A team of University of Tennessee Health Science Center (UTHSC) researchers in the College of Medicine recently received a National Institutes of Health (NIH) award to study how genetic differences may explain why some people are more susceptible to opioid addiction than others.
Hao Chen, PhD, associate professor in the Department of Pharmacology, Addiction Science, and Toxicology, and Megan Mulligan, PhD, assistant professor in the Department of Genetics, Genomics, and Informatics, received $1.7 million for their project titled, “Reduced complexity mapping of oxycodone self-administration and stress responsiveness in rats.”
“Prescription opioid use and abuse results in millions of people addicted to opioids, and we know that genetic and environmental factors, such as stress, can interact to increase addiction vulnerability,” Dr. Mulligan explained. “Unfortunately, we do not have a strong or complete understanding of how genetic differences contribute to risk of opioid addiction or contribute to stress-induced vulnerability.”
To identify genetic differences in stress response, oxycodone consumption, and stress-induced drug seeking, the team will compare voluntary oxycodone intake between two strains of rats that differ in their vulnerability to stress.
“What makes this model unique is that the two strains demonstrate large differences in addiction-relevant behavior, and they are genetically similar,” Dr. Mulligan said. “This makes it easier to identify the gene variants that cause differences in stress response, opioid intake, and stress-induced opioid intake.”
“We can swap genetic material between the strains and study if this replacement causes changes in drug intake and seeking behavior. We can even do this in specific types of cells in a certain part of the brain,” said Dr. Chen. Dr. Mulligan added, “The findings from our study have great potential to translate to the human condition of opioid addiction.”