"Paediatric anaesthetists have long suspected that children who are anaesthetised repeatedly over the course of just a few years may suffer from impaired memory and learning," says Klas Blomgren whose research team discovered, by chance, a link between stem cell loss and repeated anaesthesia when working on another study.
His research team wanted to find out what happens to the brain's stem cells when exposed to strong magnetic fields, for example during an magnetic resonance imaging scan. The study was carried out using rats and mice, and showed that while the magnetic fields did not have any tangible effects on the animals, the repeated anaesthesia did.
"We found that repeated anaesthesia wiped out a large portion of the stem cells in the hippocampus, an area of the brain that is important for memory," says Blomgren. "The stem cells in the hippocampus can form new nerve and glial cells, and the formation of nerve cells is considered important for our memory function."
Their results could also be linked to impaired memory in animals as they got older. The effect was evident only in young rats or mice that had been anaesthetised, not when adult animals were anaesthetised. This may be because stem cells are more sensitive in an immature brain, even though there are fewer of them as we get older.
"Despite extensive attempts, we have not been able to understand exactly what happens when the stem cells are wiped out," says Blomgren. "We couldn't see any signs of increased cell death, but are speculating that the stem cells lose their ability to divide."
MEDICA.de; Source: University of Gothenburg