The relation of damaged brain cell after poor sleep and chronic pain
Why poor sleep is associated with chronic pain may now have an explanation, according to neuroscientists. According to recent mouse research, nerve damage causes some brain cells to go wild while you’re sleeping, and this unexpected excitation may cause persistent pain.
https://www.livescience.com/brain-network-sleep-chronic-pain
The study suggests that on the other hand, reducing hyperactivity when sleeping may aid in pain relief.
Evidence shows that poor sleep quality is a significant risk factor for acquiring chronic pain in the first place. People with chronic pain frequently have sleep disturbances, including insomnia.
Although there is a clear connection between the two, Alban Latremoliere, an assistant professor of neurosurgery, said that the nature of the sleep issues for dicers pain situations, their specific origins or their long-term implications are yet unclear.
Neuropathic pain results from damage or illness of the nerves
The study concentrated on neuropathic pain, which results from damage to or illness of the nerves that transmit sensory data from the body to the brain. Sciatic nerve injuries, which affect one of the main nerves that run from the spinal cord to the hind legs, were investigated in mice.
According to Guang Yang, senior author of the study and associate professor of anesthesiological sciences at the Columbia University Irving Medical Center in New York, two of the three branches of the nerve that plug into the leg were damaged.
This resulted in the skin supplied by the remaining branch becoming hypersensitive. Yang says it replicates the neuropathic pain that people experience after suffering a peripheral nerve lesion.
When the scientists compared the activity of the mice’ brains before and after damage, they were able to identify clear differences in the area of the wrinkly cerebral cortex that receives sensory input from the rear leg.
Pyramidal neurons, which are brain cells with bodies shaped like pyramids, became increasingly active in the weeks following damages as the mice’s pain progressed into the chronic stage. However, their hyperactivity peaked during deep sleep, or non-rapid eye movement(Non-REM) sleep.P
How did these pyramidal neurons becone dyfuncitonal? The scientists located the anterior nucleus basalis, a group of neurons tucked away deep in the front of the brain, as the source of the problem.
The scientists discovered that following damage, the activity of this cell cluster had also risen, which caused the cells to convey the chemical messenger acetylcholine up to the cerebral cortex.
This resulted in a cascade of events that effectively lifted the breaks from the pyramidal neurons, sending them into overdrive. This change in brain activity was associated with a change in the mice’s pain sensitivity, where previously harmless stimuli became painful.
In a series of tests, the researchers discovered that they could reduce this discomfort by preventing several brain cells along the newly identified pathway from becoming overactive.
Damage from Pyramidal neurons sends brakes into overdrive and can be treated
The study’s authors concluded that blocking this route during NonREM sleep, but not when awake, corrects neuronal hyper activation and reduces pain.
Though this first study is somewhat constrained because it was conducted on mice, further research along this line may result in novel therapies for people with chronic pain.
While the same abnormalities identified in mice are likely to occur in humans, their exact profile and distribution could vary in patients, Alban said. This is largely because people have different circadian cycles than the nocturnal rodents.
Alban said, this newly discovered route contributes to other forms of chronic pain, such associated with chemotherapy or cancer.
Studying whether their findings apply for people is Yang and her colleagues’ goal. The present study raises the possibility that chronic pain may be encoded in the brain as a person sleeps, just the way memories are.
What caused the pyramidal neurons to become dysfunctional? The group determined that the anterior nucleus basalis, a group of neurons tucked away deep in the front of the brain, was to blame.
The scientists discovered that following damage, the activity of this cell cluster also increased, which caused the cells to deliver the chemical messenger acetylcholine to the cerebral cortex.
This move, which was the result of a series of events, basically pulled the brakes off the pyramidal neurons, sending them into overdrive. The mice’s altered pain sensitivity, where previously painless stimuli become unpleasant, was connected to this alteration in brain activity.
Through a series of trials, the researchers discovered that they could reduce this discomfort by stifling certain brain cell’ excitability in the newly identified brain route.
The understanding that sleep-related neural circuit remodelling has such a significant role in the development of chronic pain is extremely important to pain treatments.
Source: live science
