124 Search Results for "pain"
Posted on by Lawrence Tabak, D.D.S., Ph.D.
Chronic pain is an often-debilitating health condition and serious public health concern, affecting more than 50 million Americans.1 The opioid and overdose crisis, which stems from inadequate pain treatment, continues to have a devastating impact on families and communities across the country. To combat both challenges, we urgently need new ways to treat acute and chronic pain effectively without the many downsides of opioids.
While there are already multiple classes of non-opioid pain medications and other approaches to manage pain, unfortunately none have proved as effective as opioids when it comes to pain relief. So, I’m encouraged to see that an NIH-funded team now has preclinical evidence of a promising alternative target for pain-relieving medicines in the brain.2
Rather than activating opioid receptors, the new approach targets receptors for a nerve messenger known as acetylcholine in a portion of the brain involved in pain control. Based on findings from animal models, it appears that treatments targeting acetylcholine could offer pain relief even in people who have reduced responsiveness to opioids. Their findings suggest that the treatment approach has the potential to remain effective in combatting pain long-term and with limited risk for withdrawal symptoms or addiction.
The researchers, led by Daniel McGehee, University of Chicago, focused their attention on non-opioid pathways in the ventrolateral periaqueductal gray (vlPAG), a brain area involved in pain control. They had previously shown that activating acetylcholine receptors, which are part of the vlPAG’s underlying circuitry, could relieve pain.3 However, they found that when the body is experiencing pain, it unexpectedly suppresses acetylcholine rather than releasing more.
To understand how and why this is happening, McGehee and Shivang Sullere, now a postdoctoral fellow at Harvard Medical School, conducted studies in mice to understand how acetylcholine is released under various pain states. They found that mice treated with a drug that stimulates an acetylcholine receptor known as alpha-7 (⍺7) initially led to more activity in the nervous system. But this activity quickly gave way to a prolonged inactive or quiet state that delivered pain relief. Interestingly, this unexpected inhibitory effect lasted for several hours.
Additional studies in mice that had developed a tolerance to opioids showed the same long-lasting pain relief. This encouraging finding was expected since opioids use a pathway separate from acetylcholine. In more good news, the animals didn’t show any signs of dependence or addiction either. For instance, in the absence of pain, they didn’t prefer spending time in environments where they’d receive the ⍺7-targeted drug.
Imaging studies measuring brain activity revealed greater activity in cells expressing ⍺7 with higher levels of pain. When that activity was blocked, pain levels dropped. The finding suggests to the researchers it may be possible to monitor pain levels through brain imaging. It’s also possible the acetylcholine circuitry in the brain may play a role in the process whereby acute or temporary pain becomes chronic.
Finding treatments to modify acetylcholine levels or target acetylcholine receptors may therefore offer a means to treat pain and prevent it from becoming chronic. Encouragingly, drugs acting on these receptors already have been tested for use in people for treating other health conditions. It will now be important to learn whether these existing therapeutics or others like them may act as highly effective, non-addictive painkillers, with important implications for alleviating chronic pain.
 NIH HEAL Initiative Research Plan. NIH HEAL Initiative.
 Sullere S et al. A cholinergic circuit that relieves pain despite opioid tolerance. Neuron. DOI: 10.1016/j.neuron.2023.08.017 (2023).
 Umana IC et al. Nicotinic modulation of descending pain control circuitry. Pain. PMID: 28817416; PMCID: PMC5873975 (2017).
Pain (National Institute of Neurological Disorders and Stroke/NIH)
Opioids (National Institute on Drug Abuse/NIH)
Daniel McGehee (University of Chicago, Illinois)
NIH Support: National Institute of Neurological Disorders and Stroke, National Institute on Drug Abuse
Chronic pain and its companion crisis of opioid misuse have taken a terrible toll on Americans. But the impact has been even greater on U.S. service members and veterans, who often deal with the compounded factors of service-related injuries and traumatic stress.
For example, among soldiers in a leading U.S. Army unit, 44 percent had chronic pain and 15 percent used opioids after a combat deployment. That compares to 26 percent and 4 percent, respectively, in the general population [1,2].
This disproportionate burden of chronic pain among veterans  and service members led NIH’s National Center for Complementary and Integrative Health (NCCIH) to act. We forged a collaboration in 2017 across NIH, U.S. Department of Defense (DOD), and U.S. Department of Veteran’s Affairs (VA) to establish the Pain Management Collaboratory (PMC).
The PMC’s research focusing on the implementation and evaluation of nondrug approaches for the management of pain is urgently needed in the military and across our entire country. Nondrug approaches require a shift in thinking. Rather than focusing solely on blocking pain temporarily using analgesics, nondrug approaches work with the mind and body to promote the resolution of chronic pain and the long-term restoration of health through techniques and practices such as manual therapy, yoga, and mindfulness-based interventions.
Addressing chronic pain in ways that don’t only rely on drugs means addressing underlying issues, such as joints and connective tissue that lack adequate movement or training our brains to “turn down the volume” on pain signals. Using mind and body practices to reduce pain can help promote health in other ways. Possible “fringe benefits” include better sleep, more energy for physical activity, a better mindset for making good nutritional choices, and/or improved mood.
Indeed, there is a growing body of research on the benefits of nondrug approaches to address chronic pain. What is so powerful about PMC is it puts this knowledge to work by embedding research within military health care settings.
The PMC supports a shared resource center and 11 large-scale pragmatic clinical trials. Within this real-world health care setting, the clinical trials have enrolled more than 8,200 participants across 42 veteran and military health systems. These studies offer both strength in numbers and insights into what happens when learnings from controlled clinical trials collide with the realities of health care delivery and the complexities of daily life. 
Central to the PMC partnership is whole person health. Too often, we see health through the prism of separate parts—for example, a person’s cardiovascular, digestive, and mental health problems are viewed as co-occurring rather than as interrelated conditions. A whole person framework—a central focus of NCCIH’s current Strategic Plan—brings the parts back together and recognizes that health exists across multiple interconnected body systems and domains: biological, behavioral, social, and environmental.
The VA’s implementation of a whole health model  and their unique closed-loop health care system offers an opportunity to deliver care, conduct research, and illustrate what happens when people receive coordinated care that treats the whole person. In fact, VA’s leadership in this area was the impetus for a recent report by the National Academies of Sciences, Engineering, and Medicine. The report underscored the importance of implementing whole person health care in all settings and for every American.
There are many opportunities ahead for this interagency collaboration. It will help to achieve an important shift, from treating problems one at a time to promoting overall military readiness, resilience, and well-being for U.S. service members and veterans.
Congress appropriated $5 million to NCCIH in fiscal year 2023 to enhance pain research with a special emphasis on military populations. These additional resources will allow NCCIH to support more complex studies in understanding how multiple therapeutic approaches that impact multiple body systems can impact chronic pain.
Meanwhile, programs like the DOD’s Consortium for Health and Military Performance (CHAMP) will continue to translate these lessons learned into accessible pain management information that service members can use in promoting and maintaining their health.
While the PMC’s research program specifically targets the military community, this growing body of knowledge will benefit us all. Understanding how to better manage chronic pain and offering more treatment options for those who want to avoid the risks of opioids will help us all build resilience and restore health of the whole person.
 Chronic pain and opioid use in US soldiers after combat deployment. Toblin RL, Quartana PJ, Riviere LA, Walper KC, Hoge CW. JAMA Intern. Med. 2014 Aug;174(8):1400-1401.
 Pain and opioids in the military: We must do better. Jonas WB, Schoomaker EB. JAMA Intern. Med. 2014 Aug;174(8):1402-1403
 Severe pain in veterans: The effect of age and sex, and comparisons with the general population. Nahin RL. J Pain. 2017 Mar; 18(3):247-254.
 Justice and equity in pragmatic clinical trials: Considerations for pain research within integrated health systems. Ali J, Davis AF, Burgess DJ, Rhon DI, Vining R, Young-McCaughan S, Green S, Kerns RD. Learn Health Sys. 2021 Oct 19;6(2): e10291
 The APPROACH trial: Assessing pain, patient-reported outcomes, and complementary and integrative health. Zeliadt S, Coggeshall S, Thomas E, Gelman H, Taylor S. Clin. Trials. 2020 Aug;17(4):351-359.
Pain Management Collaboratory (Yale University, New Haven, CT)
Whole Health (U.S Department of Veteran’s Affairs, Washington, D.C.)
Consortium for Health and Military Performance (Department of Defense, Bethesda, MD)
Achieving Whole Health: A New Approach for Veterans and the Nation. (National Academies of Sciences, Engineering, and Medicine, Washington, D.C.)
Note: Dr. Lawrence Tabak, who performs the duties of the NIH Director, has asked the heads of NIH’s Institutes, Centers, and Offices to contribute occasional guest posts to the blog to highlight some of the interesting science that they support and conduct. This is the 26th in the series of NIH guest posts that will run until a new permanent NIH director is in place.
Posted on by Dr. Francis Collins
Gene editing has shown great promise as a non-heritable way to treat a wide range of conditions, including many genetic diseases and more recently, even COVID-19. But could a version of the CRISPR gene-editing tool also help deliver long-lasting pain relief without the risk of addiction associated with prescription opioid drugs?
In work recently published in the journal Science Translational Medicine, researchers demonstrated in mice that a modified version of the CRISPR system can be used to “turn off” a gene in critical neurons to block the transmission of pain signals . While much more study is needed and the approach is still far from being tested in people, the findings suggest that this new CRISPR-based strategy could form the basis for a whole new way to manage chronic pain.
This novel approach to treating chronic pain occurred to Ana Moreno, the study’s first author, when she was a Ph.D. student in the NIH-supported lab of Prashant Mali, University of California, San Diego. Mali had been studying a wide range of novel gene- and cell-based therapeutics. While reading up on both, Moreno landed on a paper about a mutation in a gene that encodes a pain-enhancing protein in spinal neurons called NaV1.7.
Moreno read that kids born with a loss-of-function mutation in this gene have a rare condition known as congenital insensitivity to pain (CIP). They literally don’t sense and respond to pain. Although these children often fail to recognize serious injuries because of the absence of pain to alert them, they have no other noticeable physical effects of the condition.
For Moreno, something clicked. What if it were possible to engineer a new kind of treatment—one designed to turn this gene down or fully off and stop people from feeling chronic pain?
Moreno also had an idea about how to do it. She’d been working on repressing or “turning off” genes using a version of CRISPR known as “dead” Cas9 . In CRISPR systems designed to edit DNA, the Cas9 enzyme is often likened to a pair of scissors. Its job is to cut DNA in just the right spot with the help of an RNA guide. However, CRISPR-dead Cas9 no longer has any ability to cut DNA. It simply sticks to its gene target and blocks its expression. Another advantage is that the system won’t lead to any permanent DNA changes, since any treatment based on CRISPR-dead Cas9 might be safely reversed.
After establishing that the technique worked in cells, Moreno and colleagues moved to studies of laboratory mice. They injected viral vectors carrying the CRISPR treatment into mice with different types of chronic pain, including inflammatory and chemotherapy-induced pain.
Moreno and colleagues determined that all the mice showed evidence of durable pain relief. Remarkably, the treatment also lasted for three months or more and, importantly, without any signs of side effects. The researchers are also exploring another approach to do the same thing using a different set of editing tools called zinc finger nucleases (ZFNs).
The researchers say that one of these approaches might one day work for people with a large number of chronic pain conditions that involve transmission of the pain signal through NaV1.7. That includes diabetic polyneuropathy, sciatica, and osteoarthritis. It also could provide relief for patients undergoing chemotherapy, along with those suffering from many other conditions. Moreno and Mali have co-founded the spinoff company Navega Therapeutics, San Diego, CA, to work on the preclinical steps necessary to help move their approach closer to the clinic.
Chronic pain is a devastating public health problem. While opioids are effective for acute pain, they can do more harm than good for many chronic pain conditions, and they are responsible for a nationwide crisis of addiction and drug overdose deaths . We cannot solve any of these problems without finding new ways to treat chronic pain. As we look to the future, it’s hopeful that innovative new therapeutics such as this gene-editing system could one day help to bring much needed relief.
 Long-lasting analgesia via targeted in situ repression of NaV1.7 in mice. Moreno AM, Alemán F, Catroli GF, Hunt M, Hu M, Dailamy A, Pla A, Woller SA, Palmer N, Parekh U, McDonald D, Roberts AJ, Goodwill V, Dryden I, Hevner RF, Delay L, Gonçalves Dos Santos G, Yaksh TL, Mali P. Sci Transl Med. 2021 Mar 10;13(584):eaay9056.
 Nuclease dead Cas9 is a programmable roadblock for DNA replication. Whinn KS, Kaur G, Lewis JS, Schauer GD, Mueller SH, Jergic S, Maynard H, Gan ZY, Naganbabu M, Bruchez MP, O’Donnell ME, Dixon NE, van Oijen AM, Ghodke H. Sci Rep. 2019 Sep 16;9(1):13292.
 Drug Overdose Deaths. Centers for Disease Control and Prevention.
Congenital insensitivity to pain (National Center for Advancing Translational Sciences/NIH)
Opioids (National Institute on Drug Abuse/NIH)
Mali Lab (University of California, San Diego)
Navega Therapeutics (San Diego, CA)
NIH Support: National Human Genome Research Institute; National Cancer Institute; National Institute of General Medical Sciences; National Institute of Neurological Disorders and Stroke
Posted on by Dr. Francis Collins
For most people, pain eventually fades away as an injury heals. But for others, the pain persists beyond the initial healing and becomes chronic, hanging on for weeks, months, or even years. Now, we may have uncovered an answer to help explain why: subtle differences in a gene that controls how the body responds to stress.
In a recent study of more than 1,600 people injured in traffic accidents, researchers discovered that individuals with a certain variant in a stress-controlling gene, called FKBP5, were more likely to develop chronic pain than those with other variants . These findings may point to new non-addictive strategies for preventing or controlling chronic pain, and underscore the importance of NIH-funded research for tackling our nation’s opioid overuse crisis.
Posted on by Dr. Francis Collins
The term “silent epidemic” sometimes gets overused in medicine. But, for prescription opioid drugs, the term fits disturbingly well. In 2012, more than 259 million prescriptions were written in the United States for Vicodin, OxyContin, and other opioid painkillers. That equals one bottle of pain pills for every U.S. adult. And here’s an even more distressing statistic: in 2011, overdoses of prescription painkillers, most unintentional, claimed the lives about 17,000 Americans—46 people a day .
The issue isn’t whether opioid painkillers have a role in managing chronic pain, such as that caused by cancer or severe injuries. They do. What’s been lacking is an unbiased review of the scientific literature to examine evidence on the safety of long-term prescription opioid use and the impact of such use on patients’ pain, function, and quality of life. The NIH Office of Disease Prevention (ODP) recently convened an independent panel to conduct such a review, and what it found is eye-opening. People with chronic pain have often been lumped into a single category and treated with generalized approaches, even though very little scientific evidence exists to support this practice.
Posted on by Dr. Francis Collins
If you’re a southern grasshopper mouse, nothing beats a delicious snack of scorpion. But what, you might ask, prevents that from being a painful or even fatal event? Well, this native of the Arizona desert has evolved an amazing resistance to the stings of the bark scorpion—stings so painful and toxic they kill house mice and other rodents of similar size.
Why am I sharing this bit of natural history? Well, it turns out that by studying the grasshopper mouse and its unusual diet, NIH-funded researchers at the Indiana University School of Medicine and collaborators at the University of Texas, Austin, have identified a new target on nerve fibers that could lead to more effective and less addictive pain medications for humans.
Posted on by Dr. Francis Collins
Chronic pain is a major medical problem, affecting as many as 100 million Americans, robbing them of a full sense of well-being, disrupting their ability to work and earn a living, and causing untold suffering for the patient and family. This condition costs the country an estimated $560-635 billion annually—a staggering economic burden . Worst of all, chronic pain is often resistant to treatment. NIH launched the Grand Challenge on Chronic Pain  to investigate how acute pain (which is part of daily experience) evolves into a chronic condition and what biological factors contribute to this transition.
But you may wonder: what, exactly, is the difference between acute and chronic pain?
Persistence Pays Off: Recognizing Katalin Karikó and Drew Weissman, the 2023 Nobel Prize Winners in Physiology or Medicine
Posted on by Lawrence Tabak, D.D.S., Ph.D.
Last week, biochemist Katalin Karikó and immunologist Drew Weissman earned the Nobel Prize in Physiology or Medicine for their discoveries that enabled the development of effective messenger RNA (mRNA) vaccines against COVID-19. On behalf of the NIH community, I’d like to congratulate Karikó and Weissman and thank them for their persistence in pursuing their investigations. NIH is proud to have supported their seminal research, cited by the Nobel Assembly as key publications.1,2,3
While the lifesaving benefits of mRNA vaccines are now clearly realized, Karikó and Weissman’s breakthrough finding in 2005 was not fully appreciated at the time as to why it would be significant. However, their dogged dedication to gaining a better understanding of how RNA interacts with the immune system underscores the often-underappreciated importance of incremental research. Following where the science leads through step-by-step investigations often doesn’t appear to be flashy, but it can end up leading to major advances.
To best describe Karikó and Weissman’s discovery, I’ll first do a quick review of vaccine history. As many of you know, vaccines stimulate our immune systems to protect us from getting infected or from getting very sick from a specific pathogen. Since the late 1700s, scientists have used various approaches to design effective vaccines. Some vaccines introduce a weakened or noninfectious version of a virus to the body, while others present only a small part of the virus, like a protein. The immune system detects the weak or partial virus and develops specialized defenses against it. These defenses work to protect us if we are ever exposed to the real virus.
In the early 1990s, scientists began exploring a different approach to vaccines that involved delivering genetic material, or instructions, so the body’s own cells could make the virus proteins that stimulate an immune response.4,5 Because this approach eliminates the step of growing virus or virus protein in the laboratory—which can be difficult to do in very large quantities and can require a lot of time and money—it had potential, in theory, to be a faster and cheaper way to manufacture vaccines.
Scientists were exploring two types of vaccines as part of this new approach: DNA vaccines and messenger RNA (mRNA) vaccines. DNA vaccines deliver an encoded protein recipe that the cell first copies or transcribes before it starts making protein. For mRNA vaccines, the transcription process is done in the laboratory, and the vaccine delivers the “readable” instructions to the cell for making protein. However, mRNA was not immediately a practical vaccine approach due to several scientific hurdles, including that it caused inflammatory reactions that could be unhealthy for people.
Unfazed by the challenges, Karikó and Weissman spent years pursuing research on RNA and the immune system. They had a brilliant idea that they turned into a significant discovery in 2005 when they proved that inserting subtle chemical modifications to lab-transcribed mRNA eliminated the unwanted inflammatory response.1 In later studies, the pair showed that these chemical modifications also increased protein production.2,3 Both discoveries would be critical to advancing the use of mRNA-based vaccines and therapies.
Earlier theories that mRNA could enable rapid vaccine development turned out to be true. By March 2020, the first clinical trial of an mRNA vaccine for COVID-19 had begun enrolling volunteers, and by December 2020, health care workers were receiving their first shots. This unprecedented timeline was only possible because of Karikó and Weissman’s decades of work, combined with the tireless efforts of many academic, industry and government scientists, including several from the NIH intramural program. Now, researchers are exploring how mRNA could be used in vaccines for other infectious diseases and in cancer vaccines.
As an investigator myself, I’m fascinated by how science continues to build on itself—a process that is done out of the public eye. Luckily every year, the Nobel Prize briefly illuminates for the larger public this long arc of scientific discovery. The Nobel Assembly’s recognition of Karikó and Weissman is a tribute to all scientists who do the painstaking work of trying to understand how things work. Many of the tools we have today to better prevent and treat diseases would not have been possible without the brilliance, tenacity and grit of researchers like Karikó and Weissman.
- K Karikó, et al. Suppression of RNA Recognition by Toll-like Receptors: The impact of nucleoside modification and the evolutionary origin of RNA. Immunity DOI: 10.1016/j.immuni.2005.06.008 (2005).
- K Karikó, et al. Incorporation of pseudouridine into mRNA yields superior nonimmunogenic vector with increased translational capacity and biological stability. Molecular Therapy DOI: 10.1038/mt.2008.200 (2008).
- BR Anderson, et al. Incorporation of pseudouridine into mRNA enhances translation by diminishing PKR activation. Nucleic Acids Research DOI: 10.1093/nar/gkq347 (2010).
- DC Tang, et al. Genetic immunization is a simple method for eliciting an immune response. Nature DOI: 10.1038/356152a0 (1992).
- F Martinon, et al. Induction of virus-specific cytotoxic T lymphocytes in vivo by liposome-entrapped mRNA. European Journal of Immunology DOI: 10.1002/eji.1830230749 (1993).
Katalin Karikó: National Heart, Lung, and Blood Institute; National Institute of Neurological Disorders and Stroke
Drew Weissman: National Institute of Allergy and Infectious Diseases; National Institute of Dental and Craniofacial Research; National Heart, Lung, and Blood Institute
Posted on by Lawrence Tabak, D.D.S., Ph.D.
For many people, they are tiny pests. These fruit flies that sometimes hover over a bowl of peaches or a bunch of bananas. But for a dedicated community of researchers, fruit flies are an excellent model organism and source of information into how neurons self-organize during the insect’s early development and form a complex, fully functioning nervous system.
That’s the scientific story on display in this beautiful image of a larval fruit fly’s developing nervous system. Its subtext is: fundamental discoveries in the fruit fly, known in textbooks as Drosophila melanogaster, provide basic clues into the development and repair of the human nervous system. That’s because humans and fruit flies, though very distantly related through the millennia, still share many genes involved in their growth and development. In fact, 60 percent of the Drosophila genome is identical to ours.
Once hatched, as shown in this image, a larval fly uses neurons (magenta) to sense its environment. These include neurons that sense the way its body presses against the surrounding terrain, as needed to coordinate the movements of its segmented body parts and crawl in all directions.
This same set of neurons will generate painful sensations, such as the attack of a parasitic wasp. Paintbrush-like neurons in the fly’s developing head (magenta, left side) allow the insect to taste the sweetness of a peach or banana.
There is a second subtype of neurons, known as proprioceptors (green). These neurons will give the young fly its “sixth sense” understanding about where its body is positioned in space. The complete collection of developing neurons shown here are responsible for all the fly’s primary sensations. They also send these messages on to the insect’s central nervous system, which contains thousands of other neurons that are hidden from view.
Emily Heckman, now a postdoctoral researcher at the Michigan Neuroscience Institute, University of Michigan, Ann Arbor, captured this image during her graduate work in the lab of Chris Doe, University of Oregon, Eugene. For her keen eye, she received a trainee/early-career BioArt Award from the Federation of American Societies for Experimental Biology (FASEB), which each year celebrates the art of science.
The image is one of many from a much larger effort in the Doe lab that explores the way neurons that will partner find each other and link up to drive development. Heckman and Doe also wanted to know how neurons in the developing brain interconnect into integrated neural networks, or circuits, and respond when something goes wrong. To find out, they disrupted sensory neurons or forced them to take alternate paths and watched to see what would happen.
As published in the journal eLife , the system has an innate plasticity. Their findings show that developing sensory neurons instruct one another on how to meet up just right. If one suddenly takes an alternate route, its partner can still reach out and make the connection. Once an electrically active neural connection, or synapse, is made, the neural signals themselves slow or stop further growth. This kind of adaptation and crosstalk between neurons takes place only during a particular critical window during development.
Heckman says part of what she enjoys about the image is how it highlights that many sensory neurons develop simultaneously and in a coordinated process. What’s also great about visualizing these events in the fly embryo is that she and other researchers can track many individual neurons from the time they’re budding stem cells to when they become a fully functional and interconnected neural circuit.
So, the next time you see fruit flies hovering in the kitchen, just remember there’s more to their swarm than you think. Our lessons learned studying them will help point researchers toward new ways in people to restore or rebuild neural connections after devastating disruptions from injury or disease.
Presynaptic contact and activity opposingly regulate postsynaptic dendrite outgrowth. Heckman EL, Doe CQ. Elife. 2022 Nov 30;11:e82093.
Research Organisms (National Institute of General Medical Sciences/NIH)
Doe Lab (University of Oregon, Eugene)
Emily Heckman (University of Michigan, Ann Arbor)
BioArt Awards (Federation of American Societies for Experimental Biology, Rockville, MD)
NIH Support: Eunice Kennedy Shriver National Institute of Child Health and Human Development