Elizabeth McCullagh, Ph.D.

Meet the Researcher

McCullagh received her Ph.D. at the University of Illinois at Chicago where, under the mentorship of David Featherstone, Ph.D., she studied molecular and behavioral neuroscience to understand the link between genetics and resulting behaviors.

She is currently a postdoctoral researcher at the University of Colorado, Anschutz Medical Campus, in the lab of Achim Klug, Ph.D.

The Research

University of Colorado
The role of the MNTB in sound localization impairments in autism spectrum disorder

The processing of sound location and the establishment of spatial channels to separate several simultaneous sounds is critical for social interaction, such as carrying on a conversation in a noisy room or focusing on a person speaking. Impairments in sound localization can often result in central auditory processing disorders (CAPD). A form of CAPD is also observed clinically in all autism spectrum disorders, and is a significant to quality-of-life issues in autistic patients.

The circuit in charge of initially localizing sound sources and establishing spatial channels is located in the auditory brain stem and functions with precisely integrated neural excitation and inhibition. A recent theory posits that autism may be caused by an imbalance of excitatory and inhibitory synapses, particularly in sensory systems. An imbalance of excitation and inhibition would lead to a decreased ability to separate competing sound sources. While the current excitation to inhibition model of autism assumes that most inhibition in the brain is GABAergic, the sound localization pathway in the brainstem functions primarily with temporally faster and more precise glycinergic inhibition.

The role of glycinergic inhibition has never been studied in autism disorders, and could be a crucial component of altered synaptic processing in autism. The brainstem is a good model to address this question since the primary form of inhibition is through glycine, and the ratio of excitation to inhibition is crucial for normal processing.

Long-term goal: To determine how the auditory brainstem functions in autism in order to lead us to greater insights to the disorder in general, as well as specifically in auditory dysfunction, and ultimately to provide a medical intervention to restore the balance of excitation and inhibition in autistic patients.