Assessment of behavioral dysfunction following experimental traumatic brain injury (TBI)

Abstract

Traumatic brain injury (TBI) is a major public health concern, as it is one of the leading causes of death and disability in the USA. Over the years, several attempts have been made to reconstruct the pathophysiological events that occur during a TBI and the behavioral abnormalities that are observed in TBI survivors. Such behavioral deficits lead to long-term neurological dysfunction and often demonstrate symptoms of chronic neurodegenerative disorders known to impair the quality of life of the patients. For example, TBI patients often suffer from learning disability and memory loss similar to that observed in cases of Alzheimer’s disease, motor dysfunction seen in Parkinson’s disease cases, and changes in mood and emotional behavior noted in patients with anxiety and depression. Although science in the field of TBI research has shown tremendous progress and advancement, more recently, trials of therapeutic agents that have shown promise in preclinical settings have consistently failed to demonstrate improvement in behavioral outcomes after clinical TBI. Therefore, there is an urgent need to develop new models while continuing to refine existing approaches used for modeling experimental TBI and related behavioral impairment. In this chapter, we describe the concept, key features, and methodology of some of the most commonly used animal models for inducing experimental TBI and evaluating behavioral dysfunction. In addition to detailing the application of different animal models, we evaluate their relevance to clinical symptoms by examining their advantages and limitations. We acknowledge that the events that occur during and after a clinical TBI are multifactorial in nature. Therefore, while developing and utilizing such animal models, it is important to focus on the diversity of the mechanisms involved in the impact during the injury, and the complexity of the secondary injury processes that lead to long-term behavioral dysfunction.