Scientists have found that the stress hormone cortisol can disrupt the brain's internal navigation system, impairing a person's ability to orient themselves in space, reports infohub.kz.
Researchers from Ruhr University Bochum, led by Osman Akan, conducted an experiment with 40 healthy men. Volunteers performed orientation tasks in a virtual environment after taking cortisol and a placebo, while their brain activity was monitored using functional MRI.
The results, published in the journal PLOS Biology, showed that cortisol significantly reduces navigation accuracy. The hormone suppresses the activity patterns of grid neurons in the entorhinal cortex, which function as the brain's internal GPS. A particularly noticeable effect was observed in the absence of stable landmarks: under such conditions, the activity of these cells almost completely disappeared.
At the same time, the scientists recorded increased activity in the caudate nucleus of the brain, indicating an attempt to compensate for the failures of the primary orientation system. The authors emphasize that these findings are important for the study of Alzheimer's disease, in which the entorhinal cortex is affected early on.