Animal Models of Neurological Disorders

Of primary concern to an investigator of neurological disorders is that of the selection of the most relevant animal model to achieve his or her research goals. According to Kornetsky (1977), three different types of animal models are typically used in medical research. Homologous models are those in animals which the etiology, symptoms, and outcome of the model duplicate those of the human disorder in every major aspect. Isomorphic models are those that resemble the human disorder, but are artificially produced in the laboratory in a way that does not reflect normal human etiology, and predictive models are those that do not necessarily resemble the human disorder in many respects, but are valuable in terms of predicting some aspect of the disorder such as the response to various drugs. The selection of the model depends on the goal of the experimenter. A predictive model allows the investigator to make certain predictions about the disorder it models; an isomorphic model permits not only predictions, but also allows the study of underlying mechanisms; and a homologous model serves as a basis for studying all aspects of a disorder, including its causes. Once the purpose of the experiment is defined, the type of model to be selected becomes apparent.