Researchers of a new study found that low levels of cytokine, a pro-inflammatory agent in the brain, are important for cognition.
The study conducted on rats found that neutralizing the cytokine interleukin-6 in the brain impaired reversal learning in both stressed and non-stressed rodents. Cognitive flexibility is very important. This allows people to change and use previously learnt information in accordance with the changing environment. Reversal learning is cognitive flexibility, which gets affected in patients suffering from psychiatric disorders like depression, schizophrenia and post-traumatic stress disorder, says the study.
"When we started the project, we thought cognitive flexibility would be impaired by stress-induced inflammation in a region of the brain called the prefrontal cortex," study author Jennifer Donegan said in a press statement. "We decided to block interleukin-6 during stress to prevent the cognitive deficit, and to our surprise this made things worse. This suggested that it may actually be beneficial to maintain a low level of this pro-inflammatory cytokine in the brain."
Researchers found that this cognitive shortfall could be fixed by lowering the level of cytokine in the prefrontal cortex of the brain. They also noted that further studies needed to be conducted to learn more about the role of interleukin-6 in cognition and in diseases like depression.
"We've replicated just one piece of a very complex disease so we can understand the biology," the authors said. "We found that, in one brain region, one cytokine facilitates cognitive flexibility and is beneficial after chronic stress. But we delivered the cytokine specifically into that brain region using a virus, which we cannot do in people. And its role in inflammation may be very different than in normal conditions. There's still a lot of work to do."
Inflammation is frequently a cause of disease in the body. Inflammation is the body's attempt at self-protection; the aim being to remove harmful stimuli, including damaged cells, irritants, or pathogens - and begin the healing process. It is the first response of the immune system to infection or irritation within the body.
