Molecular neuroimaging in adults with autism spectrum disorder

GABAergic Neurophysiology in Adults with Autism Spectrum Disorder

In current clinical practice, diagnosis of Asperger’s Disorder or Autism Spectrum Disorder (ASD) is performed by identification of behavioral and cognitive symptoms. Current treatments in ASD are based on treating symptoms, and not the underlying biological root cause. Identification of specific molecular abnormalities (e.g. aberrations involving the neurotransmission system) in targeted brain networks would allow for better assessments of abnormalities of brain circuits associated with the cognitive-behavioral deficits, and more rational and effective development of interventions that are based on molecular abnormalities in specific brain networks. Therefore, the proposed work in molecular neuroimaging in individuals with ASD will help the field to depart from the symptom-clustering approach in diagnosis and empirical approach in treatments, and move toward diagnostic and intervention strategies based on the underlying root cause.

Just like driving a car needs an accelerator and a brake, the brain functions by having an excitatory system (controlled by glutamate and glutamate receptors) and an inhibitory system (controlled by GABA and GABAA receptors). We are performing a specialized brain imaging scan, which determines how much GABA and GABAA receptors (see Figure 1) an individual has in specific regions of his/her brain. We will examine the imaging results from 40 individuals with ASD and compare them with 40 healthy volunteers.

The specialized brain imaging technology involves positron emission tomography (PET) and magnetic resonance spectroscopy (MRS), which measure the concentrations of GABAA receptors and GABA, respectively, in the brain. A tracer specific to the GABAA receptors will be injected intravenously to study participants in the beginning of imaging session. See Figure 2 for a representative PET, MRI, and fused PET/MRI images

This project utilizes state-of-the-art neuroimaging system to characterize the inhibitory neurotransmitter system in high-functioning adults with autism spectrum disorder. The overarching objective of this project is to determine the association between the GABAergic system and socio-communicative function.

Age range: 18 to 55