A Good Inflammatory Substance?

By Jane Farrell

It’s well known that inflammation is frequently a cause of disease, but new research indicates that low levels of a pro-inflammatory substance in the brain are crucial for cognition.

Researchers from the University of Texas, San Antonio, found that found that blocking the substance, interleukin-6 , impaired learning in rats. The learning area affected was cognitive flexibility – the ability to change learned thoughts and behaviors in response to a changed environment.

The scientists were then able to fix the cognitive deficit by restoring a low level of interleukin-6 in the brain’s prefrontal cortex. But the researchers caution that there’s still a lot to learn about interleukin-6’s role in cognition and illness such as depression.

“We’ve replicated just one piece of a very complex disease so we can understand the biology,” said senior study author David Morilak, Ph.D., professor of pharmacology in the university’s School of Medicine. n . “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.”

The findings were published in the Journal of Neuroscience.