scholarly journals The Threatful Self: Midbrain Functional Connectivity to Cortical Midline and Parietal Regions During Subliminal Trauma-Related Processing in PTSD

2019 ◽  
Vol 3 ◽  
pp. 247054701987136 ◽  
Author(s):  
Braeden A. Terpou ◽  
Maria Densmore ◽  
Jean Théberge ◽  
Janine Thome ◽  
Paul Frewen ◽  
...  

Background The innate alarm system consists of a subcortical network of interconnected midbrain, lower brainstem, and thalamic nuclei, which together mediate the detection of evolutionarily-relevant stimuli. The periaqueductal gray is a midbrain structure innervated by the innate alarm system that coordinates the expression of defensive states following threat detection. In participants with post-traumatic stress disorder, the periaqueductal gray displays overactivation during the subliminal presentation of trauma-related stimuli as well as altered resting-state functional connectivity. Aberrant functional connectivity is also reported in post-traumatic stress disorder for the default-mode network, a large-scale brain network recruited during self-referential processing and autobiographical memory. Here, research lacks investigation on the extent to which functional interactions are displayed between the midbrain and the large-scale cortical networks in post-traumatic stress disorder. Methods Using a subliminal threat presentation paradigm, we investigated psycho-physiological interactions during functional neuroimaging in participants with post-traumatic stress disorder (n = 26) and healthy control subjects (n = 20). Functional connectivity of the periaqueductal gray was investigated across the whole-brain of each participant during subliminal exposure to trauma-related and neutral word stimuli. Results As compared to controls during subliminal threat presentation, the post-traumatic stress disorder group showed significantly greater periaqueductal gray functional connectivity with regions of the default-mode network (i.e., angular gyrus, precuneus, superior frontal gyrus). Moreover, multiple regression analyses revealed that the functional connectivity between the periaqueductal gray and the regions of the default-mode network correlated positively to symptoms of avoidance and state dissociation in post-traumatic stress disorder. Conclusion Given that the periaqueductal gray engages the expression of defensive states, stronger midbrain functional coupling with the default-mode network may have clinical implications to self-referential and trauma-related processing in participants with post-traumatic stress disorder.

2019 ◽  
Vol 22 ◽  
pp. 101731 ◽  
Author(s):  
Armelle Viard ◽  
Justine Mutlu ◽  
Sandra Chanraud ◽  
Fabian Guenolé ◽  
Pierre-Jean Egler ◽  
...  

2021 ◽  
pp. 1-14
Author(s):  
Mi Su ◽  
Yongyan Song

<b><i>Background:</i></b> Genetic factors were suggested to have influence on the development of post-traumatic stress disorder (PTSD). The possible association between catechol-O-methyltransferase (<i>COMT</i>) Val158Met polymorphism and PTSD has been evaluated in several studies. But the results were still controversial. Therefore, we conduct this meta-analysis to address these issues. <b><i>Methods:</i></b> The PubMed, EMBASE, Cochrane Library, and Web of Science databases were searched for eligible studies. The pooled odds ratio (OR) with 95% confidence interval (CI) was calculated to estimate the association between <i>COMT</i> Val158Met polymorphism and PTSD. <b><i>Results:</i></b> Five articles including 6 studies with 893 cases and 968 controls were finally included in the present meta-analysis. The pooled analyses did not demonstrate a significant association between the <i>COMT</i> Val158Met polymorphism and PTSD in any of the selected genetic models: allele model (OR = 1.13, 95% CI: 0.97–1.31), dominant model (OR = 1.17, 95% CI: 0.93–1.46), recessive model (OR = 1.44, 95% CI: 0.78–2.66), and additive model (OR = 1.54, 95% CI: 0.85–2.80). Subgroup analyses suggested that the Hardy-Weinberg equilibrium status of genotype distributions could influence the relationship of <i>COMT</i> Val158Met polymorphism and PTSD. <b><i>Conclusions:</i></b> The present meta-analysis suggested that the <i>COMT</i> Val158Met polymorphism may not be associated with the PTSD risk. Further large-scale and population-representative studies are warranted to evaluate the impact of the <i>COMT</i> Val158Met polymorphism on the risk of PTSD.


2018 ◽  
Vol 53 (1) ◽  
pp. 68-79 ◽  
Author(s):  
Hui Juan Chen ◽  
Li Zhang ◽  
Jun Ke ◽  
Rongfeng Qi ◽  
Qiang Xu ◽  
...  

Objective: The brain functional alterations at regional and network levels in post-traumatic stress disorder patients are still unclear. This study explored brain functional alterations at regional and network levels in post-traumatic stress disorder patients with resting-state functional magnetic resonance imaging and evaluated the relationship between brain function and clinical indices in post-traumatic stress disorder. Methods: Amplitude of low-frequency fluctuation and seed-based functional connectivity analyses were conducted among typhoon survivors with ( n = 27) and without post-traumatic stress disorder ( n = 33) and healthy controls ( n = 30) to assess the spontaneous brain activity and network-level brain function. Pearson correlation analyses were performed to examine the association of brain function with clinical symptom and social support. Results: Both the post-traumatic stress disorder group and the trauma-exposed control group showed decreased amplitude of low-frequency fluctuation in the dorsal anterior cingulate cortex relative to the healthy control group. The post-traumatic stress disorder group showed increased dorsal anterior cingulate cortex functional connectivity with the right paracentral lobule and bilateral precentral gyrus/postcentral gyrus relative to both control groups. Both traumatized groups exhibited decreased dorsal anterior cingulate cortex functional connectivity with the right hippocampus and left cerebellum relative to the healthy control group. More decreased dorsal anterior cingulate cortex functional connectivity with the right hippocampus was found in the post-traumatic stress disorder group. The Checklist-Civilian Version score positively correlated with functional connectivity between the dorsal anterior cingulate cortex and the right paracentral lobule as well as between the dorsal anterior cingulate cortex and the right precentral gyrus/postcentral gyrus. The social support was associated with functional connectivity between the dorsal anterior cingulate cortex and the bilateral precentral gyrus/postcentral gyrus as well as the dorsal anterior cingulate cortex and the left middle frontal gyrus. Conclusion: Trauma exposure may result in aberrant local and network-level functional connectivity in individuals with or without post-traumatic stress disorder. Altered amplitude of low-frequency fluctuation in the dorsal anterior cingulate cortex may be a predisposing risk factor for post-traumatic stress disorder development following trauma exposure. More prominent decreased dorsal anterior cingulate cortex functional connectivity with the right hippocampus might be specific in the post-traumatic stress disorder group. Improvement of social support might possibly be significant for post-traumatic stress disorder patients.


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