MECHANICAL AND ELECTRICAL RESPONSES OF THE SQUID GIANT-AXON TO SIMPLE ELONGATION
MECHANICAL AND ELECTRICAL RESPONSES OF THE SQUID GIANT-AXON TO SIMPLE ELONGATION
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DOI：
10.1115/1.2895464
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发表时间：
1993-02-01
影响因子：
1.7
通讯作者：
MATTESON, DR
中科院分区：
文献类型：
--
作者：
GALBRAITH, JA;THIBAULT, LE;MATTESON, DR
关于神经系统对负荷的机械和功能反应，可用的信息有限。虽然大脑、脊髓或周围神经组织的变形可能会造成特别严重的后果，但这一领域的大多数研究要么集中在展示体内功能变化和揭示受影响的解剖路径，要么描述复合材料结构的材料变形。尽管这些研究已经成功地产生了可重复的创伤，但它们还没有解决这些机械性损伤的机制。因此，为了进一步了解这种复杂的现象，需要一个单细胞模型。用一台专门为此实验设计的仪器监测了一个单独的鱿鱼巨型轴突在受控单轴载荷下的力学和生理反应。这些结果表明，分离的轴突的力学性质与其他软组织相似，并包括卸载时的非线性载荷-挠度曲线和滞后环等特征。力学响应用拟线性粘弹性理论模拟(Fong，1972)。轴突对准静态负荷的生理反应是一个小的可逆超极化；随着负荷速度的增加，轴突去极化，恢复到原始静息电位所需的幅度和时间以非线性方式增加。当伸长率超过20%时，发生不可逆转的损伤，膜电位不能完全恢复到基线。
There is a limited amount of information available on the mechanical and functional response of the nervous system to loading. While deformation of cerebral, spinal, or peripheral nerve tissue can have particularly severe consequences, most research in this area has concentrated on either demonstrating in-vivo functional changes and disclosing the effected anatomical pathways, or describing material deformations of the composite structure. Although such studies have successfully produced repeatable traumas, they have not addressed the mechanisms of these mechanically induced injuries. Therefore, a single cell model is required in order to gain further understanding of this complex phenomena. An isolated squid giant axon was subjected to controlled uniaxial loading and its mechanical and physiological responses were monitored with an instrument specifically designed for these experiments. These results determined that the mechanical properties of the isolated axon are similar to those of other soft tissues, and include features such as a nonlinear load-deflection curve and a hysteresis loop upon unloading. The mechanical response was modeled with the quasi-linear viscoelastic theory (Fung, 1972). The physiological response of the axon to quasi-static loading was a small reversible hyperpolarization; ho wever, as the rate of loading was increased, the axon depolarized and the magnitude and the time needed to recover to the original resting potential increased in a nonlinear fashion. At elongations greater than twenty percent an irreversible injury occurs and the membrane potential does not completely recover to baseline.