Jerusalem: A new brain study from the Hebrew University of Jerusalem has uncovered why certain types of pain, like a bad knee or chronic backache, persist for months or even years. Published in Science Advances, the research identifies a malfunctioning pain-regulation system in the brainstem that may be responsible, opening new doors for targeted treatments.
The team focused on the medullary dorsal horn, a brainstem region that relays pain signals through projection neurons. In cases of short-term pain, these neurons typically self-regulate by reducing their activity, like a biological “brake.” However, researchers found this mechanism breaks down in chronic pain, causing neurons to become hyperactive and continually transmit pain.
Using a blend of electrophysiology and computer modeling, scientists discovered that a key electrical current, A-type potassium current (IA), plays a significant role. IA usually keeps neurons calm by helping them return to rest after firing. In acute pain, IA increases, acting like a buffer. But in chronic pain, this current fails to activate, allowing neurons to stay overactive.
“This is the first time we’ve seen how the same neurons behave so differently in acute versus chronic pain,” said Professor Alexander Binshtok, lead author and neurobiology expert. “If we can restore or mimic this natural braking system, we might be able to stop pain from becoming chronic.”
The findings carry important implications, particularly for the 1 in 5 Australians over age 45 who live with chronic pain, according to health data. Current treatments — ranging from psychological therapies and physical rehab to medications, often aim to dull pain rather than address the faulty wiring. This research could shift that approach by helping to re-regulate the brain’s pain circuits.
