Stress is the body’s natural response to any unwanted stimulus or pressure. It is something that we all face from time to time, though not all stress looks the same. Studies have established that it can increase the likelihood of developing various neuropsychiatric disorders. It has also been seen that individuals experience and respond to it in different ways; though women are more prone to having stress-related disorders, men are much more likely to die by suicide.
Since it has such a large impact on an individual’s life, it certainly has to somehow be correlated with the brain, its regions and neural pathways. The goal of this study is to compare the different behavioural impacts caused by acute and chronic stress. Moreover, the researchers also want to investigate the neural responses in the prefrontal cortex due to stress and the different effects that may occur due to sex differences.
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Literature Review
Studies have found that it can affect neural pathways involved in a person’s cognition, decision-making, anxiety, and mood. It can create negative alterations to these pathways or other brain regions, thus leading to many behavioural problems. The prefrontal cortex (PFC) is one such critical brain region that is impacted. Since PFC plays a central role in many different processes like emotional regulation, decision making, executive functioning, etc., changes in the structure of the PFC can contribute to the biological pathology of various neuropsychiatric disorders. Acute and chronic stress both seem to have different impacts on the brain structure as well as an individual’s overall physical and psychological health.
Studies have shown that exposure to acute stress can impact one’s working memory, weaken the PFC connectivity, and alter one’s cognitive functions. Whereas chronic stress seems to impact the brain function of multiple regions and affect the cellular structures. Additionally, research has demonstrated a comparison between the sexes in animal studies; they have found that females are more susceptible to PFC dysfunction because of than males are.
Despite all these findings, the link between the blood-brain barrier and various neuropsychiatric disorders remains unclear. Recent studies have linked blood-brain barrier dysfunction to neuroinflammation and the progression of neurological diseases.
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Methodology
The study used adult male and female Wistar rats to evaluate the behavioural and neurological effects of it. The rats were first acclimatised to the experimental environment and the researchers, post which they were assigned to different experimental groups. To test the acute stress effects, some of the rats were subjected to acute restraint for 6 hours outside their cage, after which they were placed back in their cages to be then given behavioural tests.
On the other hand, for chronic stress, the rats were subjected to an unpredictable chronic mild stress (uCMS) protocol for six weeks; they were randomly exposed to 3-6 stressors every day. They were given behavioural tests twenty-four hours after the last stressor. The rats’ behaviours were evaluated using various tests: the open field test (OPT) was used to evaluate locomotor and exploratory activities, and the forced swimming test (FST) was used to evaluate behaviour similar to depressive symptoms. Further, the rats underwent Western blot analysis to collect the protein concentration in the PFC to evaluate the effect of it in each sex.
Results
The study found that acute stress induces anxiety-like behaviours, whereas chronic stress results in more depressive symptoms. Both male and female rats displayed active coping signs post-acute stress exposure. Researchers also detected certain changes in neuropathology and the blood-brain barrier in both sexes after exposure to acute and chronic stress.
Discussion
Researchers have established that it contributes to various neuropsychiatric disorders and causes different behavioural and cellular changes. While some amount of stress is normal in life, excessive exposure to it can affect an individual’s normal functioning. The findings indicated that exposure to prolonged acute stress results in anxious behaviours, subjects tend to withdraw and display decreased social preference. Acute stress triggered coping behaviours, leading to increased activity in the rats and indicating anxiety-like behaviour.
Whereas chronic stress resulted in the rats becoming immobilised, as well as other depression-like behaviours. Researchers also observed some neuroinflammation and certain negative effects on blood-brain barrier proteins in human beings due to exposure to acute and chronic stress. This indicates that researchers need to conduct further studies to identify the consequences more thoroughly and effectively. Further research will also allow us to find effective ways to
prevent and treat such issues.
Conclusion
This study suggests that acute and chronic stress have distinct effects on the brain and behaviour. There also exist sex-related differences in the impacts.
References +
Simões, D. M., Carreira, J., Henriques, A., Gaspar, R., Sanches, E. S., Baptista, F. I., & Silva, A. P. (2025). Distinct behavioural and neurovascular signatures induced by acute and chronic stress in rats. Behavioural Brain Research, 493, 115706. https://doi.org/10.1016/j.bbr.2025.115706
Neuroscience News. (2025b, August 21). How stress types differently impact the brain and behaviour. Neuroscience News. https://neurosciencenews.com/stress-style-behavior-brain-29602/
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