Reid Meredith A, Whiteman Sarah E, Camden Abigail A, Jeffirs Stephanie M, Weathers Frank W
Department of Electrical and Computer Engineering, Auburn University, Auburn, Alabama, USA.
AU Neuroimaging Center, Auburn University, Auburn, Alabama, USA.
bioRxiv. 2024 Jul 18:2024.07.16.603137. doi: 10.1101/2024.07.16.603137.
Evidence from animal and human studies suggests glutamatergic dysfunction in posttraumatic stress disorder (PTSD). The purpose of this study was to investigate glutamate abnormalities in the dorsolateral prefrontal cortex (DLFPC) of individuals with PTSD using 7T MRS, which has better spectral resolution and signal-to-noise ratio than lower field strengths, thus allowing for better spectral quality and higher sensitivity. We hypothesized that individuals with PTSD would have lower glutamate levels compared to trauma-exposed individuals without PTSD and individuals without trauma exposure. Additionally, we explored potential alterations in other neurometabolites and the relationship between glutamate and psychiatric symptoms.
Individuals with PTSD (n=27), trauma-exposed individuals without PTSD (n=27), and individuals without trauma exposure (n=26) underwent 7T MRS to measure glutamate and other neurometabolites in the left DLPFC. The severities of PTSD, depression, anxiety, and dissociation symptoms were assessed.
We found that glutamate was lower in the PTSD and trauma-exposed groups compared to the group without trauma exposure. Furthermore, -acetylaspartate (NAA) was lower and lactate was higher in the PTSD group compared to the group without trauma exposure. Glutamate was negatively correlated with depression symptom severity in the PTSD group. Glutamate was not correlated with PTSD symptom severity.
In this first 7T MRS study of PTSD, we observed altered concentrations of glutamate, NAA, and lactate. Our findings provide evidence for multiple possible pathological processes in individuals with PTSD. High-field MRS offers insight into the neurometabolic alterations associated with PTSD and is a powerful tool to probe trauma- and stress-related neurotransmission and metabolism .
动物和人体研究的证据表明创伤后应激障碍（PTSD）存在谷氨酸能功能障碍。本研究的目的是使用7T磁共振波谱（MRS）研究PTSD患者背外侧前额叶皮质（DLFPC）中的谷氨酸异常，7T MRS比低场强具有更好的光谱分辨率和信噪比，从而能提供更好的光谱质量和更高的灵敏度。我们假设与未患PTSD的创伤暴露个体和未经历创伤的个体相比，PTSD患者的谷氨酸水平会更低。此外，我们还探讨了其他神经代谢物的潜在变化以及谷氨酸与精神症状之间的关系。
对患有PTSD的个体（n = 27）、未患PTSD的创伤暴露个体（n = 27）和未经历创伤的个体（n = 26）进行7T MRS，以测量左侧DLFPC中的谷氨酸和其他神经代谢物。评估了PTSD、抑郁、焦虑和解离症状的严重程度。
我们发现，与未经历创伤的组相比，PTSD组和创伤暴露组的谷氨酸水平更低。此外，与未经历创伤的组相比，PTSD组的N-乙酰天门冬氨酸（NAA）更低，乳酸更高。在PTSD组中，谷氨酸与抑郁症状严重程度呈负相关。谷氨酸与PTSD症状严重程度无关。
在这项关于PTSD的首次7T MRS研究中，我们观察到谷氨酸、NAA和乳酸浓度的改变。我们的研究结果为PTSD个体的多种可能病理过程提供了证据。高场MRS有助于深入了解与PTSD相关的神经代谢改变，是探究创伤和应激相关神经传递及代谢的有力工具。
