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Published: 2020-05-20

PTSD is associated with structural changes in the neural connections between the right and left hippocampus

Bogomolets National Medical University
PTSD Neuroimaging

Abstract

A multi-cohort analysis of the diffusion magnetic resonance imaging (dMRT) results of 3047 people from 28 cohorts, conducted by a large group of researchers from 92 scientific institutions found that PTSD is associated with structural changes in the tapetum, connecting the right and left hippocampus. These changes may explain the hippocampal dysfunction associated with behavioral and cognitive symptoms of PTSD.

Background

Post-traumatic stress disorder (PTSD) correlates with damage to the structure of the brain, which probably occurs due to the neurotoxic effects of glucocorticoids [1]. The use of diffusion magnetic resonance imaging (dMRI) allows to assess the microstructure of the white matter of the brain and to supplement the knowledge of neurobiological changes in PTSD [2]. In recent years, many studies were related to changes in the organization of white matter in people with PTSD. However, studies on this issue show conflicting results. In addition, these changes can be interpreted as constitutional risk factors that make a person more vulnerable to traumatic events, but they can also be interpreted as neurobiological changes due to PTSD. More than one hundred researchers from 92 institutes conducted a multi-cohort analysis of the results of diffusion magnetic resonance imaging (dMRI) of 3047 people from 28 cohorts participating in the PGC-ENIGMA PTSD working group [3]. They hypothesized that the greatest damage would be found in the frontolimbic tracts associated with behavioral and cognitive problems in PTSD, such as emotional regulation, working, and episodic memory problems.

Results and discussion

Structural abnormalities in the neural pathways between the right and left hippocampus, the tapetum have been found, that may explain its dysfunction and related PTSD symptoms. The cover is a small segment of the corpus callosum that connects the temporal lobes, including the left and right hippocampus, which develops rapidly at the age of about 14 years and is sensitive to trauma for a long time. This supports the theory that childhood trauma is the greatest risk factor for future PTSD vulnerability, supported by numerous studies on changes in brain structure and function in people who are traumatized in childhood. However, changes in cover cannot be the only explanation for the changes.

Other factors, such as depression, traumatic brain injury (common in PTSD veterans), and alcohol abuse may also affect white matter structure, as confirmed by other studies. It is also unknown how less intense stress affects the cover.

No PTSD-related changes in the cingulum, uncinate, fornix, and corpus callosum have been identified in a number of previous studies of PTSD brain structure.

Thus, the results of the study complement the scientific literature on the hippocampus and associated white matter as neuronal markers of structural disorders of PTSD.

References

  1. Uno H, Eisele S, Sakai A, Shelton S, Baker E, DeJesus O, et al. Neurotoxicity of glucocorticoids in the primate brain. Horm Behav. 1994;28:336–48. https://doi.org/10.1006/hbeh.1994.1030
  2. Basser PJ, Mattiello J, LeBihan D. MR diffusion tensor spectroscopy and imaging. Biophys J. 1994;66:259–67. https://doi.org/10.1016/S0006-3495(94)80775-1
  3. Dennis EL, Disner SG, Fani N, et al. Altered white matter microstructural organization in posttraumatic stress disorder across 3047 adults: results from the PGC-ENIGMA PTSD consortium [published online ahead of print, 2019 Dec 19]. Mol Psychiatry. 2019;10.1038/s41380-019-0631-x. doi:10.1038/s41380-019-0631-x

How to Cite

1.
Assonov Д. PTSD is associated with structural changes in the neural connections between the right and left hippocampus. PMGP [Internet]. 2020 May 20 [cited 2024 Mar. 29];5(1):e0501234. Available from: https://dev-ojs.e-medjournal.com/index.php/psp/article/view/234