Traumatic brain injury (TBI) continues to be a major health epidemic, with an annual incidence in the United States in excess of 1.5 million per year, leading to 50,000 fatalities and 3.7 million people living with long-term disability from TBI. TBI is particularly devastating to the young. In countries around the globe, motor vehicle crashes are the leading cause of death for all children and traumatic brain and skull injuries are the most common serious injuries sustained by children in motor vehicle crashes. While the age-dependent tolerance of the infant and toddler have been investigated no information exists on the tolerance of pre-adolescent brain to injury. The research described herein provides critical experimental and computational TBI injury tolerance information for the pre-adolescent juvenile age group. In Chapter 2, we describe the development of a pre-adolescent TBI animal model that produces injury relevant to the human including diffuse axonal injury, subarachnoid and subdural hemorrhage, and secondary brain injury. We compare results with data from infant and toddler animals and propose an empirical scaling relationship to estimate velocity and acceleration tolerance. In Chapter 3, we develop a Finite Element Model (FEM) of pre-adolescent animal based upon a validated model from the younger animals, and determine the strain threshold for TBI in the pre-adolescent and compare it to the strain threshold of the infant. In Chapter 4, we develop an ultra high resolution finite element model with element edge length in the sub millimeter range and high geometric fidelity to both internal and external brain structures. We then use this high resolution model to investigate the effects of material heterogeneity on strain and injury prediction. Finally, in Chapter 5 we discuss the implications of our research in light of our long-term goal to support the development of human FEM brain models that can be coupled with an ATD and used to evaluate safety system design.