Pathophysiological Pathways in Autism Spectrum Disorders: Focus on Brain-Periphery Interactions, pp. 231-249
Authors: Bradley D. Pearce, Poul Thorsen, Kevin M. Sullivan, P. Barry Ryan, Opal Ousley, Emory University, Rollins School of Public Health, Atlanta, Georgia, and others
Abstract: New cross-disciplinary approaches are needed to elucidate the pathophysiological chain of events leading to autism and related disorders. Current theories hold that unidentified environmental factors superimposed on inherited liabilities initiate an abnormal trajectory of brain development that is manifested as the complex behavioral symptoms and signs of autism spectrum disorders (ASD). Various environmental insults have been implicated based on theoretical and experimental grounds, including prenatal or perinatal complications, environmental toxicants, and infections. While autism is considered primarily a brain disorder, there is substantial evidence for the involvement of peripheral tissues. In this article, we examine the important role of brain-periphery interactions in ASD. We describe the expression of ASD susceptibility genes in peripheral tissues, and explore the role of endocrine hormones as possible disruptors of brain development and intellectual function in ASD. Moreover, we consider data pointing to a connection between high rates of childhood infections and ASD as revealed by analyses of Danish medical registries. Despite several intriguing theories, there remains a prominent need to weave together the diverse findings in ASD research into a cogent mechanistic framework. With that goal in mind, this commentary highlights the importance of collaboration between experts in epidemiology, neuroscience, psychology, immunology, genetics, and chemistry in the quest to understand, and better treat autism and other pervasive developmental disorders.