Experiments that employ physical models of the skull and surrogate brain have permitted an approximation of the deformations that occur within the brain during dynamic loading. The kinematical conditions under which these experiments have been conducted thus far include sagittal and coronal plane noncentroidal rotations, while the kinetic conditions used have been guided by the matrix of inertial loading parameters used in subhuman primate experiments. Macroscopic load parameters, such as the acceleration, velocity and displacement, used in these tests are compared to the deformation computed in selected anatomic regions of interest.
Intracellular calcium measurements have been made on isolated single axons and neurallike cells in culture that have been mechanically stimulated In these experiments, the magnitude and time course of the calcium transients have been analyzed with regard to the strains and strain rates that the individual cells experienced.
These data are combined in a model that presents the topographic distribution of the intracellular calcium changes throughout the brain following the inertial loading conditions imposed upon the model, These maps of the calcium events are then compared to pathology obtained from subhuman primate studies that were conducted under similar loading conditions. This approach is intended to provide insight into the relationships between the macroscopic loading parameters and the associated tissue injury, with implications for improved injury tolerance criteria and novel methods of therapeutic intervention.