Scientists have recreated the brain circuit responsible for transmitting feelings of pain for the first time.
The breakthrough, made by a team at Stanford University in the US, could help with developing better treatments for pain disorders.
The mapping of pain pathways in a lab dish could also allow experiments and tests to be conducted on nerve circuits without causing pain to laboratory animals.
“We can now model this pathway non-invasively,” said Sergiu Pasca, a professor of psychiatry and behavioural sciences at Stanford University, who led the study.
“The [lab-built circuits] don’t ‘feel’ any pain. They transmit nervous signals that need to be further processed by other centres in our brains for us to experience the unpleasant, aversive feeling of pain.”
It is the first time that scientists have witnessed waves of electrical activity travel along the entire nervous pathway responsible for sensing pain – from the body’s skin to the brain.
They did it by creating what is referred to as a “sensory assembloid”, which is a miniaturised system made from lab-grown human cells that mimics the complex pathway used for delivering pain signals.
These assembloids now hold the potential to help test painkillers, study nerve injuries, or even create personalised treatments for patients. There is also the possibility to better understand why some people suffer from chronic pain.
“Pain is a huge health problem,” said Dr Vivianne Tawfik, an associate professor of anesthesiology, perioperative and pain medicine, who was not involved in the research.
“Some 116 million Americans – more than one in three people in the United States – are dealing with chronic pain of one kind or another.
“I can’t even tell you how sad it is to sit in front of a patient who’s suffering from chronic pain after we’ve tried everything and there’s nothing left in our arsenal.”
The research was detailed in a study, titled ‘Human assembloid model of the ascending neural sensory pathway’, published in the journal Nature on 9 April.
