The Ohio State University researchers claim that constant stress causes an immune response that deteriorates memory. The study, published in The Journal of Neuroscience, debunks the idea that stress leads to brain damage that leads to memory loss.

The study supports previous research that presented the relationship between chronic stress and persistent anxiety but this is the first one to show the connection between short-term memory and prolonged stress. Apparently, stress triggers an immune response in the brain that results to inflammation, as evidenced by the presence of the immune cells called macrophages, eventually resulting to memory loss.

The study involved observing the stress responses of the mice when the researchers placed a larger “alpha” mouse with them. The research team said that the mice forgot the maze’s escape holes which they already mastered beforehand after the larger mouse’s repeated visits.



However, those who did not undergo this stressful situation still remembered the holes’ locations. Apart from that, the researchers observed that the mice became more distant and depressed after four weeks.

“Stress releases immune cells from the bone marrow and those cells can traffic to brain areas associated with neuronal activation in response to stress,” says John Sheridan, associate director of Ohio State’s Institute for Behavioral Medicine Research Sheridan. “They’re being called to the brain, to the center of memory.”

The researchers noted that the animals’ spatial memory problems went away within 28 days. When they administered the mice with a chemical that stopped inflammation, other brain changes and depressive symptoms did not disappear.

Nevertheless, this chemical made the memory loss and the macrophages go away. This convinced the researchers that post-stress memory problems are associated with inflammation, a discovery that could open immune-based treatments.

Jonathan Godbout, an associate professor of neuroscience at the Ohio State, says that this would be especially helpful to those who have suffered memory problems due to the stress of bullying, like soldiers, employees or students.