Viscoelastic properties of individual glial cells and neurons in the CNS
Viscoelastic properties of individual glial cells and neurons in the CNS
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DOI：
10.1073/pnas.0606150103
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发表时间：
2006-11-21
影响因子：
11.1
通讯作者：
Reichenbach, Andreas
中科院分区：
文献类型：
--
作者：
Lu, Yun-Bi;Franze, Kristian;Reichenbach, Andreas
150年前，神经胶质细胞I被发现是中枢神经系统中的第二种非神经元细胞类型。为了给这些新的、神秘的细胞赋予某种功能，有人建议它们要么将神经元粘合在一起（希腊语“gamma lambda i alpha”的意思是“胶水”），要么为它们提供一个坚固的支架（“支持细胞”）。尽管这两种猜测仍然被广泛接受，但它们实际上需要完全不同的力学电池特性，而且两者都没有得到实验证实。我们研究了中枢神经系统组织的生物力学，并从哺乳动物脑（海马）和视网膜急性分离单个神经元和神经胶质细胞。扫描力显微镜，体流变学，和光诱导变形被用来确定它们的粘弹性特征。我们发现：（i）在所有的中枢神经系统细胞中，弹性行为优于粘性行为;（ii）在不同的细胞区室中，如索马和细胞突起，力学性质不同，最可能是因为细胞器的不均匀局部分布;（iii）与大多数其他真核细胞相比，神经元和神经胶质细胞都非常柔软（“橡胶弹性”），和（iv）有趣的是，神经胶质细胞甚至比它们邻近的神经元更柔软。我们的研究结果表明，神经胶质细胞既不能作为结构支持细胞（因为它们太软），也不能作为神经元的胶水（因为恢复力占主导地位）。然而，从结构的角度来看，它们可能作为软的，顺应性嵌入神经元，保护他们在机械创伤的情况下，也作为一个软的基质所需的神经突生长和促进神经元的可塑性。
One hundred fifty years ago glia I cells were discovered as a second, non-neuronal, cell type in the central nervous system. To ascribe a function to these new, enigmatic cells, it was suggested that they either glue the neurons together (the Greek word "gamma lambda i alpha" means "glue") or provide a robust scaffold for them ("support cells"). Although both speculations are still widely accepted, they would actually require quite different mechanical cell properties, and neither one has ever been confirmed experimentally. We investigated the biomechanics of CNS tissue and acutely isolated individual neurons and glial cells from mammalian brain (hippocampus) and retina. Scanning force microscopy, bulk rheology, and optically induced deformation were used to determine their viscoelastic characteristics. We found that (i) in all CNS cells the elastic behavior dominates over the viscous behavior, (it) in distinct cell compartments, such as soma and cell processes, the mechanical properties differ, most likely because of the unequal local distribution of cell organelles, (iii) in comparison to most other eukaryotic cells, both neurons and glial cells are very soft ("rubber elastic"), and (iv) intriguingly, glial cells are even softer than their neighboring neurons. Our results indicate that glial cells can neither serve as structural support cells (as they are too soft) nor as glue (because restoring forces are dominant) for neurons. Nevertheless, from a structural perspective they might act as soft, compliant embedding for neurons, protecting them in case of mechanical trauma, and also as a soft substrate required for neurite growth and facilitating neuronal plasticity.