Scientists recently discovered that certain cells in human brains not only stay active after death, but actually grow. These "zombie cells" exponentially grow and sprout longer arm-like tentacles in the hours after we die.
Scientists at the University of Illinois Chicago (UIC) made the discovery by simulating a post-mortem environment on fresh brain tissue taken from a routine brain surgery.
The team analyzed gene expression of this tissue and discovered that glial cells, a specific type of inflammatory cell in our brain, in fact, grew to "gargantuan proportions."
The fact that glial cells significantly expand after death didn't surprise the scientists, as this type of cell's job is to "clean things up after brain injuries like oxygen deprivation or sroke," said Dr. Jeffrey Loeb, author of the study and head of neurology and rehabilitation at the UIC College of Medicine.
What this discovery means for neuroscience
What is important about this discovery, as Dr. Loeb explains, is its implications. Research studies on brain tissues after death don't account for the post-mortem gene expression of brain cells or cell activity. The general assumption is that all brain activity ends when a person dies, but the UIC team has proven that's not the case.
"Our findings will be needed to interpret research on human brain tissues. We just haven’t quantified these changes until now," said Dr. Loeb.
During its study, the team found out that these zombie cells' changes peaked approximately 12 hours after death.
With this new information, Dr. Loeb and his team explain that researchers need to bear in mind these genetic and cellular changes when carrying out post-mortem brain studies.
Now, researchers have a good idea about which genes and cell types in the brain degrade, remain stable, and expand after death, opening up further avenues for neuroscientists to research.
The team published its findings in the journal Scientific Reports on March 23.