What can rats tell us about neuropathic pain? Critical evaluation of behavioral tests used in rodent pain models

Background and Purpose: Animal models are a necessity in the study of neuropathic pain, and much of what we know about pain comes from studies in mice and rats. However, very few basic discoveries have been translated so far from rodent models into effective pain therapy. This review presents the most important rat models used in basic pain research, discusses their limitations and recommends better use of these models in future studies. Materials and Methods: A critical review of existing literature on rat models of neuropathic pain is made. Different models are compared and their contribution to pain research presented. Results: There are numerous models of neuropathic pain, and each has its advantages and disadvantages. However, much ethodological diversity exists and different interpretations of behavioral tests are used to assess pain in animal models. These methodological differences need to be resolved in order to achieve translation of research results into successful clinical therapeutics. Conclusions: Results of behavioral tests in animal pain models should be considered with caution. Further refinement of animal models of pain and associated methodologies is important. More work is needed for determination of the most predictive animal models, removal of user bias and introduction of more complex outcome measures in behavioral tests