Myenteric neuron numbers are maintained in aging mouse distal colon.
Myenteric neuron numbers are maintained in aging mouse distal colon.
复制标题
衰老小鼠远端结肠的肌间神经元数量得以维持。
DOI：
10.1111/nmo.12114
复制
发表时间：
2013
影响因子：
3.5
通讯作者：
Gamage PP
中科院分区：
文献类型：
--
作者：
Gamage PP
背景与年龄相关的肌间神经元丢失在几个物种中已被描述。在一些研究中，胆碱能神经元被报道为选择性脆弱，而氮能神经元则幸免于难。小鼠肠道神经系统(ENS)的老化和可能丢失的小鼠肌间神经元亚型的研究很少。方法取3-4、12-13、18-19和24-25个月龄的C57BL/6小鼠，用Huc/D抗体进行免疫双标记，以确定神经细胞总数和抗钙结合蛋白或神经元型一氧化氮合酶(NNOS)的抗血清，以确定肌间神经细胞亚群。用共聚焦显微镜对样品进行分析。采用了新的程序来确保无偏计数，并在样品制备过程中纠正肠道尺寸随年龄和拉伸的变化。结果3~4个月和12~13个月龄大鼠三叉神经丛的神经细胞总数和各亚群的神经纤维密度均无明显变化，但随着年龄的增长，肌间神经元的密度逐渐降低。随着年龄的增长，三叉神经丛内nNOS免疫反应神经纤维的密度显著增加，直至18~19月龄。在18-19和24-25个月龄的动物中，观察到大量CB和nNOS免疫阳性神经元的肿胀突起。结论与推断这些结果表明，在所研究的年龄段，衰老不会导致小鼠远端结肠肌间神经元的丧失，但确实会发生神经退行性改变，这可能会影响神经元的功能。
BackgroundAge‐associated myenteric neuronal loss has been described in several species. In some studies, cholinergic neurons have been reported to be selectively vulnerable, whereas nitrergic neurons are spared. Aging of the mouse enteric nervous system (ENS) and the subtypes of mouse myenteric neurons that may be lost have been little studied. We therefore investigated changes in the numbers of total neurons and two neuronal subpopulations in the mouse distal colon during aging.MethodsWholemount preparations from 3–4‐, 12–13‐, 18–19‐, and 24–25‐month‐old C57BL/6 mice were double immunolabeled with HuC/D antibody to identify the total neuronal population and antisera to either calbindin or neuronal nitric oxide synthase (nNOS) to identify myenteric neuronal subpopulations. Samples were analyzed by confocal microscopy. New procedures were employed to ensure unbiased counting and to correct for changes in gut dimensions with age and stretch during sample preparation. The density of nerve fibers in the tertiary plexus was also studied.Key ResultsNo significant change in numbers of total neurons or of either subpopulation with age was measured, but because of gut growth, the density of myenteric neurons decreased between 3–4 and 12–13 months. The density of nNOS‐immunoreactive nerve fibers in the tertiary plexus increased significantly with age, up to 18–19 months. Numerous swollen processes of CB and nNOS‐immunoreactive neurons were observed in 18–19‐ and 24–25‐month‐old animals.Conclusions & InferencesThese results indicate that aging does not result in a loss of myenteric neurons in mouse distal colon at the ages studied, although neurodegenerative changes, which may impact on neuronal function, do occur.