Neurobiological Factors of Executive Dysfunction in Autism Spectrum Disorders

Abstract

Autism is a pervasive neurodevelopmental disorder that is defined by difficulties in social interaction and abnormal preoccupation in repetitive and stereotypic activities. Deficit of basic executive functions, such as cognitive flexibility, inhibitory control, working memory may strongly contribute to these symptoms. Prefrontal and cingulate cortices play a crucial role in the executive functions. These brain structures are regulated by neuromodulatory systems of the brain: cholinergic, noradrenergic, serotonergic, and dopaminergic. During the early brain development these neuromodulators act as neurotrophic factors, and they regulate excitation-inhibition balance in the brain. Pathogenesis of autism is hypothesized to be linked to impairment in metabolism of one or more of these neuromodulators. The aim of this review is to consider the functional role of these neuromodulators and the significance of their imbalance in mature and developing brain, as an important factor in the development of autistic symptoms in children and adults.