Age-related differences in synaptic plasticity following muscle unloading
Age-related differences in synaptic plasticity following muscle unloading
复制标题
DOI：
10.1002/neu.10271
复制
发表时间：
2003-12-01
期刊：
影响因子：
--
通讯作者：
Wilson, MH
中科院分区：
文献类型：
--
作者：
Deschenes, MR;Wilson, MH
本研究的目的是确定肌肉卸载的一种形式的次全废用的神经肌肉接头（NMJ）的形态在年轻和老年动物的影响。将16只老年（22个月）和16只年轻成年（8个月）雄性Fischer 344大鼠分配至对照组和后肢悬吊（HS）条件下（n = 8/组）。在4周实验期结束时，收集比目鱼肌，并使用免疫荧光程序来可视化乙酰胆碱（ACh）囊泡和受体、神经末梢分支以及NCAM和NT-4表达。定量分析显示，老年对照组乙酰胆碱囊泡和受体区域的面积和周长显著减少（p < 0.05），而不影响神经终末分支数量或长度。相反，年轻的NMJ，这是弹性的卸载的影响，NMJ的老年HS大鼠表现出显着的扩张乙酰胆碱囊泡和受体的尺寸相比，老年对照组。NCAM染色的定性分析表明，单独的衰老在一定程度上增加了该分子的表达（老年对照>年轻对照）。然而，在这四组中，老年HS肌肉中检测到的NCAM含量最多，与这些肌肉中表现出的突触可塑性程度相匹配。与NCAM不同，NT-4的表达在治疗组之间没有差异。这些数据表明，虽然年轻的成年肌肉保持正常的NMJ结构在长期暴露于卸载，老年NMJ经验显着的适应，刺激。(C)2003 Wiley Periodicals，Inc.
The objective of the present investigation was to determine the effects of muscle unloading-a form of subtotal disuse- on the morphology of the neuromuscular junction (NMJ) in younger and aged animals. Sixteen aged (22 months) and 16 young adult (8 months) male Fischer 344 rats were assigned to control and hindlimb suspension (HS) conditions (n = 8/group). At the conclusion of the 4 week experimental period, soleus muscles were collected, and immunofluorescent procedures were used to visualize acetylcholine (ACh) vesicles and receptors, nerve terminal branching, as well as NCAM and NT-4 expression. Quantitative analyses revealed that aged controls displayed significant (p < 0.05) reductions in area and perimeter length of ACh vesicle and receptor regions, without affecting nerve terminal branch number or length. In contrast to younger NMJs, which were resilient to the effects of unloading, NMJs of aged HS rats demonstrated significant expansion of ACh vesicle and receptor dimensions compared to aged controls. Qualitative analyses of NCAM staining indicated that aging alone somewhat increased this molecule's expression (aged controls > young controls). Among the four groups, however, the greatest amount of NCAM content was detected among aged HS muscles, matching the degree of synaptic plasticity exhibited in those muscles. Unlike NCAM, the expression of NT-4 did not appear to differ among the treatment groups. These data suggest that although young adult muscle maintains normal NMJ structure during prolonged exposure to unloading, aged NMJs experience significant adaptation to that stimulus. (C) 2003 Wiley Periodicals, Inc.