Evidence for Brainstem Contributions to Autism Spectrum Disorders

Area of Science:

• Neuroscience
• Developmental Biology
• Genetics

Background:

• Autism Spectrum Disorder (ASD) is a neurodevelopmental condition affecting 1 in 59 US children.
• While cortical and cerebellar roles in ASD are known, early brainstem development in ASD is under-researched.
• Brainstem dysfunction aligns with ASD's sensory and motor symptoms, highlighting its potential role.

Purpose of the Study:

• To review and integrate evidence on brainstem contributions to ASD.
• To examine brainstem development in ASD through a hierarchical developmental lens.
• To explore the link between early brainstem alterations and ASD symptoms.

Main Methods:

• Literature review integrating epidemiological, behavioral, histological, neuroimaging, and animal model data.
• Analysis of data through the framework of hierarchical brain development.
• Examination of evidence on brainstem neurotransmission and development in ASD.

Main Results:

• Developmental alterations in the brainstem may have cascading effects on cortical and cerebellar development, leading to ASD.
• Perturbed development of brainstem substructures, especially monoaminergic centers, correlates with ASD or ASD-like behaviors in humans and animal models.
• Human histology, psychophysiology, and neuroimaging suggest atypical brainstem development and maturation in ASD, linked to sensorimotor and social symptoms.

Conclusions:

• Early brainstem alterations are implicated in the development of ASD.
• Further research is needed to validate early, infant-detectable, brainstem-based behaviors for ASD.
• Investigating the brainstem across the lifespan in ASD may lead to earlier diagnosis and improved treatment strategies.