Residual stress in the adult mouse brain |
| |
Authors: | Gang Xu Philip V Bayly Larry A Taber |
| |
Institution: | (1) Department of Biomedical Engineering, Washington University, One Brookings Drive, Campus Box 1097, St Louis, MO 63130-4899, USA;(2) Department of Mechanical, Aerospace, and Structural Engineering, Washington University, St Louis, MO 63130, USA |
| |
Abstract: | This work provides direct evidence that sustained tensile stress exists in white matter of the mature mouse brain. This finding
has important implications for the mechanisms of brain development, as tension in neural axons has been hypothesized to drive
cortical folding in the human brain. In addition, knowledge of residual stress is required to fully understand the mechanisms
behind traumatic brain injury and changes in mechanical properties due to aging and disease. To estimate residual stress in
the brain, we performed serial dissection experiments on 500-mum thick coronal slices from fresh adult mouse brains and developed finite element models for these experiments. Radial cuts
were made either into cortical gray matter, or through the cortex and the underlying white matter tract composed of parallel
neural axons. Cuts into cortical gray matter did not open, but cuts through both layers consistently opened at the point where
the cut crossed the white matter. We infer that the cerebral white matter is under considerable tension in the circumferential
direction in the coronal cerebral plane, parallel to most of the neural fibers, while the cerebral cortical gray matter is
in compression. The models show that the observed deformation after cutting can be caused by more growth in the gray matter
than in the white matter, with the estimated tensile stress in the white matter being on the order of 100–1,000 Pa. |
| |
Keywords: | Biomechanics Morphogenesis Cortical folding Axon Stiffness |
本文献已被 PubMed SpringerLink 等数据库收录! |
|