New device blocks pain signals from reaching brain

A new implantable device could soon put the minds of chronic pain sufferers at ease by distributing the body's own natural pain relief signals at just the right time.
Researchers at Linkoping University (LiU) and Karolinska Institutet (KI) in Sweden are the first in the world with technology that can stop pain impulses in living, freely moving rats using the body's own pain relief signals.
The implantable "ion pump" that delivers the body's own pain alleviators with exact dosage precisely to the location where the pain signals reach the spinal cord for further transmission to the brain, could be in clinical use in five to ten years, researchers said.

Firstly, the device gives hope to the seven per cent of the world's population suffering from nerve pain for whom no other cure has been found - until now, researchers said.
But the pump could also be used to supply therapeutic substances to the brain and other parts of the body in addition to the spinal cord.
"The ion pump can be likened to a pacemaker, except for alleviating pain," said Professor Magnus Berggren, head of the research.

While a pacemaker sends electrical impulses to the heart, the ion pump sends out the body's own pain alleviator - charged molecules of what are known as neurotransmitters - to the exact place where the damaged nerves come into contact with the spinal cord.

This means that the pain impulses never reach the brain. In this case, the device delivers the neurotransmitter gamma-aminobutyric acid (GABA), whose natural task is to inhibit stimuli in our central nervous system.
Researchers constructed the therapeutic implant using organic electronics - a class of materials capable of easy translation between electronic and biochemical signals - and that it has been used to block pain impulses in awake, freely-moving rats.
With the help of the ion pump, positively-charged ions can be administered in four different locations, adapted according to the exact points where the nerve endings meet the spinal cord.

An electric current through the ion pump is all that is needed for the GABA neurotransmitter to be spread as a thin cloud at these exact locations on the spinal cord. So far, the pain alleviation has had no negative side effects.
"What's unique is that we're using organic electronics to send the body's own chemical signals. The organic materials are easily accepted by the body, and they communicate just as in biology - with charged ions," said Assistant Professor Daniel Simon.
The research was published in the journal Science Advances.