Astrocytes show early biological signs of stress – a new study links brain vesicles to psychological burdens

Can biological changes in the brain explain why some individuals become more vulnerable to stress than others?

A new scientific article, published on August 21, 2025, in Frontiers in Public Health, provides new insights. The researchers followed healthcare personnel during the pandemic and examined how brain-related extracellular vesicles (EVs) in the blood changed over time in relation to psychological stress. Link to the original article.

How the Study Was Conducted

The participants were monitored at three different occasions over approximately six months. At each occasion, they completed questionnaires about mental health and stress (including K10, which measures psychological stress). At the end of the study, the group was categorized into two groups:

1. No/low distress

2. Moderate/severe distress

Simultaneously, blood samples were analyzed to measure the content of extracellular vesicles from three different brain cell types:

• Astrocytes – supportive cells in the brain, crucial for maintaining chemical balance and the function of the blood-brain barrier.

• Neurons – the signaling cells of the brain.

• Microglia – the brain’s immune cells activated during inflammation.

The researchers employed immuno-based methods to analyze their content of inflammatory signaling molecules such as IFN-γ, IL-6, IL-10, TNF-α, and MCP-1.

What the Study Found

The results indicated that individuals who later developed higher psychological stress already showed changes early on in their astrocyte-derived vesicles. They contained higher levels of several inflammatory proteins – especially IFN-γ, IL-6, IL-10, and TNF-α. In contrast, changes in neuron and microglia vesicles were significantly smaller and, in some cases, nonexistent. The researchers interpret this as astrocytes being the most reactive cells in the brain in the face of psychological stress. Likely, they attempt to regulate the brain's environment and restore balance, but the increased activity may also reflect an ongoing biological adaptation to stress.

As the authors themselves write:

“Astrocytes represent the most abundant cell type in the brain, which might explain our brain cell-specific detectable variabilities in inflammatory cargo.”

Overall, the findings suggest that the content of astrocyte-derived vesicles could serve as an early biological marker for stress-related burden. It is crucial to emphasize that the study did not investigate exhaustion or clinical diagnoses, but rather the biological changes occurring on the way – at an early stage of psychological imbalance. In their conclusion, the authors state that brain-derived EVs, along with psychological measures such as hyperarousal, could help identify individuals at risk before symptoms become severe, and these findings should be followed up in larger studies.

The Connection to the Body’s Balance

This is closely related to what we ourselves describe in our previous articles about balance in the body’s systems and “leaky brain”. In both cases, it involves how the brain’s cells try to compensate for overload and maintain equilibrium – but this regulation can become disrupted under prolonged stress. Astrocytes, which are in direct contact with the blood-brain barrier, seem to play a central role in this process. When they start sending out more inflammatory signals, it can be seen as the brain trying to defend itself, but it is also an indication that the balance in the nervous system is beginning to be disturbed.

Towards a More Proactive View on Stress

Along with similar findings in the field, this study reinforces the idea that stress can be biologically detected before it becomes apparent as evident exhaustion. It demonstrates the importance of being proactive in stress management – paying attention to the body’s early signals and seeking balance, rather than reacting only when energy levels are already depleted.

In our work with NeuroEVs, we analyze precisely these brain-related vesicles in the blood. Our goal is not to diagnose but to provide a more nuanced view of how the body reacts to stress and recovery. If you are curious about your own biological NeuroEV profile, you can read more here and book your test: About NeuroEVs – analysis of brain-related stress markers in blood samples

Summary

The new research shows that astrocyte-derived vesicles in the blood change early in psychological stress. It reinforces the view that stress is both psychological and biological – and that the brain's supportive cells play a central role in maintaining or losing the body's balance.