Relevance of transgenic mouse models for Alzheimer's disease.

Over the last several decades, a number of mouse models have been generated for mechanistic and preclinical therapeutic research on Alzheimer's disease (AD)-like behavioral impairments and pathology. Acceptance or rejection of these models by the scientific community is playing a prominent role in how research findings are viewed and whether grants get funded and manuscripts published. The question of whether models are useful has become an exceptionally contentious issue. Much time and effort have gone into investigators debating comments such as "there are no mouse models of AD," "…nice work but needs to be tested in another mouse model," or "only data from humans is valid." This leads to extensive written justifications for the choice of a model in grant applications, to the point of almost apologizing for the use of models. These debates also lead to initiatives to create new, better models of AD without consideration of what "better" may mean in this context. On the "other side," an argument supporting the use of mouse models is one cannot dissect a biological mechanism in postmortem human tissue. In this chapter, we examine issues that we believe must be addressed if in vivo AD research is to progress. We opine that it is not the models that are the issue, but rather a lack of understanding the aspects of AD-like pathology the models were designed to mimic. The goal here is to improve the utilization of models to address critical issues, not to offer a critique of existing models or make endorsements.