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January 25, 2025
In a groundbreaking study, researchers at the Laboratory of Thalamus Research, HUN-REN Institute of Experimental Medicine, have discovered a novel neuronal mechanism that plays a critical role in stress-induced changes in behavior. Using a rodent model, the team identified a sustained increase in neural activity in the paraventricular thalamus (PVT) of the brain, a region known for its involvement in stress, arousal, and motivation. The findings, published in PLOS Biology, open up new avenues for potential treatments for stress-related disorders such as post-traumatic stress disorder (PTSD).
The researchers found that after a stressful event, PVT activity increased dramatically and persisted for several days. This prolonged neural activity was linked to behavioral changes in the rodents, including restlessness during wakefulness, disturbed behavior prior to sleep, and difficulty falling asleep. However, when the researchers selectively inhibited PVT activity for just one hour after the stressor, the heightened neural activity did not persist, and the mice’s behavior returned to normal in the days following the stress event.
“This is the first time that prolonged spontaneous neural activity, lasting days after a stressful experience, has been observed in the brain,” said Dr. Anna Jász, the lead researcher of the study. “This suggests that under certain conditions, some brain regions can maintain heightened activity for extended periods, influencing behavior long after the stressor has passed.”
The PVT, a unique cluster of neurons in the thalamus, serves as a “hub” where stress, alertness, and motivation signals converge before being relayed to the cortex, influencing behavior. Its role as an integrator of stress signals makes it a critical brain region for understanding stress-related disorders. The findings suggest that the PVT’s heightened activity could be a key factor in the long-term emotional and behavioral changes observed after trauma.
In addition to this, the study also revealed that the persistent changes in neural activity are reversible, hinting that the brain may possess natural mechanisms capable of mitigating the effects of stress. This insight provides hope for developing therapies that could effectively treat stress-induced behavioral disorders.
The study’s findings are particularly relevant for understanding the underlying mechanisms of PTSD. After experiencing traumatic events, individuals can suffer from persistent emotional symptoms such as restlessness, emotional instability, and difficulty sleeping. These symptoms can last for months or even years, and current treatments, which often focus on memory extinction, have limited efficacy.
“One of the main challenges in treating PTSD is that current therapies target memory extinction, but they are not very effective in addressing the persistent emotional and behavioral changes following trauma,” said Dr. Jász. “Our findings suggest that the altered PVT activity might be an independent mechanism driving these changes, separate from memory recall processes.”
The study holds significant implications for developing new treatments for PTSD and other stress-related disorders. The researchers discovered that inhibiting PVT activity just one hour after the stressor had a lasting impact, even when applied five days post-stressor, indicating a potential therapeutic window for intervention.
This discovery could lead to more effective treatments for managing stress and trauma, offering relief to millions of individuals affected by such conditions.
Disclaimer: This article is based on a study published in PLOS Biology (2025) and is for informational purposes only. The conclusions drawn are based on rodent models and may not directly apply to human conditions. Further research is needed to confirm the applicability of these findings to human health and therapeutic development.
For more information, see:
- Anna Jász et al, Persistently increased post-stress activity of paraventricular thalamic neurons is essential for the emergence of stress-induced alterations in behavior, PLOS Biology (2025). DOI: 10.1371/journal.pbio.3002962
