正常对照组相比，极小(面积，约100微米(2))和中等(面积，545-914微米(2))神经元的频率显著降低，而较大(面积，914微米(2))神经元的频率显著增加。挫伤动物的树突束由较粗的树突组成，排列成更紧密的聚集束，并沿纵轴(吻尾轴)排列。比目鱼肌运动神经元树突形态的变化还包括树突总数显著减少，染色增加，一级树突肥大，一次、二次和三次分支显著减少。挫伤后动物的大小分布和树突形态的改变可能是由于细胞丢失和中等细胞向较大细胞转化和/或与损伤相关的中等细胞不能运输免疫标记所致。(C)2004 Elsevier Inc.保留所有权利。
This study investigated the morphological features of the soleus motoneuron pool in rats with chronic (4 months), midthoracic (T-8) contusions of moderate severity. Motoneurons were retrogradely labeled using unconjugated cholera toxin B (CTB) subunit solution injected directly into the soleus muscle of 10 contused and 6 age- and sex-matched, normal controls. Morphometric studies compared somal area, perimeter. diameter, dendritic length, and size distribution of labeled cells in normal and postcontusion animals. In normal animals, motoneurons with a mean of 110.4 +/- 5.2 were labeled on the toxin-injected side of the cord (left). By comparison, labeled cells with a mean of 93.0 +/- 8.4 (a 16% decrease, P = 0.006) were observed in the chronic spinal-injured animals. A significantly smaller frequency of very small (area, approximately 100 mum(2)) and medium (area, 545-914 mum(2)) neurons, and a significantly higher frequency of larger (area, >914 mum(2)) neurons was observed in the labeled soleus motoneuron pools of injured animals compared with the normal controls. Dendritic bundles in the contused animals were composed of thicker dendrites, were arranged in more closely aggregated bundles, and were organized in a longitudinal axis (rostrocaudal axis). Changes in soleus motoneuron dendritic morphology also included significant decrease of total number of dendrites, increased staining, hypertrophy of primary dendrites, and significant decreased primary, secondary, and tertiary branching. The changes in size distribution and dendritic morphology in the postcontusion animals possibly resulted from cell loss and transformation of medium cells to larger cells and/or injury-associated failure of medium cells to transport the immunolabel. (C) 2004 Elsevier Inc. All rights reserved.