Is your life stressful? A breakthrough Israeli study could lead to the development of a blood test that would tell whether you’re prone to stress. The results could facilitate preventive or early intervention in professions prone to high stress or trauma, such as combat soldiers, firefighters and policemen.
Through genetic research and brain-imaging technologies, researchers from Tel Aviv University have determined that the brain function responsible for regulating our stress response intertwines with molecular regulatory elements to produce a personal profile of resilience to stress.
Our ability to cope with stress depends on how efficiently our body and mind regulate their response to it. Poor recovery from extremely stressful encounters can trigger post-traumatic stress disorder (PTSD), depression, or even chronic somatic dysfunction (such as pain and fatigue) in some people. Insight into the multi-level sequence of events — from cellular changes to brain function, emotional responses, and observed behavior — will help medical professionals make more informed decisions concerning interventions.
The biological complexity of stress
“We can’t look at one measurement at one point in time and think we have the whole picture of the stress response,” TAU’s Prof. Talma Hendler, who led the study, said in a statement. “This is perhaps the first study to induce stress in the lab and look at resulting changes to three levels of the stress response — neural (seen in brain imaging), cellular (measured through genetics), and experience (assessed through behavioral report).”
According to TAU’s Dr. Noam Shomron, “vulnerability to stress is not only related to a predisposition due to a certain gene. The relevant gene can be expressed or not expressed according to a person’s experience, environment, and many other context-related factors.”
This type of interaction between the environment and our genome has been conceptualized lately as the ‘epigenetic process.’ “It has become clear that these processes are of an utmost importance to our health and wellbeing, and are probably, in some cases, above and beyond our predispositions,” he said.
The research for this study was conducted on 49 healthy young male adults. Researchers integrated the analysis of fMRI images of brain function during an acute social stress task and also measured levels of microRNAs — small RNAs that exert potent regulatory effects — obtained in a blood test before and three hours after the induced stress.
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According to TAU’s Dr. Sharon Vaisvaser, “20 minutes after the stress drill ended, we had two groups: The sustainers, those still stressed, and the recovered, those no longer stressed. The sustainers either didn’t go back to baseline or took much longer to do so.”
The researchers found that a specific alteration in the expression of miR-29c, a certain microRNA, was greater among the stress sustainers, implying a marker of slow recovery. Intriguingly, this change corresponded with modified connectivity of a major stress regulation node in the brain, the vento-medial prefrontal cortex.
Brain-guided treatment based on a blood test
“We all need to react to stress; it’s healthy to react to something considered a challenge or a threat,” said Hendler. “The problem is when you don’t recover in a day, or a week, or more. This indicates your brain and/or body do not regulate properly and have a hard time returning to homeostasis (i.e., a balanced baseline). We found that this recovery involves both neural and epigenetic/cellular mechanisms, together contributing to our subjective experience of the stress.”
According to Hendler, “knowing the brain metric that corresponds to such genetic vulnerability will make it possible to develop a personalized plan for brain-guided treatment based on a blood test.”
Added Shomron: “If you can identify through a simple blood test those likely to develop maladaptive responses to stress, you can offer a helpful prevention or early intervention.”
The study, recently published in the scientific journal PLOS One, was led by TAU’s Prof. Talma Hendler and Dr. Noam Shomron. Research for the study was conducted by TAU’s Dr. Sharon Vaisvaser and Dr. Shira Modai.
Photos: Preston Keres