MAPT and Alzheimer disease: To study the role of TBI in AD-like alterations in an animal model that may mimic pathophysiological changes of tau and associated proteins in the human brain after TBI more closely, we performed controlled cortical impact (CCI) in human tau transgenic mice, in which all six isoforms of non-mutated human tau are expressed in a mouse tau null background39 and analyzed AD-like alterations behaviorally, biochemically and immunohistochemically.