Diffuse axonal injury (DAI), a major component of traumatic brain injury, is associated with rapid deformation of brain tissue resulting in the stretching of neural axons. Focal axonal swelling, which is the morphological hallmarks of DAI pathology, leads to the disconnection of neurons from tissues, resulting in cell death. In present study, PC 12 cells, which extend structurally axon-like cylindrical protrusions in culture, were stretched to a strain magnitude of 15-100% at strain rates of 30-80 s^<-1>, or left as static culture using an in vitro stretch injury device that subjected cultured cells to a wide range of mechanical stretch that are experienced during in vivo head injury. Following mechanical loading, we assessed neurite swelling and neuronal viability. As a result, the increase in early neurite swelling was dependent on the severity of the stretch, and neuronal viability at 24 h post-injury decrease in a stretch-dependent manner. These results suggest that the formation of neurite swellings correlates with the mechanical exposure.
