Some of our brain cells are more active hours after we die, study concludes

Even after we die, some of our brain cells can experience one last big momentary explosion of life, suggests new research released on Tuesday. The study found evidence that certain “zombie genes” in our brain cells are more frequently active shortly after death, which causes some cells to expand immensely for hours. The findings will not radically change our concepts of life and death, but they may have some important implications for the study of brain tissue obtained after death.

It is no secret that our cells can stay alive and function for a while, even after we are clinically dead, before they finally disappear. But while almost all cells carry the same genetic information as the others, different types of cells express this genetic information differently, with several genes being turned on or off. And when the researchers analyzed the gene expression of different cells within an “agonizing brain”, they found some distinct patterns.

For your study, Published In Scientific Reports on Tuesday, the team analyzed samples of brain tissue donated by patients who recently underwent brain surgery for epilepsy (surgical treatments can safely remove parts of the brain involved in the seizure disorder). They then mimicked the brain death process, leaving out the freshly removed samples at room temperature for several periods of time, for up to 24 hours. Throughout the time, the team collected information about the cellular and genetic activity of these cells.

In most of the genes they studied, characterized as “household genes” that maintain basic cellular function, they found that the genes remained at the same level of activity for the entire 24-hour period. In “neuronal” genes, genes that are activated in the neuronal cells responsible for brain functions, such as thinking and memory, their activity started to drop after 12 hours.

But in a third group of genes, linked to the function of glial cells – the immune and support systems of the brain – the expression of the gene actually skyrocketed after “death” and continued to increase until 24 hours later. The glial cells themselves have also expanded massively in size and even developed new “arms”, at the same time that the neurons in these samples were degenerating.

TThe results do not prove that zombies are theoretically possible, aAnd it’s not even a big surprise that glial cells are especially active after death. The cells are probably responding to the injury and inflammation that occur in the brain when it is deprived of oxygen after someone’s final moments. But the findings present a potential wrinkle in the way that much research on the human brain is conducted, according to the authors, since many studies are based on post-mortem brain scans.

“Most studies assume that everything in the brain stops when the heart stops beating, but it doesn’t,” said study author Jeffrey Loeb, chief of neurology and rehabilitation at the University of Illinois at Chicago College of Medicine, in a demonstration launched by the university. “Our findings will be needed to interpret research on human brain tissues. We just haven’t quantified these changes so far. “

One problem is that research for diseases like Alzheimer’s disease and other forms of dementia are often dependent on post-mortem brain samples that are collected 12 or more hours later death. If the findings here are valid, then many of these studies may be missing important clues left inside the dying cells that may disappear later on. Loeb and his team hope that future studies can better explain the changes that occur in a dying brain. A potential solution, for example, may be to collect brain samples for research even earlier post-mortem or to rely more on samples from patients willing to have brain surgery anyway.

“The good news about our findings is that we now know which genes and cell types are stable, which degrade and which increase over time so that the results of postmortem brain studies can be better understood,” said Loeb.