Discovery of a new means to erase pain

Nurse gives injection to woman, New Orleans, 1941. Credit: Wikipedia.

A study published in the scientific journal Nature Neuroscience by Yves De Koninck and Robert Bonin, two researchers at Université Laval, reveals that it is possible to relieve pain hypersensitivity using a new method that involves rekindling pain so that it can subsequently be erased. This discovery could lead to novel means to alleviate chronic pain.

The researchers from the Faculty of Medicine at Université Laval and Institut universitaire en santé mentale de Québec (IUSMQ) were inspired by previous work on memory conducted some fifteen years ago. These studies had revealed that when a memory is reactivated during recall, its neurochemical encoding is temporarily unlocked. Simultaneous administration of a drug that blocks neurochemical reconsolidation of the memory results in its erasure.

The investigators wanted to see whether a similar mechanism was at play during neurochemical encoding of pain sensitization. To this end, they injected capsaicin in the foot of mice. Capsaicin, the pungent chemical in chili pepper, triggers a burning sensation. The procedure, which causes no physical damage, triggers pain hypersensitivity through a process of protein synthesis in the spinal cord. After capsaicin injections, the mechanical pressure at which mice would flinch was about a third of that in the normal situation.

Three hours later, the researchers administered a second dose of capsaicin and, at the same time, a drug that blocks protein synthesis. The hypersensitivity then vanished rapidly. Within less than 2 hours, the pressure tolerated by the mice was back to 70% of normal.

Yves De Koninck explains that "when the protein synthesis inhibitor is administered alone, the remains. The second injection of capsaicin is necessary to render the sensitivity to unstable and be able to interfere with its neurochemical reconsolidation. The challenge now will be to find inhibitors that are nontoxic and cause minimal side effects in humans".

Yves De Koninck is a professor of psychiatry and neuroscience at Université Laval and scientific director of the Institut universitaire en santé mentale de Québec. Robert Bonin is a postdoctoral fellow in Professor De Koninck's laboratory, where he works on the mechanisms underlying the etiology of . He is the recipient of a Catherine Bushnell Fellowship from the Louise and Alan Edwards Foundation. The work was supported financially by the Canadian Institutes of Health Research and the Fonds de la recherche en santé du Québec.

More information: A spinal analog of memory reconsolidation enables reversal of hyperalgesia, Nature Neuroscience (2014) DOI: 10.1038/nn.3758

add to favorites email to friend print save as pdf

Related Stories

Neuron memory key to taming chronic pain

Feb 13, 2012

For some, the pain is so great that they can't even bear to have clothes touch their skin. For others, it means that every step is a deliberate and agonizing choice. Whether the pain is caused by arthritic joints, an injury ...

Small protein plays big role in asthma severity

Aug 01, 2013

A new culprit has been identified that likely plays a big role in the severity of asthma—a small protein chemokine called CCL26. These findings were published in the Journal of Leukocyte Biology and represent the first ...

Recommended for you

Emotional adjustment following traumatic brain injury

18 hours ago

Life after a traumatic brain injury resulting from a car accident, a bad fall or a neurodegenerative disease changes a person forever. But the injury doesn't solely affect the survivor – the lives of their spouse or partner ...

New ALS associated gene identified using innovative strategy

Oct 22, 2014

Using an innovative exome sequencing strategy, a team of international scientists led by John Landers, PhD, at the University of Massachusetts Medical School has shown that TUBA4A, the gene encoding the Tubulin Alpha 4A protein, ...

User comments