Professor in ECE leading MRI study that explores PTSD biomarkers in older adults
Published: Mar 29, 2023 8:00 AM
By Joe McAdory
Much post-traumatic stress disorder (PTSD) research has been dedicated to children and young adults. But what about senior citizens? Meredith Reid, assistant professor in electrical and computer engineering, will soon add this missing piece to the puzzle.
Reid’s proposed research, “In vivo assessment of glutamate in older adults with post-traumatic stress disorder: a 7T magnetic resonance spectroscopy study,” in conjunction with the university’s Thomas Walter MRI Research Center, will utilize brain scans of 40 adults 50 years and older to measure glutamate – the brain’s major excitatory neurotransmitter necessary for cognitive function. Studies associate PTSD with glutamatergic dysfunction, Reid said.
The proposal is sponsored by the Center for Clinical and Translational Science.
“Given the evidence that glutamate decreases with age and that aging is accelerated with PTSD, the central hypothesis motivating this research is that aging differently affects glutamate levels in people with PTSD,” Reid said.
“If we can better understand the pathophysiology of what is happening with older adults, then we can identify biomarkers that could allow us to perhaps develop medications for that population. There are not many medications specifically for PTSD right now. Some of those medications are used for depression and/or anxiety. If we could identify glutamate as a biomarker, then drug companies could develop those medications that target the glutamate system.”
Utilizing the new Siemens Terra.X 7 Tesla MRI scanner at the university’s MRI Research Center, Reid is actively recruiting adults 50 years and older, with and without PTSD, to volunteer for the study.
“We propose to measure glutamate in two brain regions, the dorsolateral prefrontal cortex (DLPFC) and the anterior cingulate cortex (ACC),” she said. “Focusing on the DLPFC will allow us to leverage our existing DLPFC data from 19-55-year-old participants to better understand the glutamate-age association across the adult lifespan. Because the DLPFC is a critical brain region for working memory, which is affected in people with PTSD, and is involved in the integration of emotion and cognition, there is a need for additional studies of glutamate in the DLPFC.
“Furthermore, an open question is whether glutamate alterations with exhibit regional variations. Previous studies reported glutamate reductions in the anterior cingulate cortex, but elevations in the hippocampus. It remains to be determined whether such regional effects exist within the prefrontal cortex. Therefore, we will also measure glutamate in the anterior cingulate cortex.”
Reid plans to begin enrolling participants in May.
Results of the study could also be used as a monitoring tool, Reid said. Glutamate is affected by treatment, but how much? “If we were able to scan people before and after treatment, we could see how that glutamate is changing,” Reid said.
“Our new Siemens Terra.X 7 Tesla MRI scanner has some advanced capabilities that can enable Dr. Reid to investigate metabolic changes due to PTSD in more parts of the brain,” said Tom Denney, director of the Auburn University Thomas Walter MRI Research Center. “Her work is important to understanding how brain metabolism in older people with PTSD differs from younger people with PTSD and we are thrilled to take part in this very important study that could have an impact on the way PTSD is treated in older versus younger people.”
Reid noted that a larger, follow-up study would not only focus on glutamate with spectroscopy, but also peripheral, blood-based biomarkers of aging and brain structure.
“There’s a technique that allows you to estimate something called brain age, which is different from your chronological age,” she said. “We would already have a measure of glutamate from spectroscopy, peripheral biomarkers and structural brain scans. With this information, we could analyze the data together and see how those things are related to better characterize the aging process in people with PTSD.”
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Meredith Reid, assistant professor in electrical and computer engineering, is hoping results of the study can identify biomarkers that could lead to PTSD medication for older adults.
