When the heart stops beating and someone dies, the systems that work inside the body also shut down and their natural processes stop.
Or at least that's what it's supposed to be.
But now it has been revealed that at least one type of cell survives after death, and in the hours after death, its genetic activity increases and begins to grow very rapidly.
The study, published in the medical journal Scientific Reports, examined brain tissue several hours after death and sought to find out what happens after death.
The researchers collected these tissue samples during routine surgeries.
They discovered a surprising increase in the activity of genes in cells called slingshots.
These cells are part of the nervous system, but they do not send or receive electrical signals, but rather support other brain cells, connect neurons, and help them function.
When the research created an artificial environment for death, the genetic activity of these cells increased while the volume increased and they became longer arms.
The activity of these genes peaked 12 hours after death, while other brain activities such as memory and thinking ceased immediately after death, while other activities remained stable for 24 hours without much change.
The researchers said they were not surprised by the results because the slingshot cells also clean up after a disease and brain injury, which is why they expected the genes to be still active.
But he said the growth seen in these cells was astonishing because no previous research had worked on such changes after death.
He said that more research work is needed in this regard so that these results can be properly explained.
Professor Jeffrey Leub, who was involved in the study at the University of Illinois at Urbana-Champaign in the United States, said that most research reports suggest that everything stops in the brain after the heart stops beating, but this does not happen.
"The good news of our discovery is that we now know which genes and cell types are stable, which are beginning to disappear and which are starting to increase after death," he said.
He said the findings would help to better understand future research work on the brain after death.
