After years of dedicated research, Hailey Welch, a doctoral student in cognition and neuroscience, has achieved two significant milestones. In September, she was awarded the Ruth L. Kirschstein National Research Service Award Individual Predoctoral Fellowship from the National Institutes of Health (NIH) to support her doctoral studies at The University of Texas at Dallas. Simultaneously, Welch became the lead author of a groundbreaking study published on November 5 in the journal Cell Reports, which explores the role of the vagus nerve in digestive signaling.
“I’m getting my first first-author publication and this funding at the same time. It’s so incredibly validating,” Welch expressed, highlighting the dual achievements that mark a pivotal point in her academic career.
Understanding the Vagus Nerve
The focus of Welch’s research is the vagus nerve, a critical component in forming dietary habits. The nerve comprises left and right branches, each with distinct functions. Previous studies conducted in the Motor and Habit Learning Lab at UT Dallas, led by Dr. Catherine Thorn, suggest these branches play different roles in transmitting food-related information from the gut to the brain.
“We know that the vagus nerve transmits information about the nutritional and reward aspects of food from the gut to the brain,” Welch explained. “What we are discovering is that such reward signaling is lateralized — mainly right-sided.”
Welch’s study in Cell Reports delved into the molecular and functional profiles of sensory neurons in the vagus nerve, using genetic sequencing, imaging, and functional assays. Conducted in rodent models, the research provides insights into why right-sided vagus nerve signaling might trigger dopamine release in the brain, a hormone associated with pleasure and reward.
“We found that the right vagus nerve includes a unique population of sensory neurons consistent with sensing signals from the digestive system. There are about half as many of these neurons on the left side,” Welch noted.
Implications for Modern Diets
The human inclination towards energy-dense, high-fat, and high-sugar foods has been a constant through history. In today’s world, where such foods are readily available, this craving can lead to obesity and metabolic disorders. Welch’s research aims to address these challenges by exploring how the vagus nerve influences dietary behaviors.
Building on her findings, Welch’s F31 fellowship project will further investigate the specific nerve cells within the right vagus nerve. “We’re currently working on techniques to lesion these specific neurons to learn the effect on food preferences,” Welch said. “We’re hoping that introducing a specific lesion will allow us to learn more about the possibly lateralized development of preference for high-fat diets.”
Broader Impacts and Future Directions
Dr. Catherine Thorn, Welch’s mentor, emphasized the broader implications of this research. “Hailey’s research on the vagus nerve has implications for improving treatments not only for obesity or metabolic diseases, but possibly movement disorders, depression, and substance abuse,” Thorn stated.
Thorn added, “We know that there are differences between the right and left sides in how the vagus nerve encodes these reward signals, and Hailey has found a possible molecular underpinning for such side-specific functions.”
Growing up in Tulsa, Oklahoma, Welch’s passion for neuroscience began early. By high school, she was already expanding her knowledge through podcasts. Her journey continued at the University of Oklahoma, where she studied chemical biosciences and researched the relationship between iron deficiency and dopamine. A self-proclaimed “foodie,” Welch was initially drawn to UT Dallas for its strong pain research program, but found her true calling in Thorn’s lab.
“Continuing this gut-brain research is a perfect fit. It’s not what I foresaw myself doing, but it makes total sense, and I love it so much,” Welch said. “Science is hard, and experiments generally don’t work the first time, but the passion for figuring out what’s going on is the thing that keeps me going.”
Dr. Thorn praised Welch’s innovative approach, stating, “Hailey is using many different approaches to answer this massively complex question of how gut-brain circuits can impact decision-making. Her research is taking the lab in exciting new directions.”
Collaborative Efforts and Funding
The Cell Reports paper was a collaborative effort, including contributions from Dr. Ted Price, Ashbel Smith Professor of neuroscience and director of the Center for Advanced Pain Studies; Dr. Benedict Kolber, professor of neuroscience; and several other distinguished researchers and students. The research received funding from multiple NIH institutes, including the National Institute on Drug Abuse and the National Institute of Neurological Disorders and Stroke.
The research described in Cell Reports was funded by the National Institute on Drug Abuse; the National Institute of Neurological Disorders and Stroke; and the National Institute of Diabetes and Digestive and Kidney Diseases (R21DA055166, R01NS065926, R01DK115478, and F31NS129269).
As Welch continues her groundbreaking research, the scientific community eagerly anticipates the potential applications of her findings, which could transform our understanding of dietary behaviors and their impact on health.
