Funded Projects

Prescription opioids provide pain relief, but overdose can be fatal because opioids also depress breathing through opioid-induced persistent apnea, when breathing stops. This research will determine whether targeted activation of a specific, opioid-insensitive brain region that triggers exhalation can increase tolerance to fentanyl-induced apnea. The research also seeks to identify the receptors responsible for this exhalation, which could be targets for new medications that prevent the negative impact of opioids on breathing. This research lays the groundwork for more preclinical and translational studies to prevent opioid-induced persistent apnea. 

Currently available treatments for opioid use disorder (OUD) are insufficient for many patients. Novel compounds that can promote alterations in brain connections (i.e., neural plasticity) possess enormous potential for improving substance use disorder (SUD) treatments. Psychedelic compounds induce neural plasticity and can elicit long-lasting, beneficial impacts on a wide variety of SUDs. However, these compounds have significant side effects, including hallucinations and cardiotoxicity. Researchers have developed a novel, synthetic derivative of the psychedelic ibogaine, called tabernanthalog, that does not have these side effects. This compound has demonstrated both short- and long-term therapeutic effects in a preclinical model of OUD. This research study will determine the molecular and neural mechanisms through which tabernanthalog affects opioid seeking. It will also evaluate whether the effects are specific to opioids and do not alter response to natural rewards and will examine the efficacy of tabernanthalog in a preclinical model of comorbid opioid and alcohol use disorder.

Chronic opioid use results in tolerance, a primary driver for opioid misuse and overdose that directly contribute to increased morbidity and mortality. Changes in neuronal connectivity known as synaptic plasticity are a key determinant of opioid tolerance, but the underlying molecular mechanisms remain unclear. Tiam1 is a protein known to control the development of nerve cells and their connections and is also involved in morphine-induced neuronal changes. This research will examine Tiam1-mediated synaptic plasticity underlying opioid tolerance and validate Tiam1 as a potential therapeutic target for prevention of tolerance development.

This project aims to develop a new way to stimulate the delta opioid receptor to treat withdrawal and abstinence from chronic opioid use. Withdrawal can cause pain, depression, and anxiety, which contribute to relapse. The research will test promising drug candidates in animal models with the intention of bringing at least one effective and safe compound to the final stage of drug development before human clinical trials can begin.

Opioids can be effective analgesics but can also be fatal due to opioid-induced respiratory depression after overdose. This project will use cutting-edge molecular, physiological, behavioral, and imaging techniques to better understand and distinguish opioid-induced respiratory depression and opioid-mediated analgesia. Nerve cell-specific, single-cell transcriptomic analysis will be used to identify functional markers expressed in nerve cells that play a specific role in opioid-induced respiratory depression, but not opioid analgesia. This research study will help to identify novel therapeutic targets that could selectively rescue opioid-induced respiratory depression while maintaining the beneficial pain-relieving effects of opioids. 

Currently no medications are approved by the U.S. Food and Drug Administration to treat cocaine use disorder, which compromises cognitive function associated with achieving goals such as working memory, the ability to update information, and mental flexibility. This project will test whether  stimulating dopamine activity in the brain with the drug rotigotine (approved to treat Parkinson’s disease) is effective for treating cocaine use disorder. Past research has also shown that rotigotine can improve nerve cell and cognitive function in Alzheimer’s disease. This project will conduct a clinical trial to test whether treatment with rotigotine combined with cognitive behavioral therapy can reduce cocaine use in people with cocaine use disorder.

Low back pain (LBP) is one of the most common reasons for all physician visits in the U.S. The financial costs associated with the care of LBP are staggering. The treatments for chronic low back pain (cLBP) are far from satisfactory, and opioids are often prescribed with varying degrees of success. This study builds on prior work suggesting that auricular transcutaneous vagus nerve stimulation (tVNS), a non-invasive therapeutic, can significantly reduce symptoms of chronic pain and common comorbidities of chronic pain, such as depression and anxiety. This proposal aims to investigate the treatment effect and underlying mechanism of tVNS on chronic low back pain. Patients with chronic low back pain will be randomized to either real or sham tVNS treatment for 1 month, with a 3-month follow-up. This study, if successful, could provide new treatment options for chronic low back pain and reduce the use of opioid analgesics in chronic pain management.

Sublingual buprenorphine is a standard treatment for opioid use disorder and is considered safe and effective. However, in 2022 the U.S. Food and Drug Administration advised that buprenorphine is linked to oral disease. However, the underlying studies did not measure when oral disease started, how it progressed, or if other risk factors were present. How sublingual buprenorphine may impact oral health also remains unclear. This project will follow adults in two U.S. states who take sublingual buprenorphine or other medications for opioid use disorder to understand if and how these medications increase the extent, onset, and progression of oral disease, accounting for other risk factors.

The United States has seen dramatic increases in fatal overdoses due to heroin, counterfeit prescription drugs, and cocaine adulterated with fentanyl or fentanyl-like analogs. Current medications may not be sufficient to address the opioid overdose epidemic. As a complementary strategy, the researchers plan to develop vaccines against fentanyl and fentanyl-like compounds to reduce their abuse liability and the growing incidence of fatal overdoses. This research team has already developed vaccines against heroin and oxycodone that stimulate the production of antibodies effective in reducing opioid distribution to the brain, opioid-induced behaviors, and opioid-induced respiratory depression and have identified a promising fentanyl vaccine candidate cued up for optimization. Successful completion of an anti-fentanyl vaccine development project could offer a long-lasting, safe, and cost-effective intervention complementary to medication-assisted treatment (MAT) and may reduce overdoses in opioid users as well as protect people in professions (e.g., law enforcement, airport security, postal workers) at risk of accidental exposure to fentanyl and fentanyl analogs.