Criteria for determining whether mismatch responses exist in animal models: Focus on rodents

The mismatch negativity (MMN) component of the auditory event-related potential, elicited in response to unexpected stimuli in the auditory environment, has great value for cognitive neuroscience research. It is changed in several neuropsychiatric disorders such as schizophrenia. The ability to measure and manipulate MMN-like responses in animal models, particularly rodents, would provide an enormous opportunity to learn more about the neurobiology underlying MMN. However, the MMN in humans is a very specific phenomenon: how do we decide which features we should focus on emulating in an animal model to achieve the highest level of translational validity? Here we discuss some of the key features of MMN in humans and summarise the success with which they have been translated into rodent models. Many studies from several different labs have successfully shown that the rat brain is capable of generating deviance detection responses that satisfy of the criteria for the human MMN.