July 2016 \\ Category: Stress
Recently (in March 2016) we read a very interesting piece of research on mice in the Journal of Neuroscience published by neuroscientists from The Ohio State University. This will be a game-changer of how we understand stress and what it actually does to the brain - through the immune system.
The interesting conclusion from the researchers is that due to stress, the immune system attacks the body’s own brain cells, which causes inflammation in the brain. And the inflammation leads to memory loss and depression. It is the first study of its kind to establish the relationship between stress, inflammation, short-term memory loss and depression.
The researchers stressed out mice by periodically putting a much more aggressive and larger mouse into their cages - a nasty intruder mouse. The mice'’s job was to find the escape hole in a maze. They mastered this perfectly prior to the upcoming stressful period. When they were repeatedly exposed to the aggressive intruder they didn’t recall where the escape hole was. The mice that weren’t stressed, had no problems remembering it.
The researchers found out that the mice exposed to the intruder mouse had measurable changes in their brains, including inflammation caused by the immune system’s response/reaction to the outside stressful pressure. This was associated with the presence of immune cells, called macrophages, in the brain of the stressed mice. The macrophages were preventing the growth of more brain cells. So the stress, it seemed, was causing the mice’s immune systems to attack their own brains, causing inflammation.
The researchers gave the mice a drug to reduce inflammation to see how they would respond. The result was that the mice had fewer macrophages (immune cells) in their brains and their memories returned to normal.
Most of us probably recognise that our brain and memory doesn't work well under severe stress, but this study gives the important explanation, that it is due to an inflammatory condition in the brain, where the the immune cells attacks the functioning brain cells. So the study gives important knowledge about that the brain inflammation (and memory loss) is directly linked to the immune system - rather than to a damage to the brain.
These findings are important and new discoveries for the researchers as it will pave the way for immune-based treatments to stress.
Next question is therefore - would it be possible to help to reduce stress by living an anti-inflammatory life?