In 2 independent studies, researchers at the university of Basel have demonstrated that both the structure of the brain and several memory functions are linked to immune system genes. The scientific journals Nature communications and nature human behavior have published the results of the research.
The body’s immune system is vital for defense mechanism against bacteria and cancer cells. However, the human brain is separated from immune cells in the blood stream by the so-called blood-brain barrier. This barrier protects the brain from pathogens and toxins circulating in the blood while also dividing the immune cells of the body into those that fulfill their function in the blood and those that work specifically in the brain. Until recent times, it was thought that the brain function was largely unaffected by the peripheral immune system.
Evidences has accumulated in the past few years to indicate that the blood’s immune system could have few impact on the brain.
Search for regulatory patterns:
Researchers looked for epigenetic profiles, that is the regulatory patterns in the blood samples of 533 young, healthy people. In their genome wide search, they identified an epigenetic profile that is strongly correlated with the thickness of the cerebral cortex – which is important for memory functions. This finding was confirmed in an independent examination of further 596 people. It also showed that it is specifically those genes that are responsible for the regulation of important immune functions in the blood that explain the link between the epigenetic profile and the properties of the brain.
Gene variant intensifies traumatic memories:
In another study, researchers investigated the genomes of healthy participants who could remember negative images particularly well and those did poorly. A variant of the TROVE2 gene, whose role in immunological diseases is currently being investigated was linked to participants ability to remember a particularly high number of negative pictures whilst their general memory remains unaffected.
The gene variant also led to increased activity in specific regions of the brain that are important for the memory of emotional experiences. Researchers also discovered that the gene is linked to strengthen traumatic memories in people who has experienced traumatic events.
The results of two studies show that both brain structure and memory are linked to the activity of genes that also perform important immune regulatory function in the blood. However, the precise mechanism behind these links are yet to be discovered, these studies would ultimately lead to new therapeutic possibilities. The immune system can be precisely affected by certain medications and such medications could also have positive effect on impaired brain functions.