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Study of changes of neuronal membrane functions with aging by tissue culture method

组织培养法研究神经元膜功能随衰老的变化

基本信息

批准号：
63570041
负责人：
HORIE Hidenori
金额：
$ 1.28万
依托单位：
Yokohama City University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1988
资助国家：
日本
起止时间：
1988 至 1989
项目状态：
已结题

项目摘要

The effects of a hypotonic solution on morphology and electrophysiological functions in cultured dissociated neurons can be precisely studied. From the analysis of video pictures from Nomarski optics, diameters of the cells were seen to increase and then recover to the initial values after the application of a hypotonic solution. The rate of increase of cell size in fetal neurons was 4-5 times faster. than in mature neurons. This transient depolarization and decrease of the resistance corresponded to morphological changes. However, the amplitude of an action potential scarcely changed during the cell membrane expansion. It is plausible that increased membrane tension caused by the membrane expansion might facilitate the opening of the channel. The cell membrane expansion might also increase ionic permeability through the membrane.This may reduce a swollen cell volume to the initial one by diluting the intracellular solute concentration. After this adaptation the cultured neurons were a … More ble to survive for a long time and extend process in the hypotonic environment.Cell membrane elasticity has been measured in erythrocytes by the method of Elastic Area Compressibility Modulus(EACK). A dissociated neuron is aspirated by a negative pressure into a siliconized capillary, the diameter of which is about a half that of the neuron. Cell surface area can be calculated from pictures of the aspirated neuron on a TV monitor screen. Dorsal root ganglion neurons from fetal and 3-month-old mice were dissociated and their values of the area compressibility modulus (K) were measured. The K value of adult mouse neurons was 21.3<plus-minus>10.3 dyn/cm which is about 1/10 that of erythrocytes. The K value of fetal mouse DRG neurons was 2.8<plus-minus>0.5 dyn/cm. The cell membrane elasticity decreases with aging. Since neuronal cell membrane functions closely relate to intracellular cytoskeltal filaments, elasticity of the membrane may be affected by disruption of the filaments. When 10 muM cytochalasin D was treated to adult cultured neurons, the elasticity scarcely changed. However, when 10 muM colchicine was applied to the neurons, the K value decreased to 7.80 dyn/cm. This result suggests that intracellular microtubules in a neuron may mechanically bind to the cell membrThese results suggest that a neuronal membrane becomes rigid with aging and this rigidity might cause a capability of neurite regeneration to decrease with aging. Less

可以精确研究低渗溶液对培养的分离神经元形态和电生理功能的影响。从诺马尔斯基光学器件的视频图片分析中可以看出，在应用低渗溶液后，细胞的直径会增加，然后恢复到初始值。胎儿神经元细胞大小增加的速度快4-5倍。比成熟的神经元。这种短暂的去极化和电阻的降低与形态变化相对应。然而，动作电位的振幅在细胞膜扩张期间几乎没有变化。膜膨胀引起的膜张力增加可能有利于通道的打开，这似乎是合理的。细胞膜扩张还可能增加离子通过膜的渗透性。这可以通过稀释细胞内溶质浓度将肿胀的细胞体积减少到初始体积。经过这种适应，培养的神经元能够在低渗环境中长期存活并延长过程。通过弹性区域压缩模量（EACK）的方法测量了红细胞的细胞膜弹性。分离的神经元被负压吸入硅化毛细管中，其直径约为神经元直径的一半。细胞表面积可以根据电视监视器屏幕上的抽吸神经元的图片来计算。分离胎儿和 3 个月大小鼠的背根神经节神经元，并测量它们的面积压缩模量 (K) 值。成年小鼠神经元的K值为21.3±10.3dyn/cm，约为红细胞的1/10。胎儿小鼠DRG神经元的K值为2.8±0.5dyn/cm。细胞膜弹性随着衰老而降低。由于神经元细胞膜的功能与细胞内的细胞骨架丝密切相关，膜的弹性可能会受到丝的破坏的影响。当用 10 μM 细胞松弛素 D 处理成年培养的神经元时，弹性几乎没有变化。然而，当向神经元施加10μM秋水仙碱时，K值下降至7.80dyn/cm。该结果表明神经元中的细胞内微管可能与细胞膜机械结合。这些结果表明神经元膜随着衰老而变得坚硬，并且这种刚性可能导致神经突再生的能力随着衰老而降低。较少的