University Of Minnesota

NIH Research Projects · FY 2025 · 2023-09

PROJECT SUMMARY Cocaine use disorder (CUD) is a chronic relapsing disease that leads to neuroadaptations in energy homeostasis after repeated drug exposure. There is currently no FDA-approved treatment that lowers the risk of relapse in CUD. Reported annual deaths involving cocaine have nearly quintupled in the United States from 4,939 in 2013 to 24,538 in 2021, making this a major public health concern. Despite recent scientific advances elucidating critical neuronal circuitry and biological conditions that drive cocaine-seeking behaviors, the development of interventions to disrupt the repeating cycle of addiction has proved more difficult. The operant behavioral model of drug self-administration, extinction, and cue-induced reinstatement emulates cue priming and drug craving in patients in recovery experiencing settings, cues, or memories associated with past drug use. Craving and relapse of cocaine seeking is driven by glutamatergic (Glu) neurotransmission in the NAcC, observed in both humans and animal models. Clinically, susceptibility to cocaine relapse is notably higher in female patients with reports of stronger craving to cocaine-paired cues. This significant sex difference, also reflected in animal models of CUD, represents an obstacle in treatment development that yields therapeutic benefit across sexes. Our lab has demonstrated that metformin (MET), an FDA-approved Type II Diabetes (T2D) treatment, has pre-clinical promise in reducing cue-induced cocaine reinstatement after a period of withdrawal when administered intracranially in both female and male rats. My own preliminary data shows that systemic metformin reduces the conditioned rewarding effects of cocaine in male rats. In T2D, MET improves glucose management in part through activation of adenosine monophosphate activated protein kinase (AMPK), which when phosphorylated, restores the intracellular ratio of AMP to ATP in response to environmental stressors. AMPK is decreased in the nucleus accumbens core (NAcC) after chronic exposure to cocaine, with MET-induced increases in AMPK activity thus providing a promising putative mechanism of action. Still, it remains unknown how oral MET is biodistributed to the NAcC and how it may impact critical Glu circuitry underlying cocaine relapse events. This study will explore the therapeutic potential of MET by defining central pharmacodynamics and pharmacokinetics of oral MET in the NAcC. This proposal tests the hypotheses that oral administration of MET will: 1) have a more robust effect in reducing cue-induced cocaine-seeking behavior after self-administration in male rats as compared to female rats, 2) reduce cue-induced reinstatement via activation of AMPK, and 3) augment Glu neurotransmission in the NAcC reducing the signal to noise of cue-associated glutamate transmission as measured by in vivo fiber photometry. The goal of the proposed work is to provide significant evidence that supports the potential repurposing of MET as a treatment for CUD.

NIH Research Projects · FY 2024 · 2023-09

PROJECT SUMMARY/ABSTRACT Advancement of health equity requires evidence and tools tailored for minority groups. The shift towards individualized precision medicine requires risk prediction tools to guide prevention and intervention. Due to the genetic heterogeneity and social economic disparity, risk factors may disproportionately impact race/ethnicity (R/E) groups. Overall risk prediction constructed from predominantly white populations can perform poorly on other ethnic groups, leading to mis-diagnosis, over-treatment and other adverse health consequences. Efforts on developing R/E-specific risk prediction at local healthcare systems are limited by the small sample size caused by inadequate representability of minority populations. To address the gap and to advance precision medicine for non-white patients, it is crucial to harness minority enriched clinical data and develop risk models transferable to point of care. The All of Us (AoU) program offers a wealth of comprehensive multi-modal data on whole genome sequencing (WGS), real-world electronic health records (EHR) and patient reported outcomes (PRO) with enhanced minority participation, providing the common evidence base for learning general R/E-specific risk patterns and training risk models for minority populations at local healthcare systems. In this proposal, we develop innovative methods for risk modeling in AoU data tailored for minority populations and its validation on external healthcare data. We will showcase the proposed methods in two use cases: 1) rheumatoid arthritis (RA) genome-wide association study (GWAS) at Mass General Brigham (MGB) focusing on the genetic risk factors; 2) cancer cardiotoxicity prediction study at M Health Fairview (MHF) focusing on clinical and social determinants of health (SDoH) risk factors. In Aim 1, we integrate risk factor and disease onset outcome data across WGS, EHR and PRO in AoU data to construct the risk prediction model that yields better risk prediction accuracy, risk factor identification and fairness across R/E groups. In Aim 2, we design privacy preserving algorithms to validate the generalizability risk modeling from AoU data on external healthcare data and establish the transfer learning strategy to adapt AoU risk models for local healthcare systems. We intend for the methods to facilitate development of risk modeling using AoU data with focus on minority populations, as well as toe demonstrate the potential impact of the AoU program on improving care at local healthcare.

NIH Research Projects · FY 2025 · 2023-09

PROJECT SUMMARY This career development award will establish the candidate, Dr. Katherine Arlinghaus, as an independent investigator with expertise in the development, implementation, and evaluation of community-based, interventions that are strategically designed to address the interconnection between physical and mental health to optimize the reduction of risk for cardiovascular disease development among underserved youth. Cardiovascular disease is the leading cause of death worldwide. Most pediatric prevention programs focus on key modifiable physical health behaviors like physical activity, diet, and more recently sleep. While important components for prevention, the physical health focus can overlook the importance of mental health and wellbeing as a preventative factor for cardiovascular disease development. The omittance of intervention explicitly aimed at preventing depression has been highlighted by the recent substantial increases in rates of youth depression symptoms. To reduce the number of youth at high risk for developing CVD, we need to create accessible and appealing prevention interventions that synergistically address youth mental and physical health needs and have realistic pathways to large-scale dissemination. To address this critical need, Dr. Arlinghaus designed an afterschool program that uses a mentorship model to simultaneously address mental and physical health among youth. While well-liked, challenges regarding intervention reach encountered during the proof-of-concept study require further revision and augmentation. Dr. Arlinghaus’s K01 project will return to the design phase of intervention optimization and work with current and new school sites to augment and revise the intervention to increase its reach and impact. Preliminary testing of the intervention will be conducted at the new school sites to identify needs for further revisions and harmonize research methodologies to prepare for a future fully-powered, real-world efficacy trial. Specifically, Dr. Arlinghaus will use informative qualitative methods to collaboratively identify intervention augmentations and revision with stakeholders to improve intervention reach and impact (Aim 1), and will then conduct a two year quasi- experimental crossover pilot trial to characterize the feasibility, acceptability and preliminary impact on physical activity and depression outcomes among adolescents and young adult mentors (aim 2). These research aims will provide hands-on-experience for Dr. Arlinghaus to apply didactic training in qualitative methods skills, content area knowledge of the connection between mental health and physical activity, accelerometry skills, and community-based intervention study design and implementation. She will be supported by a multidisciplinary team of mentors with expertise in each of these areas. This proposal addresses NHLBI priorities to optimize novel cardiovascular disease prevention strategies and implementation research and identify how community-based implementation strategies can address cardiovascular disease inequities.

NIH Research Projects · FY 2025 · 2023-09

ABSTRACT Chronic pancreatitis (CP) is an often painful and disabling condition with few treatment options. For those with pain and impaired quality-of-life (QoL) who have failed medical and endoscopic therapies, complete removal of the pancreas may be considered with a procedure called total pancreatectomy with islet autotransplant (TPIAT). For many patients, TPIAT can be life-changing, with meaningful pain reduction. However, up to 20% have significant persistent pain after TPIAT. We lack objective measures to predict who will respond to TPIAT. In those who do respond, it is presumed that the pain is resolved simply because the pancreatectomy has removed the visceral source of pain, while non-responders have more complex pain syndromes involving changes in the central nervous system. Complementary work by our group in CP (without TPIAT) suggests that plasma or urinary biomarkers may distinguish pain phenotypes. The current proposal will leverage the largest TPIAT database and biorepository from a multicenter study of patients undergoing TPIAT (POST study) to develop biomarkers that predict response to TPIAT. Of note: Dr. M. Bellin, the PI of the POST study, is also PI on this application. In the NIDDK-funded POST study, over 400 enrolled participants underwent TPIAT, with detailed phenotyping for pain and QoL before and 1 year after TPIAT. In addition, biospecimens including plasma and urine were collected before TPIAT in all consenting participants (n=384) and 1 year after TPIAT in a subset (n=183) with in-person follow up. Based on preliminary data from our and other labs, we hypothesize that a set of objective biomarkers from blood and/or urine can distinguish those who benefit from TPIAT (pain reduction/relief) from those who respond poorly. This clinical question is particularly important because TPIAT is a major, costly intervention with irreversible lifelong health implications. In SA 1, we will identify plasma biomarkers collected before TPIAT that predict persistent pain after TPIAT using samples and data from POST. Samples will be divided into FDA-compliant discovery and validation groups. Pain response to TPIAT will be defined by opioid use and pain scores at 1 year. Secondary measures for QoL and pain interference with daily function will also be assessed. In SA 2, we will use the same approach to identify pre-TPIAT urine biomarkers that predict persistent pain after TPIAT. In SA 3, we will assess change in biomarkers from pre-TPIAT to 1 year using plasma and urine biomarkers validated in SA 1/2 (SA 3a) and also using a discovery and validation approach to identify additional plasma and urine biomarkers that may have distinct patterns over time in patients with vs. without persistent pain (SA 3b). Identifying plasma and urinary biomarkers will improve TPIAT patient selection, reducing negative impact on patients and health care infrastructure. Data from this study will identify biomarkers that can also be investigated in the larger populations with CP and other pain syndromes.

NIH Research Projects · FY 2025 · 2023-09

Project Summary Recent technological advances have enabled the production of vast amounts of diverse multi-omics data types (e.g., genomics, epigenomics, proteomics, transcriptomics) of complex diseases such as cancer, cardiovascular diseases and neurodegenerative disorders. The integration of multi-omics data from those heterogeneous diseases can help in unraveling the underlying biological mechanisms at multiple omics data levels, in improving prediction of clinical outcomes, and to transform medicine, but at the same time presents significant challenges to identify important biomarkers from a large size of heterogeneous molecular data points (i.e. hundreds of thousands). We will develop and apply novel and powerful Bayesian statistical learning methods that will capture linear and nonlinear relationships of multi-omics data. The methods will be used to identify i) important predictive pathways and their corresponding important molecules; ii) clinically meaningful molecular disease subtypes, and iii) predictive and prognostic biomarkers that contribute to the joint association (or regulatory networks) between omics data types. The proposed method will be applied to multiple publicly available datasets such as The Cancer Genome Atlas, dbGAP, and Genotype-Tissue Expression, and to non public data sets obtained from our collaborators. We will develop robust, computationally efficient, and user-friendly software free of charge for the application of our methods.

NIH Research Projects · FY 2024 · 2023-09

Project Summary/Abstract The world we knew prior to the COVID-19 pandemic is unlikely ever to return. Structural and behavioral changes, such as remote working, socialization, and learning, are now part of everyday life. Telehealth has emerged as a solution for health care delivery, and social connections have been maintained through Zoom, Teams, and other software applications. These are good solutions for the general population, but people with hand spasticity may not be able to use electronic devices without assistance. Spasticity, a sequela of some neurological conditions, causes tight muscles, interferes with functional movements, affects activities of daily living (ADLs), and increases caregiver burden. Moderate to high levels of spasticity cause loss of independence and even institutionalization. The goal of spasticity care is to achieve optimal independence in all aspects of life, with the assistance of others and aid of technology only as needed; however, the degree to which individuals with moderate to high levels of hand spasticity can access and draw upon technology to maintain their independence is unknown. Therefore, this application responds to the notice of special interest to investigate the impact of COVID-19 on people with hand spasticity and identify current rehabilitation needs to inform future interventions. The long-term goal of this research is to support optimal independence for people with spasticity and good quality of life. The rationale for this exploratory sequential mixed-method study, which is guided by the socio-ecological model, is to determine the impact of telehealth access on the receipt of health care and the ability of adults with hand spasticity to maintain independence. Specific aims are to: Aim 1. Identify access to health care and telehealth for adults with moderate to high levels of hand spasticity in the community. Aim 2: Identify computer literacy and barriers and facilitators to accessing telehealth for adults living with moderate to high levels of hand spasticity in the community. Aim 3: Identify the extent to which telehealth access and computer literacy affect independence for adults living with moderate to high level of spasticity in the community. Approach. Thirty adults with moderate to high levels of hand spasticity living in the community will be recruited. NIH and PROMIS tools will assess Coronavirus Impact, access to technology, upper dexterity, physical functioning, ADLs and Instrumental ADLs, psychological impact, loneliness, and social and emotional health. Using the Coronavirus Impact and access to technology tools, we will first quantify the effect of the pandemic on health care, telehealth, and independence. Then we will conduct 45- to 60-minute semi- structured interviews that will offer greater insight into telehealth literacy, its barriers and facilitators, and its impact on maintaining independence. This study is significant because it pinpoints unaddressed Covid-related experiences and concerns affecting the ability of this population to maintain independence.

NIH Research Projects · FY 2024 · 2023-09

Modified Project Summary/Abstract Section Weather extremes and natural disasters associated are wreaking havoc on human health worldwide, and these events will become more frequent and more intense in coming years. Other disruptive shocks – such as exposure to armed conflict and disease outbreaks – also have significant impacts on health globally. Shock-induced mobility patterns likely play a role in linking shocks to adverse health outcomes. Despite the importance of understanding these relationships, little research has been conducted to date due to a dearth of detailed temporal and spatial data on mobility patterns, particularly in settings with limited resources. Novel location data derived from mobile phone use promises to elucidate granular human mobility patterns. Leveraging established partnerships to obtain the data and machine learning methods to process it, the proposed research will provide critical information on the health of shock-affected populations in Kenya, an east African country with increasing environmental volatility and a history of armed conflict. Further, this project will demonstrate the utility of applying these data to address critical population health problems. The proposed Pathway to Independence Award will provide essential and synergistic training to position Dr. Luetke as a leading expert in using big data and artificial intelligence methods to elucidate the social and health implications of shocks and human mobility responses in the context of increasing environmental variability and global insecurity. The mentored phase of the proposed project will provide training in (1) geospatial methods and population-environment research, (2) machine learning for spatial big data, (3) demographic theories and methods related to human migration, and (4) career development activities to prepare to be an independent investigator and future tenure-track faculty member. The empirical research of the proposed project will address three primary aims: (Aim 1) Use artificial intelligence methods to process the mobile phone data to identify mobility patterns over time (2018-2022) and space; (Aim 2) Test the role of environmental variability, natural disasters, and armed conflict as mechanisms to explain changes in these mobility patterns; and (Aim 3) Quantify the effect of weather extremes, natural disasters, and armed conflict on women’s exposure to intimate partner violence and explore mobility patterns, particularly when crisis-induced, as a mediator of these associations. The training and research detailed in this proposal will form a solid foundation to launch a rigorous and sustainable research agenda and provide the pilot work for a future R01 proposal. The additional training and mentorship will be an important step toward establishing a rich, independent research career aimed at reducing social and health disparities. A strong interdisciplinary mentorship team and an outstanding supportive training environment at the Minnesota Population Center provide a foundation for Dr. Luetke to fill an important scientific niche on understanding the impacts of external shocks, migration, and health outcomes for women in Sub-Saharan Africa.

NIH Research Projects · FY 2025 · 2023-09

Clinical and translational science (CTS) is at the crossroads of major technology advances requiring strong academia–community partnerships anchored in trust for the effective and rapid deployment of best practices. The UMN CTSA Hub will build on proven commitments to accelerate impactful CTS. Aim 1 will provide novel infrastructure to reduce research barriers and accelerate translation to practice via a new Office of Clinical Research and Community Affairs. This office will augment CTSI’s capacity to respond to and facilitate robust and sustainable community relationships that extend beyond single investigator projects. Aim 2 will deliver highquality and efficient research services and resources through the Clinical Research Support Center (85 staff) that will lessen trial barriers and support all aspects of study design, biostatistics, bioinformatics, regulatory compliance, contracting, and more. Expanding representation in clinical studies will strengthen connections to the state’s broad population. A learning health system (LHS) and continuous quality improvement program will expedite the implementation of novel enhancements. Aim 3 will cultivate and train a capable and well-prepared CTS workforce with new tools and programs; develop and test novel trial processes and participant satisfaction; and disseminate and implement learnings locally and nationally. Tailored enhancements will personalize CTS training for community, academic, and workforce professionals, including improved informed consent processes, an investigator primer, a research career development series, and more. CTSI’s Rural Health Program offers a postdoctoral fellowship in health policy and leadership and a year-long training program for community leaders. Training with community health workers (CHWs) will strengthen engagement with Minnesota’s communities. Aim 4 will foster leadership, team science, and data sharing to support collaborations through leadership programs, professional coaching, vertically integrated retreats, team function seminars, Innovative Team Science programs adapted for early career faculty, and incentives to gain CTSI leadership skills. Health Informatics will support advanced data management and analytic infrastructures integrated with electronic health record and LHS systems. Aim 5 will address barriers to health access by deploying evidence-based and improved research practices to train CHWs and Hub Partners for broad community input and decision-making. We will build a national, population-level geo-database of quantifiable measures using novel Multidimensional Measures of health and the environment in a Healthy Communities Data Portal. This portal will link health and clinical data to define national impacts on access to care, study enrollment, data collection, and more with validation projects on telehealth and education and early childhood cognitive function after prenatal methamphetamine exposure. Impact. With a robust infrastructure, the next generation of research leaders, and a well-trained workforce, our Hub and regional community will co-develop and implement CTS advancements to improve health.

NIH Research Projects · FY 2025 · 2023-09

PROJECT SUMMARY/ABSTRACT In collaboration with the Masonic Cancer Center of the University of Minnesota, Britt Erickson, MD, has developed a research strategy that will leverage her skills in clinical trial design and execution, as well as her experience as a mentor and educator, to improve access to NCI clinical trials within the Masonic Cancer Center and throughout greater Minnesota. She will open and enroll to more NCI prevention and therapeutic trials in gynecologic oncology. She will collaborate with other disease site leaders and cooperative group principal investigators in order to prioritize trials with the highest chances for success at the University of Minnesota. She will be the community clinical trial liaison for the Masonic Cancer Center, opening gynecologic oncology specific NCI trials at community sites and mentoring community oncologists in the process of clinical trial leadership and accrual. This community extension will be done through the M Health Fairview Cancer Service Line, a novel clinical entity established in 2019 as a result of combining efforts between the University of Minnesota and Fairview, a non- profit healthcare delivery service. The M Health Fairview Cancer Service Line includes seven community sites throughout the Minneapolis/St Paul metropolitan area and presents an opportunity to break down traditional barriers between academic and community medicine, uniting with a common vision of increasing access to therapeutic clinical trials. The Cancer Service Line has also extended to two underserved sites in rural central Minnesota with a substantial Native American population and historically limited clinical trial access. At these locations—working with community oncologists, existing NCORP infrastructure, and pre-existing collaborations through the Minnesota Cancer Clinical Trials Network (a state funded network since 2017, housed at the University of Minnesota)—Dr. Erickson will be integral to the mission of expanding NCI clinical trial access to all Minnesotans. Dr. Erickson’s experience and current involvement locally and nationally in NCI clinical trial work make her an ideal candidate for the proposed plan. In addition to expanding trial availability, she will continue her local and national service. This includes serving as a member of the Cancer Protocol Review Committee and as co-chair of the Gynecologic Oncology Interdisciplinary Site Committee within the Masonic Cancer Center. It also involves serving as a core member of the Uterine Corpus Committee and Cancer Prevention and Control Committee of NRG oncology. She will also continue her work as the national PI of the phase II DCP trial of exemestane in endometrial cancer (UWI-2016-08-01) and national PI of a new cooperative group study, NRG- GY026, which is exploring the role of HER2 directed therapy in HER2 positive endometrial cancer, set to open in June of 2022 with planned accrual of 525 patients.

NIH Research Projects · FY 2025 · 2023-09

Because children with intellectual and developmental disabilities (IDD) are frequently unable to report their pain verbally, parents often serve as proxy reporters in interpreting and describing their child's pain. Although there is substantial evidence that interactions among biological, psychological, and social factors at the level of both the child and the parent influence children's behavioral pain expression and parents' interpretation of pain behavior in the general population, there has been almost no work investigating the influence of dyadic parent-child relationships on pain assessment among children with IDD. The long-term goal of this project is to improve the understanding of dynamic and reciprocal processes influencing how parents rate and respond to pain in children who have difficulty expressing themselves verbally due to IDD and who may exhibit idiosyncratic pain signs. To achieve this end, the short-term goal of this project is to identify the specific parent and child factors associated with pain expression among children with IDD and differences in parental pain intensity ratings. The project will achieve this objective by recruiting a large sample of parent-child dyads in which the children are between the ages of 1.5 and 5 years and have been diagnosed with global developmental delay (GDD). Dyads will be video recorded during a clinically-indicated blood draw to evaluate pain expression, parents' pain intensity ratings, and parental behaviors during the pain event. Information on parents' overall judgments of their children's pain sensitivity will also be collected. We will collect information on the children's adaptive behavior, communication abilities, and gross motor function, as well as several standardized rating scales to categorize parents' general negative affect and pain-related beliefs and cognitions. Completion of the proposed project will lead to improved understanding of how parent-child factors interact to influence parents' judgments of pain among children who cannot self-report.

NIH Research Projects · FY 2025 · 2023-09

PROJECT SUMMARY Recent developments in Magnetic Resonance Imaging (MRI), biophysical modeling, and computing have improved the sensitivity of imaging metrics to detect disease-related changes in the central nervous system in neurological disorders. This improved sensitivity has paved the way for utilizing these metrics as potential biomarkers of disease, in particular, to measure disease progression over short durations. We hypothesize that the multimodal analysis of MRI biomarkers (microstructure and morphology) from the brain and spine will improve sensitivity to detect disease-related changes over durations as short as 3 to 6 months. Our hypothesis is based on our prior work detecting longitudinal changes in brain microstructure over 6 months in an ALS cohort with modest change in functional measures over that time, and that a multimodal analysis combining brain and spine MRI measures can improve disease diagnosis accuracy. In this project, we will establish the scalability, sensitivity over shorter durations, and overall clinical trial readiness of these metrics through a two-site study. We also propose to improve the sensitivity of imaging metrics by combining multiple complementary measures from the brain and spine in a longitudinal multimodal statistical framework. Additionally, we will demonstrate how these imaging metrics correlate with fluid biomarkers and functional progression measures. We will acquire structural (T1 and T2) and diffusion MRI data from 40 participants with ALS and 10 control participants at two sites: the University of Minnesota (host institution) and the University of Florida. We will scan the brain and cervical spine of participants at baseline and 3 follow-up visits (3, 6 and 12 months). We will complete a neurological examination, ALSFRS-R, and UMN score at enrollment and obtain longitudinal ALSFRS-R and plasma neurofilament light (NfL) measurements. We will extract microstructural and morphological information from MRI data using dedicated computational methods and modeling. We will also apply novel statistical tools to combine those complementary imaging metrics into a multimodal analysis. Finally, we will analyze correlations between NfL, change in ALSFRS-R, and multimodal MRI metrics. Upon completion of our project, we anticipate that the enhanced sensitivity of our proposed longitudinal MRI biomarkers will have an impact on ALS treatment by providing novel surrogate markers as potential outcome measures for clinical trials. The expected increased effect size will also reduce the cohort size needed to conduct trials, thereby increasing their feasibility. Beyond the scope of clinical trials, our multimodal MRI biomarkers will serve as an objective measure of upper motor neuron degeneration at the single patient level. Our MRI measures will also be cross validated with fluid biomarkers and will contribute to efforts to stratify ALS patients into clinically homogeneous cohorts. 1

NIH Research Projects · FY 2025 · 2023-09

ABSTRACT Neonatal respiratory distress syndrome (NRDS) and acute respiratory distress syndrome (ARDS) afflict upwards of 250,000 Americans every year. NRDS affects premature infants due to their underdeveloped lung’s inability to produce sufficient functional lung surfactant. Animal replacement surfactant treatment options exist for NRDS, although concerns over bio-variability, interspecies disease transmittance, and religious questions over porcine versus bovine derived surfactants remain. ARDS was seen in ~75% of all admitted COVID-19 ICU patients and is currently untreatable leading to a mortality rate of ~40%. ARDS is initiated by lung trauma or disease that leads to inflammation, causing an uncharacteristic increase of the surface tension within the lungs, leading to atelectasis. A deeper understanding of the fundamental structure and limiting behavior of lung surfactant monolayers may be the avenue to suggest new synthetic replacement surfactant treatments that could mitigate the biological concerns in NRDS as well as develop treatment options for patients with ARDS. My group has previously identified that the “collapse” of a monolayer determines the lower surface tension limit during the alveolar area compression accompanying exhalation. The physical and chemical factors that govern collapse may be altered in patients who develop dysfunctional, high surface tension lung surfactant during ARDS. Monolayers of healthy lung surfactant phase separate into domains of a semi-crystalline ordered phase and a disordered liquid phase of varied composition. We hypothesize that this phase separation dictates many of the dynamic and rheological properties of the monolayer that influence collapse. However, there is little direct information on the composition of the different domains in multicomponent lung surfactants. I will address monolayer collapse and phase separation in the following two aims. In Aim 1, I will visualize monolayer collapse structures using the 3-D serial sectioning capabilities of the confocal fluorescence microscope to determine how monolayer domains alter collapse behavior and the minimum surface tension. I have also recently found that collapse behavior changes on curved, alveolar-size interfaces compared to the flat surfaces in a Langmuir trough, and I will use confocal imaging to determine the relationship between collapse morphology and interfacial curvature. Aim 2 is to pioneer infrared-coupled atomic force microscopy (AFM-IR) methods to map the lateral distribution of the chemical species and their local ordering in multicomponent lung surfactant monolayers. I will use AFM-IR to examine the hypothesis that cholesterol concentrates at domain boundaries to lower the line tension while palmitic acid and hexadecanol promote crystallization of dipalmitoylphosphatidylcholine, increasing the fraction of solid phase in the monolayer. Successful completion of this project will provide a detailed description of the two-dimensional chemical distribution in laterally phase separated lung surfactant monolayers and how this phase separation influences the minimum surface tension at monolayer collapse.

NIH Research Projects · FY 2025 · 2023-09

PROJECT SUMMARY To understand complex neural pathways and networks and their remarkable ability to generate human behaviors, it is critical to precisely map brain connectomics in vivo. We propose to make significant advances in such brain mapping by founding the Center for Mesoscale Connectomics (CMC). We will first map the mesoscale connections between the frontal and parietal cortices. These connections likely subserve higher-order functions such as attention, decision-making, prospection, and executive control. One key, underappreciated feature of cortical connectivity is its specific variations within a given brain region, further supporting the critical need for descriptions of connectivity at a finer scale. Unfortunately, there has traditionally been a major gap in our pursuit of creating a human brain “wiring diagram” at high spatial resolution, especially since the gold standard for mesoscale brain connectivity, anatomical tract-tracing, cannot be performed in humans. Moreover, techniques that can be applied to humans, such as diffusion MRI tractography, may not recapitulate anatomical connectivity at this scale. Due to this gap, we are lacking an accurate wiring diagram of the human brain that can only be obtained through a multi-modal, cross-species, multi-scale approach. Here, we propose to combine advanced anatomical tract-tracing (Aim 1), polarization-sensitive optical coherence tomography (PS-OCT) (Aim 2), and ultra-high field diffusion tractography (Aim 3) to create such accurate wiring diagrams of human and macaque brains while bridging spatial resolutions and species. Importantly, we will computationally bridge species, methods, and spatial scales via state-of-the art registration and joint (multimodal) modeling of fiber orientations. Subsequently, the remarkable amount of information available in each dataset will be further enhanced using optimized tractography methods. At the end of the proposed funding period, we expect to have complete maps of the mesoscale organization of fronto-parietal connections. We will be poised to apply our multimodal, cross-species methods brain-wide, including both cortical and subcortical circuits. Importantly, the foundation will be laid for computing noninvasive, in vivo, accurate, mesoscale connectivity maps of whole human brains through dMRI tractography, which will allow researchers to link brain connectivity with cognition, behavior, and disease.

NIH Research Projects · FY 2025 · 2023-09

PROJECT SUMMARY/ABSTRACT In this proposal, we will leverage our laboratory’s extensive expertise and experience in National Institutes of Health (NIH) observational studies and provide kit management, specimen management, study management, routine diagnostic testing, and specialty renal biomarker testing for the Chronic Kidney Disease in Children (CKiD) study. The University of Minnesota’s Advanced Research and Diagnostic Laboratory (ARDL) has become a trusted resource for clinical trial testing. Here we emphasize our ability to perform accurate and precise iohexol measurements using liquid chromatography tandem mass spectrometry (LC-MS/MS) to allow for gold standard measured glomerular filtration rate (mGFR) determinations in CKiD subjects. This and routine diagnostic testing is instrumental in understanding the relationships of chronic kidney disease (CKD) to neurocognitive development, behavior development, social development, and cardiovascular disease risk. CKiD investigators previously developed the CKiD under 25 (U25) equation to estimate GFR (eGFR) since adult eGFR equations do not perform well in this young demographic. Our specific aims are (Aim 1) to analyze specimens undergoing the CKiD iohexol mGFR protocol for adolescents in the 14-17 years of age via new recruitment to better validate and possibly improve upon the U25 eGFR equation accuracy. We are approaching this with the hypothesis that when incorporating a larger pediatric population with mGFR results into the U25 eGFR equation, specifically in the emerging adult population where data is sparse, the accuracy of the U25 eGFR equation will be tested, validated, and potentially improved should the U25 equation model need adjustment. Aim 2 involves acquiring mGFR results and specimens from a healthy young adult kidney donor population at M Health Fairview to evaluate the U25 equation. Our hypothesis is since the current U25 equation was primarily generated from a CKD pediatric population, by evaluating young healthy patients with this equation, the study will examine U25 equation continuity in all patients or it will assist in formulating a new model that provides a better estimate of GFR in healthy and diseased pediatric populations. Lastly, Aim 3 sets out to analyze routine and novel biomarkers to assess clinical interpretation and their relation to eGFR, cardiovascular risk, social/behavioral development, and CKD progression. Our hypothesis is that biomarkers such as creatinine and cystatin C will be input into the U25 equation and the results will allow for following CKD progression. Biomarkers T50 and FGF23 will assist investigators in evaluating cardiovascular health in subjects ≥14 years old with CKD at stages 4-5

NIH Research Projects · FY 2025 · 2023-09

ABSTRACT The immunology of pregnancy is complex and delicately balanced. While failure to tolerate fetal antigens during pregnancy can result in fetal loss, ineffective immunity to pathogens can threaten the survival of both the fetus and the mother. Fetal tissues and the maternal immune system continuously communicate to maintain this balance. This proposal focuses on two understudied mechanisms of maternal-fetal communication: extracellular vesicles (EVs) – lipid-bound particles carrying immunomodulatory proteins and miRNAs secreted by cells, and maternal microchimeric cells (MMc) – the vertical transfer of maternal immune cells to fetal organs. Specifically, we aim understand how these processes are influenced by normal microbial experience to better understand their function during normal pregnancies. Much of what we know about EVs and MMc during pregnancy has been discovered using conventional specific pathogen free (SPF) mouse models, which have limited microbial diversity and are nearly devoid of pathogens. These artificially hygienic conditions are in stark contrast to nature, where microbes are ubiquitous and diverse. Indeed, we and others have demonstrated that the immune systems of mice raised under SPF conditions are underdeveloped relative to humans and feral/pet store mice. We posit that the character and function of EVs and MMc in SPF pregnancies are impaired by the lack of diverse microbial experience, thus reducing the predictive power of SPF studies. Our lab has developed a preconception normal microbial experience (pNME) model whereby laboratory mice are cohoused with pet store mice prior to breeding to naturally expose them to the diverse microbial communities. Cohousing continues throughout gestation and early life, ensuring the offspring receive ‘mature’ maternal factors and encounter diverse microbes from the earliest natural time to replicate normal mammalian immune development more accurately. Using this model, we have found that the immune systems of pNME mice are broadly expanded and achieve immune developmental milestones earlier than SPF mice. pNME mice also demonstrate enhanced survival and immune defense relative to SPF mice. The gap in immunity between conventional SPF models and natural immune development has contributed to the slow progress toward mechanistic understanding of maternal-fetal immune communication and fetal immune development. The proposed research describes a natural model of immune development (pNME) that combines the ample resources and tools of laboratory mouse strains with physiological microbial experience to gain a deeper understanding of the mechanisms of normal maternal-fetal immune communication and their influence on fetal immune development. Further, these experiments will lay the groundwork for improved preclinical models investigating biomarkers, treatments, and preventions for immune pathologies during pregnancy and early life.

NIH Research Projects · FY 2025 · 2023-09

PROJECT SUMMARY The overall objective of this proposal is to conduct the first mechanistic clinical trial of pediatric Comprehensive Behavioral Intervention for Tics (CBIT) to identify bio-behavioral predictors and correlates of response and the most potent aspects of CBIT delivery. Chronic tics affect 1-3% of youth in the US and are a disabling neuropsychiatric symptom associated with multiple childhood-onset mental disorders. CBIT is the current first-line, gold-standard treatment for tics and focuses on skills to enhance voluntary tic suppression and reduce tic triggers. However, about 50% of youth do not benefit from CBIT. The current study aims to use multimodal measurements to identify predictors of response (for whom does CBIT work?), the therapeutic processes that activate change (what are the potent aspects of CBIT delivery?), and correlates of response (what changes occur in patients whose tics improve?). Study hypotheses, based on the literature and our preliminary data, predict that CBIT relies upon, engages, and strengthens connectivity within and between functional brain networks that support top-down control over motor functions. Youth ages 10-17 years with chronic tics (N = 100) will complete a course of 8 outpatient, weekly sessions of CBIT and pre-, post-, and 3-month follow up assessments. Multimodal assessments will include: 1) neural measures of functional connectivity among the brain's large-scale functional networks using fMRI and EEG during rest and tic expression and suppression, 2) direct-observation behavioral measurement of tics, and 3) psychosocial measures, including assessments of clinical symptoms and patient-centered outcome measures informed by preliminary data and our Patient Advisory Board. CBIT process will be assessed via a novel video-based behavioral coding of CBIT sessions. This project has the potential to directly benefit patients both immediately and in the long-term. Results will have a downstream impact on clinical practice by informing individualized treatment planning and efforts to streamline and improve CBIT quality. Results will also have an upstream impact on treatment development by identifying novel neural targets for intervention and strategies for improving CBIT outcomes via refinement or adjunctive procedures.

NIH Research Projects · FY 2024 · 2023-09

PROJECT SUMMARY The overall objective of this proposal is to conduct the first mechanistic clinical trial of pediatric Comprehensive Behavioral Intervention for Tics (CBIT) to identify bio-behavioral predictors and correlates of response and the most potent aspects of CBIT delivery. Chronic tics affect 1-3% of youth in the US and are a disabling neuropsychiatric symptom associated with multiple childhood-onset mental disorders. CBIT is the current first-line, gold-standard treatment for tics and focuses on skills to enhance voluntary tic suppression and reduce tic triggers. However, about 50% of youth do not benefit from CBIT. The current study aims to use multimodal measurements to identify predictors of response (for whom does CBIT work?), the therapeutic processes that activate change (what are the potent aspects of CBIT delivery?), and correlates of response (what changes occur in patients whose tics improve?). Study hypotheses, based on the literature and our preliminary data, predict that CBIT relies upon, engages, and strengthens connectivity within and between functional brain networks that support top-down control over motor functions. Youth ages 10-17 years with chronic tics (N = 100) will complete a course of 8 outpatient, weekly sessions of CBIT and pre-, post-, and 3-month follow up assessments. Multimodal assessments will include: 1) neural measures of functional connectivity among the brain's large-scale functional networks using fMRI and EEG during rest and tic expression and suppression, 2) direct-observation behavioral measurement of tics, and 3) psychosocial measures, including assessments of clinical symptoms and patient-centered outcome measures informed by preliminary data and our Patient Advisory Board. CBIT process will be assessed via a novel video-based behavioral coding of CBIT sessions. This project has the potential to directly benefit patients both immediately and in the long-term. Results will have a downstream impact on clinical practice by informing individualized treatment planning and efforts to streamline and improve CBIT quality. Results will also have an upstream impact on treatment development by identifying novel neural targets for intervention and strategies for improving CBIT outcomes via refinement or adjunctive procedures.

NIH Research Projects · FY 2025 · 2023-09

PROJECT SUMMARY/ABSTRACT This project proposes to develop methods for automated, real-time, single-voxel magnetic resonance spectroscopy (MRS) in brain tumors, integrate these methods with a clinical MRI system, evaluate their performance, and make them available as open-source tools to the research community. MRS can provide metabolic information noninvasively for assessment of tumor phenotype and therapeutic response. Single- voxel MRS methods provide the best quality and most reliable data, but require the scanner operator to have a high skill level and expertise to produce good quality results. The need for this expert involvement in both acquisition and analysis remains a critical barrier to the translation of MRS methods to clinical research sites without spectroscopy experts and to clinical practice. The first part of this project is to develop a method for 3D voxel placement using image guidance, integrate this method with a clinical MR system, and evaluate its performance. In the second part, we will automate our advanced MRS methods. In the third part, we will create real-time, automatic quantification tool specific to the obtained MRS data that will provide clinically interpretable results. In the final part, we will assess the performance of automated methods in prospective in vivo study. Successful completion of this project will improve data robustness and quality, eliminating the need for the expert interaction at the time of the scan and enabling adoption of MRS in multi-site clinical trials and clinical practice.

NIH Research Projects · FY 2024 · 2023-09

Arthroscopic-assisted tibial plateau fixation (AATPF) vs. Open reduction internal fixation (ORIF): A multicenter randomized controlled trial Project Summary/Abstract The current standard treatment for tibial plateau fracture fixation, open reduction internal fixation (ORIF), has significant limitations including surgical site infections, pain, stiffness, and a prolonged period of non-weight bearing restrictions. The large soft tissue dissection for ORIF is associated with an increased risk of surgical site infections, and limited visualization of joint reduction in this surgical approach is associated with an increased risk of future total knee arthroplasty secondary to post-traumatic osteoarthritis.1-6 Arthroscopic-assisted tibial plateau fixation (AATPF) provides direct visualization of the articular surface with minimal invasiveness, accelerated post-operative recovery, and preserves joint longevity.7,8 Several studies have reported good outcomes with low complication rates of AATPF for lateral tibial plateau fractures.9,10 However, there is no Level I evidence comparing outcomes of AATPF and outcomes of the traditional ORIF approach. We have designed a randomized controlled trial (RCT) comparing patient-reported, clinical, and radiographic outcomes of patients with lateral tibial plateau fractures treated with AATPF vs. ORIF to provide high level evidence-based data for clinicians. The proposed R34 pre-study planning period is essential to successfully initiate and complete the RCT.

NIH Research Projects · FY 2024 · 2023-09

PROJECT SUMMARY/ABSTRACT Older adults in rural communities experience disparities in food and nutrition security and cardiovascular disease outcomes. Enhancing access to healthy food through the emergency food system (food pantries, food banks, and other direct food aid organizations) has the potential to improve dietary intake for low-income older adults, enhance food and nutrition security, and serve as a prevention measure for cardiovascular diseases, but this resource is underutilized by older adults. Thus, aligned with the Strategic Plan for NIH Nutrition Research’s focus on promotion of healthy aging through nutrition, research is critically needed to understand how to effectively encourage older adults to use the emergency food system. In the proposed project, Dr. Brady, a mixed-methods researcher, will collaboratively work with stakeholders in the emergency food system and older adults to co-produce research on barriers and facilitators to access and develop an intervention to connect older adults to food pantries in their communities. With a diverse mentorship team and the resources available through the University of Minnesota, this Pathway to Independence Award will support Dr. Brady in filling critical gaps in his training in community engaged research, the intervention development process from conception to dissemination, and dietary assessment to begin his career as an independent investigator working with communities to co-produce solutions to food and nutrition security and diet-related chronic disease. To prepare for this role, Dr. Brady will complete a comprehensive training plan including coursework, mentorship, engagement, and research in (1) applied expertise in community-engaged research, (2) intervention development, testing, implementation, and dissemination, and (3) dietary and nutrition assessment methods. This training will prepare Dr. Brady to conduct the proposed research. During the mentored K99 phase, he will identify barriers and facilitators to emergency food access for older adults in rural communities in a mixed methods study using a community engaged approach (Aim 1). In the independent R00 phase, Dr. Brady will use human centered design approaches to co-develop intervention strategies to increase access to emergency foods with older adults and stakeholders in the emergency food system (Aim 2). Finally, he will test this intervention in a preliminary study to assess the feasibility, acceptability, and potential to improve food and nutrition security, dietary intake and cardiovascular disease outcomes (Aim 3). The findings from this proposed research will be used as the foundation for an intervention study examining the effectiveness of these strategies to improve dietary intake and cardiovascular disease outcomes through enhancing food and nutrition security and facilitate Dr. Brady’s transition to a successful, independent research career.

NIH Research Projects · FY 2025 · 2023-09

PROJECT SUMMARY This K01 award will provide training and protected research time for Alexandra Armstrong, DVM, DACVP, PhD to achieve her career goal of becoming an independently-funded investigator with specialty expertise in animal models of developmental orthopedic diseases, including the application of spatialomic profiling and quantitative magnetic resonance imaging (MRI) techniques. Legg-Calvé-Perthes disease (LCPD) is a developmental orthopaedic disease with uncertainty regarding its pathogenesis or the ideal treatment regimen. Importantly, a key aspect of the pathogenesis is ischemic injury to the growth cartilage in the proximal femur: both the epiphyseal growth cartilage, underlying the articular surface, and the growth plate cartilage, within the femoral neck. Dysfunction of these growth cartilages can contribute to collapse of the femoral head and to growth arrest and leg length discrepancies, respectively. Despite the known role of ischemic injury to cartilage in LCPD, little attention has been paid to the contribution of growth cartilage to either recovery or disease progression. To address this critical gap, Dr. Armstrong will use a well-validated piglet model of LCPD to identify differentially expressed genes within the growth cartilage associated with growth disturbances (Aim 1) and the response of the growth plate and epiphyseal cartilage to transphyseal drilling (Aim 2), a treatment that may benefit children with LCPD-induced growth disturbances. The patterns and pathways identified by spatialomics profiling will be correlated with the histological features and compared to the quantitative MRI features of the epiphyseal cartilage, with the potential to identify translational biomarkers of growth cartilage injury. Dr. Armstrong has a strong scientific foundation, including expertise in musculoskeletal pathology, but she requires additional training and dedicated time to develop her orthopaedic research program addressing questions of pathogenesis of pediatric orthopaedic diseases using animal models. During the five-year training period, she will gain knowledge in the clinical management of developmental orthopaedic disorders, develop expertise in novel spatialomics methods and analysis, develop a strong knowledge base in cutting-edge musculoskeletal MRI techniques, gain crucial experience in grantwriting, and undergo professional development in diversity, mentoring, teaching, and leadership that will benefit her as a tenure-track faculty member with a primarily research-focused appointment. This training will culminate in Dr. Armstrong achieving R01 or equivalent funding. She will be mentored by leading experts in animal models, orthopaedic surgery, musculoskeletal imaging, rheumatology, and pathology, along with didactic training in the analysis of genomic data, hands-on experiences, seminars/workshops, and conferences. Dr. Armstrong’s work will be centered on the UMN Veterinary Clinical Sciences department, where three of her four mentors are situated. Dr. Armstrong’s K01 training will fully prepare her to launch an independent research career focused on improving the health of children affected by pediatric orthopaedic diseases.

NIH Research Projects · FY 2024 · 2023-09

ABSTRACT: Immunoprofiling of Opioid Use Disorder Patients to inform structure-guided design of opioid- specific monoclonal antibodies The opioid use disorder (OUD) and opioid-related overdoses are a national emergency. Over >100,000 overdose deaths occurred in the period between April 2020 and April 2021, which are largely driven by fentanyl alone or mixed with other opioids or psychostimulants. Since the initiation of the COVID-19 pandemic, there has been an increase in non-fatal overdoses requiring hospitalization. These statistics clearly indicate that approved pharmacotherapies are not sufficient in preventing or treating OUD and opioid overdose. Antigen- specific monoclonal antibodies (mAbs) are isolated from the antigen, or by vaccine-induced polyclonal antibody response. Compared to conventional treatment methods based upon small molecule-based pharmacotherapies targeting the brain mu opioid receptor (MOR), mAbs bind and form a complex with the drug molecule in circulation. Hence, administration of mAbs impedes drugs from crossing blood-brain-barrier through sequestration of the molecules, blunting their CNS effects. Compared to MOR-ligands, mAb offer longer lasting efficacy and no interference with off-target drugs. Therefore, the proposing study focuses on: 1) functional characterization of the human opioid-specific B cell receptor (BCR) repertoire paired with isolation of opioid-specific mAb; 2) structure-guided design of humanized and human mAbs with greater efficacy and selectivity. The research approach will involve complementary strategies to identify potential mAb candidates including next-generation sequencing based-BCR sequencing, antibody display and antibody engineering, to validate the hypothesis that pairing OUD- or vaccine-induced BCR genetic variability with structure-guided antibody design will identify mAb with greater therapeutic potential. Moreover, the proposed study will inform us of how OUD and vaccination introduces antigen-specific genetic perturbations in BCRs. With knowledge of antibody structure, the result of this study will lead to generation of mAbs with improved affinity. To achieve these goals, AIM 1 delineates the evolution of human BCR repertoire in OUD patients who are immunized with a conjugated oxycodone-specific vaccine in Phase I clinical trials (NCT04458545) and unimmunized OUD patients. AIM 2 tests the relevance of the opioid-specific Fab structure to the mAb efficacy and selectivity. The results of the study will expand our understanding on the human opioid-specific antibody and B cell repertoire, supporting structural-based antibody engineering to generate mAbs with high affinity. Moreover, the results can accelerate the development of antibody-based strategy as an alternative and complementary solution treating opioid overdose.

NIH Research Projects · FY 2025 · 2023-09

Abstract The majority of Dementia with Lewy bodies (DLB) patients have a clinical syndrome of dream enactment that typically develops years before the onset of cognitive impairment. Under normal physiological conditions, rapid eye movement (REM) sleep is characterized by vivid dream mentation combined with skeletal muscle atonia. This REM paralysis is lost in REM sleep Behavior Disorder (RBD), resulting in patients who trash, punch and kick at night. RBD is a common condition affecting 80 million people worldwide and >5% of those older than 70. The presence of RBD is highly indicative of underlying neurodegeneration as nearly 75% will develop a neurodegenerative disorder in 12 years, most commonly DLB or other disorder of alpha-synuclein pathology such as Parkinson's disease (PD). Among patients with RBD approximately half have developed, or have had exacerbated, their dream enactment after starting a serotonergic antidepressant (usually a selective serotonin reuptake inhibitor-SSRI). This emergence of dream enactment after starting an SSRI, is termed serotonergic RBD (5-HT RBD) and was until recently assumed to be caused by a toxic effect on REM sleep circuitry. However, careful scrutiny of patients with 5-HT RBD reveals neurodegenerative findings suggestive of impending DLB, such as impaired color vision, mild cognitive impairment and subclinical motor deficits. These insights suggest that SSRI antidepressants do not induce RBD but instead unmask RBD in an individual who is already burdened by early alpha-synuclein pathology. However, this has not been proven, and it remains critical to understand whether 5-HT RBD is, as we suspect, an indicator of prodromal Lewy-body type pathology. This project will test the hypotheses that people with 5-HT RBD have systemic alpha-synuclein pathology, brainstem lesions in regions that control REM sleep, and prodromal DLB signs. AIM 1 will seek to detect abnormally phosphorylated alpha-synuclein aggregates on skin biopsy in a cohort of people with 5-HT RBD and matched controls (taking SSRIs but without RBD). Aim 2 will use ultra-high field MRI at 7T to examine the pontine region of the coeruleus/subcoeruleus complex for evidence of neurodegeneration as well as segment and parcellate REM sleep related neuronal structures. Aim 3 will test for prodromal deficits in speech consistent with Lewy body disease. While these Aims are independent we suspect that the severity of speech deficits will correlate with loss of neuromelanin signal on MRI and pathology on skin biopsy. These studies are important because confirming neurodegeneration in 5-HT RBD would be a breakthrough in understanding the natural history and progression of DLB pathology. Most importantly, by identifying an early prodromal syndrome and biomarkers of disease progression, this project will help speed up the development of therapies to impede or prevent the progression of Lewy body pathology.

NIH Research Projects · FY 2025 · 2023-09

PROJECT SUMMARY/ABSTRACT Cannabis is the most frequently used illicit drug in the United States. Onset of cannabis use usually occurs during adolescence, which represents a vulnerable period in neurobiological development. Due to uncertainty surrounding the long-term consequences of adolescent cannabis exposure, there is mounting concern that relaxing legal restrictions will result in increased adolescent use. Approximately 30% of users develop cannabis use disorder (CUD), and nearly half of all regular cannabis users develop cannabis withdrawal syndrome which is marked by negative affective symptoms and craving that may drive relapse. During abstinence craving may increase over time or “incubate” resulting in a period of heightened vulnerability to relapse in response to drug-related cues. Withdrawal symptoms during abstinence are clinically significant because they may impact efforts to reduce cannabis use, promote use of other substances of abuse, and adversely influence treatment outcomes. Currently there are no approved pharmacotherapies for CUD. The primary objective of this proposal is to determine how chronic cannabinoid use in adolescence impacts glutamatergic transmission and plasticity in the nucleus accumbens (NAc), and the contribution of these adaptations to later relapse-like behavior and craving. Our central hypothesis is that cannabinoid self- administration and withdrawal induces changes in glutamate transmission and synaptic connectivity in the NAc that promote negative affective processes and ultimately trigger relapse. To test this hypothesis we will use behavior, whole mount immunohistochemistry and light sheet microscopy, optogenetic aided neurophysiology, and chemogenetic manipulation techniques to assess the involvement of pathway specific glutamatergic neuroplasticity in cannabis seeking. We will use a model of adolescent intravenous D9-tetrahydrocannabinol (THC) self-administration and withdrawal to confirm the presence of an incubation of drug seeking effect at an intermediate or protracted withdrawal time point. We will assess somatic and non-somatic symptoms of spontaneous withdrawal based on alignment with DSM-5 criteria and the Research Domain Criteria framework. Unbiased mapping of whole brain c-Fos immunoreactivity will be used to identify regional neural activation associated with cannabinoid withdrawal and cue-reactivity. We will examine input-specific cannabinoid withdrawal-induced plasticity at glutamatergic synapses in identified D1 and D2 medium spiny neurons in NAc core and shell coupling in vitro slice electrophysiology with optogenetically evoked EPSCs. Finally, we will utilize chemogenetic neuromodulation to test the importance of one of these circuits for regulating relapse-like behavior and endophenotypes of withdrawal. These studies will inform our understanding of the mechanisms underlying cannabis withdrawal syndrome, an important and understudied facet of CUD, and how glutamate transmission and synaptic plasticity is altered over the course of withdrawal. This may have important implications for identifying unique therapeutic targets.

NIH Research Projects · FY 2025 · 2023-09

PROJECT SUMMARY Associating stimuli in the environment to biologically relevant outcomes, such as reward or threat, is necessary to survive and foundational to decision making. Given the prevalence of disordered decision making, there is a pressing need to understand the basic neurobiological mechanisms of associative learning underlying cue-guided motivation and behavior. The Ventral Tegmental Area (VTA) is essential to this behavioral process through its two main neuronal subtypes: dopamine (DA) and GABA. GABA neurons synapse directly onto local DA neurons and modulate DA transmission. DA neurons increase activity to cue-reward associations, modulating firing based on the extent to which reward predicted matches reward expected in a phenomenon known as reward prediction error (RPE). GABA neurons also increase activity in reward learning and their signaling contributes to RPE DA dynamics. In contrast, DA neurons are inhibited in aversive contexts while GABA neurons increase activity. Given VTA GABA’s role in both appetitive and aversive processing, these neurons may be uniquely engaged to integrate valence in decision making. Understanding the role of these neurons in multi-valent learning is important, because behavior often takes place in situations of motivational conflict, where opposing goals (i.e., consuming food and avoiding threats) occur simultaneously, requiring the appetitive and aversive elements to be weighed and integrated to guide choices. This proposal will make use of new tools to target, record, and manipulate VTA DA and GABA neurons, to investigate their functional connectivity (Aim 1) and their roles in valence integration (Aim 2). First, I will optogenetically inhibit GABA neurons while recording the activity of VTA DA neurons through in vivo fiber photometry. These experiments will test the hypothesis that the VTA GABA modulates local DA neurons and this relationship can change with experience. I will also manipulate and record DA and GABA dynamics during a motivational conflict task in which there are two opposing goals (consuming sucrose and avoiding shock) to dissect the roles these populations play in valence integration. These studies will test the hypothesis that VTA DA and GABA neurons produce value and salience signals, respectively, that are collectively necessary to integrate valence, for dynamic reward seeking.