抄録
The aim of this study was to examine micro injuries of brain tissue to gain a better understanding of head injury tolerance. Compression stress relaxation experiments were conducted in vitro, using porcine brain tissue and subsequently analysed using two stain methods; immunofluorescent stain and immunoenzymatic stain. In these in vitro stress relaxation experiments, brain specimens were compressed quasi-statically at 1 mm/s, for compression strains ranging from 10% to 50%, in ten percent increments. Using the immunofluorescent stain method, it was observed that axon tear occurred at a compression strain of 30% or greater. The distribution of the damage ratio of the transverse length to the longitudinal length of brain nerve cells (referred to as an aspect ratio) using immunoenzymatic stain method in the brain tissue under loading was also examined. This indicated that at a compression strain of 30% or greater the aspect ratio exceeded 2.0. The results of this study show that a compression strain of 30% corresponds to the threshold for the extreme aspect ratio of 2.0; where the transverse length of deformed nerve cell is two times greater than longitudinal length.
