Spotlight on Kathleen Yee, PhD
Assistant Professor, University of Mississippi Medical Center
and 2021 AHRF Grant Recipient.
Article by Matsya Thulasiram
“I always felt that I was looking for the truth and that’s not really what you can get in a lot of professions.”
Dr. Kathleen Yee’s pursuit for how things work has led her down an exciting path in science that serves as a reminder that all systems in our body are connected. Throughout her graduate and postdoctoral work, Yee was interested in the way neurons use cues from their environment to migrate to their appropriate anatomical location and make functional connections with other cells. She began to study the connection between spiral ganglion neurons in the cochlea and a region of the brainstem called the cochlear nucleus. This morphed into studying different kinds of potential trauma to the auditory system, specifically, mild traumatic brain injury, or concussion. This is the work that Yee is actively pursuing at the University of Mississippi Medical Center.
Concussion’s Impact on Hearing: What about Youth and Women?
While there are several studies on concussion, there are clear gaps in the field that Yee’s work has been instrumental in filling. First, the consequences of concussion on hearing function are not well known. Second, the majority of concussion studies have been conducted in adult males. This means many cases in females and developmentally younger individuals have been largely overlooked.
When it comes to contact recreational sports, 2.8 million children engage in these activities, 5% of whom sustain clinically diagnosed concussion. One in three women in the United States are physically abused through intimate partner violence, and 1.6 million of these women experience concussions repetitively. The sex and age biases in concussion research have led to a substantial lack of data essential for tailored medical treatments for women and youth experiencing concussions. “It’s not a one-size-fits-all solution for everyone”, Yee points out. “We need more research in these areas to reveal these differences, and we need to, as researchers, make sure that our message gets out.”
Yee’s study approach
Yee’s AHRF-funded study focuses on the effects of concussion on hearing loss, comparing young and mature subjects, as well as male and female subjects.
Yee used a concussion model that is more controlled and less invasive than existing systems, termed the Closed Head Impact Model of Engineered Rotational Acceleration, or CHIMERA. In this system, an impactor, driven by a pulse of air, hits the back of a mouse’s skull and causes the head to roll forward and backward, which closely mimics the type of motion leading to brain injury experienced by humans during concussive events.
Following the induced injury, Yee assessed hearing using auditory brainstem response measurements and found that younger mice and male mice exhibited more pronounced hearing loss than mature mice and female mice, respectively. In parallel, Yee identified an associated increase in the immune response within the cochlea following concussive events.
By investigating these effects in underrepresented populations, Yee identifies the differing consequences of concussion and brings to light the importance of inclusive research. The implications of Yee’s work broadly impact not only auditory research but research in general, and directly contributes to treating real people who experience concussion every day.
This article was contributed by Matsya Thulasiram, PhD candidate at the University of Toronto.