0258 GMT November 22, 2019
When head injuries harm the master genes, they can increase a person's risk of developing neurological and psychiatric disorders such as post-traumatic stress disorder, attention deficit hyperactivity disorder, autism spectrum disorder, depression, schizophrenia, stroke, and Alzheimer's and Parkinson's diseases, UPI reported.
"We believe these master genes are responsible for traumatic brain injury adversely triggering changes in many other genes," Xia Yang, associate professor of integrative biology and physiology at UCLA, said in a press release.
Researchers uncovered two ways damage to master genes can translate into changes to other genes — the brain injury can cause the genes to produce proteins of irregular forms, or the injury can change the number of expressed copies of a gene in each cell, both of which prevent the gene from working properly. When a gene turns into the wrong form of protein, it can lead to the development of neurodegenerative diseases such as Alzheimer's disease.
"Very little is known about how people with brain trauma — like football players and soldiers — develop neurological disorders later in life," said Fernando Gomez-Pinilla, professor of neurosurgery and integrative biology and physiology at UCLA.
The team at UCLA trained 20 rats to escape from a maze and then used a fluid to induce a concussion-like brain injury in half of the rats. Researchers found the rats that had a brain injury took 25 percent longer to escape from the maze than the rats that did not have a brain injury.
Researchers drew RNA from the hippocampus, the region of the brain that regulates learning and memory, and from leukocytes, white blood cells that are vital to the immune system, and analyzed the genes. Results showed the rats that sustained brain injuries had a core group of 268 genes in the hippocampus that were altered, as well as a core group of 1,215 genes in the leukocytes that were altered.
"A surprise was how many major changes occurred to genes in the blood cells," Yang said. "The changes in the brain were less surprising. It's such a critical region, so it makes sense that when it's damaged, it signals to the body that it's under attack."
According to Yang, the study indicated which genes are affected by traumatic brain injury and linked to serious disease, but also could point to genes that govern metabolism, cell communication and inflammation, which could lead to treatments for brain disorders.