SCI Rep: why does radiation damage brain connectivity

December 19, 2019 / BIOON / -- one of the possible side effects of brain radiotherapy is cognitive impairment Now, researchers may have figured out why this happens, and these findings may point the way to protecting the brain from radiation damage The new study is published in the journal scientific reports Studies have shown that radiation triggers an immune response in the brain, cutting off connections between nerve cells Although the role of the immune system in remodeling the complex network of connections between neurons is normal in a healthy brain, radiation seems to make the process over run, resulting in damage, which may be the cause of cognitive and memory problems patients often face after radiotherapy Dr Kerry o'banion, a professor at the University of Rochester, said: "the brain experiences a constant process of self-renewal Cells in the immune system are like gardeners, carefully pruning the synapses connecting neurons When exposed to radiation, these cells become hyperactive and destroy the nodules on nerve cells, thereby destroying the connections they form with their neighbors " The main culprit is cells in the immune system called microglia These cells act as outposts for the brain, looking for and eradicating infections, and cleaning up damaged tissue after injury In recent years, scientists have gradually understood the role of microglia in cognitive process In the new study, researchers exposed mice to radiation and observed that microglia in the brain activated and disrupted prominent connections between neurons The researchers speculate that this may be important for encoding new memories, a finding that may explain the cognitive difficulties encountered by many patients The researchers also observed that the damage found in the brain after radiation was more pronounced in male mice In recent years, despite the progress of brain radiotherapy program and technology, clinicians can better target tumors and limit the brain areas exposed to radiation, but the research results show that there are still high risks in the treatment of brain There are two possible ways to prevent damage to neurons One is to block the receptor of Cr3, which mediates the activity of microglia When CR3 receptor in mice is inhibited, there is no synaptic inactivation in animals exposed to radiation Another approach might be to suppress the immune response of the brain when the person is being treated with radiation to prevent microglia from hyperactivity Information sources: radiation breaks connections in the brain original sources: Joshua J Hinkle, John A olschowka, tanzy M love, Jacqueline P Williams, M Kerry o'banion Critical radiation mediated spin loss is sex specific and complex receiver-3 dependent in male mice Scientific reports, 2019; 9 (1) doi: 10.1038/s41598-019-55366-6