A chemical in the brain typically associated with cognition, movement and reward-motivation behaviour, among others, may also play a role in promoting chronic pain, according to new research from researchers at The University of Texas, University of Arizona and the University of Alabama. The chemical, dopamine, sets the stage for many important brain functions, but the mechanisms that cause it to contribute to chronic pain are less well understood.
In a recent paper published in The Journal of Neuroscience, the researchers followed the sequence of pain impulses traveling from the brain to the spinal cord in mice. They found that by removing a collection of neurons called A11 that contain dopamine, chronic pain was selectively diminished. The data findings demonstrated a novel role for how dopamine contributes to maintaining chronic pain states.
The team hypothesize that this may open up new opportunities to target medicines that could reverse chronic pain. They go on to explain that pain signals travel like electricity from an injury to the spinal cord where they pass on electrical or chemical pain signals to other cells. Those pain signals then travel upward and relay that information to neurons in the brain where they can be distributed throughout. There is no single pain center in the brain, but there is substantial evidence that chronic pain changes how these pain centers are activated.
In people with chronic pain, neurons continue to send pain signals to the brain, even in the absence of injury, but the causes of this are not known, the researchers explain. A potential explanation comes from A11. In the current study these neurons didn’t affect acute pain, but they did have a profound effect on chronic pain. By targeting these neurons in mice with chronic pain, the researchers permanently reversed a chronic pain state.
Previous studies have examined the role of other neurotransmitters in chronic pain including norepinephrine and serotonin. By process of elimination the team decided to look more closely at dopamine. The researchers used a toxin that affected A11 neurons, and that’s when they found that acute pain signals were still normal, but chronic pain was absent.
In 2011, the Institute of Medicine estimated that more than 100 million Americans suffer from chronic pain, a condition that costs more than $600 billion each year in medical care and lost productivity.
The team surmise that understanding the basis of chronic pain and all of its contributing factors could help point to more effective treatments. In future studies, the researchers state that they would like to gain a better understanding of how stress interacts with A11 and how the interaction between molecular mechanisms promote chronic pain and dopamine.
Michelle Petersen is the founder of Healthinnovations, having worked in the health and science industry for over 21 years, which includes tenure within the NHS and Oxford University. Healthinnovations is a publication that has reported on, influenced, and researched current and future innovations in health for the past decade.
Michelle has been picked up as an expert writer for Informa publisher’s Clinical Trials community, as well as being listed as a blog source by the world’s leading medical journals, including the acclaimed Nature-Springer journal series.
Healthinnovations is currently indexed by the trusted Altmetric and PlumX metrics systems, respectively, as a blog source for published research globally. Healthinnovations is also featured in the world-renowned BioPortfolio, BioPortfolio.com, the life science, pharmaceutical and healthcare portal.
Most recently the Texas A&M University covered The Top 10 Healthinnovations series on their site with distinguished Professor Stephen Maren calling the inclusion of himself and his team on the list a reflection of “the hard work and dedication of my students and trainees”.
Michelle Petersen’s copy was used in the highly successful marketing campaign for the mega-hit film ‘Jumanji: The Next Level, starring Jack Black, Karen Gilian, Kevin Hart and Dwayne ‘The Rock’ Johnson. Michelle Petersen’s copywriting was part of the film’s coverage by the Republic TV network. Republic TV is the most-watched English language TV channel in India since its inception in 2017.
An avid campaigner in the fight against child sex abuse and trafficking, Michelle is a passionate humanist striving for a better quality of life for all humans by helping to provide traction for new technologies and techniques within healthcare.