Pain is not simply a matter of nerves, but one that significantly involves our glial cells, the most common type of cell in the human brain and spinal cord, according to a new study by researchers at the Division of Neurophysiology at MedUni Vienna’s Center for Brain Research.
Glial cells surround neurons and play an important supporting role. When glial cells are activated — by pain processes, for example — they are able to release messenger substances, such as inflammatory cytokines. This results in a strong pain-amplifying effect.
The findings may help explain why opioid withdrawal produces such severe pain throughout the entire body, a phenomenon that has been unclear until now.
Other factors that can lead to activation of glial cells include neuroinflammatory diseases of the brain, environmental factors, and even a person’s own lifestyle choices, such as exercise and diet. Examples from the current literature are depression, anxiety disorders and chronic stress, multiple sclerosis or Alzheimer’s and diabetes, as well as lack of exercise and poor diet.
“The activation of glial cells results in a pain-amplifying effect, as well as spreading the pain to previously unaffected parts of the body. For the very first time, our study provides a biological explanation for this and for other hitherto unexplained pain phenomena in medicine,” said Jürgen Sandkühler, M.D., Ph.D., head of the Division of Neurophysiology at MedUni Vienna’s Center for Brain Research.
Over-activation of glial cells in the spinal cord can be triggered by strong pain stimuli from a wound or surgical intervention — or even by opiates.
“This could also explain why opiates are initially very good at relieving pain but then often cease to be effective. Another example is the phenomenon of withdrawal in drug addicts, where activated glial cells cause severe pain throughout the body,” said Sandkühler.
“Glial cells are an important factor in ensuring the equilibrium of a person’s neuroinflammatory system,” said Sandkühler.
The new findings suggest that improvements in a person’s lifestyle could have a beneficial impact upon this system and ensure that they generally suffer less pain or “minor niggles,” said Sandkühler.
“It is therefore in our own hands: 30 minutes of moderate exercise three or four times a week, a healthy diet, and avoiding putting on excess weight can make a huge difference.”
The study is published in the journal Science.
Source: Medical University of Vienna