Funded Projects

Complex regional pain syndrome is a difficult-to-treat chronic condition that causes excess and prolonged pain and inflammation after injury to an arm or leg and includes damage to skin of affected limbs. Although it is known that aberrant immune system function plays a role in this condition, the details remain unclear about how this occurs – in particular, through the adaptive immune system that relies on specialized immune cells and antibodies to protect the body from harm.  This project will study the role of certain immune cells (T cells) that circulate throughout the body or reside in bone using both rat or human bone samples from patients with complex regional pain syndrome.

Endometriosis is an often-painful disorder in which uterine tissue grows outside the uterus. Treatment of endometriosis-associated pain involves use of opioids in many women. This project aims to study a culprit gene thought to be involved with the disorder (capillary morphogenesis gene or CMG2) as a target for new, nonopioid pain medications. The research will also clarify how CMG2 s affects endometriosis-associated pain to test the effects of new medications for endometriosis pain.

This project will identify molecular characteristics of human sensory neurons and non-neuronal cells from the human dorsal root ganglia. This structure located outside the spinal cord is integrally involved in communicating pain signals to and from the brain. The research will use molecular approaches to characterize tissues obtained from organ donors and in patients who experience chronic pain. The findings will also help generate a connectivity map, or “connectome,” of nerve cell connections between the dorsal root ganglia of the spinal cord and the brain.

Oral cancers are painful and often require use of opioid medications to manage pain. However, the effectiveness of opioids often wanes quickly, and many patients require higher doses because they develop tolerance to these medications. This project will study the potential value of blocking epidermal growth-factor receptors interacting with peripheral nerves to treat oral cancer pain. The findings will advance understanding of the molecular mechanisms underlying oral cancer pain and provide a rationale for repurposing epidermal growth-factor receptor blockers, which is already approved for head and neck cancer treatment for treating oral cancer and associated pain.

Chronic visceral pain disorders, such as interstitial cystitis/bladder pain syndrome, are among the most difficult types of pain to treat. This project will conduct a detailed analysis of an enzyme thought to be involved with the disorder (purine nucleoside phosphorylase, or PNPase) as a target for new nonopioid pain medications to treat interstitial cystitis/bladder pain syndrome. The research will lay the groundwork for developing targeted treatments for visceral pain disorders.

This project will use state-of-the-art technologies to analyze individual cells to characterize how human pain receptors communicate pain between the human dorsal root ganglia and the brain – including how the signals vary across diverse populations. This research will generate useful, high-quality human data about pain for further analysis and re-use by other scientific teams, toward identifying and prioritizing novel therapeutic targets for pain.

About 14% of U.S. adults report experiencing migraine symptoms within any given 3-month period, making it the second most disabling illness in the world. Nonspecific pain medications used in migraine (e.g., acetaminophen, nonsteroidal inflammatory drugs, opioids) are often not effective for severe migraine symptoms or cause significant adverse effects. A research team of migraine care specialists, device and drug developers, and clinical research specialists has created a technology for accurately delivering self-administered migraine medication to the upper nasal cavity. The technology enables development of a self-administered therapy to provide rapid pain relief without harsh and addictive side effects of existing migraine medications. This project will establish efficacy and evaluate commercial design feasibility for this treatment.

Clinician bias causes inequities in healthcare, and interventions are needed to mitigate and eradicate this bias. This project aims to develop and test the impact of two interventions on overcoming clinician implicit bias in the management of pain for children from ethnic minorities treated in the emergency department. The study will include pediatric patients from under-represented minority groups with pain from long-bone fractures or acute appendicitis who are cared for by racially and ethnically diverse caregivers. Researchers will use stakeholder-informed approaches to establish quality of care metrics and then use clinician audit and feedback as well as data from electronic health records to quantify evidence of bias.      

Despite the need for non-opioid treatments for chronic pain, few alternative treatment approaches exist. Transcutaneous auricular neurostimulation (tAN) is a safe and effective treatment for pain during opioid withdrawal; however, researchers do not understand how tAN reduces pain, which limits its clinical use. A better understanding of how tAN affects neurophysiological processes to provide pain relief would likely expand tAN development and use. This interdisciplinary project will conduct research in both healthy adults and those with chronic pain to explain the neurochemical and neurophysiological mechanisms for tAN-based pain relief, and also help optimize treatments and their use.

This research project will include focus group interviews with clinicians, patients, medical interpreters, and healthcare administrators to identify barriers and facilitators to administering the GetActive+ intervention in a group visit at a clinic for older adults with chronic pain, to inform development of a therapy manual. The project will then test the GetActive+ intervention for changes in physical function immediately post-intervention and after 6 months, as well as for changes in pain, sleep, depression, and anxiety at both time points. This research will also assess feasibility, acceptability, fidelity, and adoption of the intervention with patients, providers, and healthcare staff. 

Chronic pain is a debilitating condition for which there is a pressing need for safe, effective treatments. Neurostimulation therapies that target nerve structures such as the dorsal root ganglion (DRG) and the spinal cord, have shown promising results for treating chronic pain, but researchers don’t know how they work. This project focuses on two prevailing models used to explain the therapeutic effects of neurostimulation: the gate-control model in which pain signals are blocked from reaching the brain and the T-junction filtering model in which pain signals are blocked from reaching the spinal cord. Strategies will include innovative behavioral, electrophysiological, imaging, and computational modeling techniques. The results of these studies will help explain why neurostimulation therapies work and potentially offer new treatment strategies for improved pain relief.

There are significant and persistent gaps in knowledge about effective pain management for acute and chronic sickle cell pain. This is an area of relevant interest for the NIH HEAL Initiative's Early Phase Pain Investigation Clinical Network (EPPIC-Net). In order to provide guidance for hospital-based administration of the medication ketamine, this project will conduct a cross-sectional survey study of healthcare professionals within EPPIC-Net who provide care for people with sickle cell disease. This information can be used to design a clinical protocol for a multisite, randomized clinical trial of sub-anesthetic (low) doses of ketamine for challenging vaso-occlusive episodes (“pain crises”) in people with sickle cell disease.

Recent studies have reported that neuropathic pain involves changes in the central nervous system that are linked to necroptosis (programmed necrotic cell death) and release of cellular components that create neuroinflammation. Necroptosis is a type of necrotic cell death affected by the protein receptor-interacting serine/threonine-protein kinase 1 (RIPK1 or RIP1). Preliminary studies also indicate that pain increases levels of RIPK1 in key brain regions implicated in pain processing. This project aims to further validate RIPK1 as a target for neuropathic pain using a newly developed positron emission tomography imaging approach. The work will pave the way for new brain-penetrant RIPK1 inhibitors as a safe, effective, and nonaddictive treatment approach for neuropathic pain.