scholarly journals Role of the dorsal periaqueductal gray in posttraumatic stress disorder: mediation by dopamine and neurokinin

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
M. L. Brandão ◽  
T. A. Lovick
Keyword(s):  
Posttraumatic Stress Disorder ◽  
Functional Connectivity ◽  
Posttraumatic Stress ◽  
Animal Studies ◽  
Stress Disorder ◽  
Early Stage ◽  
Brain Structures ◽  
Periaqueductal Gray ◽  
Contextual Processing ◽  
Learned Fear

Abstract In susceptible individuals, exposure to intensely traumatic life events can lead to the development of posttraumatic stress disorder (PTSD), including long-term dysregulation of the contextual processing of aversive stimuli, the overgeneralization of learned fear, and impairments in the ability to learn or respond to safety signals. The neuropathophysiological changes that underlie PTSD remain incompletely understood. Attention has focused on forebrain structures associated with fear processing. Here we consider evidence from human and animal studies that long-lasting changes in functional connectivity between the midbrain periaqueductal gray (dPAG) and amygdala may be one of the precipitating events that contribute to PTSD. Long-lasting neuroplastic changes in the dPAG can persist after a single aversive stimulation and are pharmacologically labile. The early stage (at least up to 24 h post-stimulation) involves neurokinin-1 receptor-mediated events in the PAG and amygdala and is also regulated by dopamine, both of which are mainly involved in transferring ascending aversive information from the dPAG to higher brain structures, mainly the amygdala. Changes in the functional connectivity within the dPAG-amygdala circuit have been reported in PTSD patients. We suggest that further investigations of plasticity and pharmacology of the PAG-amygdala network provide a promising target for understanding pathophysiological circuitry that underlies PTSD in humans and that dopaminergic and neurokininergic drugs may have a potential for the treatment of psychiatric disorders that are associated with a dysfunctional dPAG.

scholarly journals Efficacy and Underlying Mechanism of Acupuncture in the Treatment of Posttraumatic Stress Disorder: A Systematic Review of Animal Studies

2021 ◽  
Vol 10 (8) ◽  
pp. 1575
Author(s):  
Chan-Young Kwon ◽  
Boram Lee ◽  
Sang-Ho Kim
Keyword(s):  
Posttraumatic Stress Disorder ◽  
Posttraumatic Stress ◽  
Stress Responses ◽  
Methodological Quality ◽  
Animal Studies ◽  
Large Scale ◽  
Stress Disorder ◽  
Spatial Learning And Memory ◽  
Expectancy Effects ◽  
Therapeutic Mechanisms

Acupuncture is a nonpharmacological intervention that can be useful in the clinical management of posttraumatic stress disorder (PTSD), especially in situations with a lack of medical resources, including large-scale PTSD events such as disasters. Some clinical studies have reported the clinical effect of acupuncture in improving PTSD symptoms, but the underlying therapeutic mechanism has yet to be explored. Therefore, this review summarized the underlying therapeutic mechanisms of acupuncture in animal PTSD models. A comprehensive search was conducted in 14 electronic databases, and two independent researchers performed study selection, data extraction, and the methodological quality assessment. Twenty-four relevant studies were included in this review and summarized according to the proposed main mechanisms. In behavioral evaluation, acupuncture, including manual acupuncture and electro-acupuncture, reduced anxiety and fear responses and weakened fear conditioning, improved sleep architecture, reduced depressive symptoms, and alleviated disturbance of spatial learning and memory of PTSD animal models. The therapeutic mechanisms of acupuncture proposed in the included studies could be classified into two categories: (1) regulation of stress responses in the neuroendocrine system and (2) promotion of neuroprotection, neurogenesis, and synaptic plasticity in several brain areas. However, the methodological quality of the included animal studies was not high enough to produce robust evidence. In addition, mechanistic studies on specific aspects of acupuncture that may affect PTSD, including expectancy effects, in human PTSD subjects are also needed.

scholarly journals Trauma and posttraumatic stress disorder modulate polygenic predictors of hippocampal and amygdala volume

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yuanchao Zheng ◽  
Melanie E. Garrett ◽  
Delin Sun ◽  
Emily K. Clarke-Rubright ◽  
Courtney C. Haswell ◽  
...  
Keyword(s):  
Posttraumatic Stress Disorder ◽  
Posttraumatic Stress ◽  
Childhood Trauma ◽  
Stress Disorder ◽  
Brain Structures ◽  
Hippocampal Volume ◽  
Subcortical Structures ◽  
Polygenic Scores ◽  
Amygdala Volume ◽  
Subcortical Volumes

AbstractThe volume of subcortical structures represents a reliable, quantitative, and objective phenotype that captures genetic effects, environmental effects such as trauma, and disease effects such as posttraumatic stress disorder (PTSD). Trauma and PTSD represent potent exposures that may interact with genetic markers to influence brain structure and function. Genetic variants, associated with subcortical volumes in two large normative discovery samples, were used to compute polygenic scores (PGS) for the volume of seven subcortical structures. These were applied to a target sample enriched for childhood trauma and PTSD. Subcortical volume PGS from the discovery sample were strongly associated in our trauma/PTSD enriched sample (n = 7580) with respective subcortical volumes of the hippocampus (p = 1.10 × 10−20), thalamus (p = 7.46 × 10−10), caudate (p = 1.97 × 10−18), putamen (p = 1.7 × 10−12), and nucleus accumbens (p = 1.99 × 10−7). We found a significant association between the hippocampal volume PGS and hippocampal volume in control subjects from our sample, but was absent in individuals with PTSD (GxE; (beta = −0.10, p = 0.027)). This significant GxE (PGS × PTSD) relationship persisted (p < 1 × 10−19) in four out of five threshold peaks (0.024, 0.133, 0.487, 0.730, and 0.889) used to calculate hippocampal volume PGSs. We detected similar GxE (G × ChildTrauma) relationships in the amygdala for exposure to childhood trauma (rs4702973; p = 2.16 × 10−7) or PTSD (rs10861272; p = 1.78 × 10−6) in the CHST11 gene. The hippocampus and amygdala are pivotal brain structures in mediating PTSD symptomatology. Trauma exposure and PTSD modulate the effect of polygenic markers on hippocampal volume (GxE) and the amygdala volume PGS is associated with PTSD risk, which supports the role of amygdala volume as a risk factor for PTSD.

scholarly journals Disrupted amygdala-prefrontal functional connectivity in civilian women with posttraumatic stress disorder

2013 ◽  
Vol 47 (10) ◽  
pp. 1469-1478 ◽  
Author(s):  
Jennifer S. Stevens ◽  
Tanja Jovanovic ◽  
Negar Fani ◽  
Timothy D. Ely ◽  
Ebony M. Glover ◽  
...  
Keyword(s):  
Posttraumatic Stress Disorder ◽  
Functional Connectivity ◽  
Posttraumatic Stress ◽  
Stress Disorder ◽  
Civilian Women

scholarly journals An investigation of resting state functional connectivity of the anterior and posterior Hippocampal subregions in posttraumatic stress disorder and its relationship with symptoms

2021 ◽  
Author(s):  
Bailee L. Malivoire
Keyword(s):  
Posttraumatic Stress Disorder ◽  
Functional Connectivity ◽  
Posttraumatic Stress ◽  
Resting State ◽  
Stress Disorder ◽  
Brain Regions ◽  
Imaging Biomarkers ◽  
Resting State Functional Connectivity ◽  
Hippocampal Activity ◽  
The Right

Posttraumatic stress disorder (PTSD) is associated with abnormal hippocampal activity; however, the functional connectivity (FC) of the hippocampus with other brain regions and its relations with symptoms warrants further attention. I investigated FC of the hippocampus at a subregional level in PTSD during a resting state compared to trauma exposed controls (TECs). Based on imaging literature in PTSD, I targeted the FCs of the hippocampal head and tail subregions with the amygdala, medial prefrontal cortex (mPFC), and the posterior cingulate (PCC). The PTSD group had significantly greater FC compared to the TEC group between the left hippocampal head and the right amygdala, and for the left hippocampal tail with bilateral PCC. Resting state FC predicted symptom severity at time of scan and 4-months post-scan. These results highlight abnormal illness-related FC with both the hippocampal head and tail and provide support for future investigations of imaging biomarkers predictive of disease progression.

scholarly journals Resting‐state brain fluctuation and functional connectivity dissociate moral injury from posttraumatic stress disorder

2019 ◽  
Vol 36 (5) ◽  
pp. 442-452 ◽  
Author(s):  
Delin Sun ◽  
Rachel D. Phillips ◽  
Hannah L. Mulready ◽  
Stephen T. Zablonski ◽  
Jessica A. Turner ◽  
...  
Keyword(s):  
Posttraumatic Stress Disorder ◽  
Functional Connectivity ◽  
Posttraumatic Stress ◽  
Resting State ◽  
Stress Disorder ◽  
Moral Injury
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