Autism Spectrum Disorder, Fear Response, and Environmental Exposures

Autism spectrum disorder (ASD) is a developmental condition characterized by impaired social interactions and communication, as well as by stereotypic movements, that affects 1 in 59 children. ASD is expected to reach 1 in about 40 children by 2020, yet it remains without distinct pathogenesis and effective treatment. Children with ASD respond with high anxiety to almost any unknown stimulus and appear to misread danger/threat signals, and may not experience anxiety in situations where normotypic children do. The authors propose that environmental stimuli stimulate the unique immune cells, known as mast cells (MC), which then trigger microglia, leading to dysfunctional neuronal connectivity in the amygdala. This process lowers or disrupts the “fear response” and leads to an exaggerated “fight-or-flight” reaction. corticotropin-releasing hormone (CRH) could have a synergistic effect with environmental stimuli, especially mycotoxins. Recognizing this association and preventing stimulation of mast cells/microglia could lead to effective treatment of ASD.