Aberrant Brain Plasticity in Autism Spectrum Disorders

Abstract

Plasticity enables the human brain to adapt to developmental challenges and rapidly changing environmental demands, acquire new skills, and cope with injury. However, aberrant or mistimed brain plasticity can lead to maladaptive brain changes, unstable structural connections, and a breakdown of functional systems necessary for normal cognition and behavior. This chapter argues that disorders on the autism spectrum (ASD) are the result of aberrant plasticity due to dysfunctional inhibitory control over excitatory synaptic plasticity. This developmental pathophysiology impacts anatomical and functional connectivity of specific neural circuits and accounts for characteristic behavioral impairments of ASD, but also provides a sensible account for the paradoxically, sometimes supranormal skills displayed by individuals with ASD. If this theory is correct, measures of brain plasticity may serve as an early ASD endophenotype and biomarker, and novel therapeutic approaches to control brain plasticity may reduce or prevent anatomical and functional brain abnormalities in ASD.