Some cells of our brain become particularly active after death. In any case, it confirms a team of researchers from the University of Illinois at Chicago (United States).
After a genetic analysis of postmortem brain tissue, scientists have actually found that when the organism moves from life to death, some cells retain biochemical activity for several hours, and are even more active. Dr. Jeffrey Loeb said, “Most studies assume that everything in the brain stops when the heart stops beating, but it doesn’t”.
More precisely, these “zombie gene” inflammatory cells, or glia, underline the authors in a study recently published on the specialized site Science Daily. However, as Drs. Jeffrey Loeb explains, “The fact that glial cells react even after death is not surprising,” since their role is to protect neurons, clean cellular debris, and limit damage. For example damage after a stroke.
Before arriving at this conclusion, the researchers simulated 24-hour death conditions on brain tissue at room temperature. Then, they analyzed the gene expression of the cells. They then found that about 80% of genes remained stable for 24 hours. Most of these genes, called “domestic” genes, perform essential functions for the life of all cell types.
The authors also noticed that another group of genes, present in neurons, and often studied some pathologies, such as Alzheimer’s disease, were broken up within hours after death. This is the third group of genes that have particularly attracted their attention, the so-called “zombie” genes. They noticed that their activity increased at the very moment when the neural genes were decreasing.
In 2016, another team of researchers from the University of Washington had already shown in mice and zebrafish that the genetic activity of some cells persists or wakes for several hours after death.