What happens in the brain of patients suffering from post-traumatic stress? In 2020, Professor Pierre Gagnepain, researcher at Inserm*, relayed the results of the Remember study. The author of this work looked “at the construction and evolution of memory in connection with the terrorist attacks that hit Paris in 2015”.
The objective being “to explore the effects of a traumatic event on the brain and the mechanisms of resilience”, he relays on the echosciences-normandie.fr site.
Different reactions after trauma
What emerged from listening to the 1,000 survivors, relatives of the victims, law enforcement and health professionals present on the scene, all included in the study? For half of the participants, this post-traumatic stress disorder results in “intrusive memories – images, sensations, emotions associated with the trauma experienced which suddenly arise, at any time”.
If half of the cohort seems to have been spared from post-traumatic stress disorder, does this mean that our brains would react differently after exposure to trauma? Yes, some of us “manage to inhibit these intrusive memories”, detail the researchers, at least for a certain time because it can happen that the post-traumatic stress disorder wakes up at a distance from the events.
In question ? Among other things, very clear differences in the structures of the hippocampus, the region of the brain where our memories are housed, between “individuals not exposed to attacks; individuals exposed to the attacks and presenting post-traumatic stress disorder; attack-prone and resilient individuals”.
At the origin of permanent fear
In another study published on March 13, Inserm researchers sought to understand the mechanisms by which this trauma can become so pervasive on a daily basis. And this to the point of “altering the ability to manage emotions and inducing an almost permanent feeling of fear”, underlines the team of Dr. Stéphanie Daumas**.
A “generalized fear that paralyzes in contexts that are a priori not anxiety-provoking”. And which generates “a significant handicap” at the origin of modifications of “habits and behaviors so as not to find themselves daily paralyzed by fear”.
A study to date carried out in animals: they thus isolated in mice a protein found in certain neurons of brain regions responsible for memory and fear: it is the transporter VGLUT3, a priori involved in this mechanism of overwhelming fear. And therefore potentially the target of future treatments.
Towards new treatments?
In general, this better understanding of post-traumatic stress makes it possible to develop “new therapeutic strategies to counter these intrusions, sources of great distress for the people concerned”.
And to complete the arsenal already deployed but insufficient in certain points: “psychotherapy sessions, often associated with drugs (sedatives, antidepressants, anxiolytics) whose effectiveness is however limited”, attests the team of Stéphanie Daumas.
“Having more specific drug treatments could be a game-changer for patients. It would be possible to offer more cognitive-behavioral therapies thought “on the model of dissociating fear and lived situations”.
*neuropsychology and imaging of human memory – nimh | umr-s 1077 unicaen-ephe-inserm
** the Neuropharmacology of VGLUTs team at the Neuroscience Paris-Seine laboratory of the Paris-Seine Institute of Biology (unit 1130 Inserm/CNRS/Sorbonne University), in Paris.
