Harvard scientists identify link between pain and poor sleep
Most of us have woken up with an aching back after a night of tossing and turning, only for that pain to then keep us awake the next night. Now, Harvard scientists have discovered a potential link between pain and poor sleep, and maybe even a way to break the loop.
Millions of people suffer from chronic pain, which can prevent them from doing certain activities in their daily lives. One of the most important of these is sleep – after all, aches and pains aren’t conducive to a good night’s rest. Worse still, impaired sleep can actually make people more sensitive to pain, leading to an unpleasant feedback loop.
In a new study, scientists at Harvard and Massachusetts General Hospital (MGH) have identified one factor that links pain and poor sleep, which is the first step towards developing treatments for it. The key, it turns out, is a neurotransmitter called NADA.
Neurotransmitters are chemicals released by neurons to communicate with each other, and NADA is known to target cannabinoid receptor one in the brain. This receptor seems to play a role in controlling pain perception, and it’s also targeted by some marijuana strains, which could explain the pain relief properties of the drug.
In tests in mice, the researchers found that chronic sleep disruption reduced levels of NADA in the brain. This doesn’t necessarily increase the levels of pain present, but it does seem to heighten the perception of it, making that pain feel worse than the day before.
“Pain in human beings is a very subjective experience,” said Shiqian Shen, lead author of the study. “After sleep loss, even if there’s no exaggerated stimulation, we still feel pain. That means something internal is controlling the pain, like a room thermostat controlling temperature.”
And the team may have found a way to turn down that thermostat. When the researchers gave the sleep-deprived mice more NADA, they found that the pain perception went back down. This suggests that developing drugs that increase NADA levels in humans could help with pain relief and breaking the vicious cycle between pain and poor sleep.
Of course, this work is still in the very early stages, with more tests needed to explore whether the same effect is at play in humans.
The research was published in the journal Nature Communications.