It’s 3 a.m. during finals week. Exhaustion sets in, but the heart continues to race. You lie in bed knowing you desperately need sleep, but your mind won’t shut off. While most students view this as a typical symptom of end-of-semester burnout, Dr. Michelle Chandley views it as a biological window into how chronic stress physically rewires the human brain.
Contributed/ETSU
Chandley, an associate professor in biomedical sciences at East Tennessee State University, did not begin her career in a neuroscience laboratory. While teaching middle school science, she noticed a growing number of students struggling with developmental and behavioral challenges.
“I saw developmental disabilities everywhere,” Dr. Chandley recalls. “I was fascinated by how this happens and whether we’re truly seeing an increase in incidence or if we’re just diagnosing it better.”
The observation prompted her to leave teaching and pursue a doctorate in biomedical sciences.
Initially, Chandley analyzed postmortem brain tissue from individuals diagnosed with psychiatric and developmental disorders. However, tissue samples provided only a single snapshot of dynamic neurological processes. To observe real-time brain adaptation under pressure, she shifted her research toward animal models and stress responses.
“You only get one point in time,” Chandley said. “You can’t watch how the brain changes or what causes that change to happen in the first place.”
That shift led to a collaboration with ETSU researcher Dr. Matthew Zahner, who studies the cardiovascular system and fight-or-flight responses driven by the sympathetic nervous system.
“The sympathetic system is related to all sorts of diseases,” Zahner said, “and it’s so understudied.”
Together, Chandley and Zahner found that chronic stress does more than produce feelings of anxiety; it rewires the neural pathways governing heart rate and blood pressure. Under normal conditions, the sympathetic nervous system activates during threats and deactivates once safety is restored. Chronic stress keeps the system continuously engaged, causing persistent muscle tension and elevated heart rates.
This physiological loop has significant health implications. For example, young military veterans returning from deployment often suffer from chronic stress and anxiety. Despite overall physical fitness, these veterans develop high blood pressure and metabolic issues at higher rates than their peers.
To expand their research, Chandley and Zahner recently secured an R16 research grant. Using advanced techniques to selectively control targeted brain regions, the team aims to isolate the specific neural pathways responsible for stress-induced cardiovascular changes.
“The idea is to understand which parts of the brain are driving this response,” Chandley said, “so we can eventually intervene.”
The long-term goal of the lab is to map the complete neuronal circuitry involved in stress, laying the groundwork for future clinical treatments.
“We want to make a great discovery,” she said, “one that helps people.”
From a high school classroom asking why some students struggled to a sophisticated neuroscience lab investigating the brain’s stress response, Chandley’s journey reflects a deeper truth: the best research often begins with simple, human curiosity.
You must be logged in to post a comment.