Researchers have discovered a kind of “brake” against chronic nerve pain in the brains of mice. Certain receptors in a small brain region can calm an overactive pain circuit – a possible route to more targeted pain therapies.
A tiny region with a big effect
Deep at the base of the brain sits the locus coeruleus, the main alert and stress center. A small cluster of nerve cells there normally dampens pain signals traveling up from the spinal cord. After a nerve injury, however, this system can “flip” and itself become an engine for chronic pain.
Receptors as a natural brake
In mice, the team identified receptors (mu opioid receptors) on these cells that act as a biological brake. Without them, the animals reacted even more sensitively to touch and heat; when they were restored, the hypersensitivity disappeared. The study was published on 17 August in the journal Current Biology.
Hope for more targeted drugs
Targeting this system more precisely could one day relieve pain without acting throughout the entire body like conventional opioids – with correspondingly fewer side effects. Applying it in humans, however, is still a long way off.
Sources: WashU Medicine, EurekAlert.
