Researchers identify which sensory nerve cells contribute to chronic nerve pain

August 17, 2012
Researchers identify which sensory nerve cells contribute to chronic nerve pain
Computer-generated artwork illustrating a migraine. Credit: Adrian Cousins, Wellcome Images.

(Medical Xpress) -- New research from the University of Bristol has identified the subtypes of sensory nerve cells that are likely to contribute to long-term nerve pain from partial nerve injury. It is hoped this will aid in the development of more effective painkillers.

Partial can be caused by several things, such as an accident, surgery or a disease (e.g. diabetes). Although some nerve cells will degenerate and die as a result of the injury, some will survive and continue to conduct through the damaged or inflamed nerve. This can result in serious long-term neuropathic pain.

Neuropathic pain is experienced in different ways. The most debilitating is an often relentless, spontaneous and ongoing burning or sharp shooting pain. Some people may experience extreme tenderness and pain in response to normal touch or normal movements, as well as greater pain than usual in response to normally painful events. They may also feel strange, and often unpleasant - but non-painful - sensations.

In all cases, neuropathic pain remains very hard to treat clinically, partly because we don't fully understand the types of nerve cells responsible for these different types of pain.

Sensory nerve cells are responsible for carrying signals from the tissues, such as skin, muscle and organs, to the . The cells responsible for transmitting pain are called nociceptors. They sense and signal or , activating pathways to the brain, which results in pain.

In the study, published this week in the journal Pain, the researchers report profound changes in properties of different subpopulations of the sensory nerve cells that survive without damage after nerve injury. First, they observed spontaneous ongoing firing in different groups of pain nerve cells, which would cause ongoing burning and sharp shooting pain.

They also report spontaneous firing in non-pain nerve cells that could cause the abnormal non- that are associated with neuropathic pain. In addition, they found an increased sensitivity of fast-conducting nociceptors, which could underlie the increased pain resulting from stimulation of the tissues.

Professor Sally Lawson, who led the research at the University of Bristol, said: "We hope that our findings will trigger further studies that will clarify how and why these nerve cells with uninjured fibres running through a damaged nerve change so remarkably and contribute to pathological pain, and determine how to reverse these changes."

Dr Laiche Djouhri, now at the University of Liverpool, added: "This should help the understanding of how to target pathological pain more effectively, taking into account the different neuron types involved. This may, in the longer term, help development of more effective painkillers to help sufferers of ."

The study was funded by the Wellcome Trust and the Medical Research Council.

More information: Djouhri L et al. Partial nerve injury induces electrophysiological changes in conducting (uninjured) nociceptive and nonnociceptive DRG neurons: possible relationships to aspects of peripheral neuropathic pain and paresthesias. Pain 2012:153;1824-36. www.ncbi.nlm.nih.gov/pubmed/22721911

Related Stories

New insight into pain mechanisms

April 25, 2012

(Medical Xpress) -- Researchers in the UCL Wolfson Institute for Biomedical Research have made a discovery which could help the development of analgesic drugs able to treat nerve damage-related pain.

A new drug to manage resistant chronic pain

April 30, 2012

Neuropathic pain, caused by nerve or tissue damage, is the culprit behind many cases of chronic pain. It can be the result of an accident or caused by a variety of medical conditions and diseases such as tumors, lupus, and ...

Study discovers unexpected source of diabetic neuropathy pain

May 15, 2012

Nearly half of all diabetics suffer from neuropathic pain, an intractable, agonizing and still mysterious companion of the disease. Now Yale researchers have identified an unexpected source of the pain and a potential target ...

How does exercise affect nerve pain?

June 1, 2012

Exercise helps to alleviate pain related to nerve damage (neuropathic pain) by reducing levels of certain inflammation-promoting factors, suggests an experimental study in the June issue of Anesthesia & Analgesia, official ...

Recommended for you

Crystal clear images uncover secrets of hormone receptors

July 31, 2015

Many hormones and neurotransmitters work by binding to receptors on a cell's exterior surface. This activates receptors causing them to twist, turn and spark chemical reactions inside cells. NIH scientists used atomic level ...

A cheaper, high-performance prosthetic knee

July 30, 2015

In the last two decades, prosthetic limb technology has grown by leaps and bounds. Today, the most advanced prostheses incorporate microprocessors that work with onboard gyroscopes, accelerometers, and hydraulics to enable ...

Flow means 'go' for proper lymph system development

July 27, 2015

The lymphatic system provides a slow flow of fluid from our organs and tissues into the bloodstream. It returns fluid and proteins that leak from blood vessels, provides passage for immune and inflammatory cells from the ...

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

Vendicar Dickarian
1 / 5 (1) Aug 17, 2012
"New research from the University of Bristol has identified the subtypes of sensory nerve cells that are likely to contribute to long-term nerve pain from partial nerve injury. It is hoped this will aid in the development of more effective painkillers."

All well and good. But, as a sufferer of neuropathic pain myself, it is my hope that a cure or workaround may be found eventually, NOT better painkillers. Enough of those already thanks much.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.