New York University

NIH Research Projects · FY 2026 · 2023-02

Program Summary/Abstract The overall goal of this research is to understand how organisms safely break their own DNA. DNA double- strand breaks (DSBs) are highly hazardous lesions whose improper repair can cause loss of heterozygosity and copy-number variations, leading to numerous psychiatric and developmental disorders, as well as cancers. Despite these risks, most eukaryotes introduce programmed DSBs into their genomes at one or more points in their life cycle. These breaks occur in the soma and the germ line and function to create genetic diversity, remove unwanted DNA, and support adaptation to changing environments. Cells go to great lengths to keep programmed DSBs safe. They control the location and timing of DSBs, promote correct repair-template choice, and use surveillance mechanisms to coordinate DSB formation with other cellular processes, including cell-cycle progression. Defects in any of these layers of control leave organisms with a higher risk of genome instability, and thus provide key insights into the genome instability associated with cancers and the chromosomal abnormalities that lead to birth defects and infertility. To investigate safe DSB formation, the proposed work focuses on two highly conserved instances of developmentally induced DNA breakage: (1) meiotic recombination, which involves hundreds of DSBs per meiotic germ cell, and (2) programmed copy-number changes in the ribosomal DNA (rDNA), the most highly expressed gene locus in eukaryotes. The proposed work uses genetics, molecular biology, and genomics to investigate these processes. Most of the work is conducted in the yeast Saccharomyces cerevisiae, but conservation of rDNA copy-number control is also tested in human cell lines. To investigate meiotic DSBs, research over the next 5 years will build on results of a phospho-proteomics screen to dissect the surveillance network that coordinates many meiotic processes with DSB formation. Experiments will also define the role of chromosome architecture in making DSB hotspots hot, and a genome- wide approach will be developed to measure meiotic repair-template choice across the genome. To analyze copy-number dynamics in the rDNA, research will focus on the mechanisms that drive re- expansion of critically short rDNA clusters and investigate the role of a novel DNA repair intermediate in this process. In addition, the proposed work will investigate the spreading of genetic variants among repeats of an rDNA cluster over evolutionary time scales and upon selection in the laboratory. Together, these analyses will provide fundamental insights into the dynamics of developmentally induced DSBs, open avenues for understanding how these endogenous processes contribute to genomic plasticity in health and disease.

NIH Research Projects · FY 2026 · 2023-01

PROJECT SUMMARY Shortly after fertilization, a dramatic reprogramming of the genome and transcriptome occurs, enabling the embryo to develop quickly and robustly. This is especially exemplified in the Drosophila embryo, which within a two-hour period undergoes 13 mitotic cycles, cellularizes the blastoderm, patterns the body plan, and gets ready for gastrulation. While the gene networks underlying these processes have been well studied, it is not clear how they are collectively initiated, a process referred to as zygotic genome activation. Moreover, although it was observed that DNA replication occurs before transcription, the mechanisms that control this timing are not known. Previously, we demonstrated that a single factor, Zelda, acts globally to activate early-expressed genes. We found that Zelda binding to CAGGTAG sites across the genome lowers nucleosome barriers at enhancers, thereby facilitating the binding of other key transcription factors. Zelda and these other factors are present in sub-nuclear “hubs” (discrete foci) that were seen to colocalize at enhancers. We aim to use high-resolution microscopy to investigate the which structural features of Zelda mediate hub formation. In addition, we are interested in the regulatory mechanisms that control the timing of transcription and DNA replication so that conflicts between the two processes are avoided. We propose that Zelda plays a dual pioneering role: 1) to open chromatin for the Origin Recognition Complex to load and subsequent formation of the Pre-replication Complex, which occludes the transcriptional machinery until origins have fired, and 2) to open newly formed chromatin for transcription to initiate. Our goal is to first define origins of replication in early embryos, and to characterize Zelda's role in origin licensing and transcriptional initiation. Our studies will lend into how these two fundamental processes of DNA replication and transcription are coordinated during genome activation.

NIH Research Projects · FY 2026 · 2023-01

Project Summary: Bacterial cells have a repertoire of responses that can be used to survive under different types of environmental stress. Changes in carbon sources cause cells to turn on specific metabolic genes, which are later repressed when those sources are depleted. Antibiotic exposure can trigger the expression of molecular pumps that remove the antibiotic from the cell, or the production of enzymes that specifically inactivate or degrade it. In a continually fluctuating environment, the process of turning genes on and off can be inefficient and cause growth lags. Our work shows that bacteria combine their responses with phenotypic memory – the passage of stable proteins from mother to daughter cells – which allows cells to avoid growth lags in fluctuating environments. Using a combination of quantitative microbiology, microfluidics, microscopy, sequencing, and modeling, we will study the costs and benefits of gene regulation in fluctuating environments. We will measure and model the fitness landscape of phenotypic memory using a library of strains with perturbed memory levels. Competition experiments in fluctuating environments will be used to test biophysical and population dynamics models. We present an innovative modular system that enables direct comparison of different gene regulatory strategies – including responsive, bistable, and constitutive regulation – for any gene of interest. We apply the system to study different classes of antibiotic resistance mechanisms. The proposed experiments make use of a custom-built microfluidic ‘chemoflux’ system that we developed, in which bacterial populations grow in monolayers, tracked at single cell resolution under the microscope, while the growth media can be arbitrarily fluctuated in time. Using the chemoflux and our image analysis algorithms, we are able to simultaneously track hundreds of independent bacterial populations, and thereby measure population dynamics in fluctuating environments. We combine experiments with biophysical modeling to gain insights into the costs and benefits of gene regulation and memory. Models are parameterized using experimental data in a wide range of conditions, and rigorously tested by their predictions on competition experiments in fluctuating environments. The range of experiments and modeling employed address different aspects of gene regulation and memory, and allows us to bridge from detailed laboratory measurements to the general biological principles that underlie bacterial survival.

NIH Research Projects · FY 2026 · 2023-01

PROJECT SUMMARY/ABSTRACT The long-term goal of this research program is to understand the mechanistic and evolutionary causes of variation in complex traits. The primary experimental approach is to perform large-scale analyses of single-cell traits of the budding yeast, Saccharomyces cerevisiae, and follows two major lines of work. One line of work aims to understand how interaction between genes (epistasis) contributes to natural trait variation. Understanding the sources of variation in complex traits is a major goal in biomedical research because this knowledge impinges directly on the prospect of personalized medicine, for example the prediction of disease risk from an individual’s genotype. If not taken into account, epistasis can confound such predictions. Epistasis is also important because it can constrain evolutionary adaptation to follow particular paths, making adaptation more predictable. This predictability could be valuable in the treatment of diseases that have a strong evolutionary component, such as microbial infections and cancer. Although epistasis has been well studied using lab- derived mutations, as well as in some cases of viruses or microbes under strong pressures to evolve, its role in determining how traits vary in natural populations is poorly understood. Key goals of this research program are to perform experiments with dramatically increased power to detect interactions, and to expand the range of traits that are studied to include cell shape and size, which are important in many disease processes. These studies will leverage recent progress in using high-throughput, microscopy-based methods to quantify many independent cellular features, and they will create and use strains of S. cerevisiae that make searching for epistasis much more powerful. The other line of work aims to understand molecular mechanisms that allow clonal cell populations to generate heterogeneity that might be beneficial in the face of environmental uncertainty. Such heterogeneity is seen in the responses of pathogenic microbes and tumor cells to drugs, and therefore has major clinical implications, yet there is very little known about how heterogeneity is regulated and how it can be altered. Recent work has shown that clonal populations of S. cerevisiae contain fast-growing cells that are susceptible to acute stress and slow-growing cells that are tolerant of acute stress, and that these differences are mediated by variable activity of the conserved Ras/cyclic AMP/protein kinase A pathway. The role of this kinase in tuning growth rates and stress tolerances will be probed using chemical-genetic manipulation. The goal is to better understand the mechanistic basis of adaptive heterogeneity in this model system, and ultimately to advance treatment of persistent pathogens and cancers.

NIH Research Projects · FY 2026 · 2022-12

An oral health care workforce of both clinicians and researchers is critical for advancing fundamental knowledge about dental, oral, and craniofacial health and disease, and to translate the knowledge into prevention, early detection, and treatment strategies that improve overall health for all individuals and all communities across the lifespan. The long-term goal is a sustainable summer research education program, Research Education in Oral Health Sciences (REOHS), that stimulates trainees and provides mentorship support for students to pursue future training opportunities in oral health research. The overall objectives in this application are to (i) encourage the pursuit of further studies or careers in oral health research; and (ii) foster a better understanding of biomedical, behavioral and clinical research and its implications. The rationale for this proposed program is that early exposure increases interest and consideration of health science careers. The overall objectives will be pursued through three specific aims: 1) Develop, implement, and evaluate, and sustain a 9-week comprehensive summer program that provides hands-on exposure to research and supports participants’ scientific and career development; 2) Recruit, enroll and retain a cohort of 8-10 high school and undergraduate student participants, annually; and 3) Evaluate the effectiveness of the REOHS program. The proposed program will emphasize translational science principles and education of social determinants of health. Ultimately, the proposed summer research education program, REOHS, has the potential to enhance the training of an oral health workforce to meet the nation’s biomedical, behavioral and clinical research needs.

NIH Research Projects · FY 2024 · 2022-09

TITLE: Readthrough of disease-causing nonsense mutations by targeted selenocysteine recoding PROJECT SUMMARY Nonsense (stop) mutations comprise about 10% of disease-causing mutations, and are common in Duchenne muscular dystrophy, cystic fibrosis, and cancer. These mutations cause early termination of translation and lead to non-functional proteins. Therapies that enable readthrough of these premature termination codons have been sought for many years with limited success. Existing approaches are limited by lack of specificity, low efficiency, or the need to deliver small genes. The amino acid selenocysteine (Sec), sometimes known as the 21st amino acid, is incorporated into human proteins via recoding of opal (UGA) stop codons. This recoding mechanism is activated by the presence of a Sec incorporation sequence element (SECIS) in the 3’ untranslated region (3’UTR). This element was shown to be sufficient to stimulate selenocysteine incorporation and is active even when located far from the UGA codon. Here we will develop a novel approach for inducing readthrough of opal nonsense mutations through Sec recoding. This will be achieved through the use of short hybridizing oligonucleotides that bring the targeted mRNA in proximity to a SECIS element, inducing readthrough in a gene-specific manner, and restoring a functional protein. In Aim 1, we will screen oligonucleotides that hybridize to both the target mRNA and an endogenous SECIS-containing transcript. In Aim 2, we will develop a high-throughput cell sorting-based assay, allowing the identification of optimal oligonucleotides among the combinatorially large number of possible designs. We will screen multiple possible designs, including oligonucleotides containing a hybridizing part and a (possibly abbreviated) SECIS element. We will demonstrate our approach using two disease-associated genes (DMD and CFTR) and validate the identified oligonucleotides in disease cell models. The proposed approach has several important advantages over currently available therapeutic approaches to nonsense mutations. First, the oligonucleotides are specific to the targeted gene, reducing concerns of off-target effects. Second, the same oligonucleotide can potentially be used for any nonsense mutation in the same gene, reducing development cost and addressing patients with very rare mutations. Finally, safe and efficient delivery of short oligonucleotides to several tissues has already been demonstrated. Together, the specificity, broad usability, and use of proven delivery technologies, make our approach particularly attractive for therapeutic purposes. Aligned with NIBIB’s interests, this project will develop a platform technology that is applicable to a broad spectrum of disorders and diseases. If successful, the project will have a tremendous impact on the quality of life of people suffering from genetic diseases caused by nonsense mutations and from cancer.

NIH Research Projects · FY 2025 · 2022-09

Project Summary/Abstract Oral cancer patients suffer from severe pain that is treated with opioids. However, opioid tolerance develops quickly. Currently, there are no other approaches to alleviate oral cancer pain or to forestall the development of opioid tolerance. In exploring a potential role of the epidermal growth factor receptor (EGFR) in oral cancer pain and opioid tolerance, we made an exciting discovery that one of the EGFR ligands, HB-EGF, is upregulated in patients with severe pain, and that EGFR interacts with both the mu opioid receptor (MOR) and the glutamate N-Methyl-D-aspartic acid receptor (NMDAR), two proteins important for chronic pain and opioid tolerance. This led us to hypothesize that HB-EGF mediated signaling in trigeminal (TG) neurons would: a) desensitize and down-regulate MOR and b) potentiate NMDAR-dependent synaptic transmission, contributing to oral cancer pain and opioid tolerance. We will test our hypothesis in three specific aims. Aim 1 will discover whether HB-EGF and trigeminal EGFR regulate pain, opioid tolerance, and NMDAR-mediated synaptic transmission in oral cancer. We will use pharmacological and genetic approaches to determine if HB-EGF and trigeminal EGFR are essential for oral cancer pain and opioid tolerance. Behaviors related to pain and opioid tolerance will be measured using a battery of assays. NMDAR mediated synaptic transmission will be studied using electrophysiological recordings in a newly developed brainstem preparation. We will quantify NMDAR expression in the mouse TG and brainstems using western blot. Aim 2 will discover whether HB-EGF and EGFR modulate MOR signaling and endocytosis. We will use BRET-based biosensors and super resolution imaging in model cell lines and TG neurons to study the impact of HB-EGF and EGFR on MOR cAMP activity, G-protein coupling, βARR recruitment and trafficking to endosomes. We will determine the effect of EGFR gene deletion and inhibition on MOR expression by qPCR, western blot, and fluorescence imaging in mouse TG neurons. Aim 3 will validate HB-EGF and EGFR as potential targets for pain and opioid tolerance in three oral cancer patient cohorts. First, we will model EGFR ligand expression in the tumor with self-reported pain, quantitative sensory testing scores, and opioid intake and explore the cellular origin of EGFR ligands by single cell RNA sequencing in tumor tissues. In the second cohort, we will model HB-EGF and EGFR expression in tumor tissues using immunofluorescence staining as a function of self-reported pain and opioid intake using data generated in a phase II anti-cancer trial examining the effect of an EGFR inhibitor erlotinib as an adjuvant to standard chemotherapy for cancer regression. In the third cohort, we will model peripheral EGFR and ligand(s) expression from self-reported pain. EGFR inhibitors are FDA-approved therapies for cancer management. HB-EGF is an emerging cancer target and a pain mediator. Targeting HB-EGF and EGFR therefore has the potential for rapid clinical translation to reduce oral cancer pain and opioid tolerance.

NIH Research Projects · FY 2024 · 2022-09

PROJECT SUMMARY/ABSTRACT Irritable bowel syndrome (IBS) is a highly prevalent disorder characterized by visceral pain and dysmotility. IBS causes substantial morbidity in children and adults and current therapy is inadequate. Serotonin (5-HT) signaling plays roles in pain and motility, but the efficacy of modifying 5-HT signaling to treat IBS is limited and fraught with adverse effects. A greater understanding of how enteric 5-HT contributes to IBS pathophysiology may therefore provide for novel and effective treatments for the condition. Enterochromaffin (EC) cells in the gastrointestinal (GI) epithelium produce most of the 5-HT in the gut, which is thought to stimulate extrinsic primary afferent neuron (ExPAN) and intrinsic primary afferent neuron (IPAN) terminals to promote sensory and motor signaling, respectively. The serotonin reuptake transporter (SERT), present throughout epithelial cells, rapidly inactivates 5-HT. Selective serotonin reuptake inhibitors (SSRIs) inhibit SERT and thus increase 5-HT availability for IPAN and ExPAN stimulation. Despite their use for pediatric IBS, SSRIs are often ineffective and plagued by adverse GI effects, which may be due to their effects at sites other than the GI epithelium. My prior and preliminary data strongly suggest that epithelial-restricted 5-HT modulation may limit unwanted effects and thus improve therapy. My data also show a novel visceral pain mechanism involving SERT regulation of mucosal 5- HT. In the current proposal, I will investigate the effects of epithelial 5-HT on GI motility and visceral nociception using optogenetic tools that induce or inhibit EC cell secretion, mouse lines that either lack mucosal 5-HT or SERT, and pharmacological interventions that alter mucosal 5-HT signaling. The proposed research strategy will allow me to test the hypotheses that 1) 5-HT released from EC cells and 2) SERT-mediated regulation of mucosal 5-HT availability modulate visceral nociception and GI motility.

NIH Research Projects · FY 2026 · 2022-09

Prenatal alcohol exposure increases the risk for Fetal Alcohol Spectrum Disorders. To address this public health threat, we propose an exciting collaboration between researchers at NYU, the University of Texas Health Science Center-Houston, Purdue University, and CIFASD to develop, implement, and evaluate an alcohol intervention for women in prenatal care. We propose a randomized trial (N=600) to assess the efficacy of an alcohol intervention, relative to usual prenatal care, in reducing (1) women’s alcohol use, and (2) poor infant birth outcomes. We recruit women at their first prenatal care visit. Eligibility criteria include (1) age ≥18 years; (2) ≤8 weeks gestation; (3) a positive rapid point-of-care ethyl glucuronide test or self-reported alcohol use in the prior three weeks; and (4) written informed consent. Eligible women complete a baseline assessment by a Project Research Nurse consisting of a self-paced audio-computer-assisted interview and provide bloodspots to biologically assess alcohol use. Next, women are randomized to (1) the intervention condition, usual prenatal care plus the alcohol intervention, or (2) the comparison condition, usual prenatal care only. Usual prenatal care involves clinicians assessing alcohol use and counseling women on alcohol-related risks. The alcohol intervention consists of (1) a self-paced computer-delivered module to enhance knowledge, norms, and motivation for alcohol reduction, and (2) a nurse-delivered module that reinforces the computer-delivered content and addresses women’s specific questions. Both components are theory-driven, based on Motivational Enhancement Theory, and use motivational strategies to promote alcohol reduction. The intervention is developed with guidance from multiple sources, including (1) the project’s Women’s Advisory Board, consisting of women who received prenatal care at participating clinics, and (2) project investigators and consultants with extensive experience in developing and implementing interventions to reduce alcohol and other drug use among women, including pregnant women. The intervention is delivered on 3 occasions, following the baseline, 2nd- and 3rd-trimester assessments. Women in the comparison condition complete assessments on the same schedule as the intervention condition. We use generalized estimating equation models and an intent-to-treat analysis to evaluate the efficacy of the intervention condition, relative to the usual prenatal care condition, in (1) reducing the proportion of women with a laboratory-confirmed positive blood test for alcohol, and (2) reducing the proportion of adverse birth outcomes among infants.

NIH Research Projects · FY 2024 · 2022-09

PROJECT SUMMARY Even transient developmental hearing loss (HL) can cause lasting deficits to auditory perception, affecting speech and language acquisition and subsequent educational attainment for many children. Although research suggests that developmental HL can impair temporal processing (e.g., amplitude modulation processing), there is evidence that impairments to the perception of the spectral content are closely correlated with speech comprehension. Furthermore, there is evidence that these deficits are due, in part, to a long-lasting reduction in the strength of inhibitory synapses in auditory cortex (AC). Therefore, the goals of this proposal are to assess the impact of developmental HL on a spectral modulation (SM) detection task in gerbils and to identify a causal relationship between perceptual deficits and reductions in GABAB receptor-mediated inhibition in AC. The core hypothesis of this proposal is that developmental HL will cause a reduction in the function of postsynaptic GABAB receptors, thereby impairing AC encoding of spectrally modulated stimuli and leading to SM detection deficits. Two aims test predictions emerging from this hypothesis: Aim 1A will determine the influence of developmental hearing loss on detection of SM stimuli. Gerbils will be reared with bilateral earplugs from P11- 23, a time when AC inhibition is particularly vulnerable. Twelve days after earplug removal, animals will be tested on a SM detection task. SM thresholds will be obtained across 10 days so that perceptual learning and asymptotic performance can be compared between control and HL-reared animals. Aim 1B will determine whether developmental HL impairs AC neuron encoding of SM stimuli using an awake-behaving preparation. AC will be implanted with an electrode array and recordings will be acquired during SM task performance. Neural sensitivity to a range of modulation depths will be measured between normal hearing and HL animals. Aim 2 will test the prediction that reduced functional GABAB receptors in AC contribute to impaired perception of SM after developmental HL. Using a novel AAV vector to express a gerbil-specific GABAB receptor subunit (Gabrb1b) obtained from the recently sequenced gerbil genome in AC after developmental HL. The AAV-Gabrb1b vector will be injected bilaterally into AC after earplug removal. Behavioral testing will then be performed to determine whether normal SM detection thresholds are restored. Together, these aims will advance our understanding of the neural mechanisms underlying perceptual deficits attending developmental HL and identify a path towards developing the first pharmaceutical treatments for its lasting consequences.

NIH Research Projects · FY 2025 · 2022-09

PROJECT SUMMARY Because most high-level cognition depends on working memory (WM) and its dysfunction causes a host of cognitive impairments, researchers have spent decades trying to understand the neural mechanisms that support WM. Recently, using sophisticated computational neuroimaging approaches researchers have repeatedly decoded the contents of WM from patterns of neural activity in a widely distributed number of brain areas. The format of the WM representation in early visual cortex, for instance, might have the same “sensory- like” properties as the visual stimulus. Although sensory-like representations are less likely in higher-order brain areas, the nature of these alternative representations has yet remained impenetrable. This gap in our knowledge is a critical problem because a host of psychiatric and neurologic disorders stems from a primary WM dysfunction. Our long-term goal is to understand the mechanisms by which neural populations across the brain encode WM representations, and how we might develop strategies to mitigate WM problems that impact the quality of cognition. Our overall hypothesis is that what one sees and what one stores in WM can be distinct and that distinction differs across the cortical hierarchy. The central aim of the project is to develop incisive data analytic approaches that will reveal the nature of what is actually being encoded in the neural population dynamics underlying WM storage. The rationale for the proposed research is that as we better understand the neural mechanisms of WM, a strong theoretical framework will emerge within which strategies for understanding and treating cognitive dysfunction will emerge. We test our central hypothesis by pursuing two specific aims. 1) We will model the neural population dynamics that code for distinct formats of WM representations. 2) We will identify when and where neural populations encode WM representations that are abstractions of sensory features. Strong preliminary data demonstrate the feasibility of proposed work as well as initial support for the hypotheses. Under Aim 1, using novel dimensionality reduction techniques suggest that neural populations code for both a representation of the memorized stimulus and a representation of the specific stimulus feature that is task relevant. Under Aim 2, using novel means to model and visualize WM representations revealed that neural populations that are traditionally thought to encode visual stimulus features in WM also store abstractions that can bear little resemblance to the original visual stimulus. Overall, the proposed work will generate the data needed to unmask the representational format of WM across the cortical hierarchy. The approach is innovative because it uses direct and unbiased computational approaches to model and visualize the representational format of WM in ways that have not been applied in neuroimaging. The proposed research is significant because it will provide key insights into the nature of WM representations in the human brain, in addition to providing new targets for cognitive remediation in psychiatric, neurologic, and geriatric populations.

NIH Research Projects · FY 2025 · 2022-09

One major challenge facing the field of Communication Sciences and Disorders (CSD) is its relatively small research workforce. Unlike in many other fields, where there are too many doctoral graduates to occupy a small number of faculty positions (e.g., Ortega & Kent, 2018), CSD has faced a dearth of basic and clinical researchers (CAPSCD & ASHA, 2008). The field is in need of more researchers as well as of clinicians who are well trained in consuming and conducting research, and who are therefore capable of being at the forefront of the field and its rapidly changing needs. The proposed research education program—Summer Health Academic Research Experience in Communication Sciences and Disorders (SHARE-CSD)—is a 6-week summer research experience for undergraduate students. Program participants will engage in activities in three main areas: (i) research (depth and breadth components), (ii) academic and career preparation, and (iii) extensive mentoring from peers and faculty resulting in a robust social network. Social networks play an important role in students’ academic achievement. Taken together, these activities are expected to increase program participants’ academic and skills preparedness for research and clinical careers. The program will undergo rigorous evaluation to assess its efficacy for program participants both short- and long-term.

NIH Research Projects · FY 2025 · 2022-09

G protein-coupled receptors (GPCRs) at the cell surface regulate most physiological processes and are important drug targets with ~34% of all prescribed drugs targeting them. Classically, upon agonist stimulation, GPCRs activate heterotrimeric G proteins, causing downstream signaling throughout the cell. In order to terminate G protein signaling, cells have devised a specialized desensitization mechanism that includes receptor phosphorylation by GPCR kinases and subsequent recruitment of β-arrestins (βarrs) to the phosphorylated receptors. The GPCR–βarrs interaction both blocks the G protein-binding site at the receptor core and promotes receptor endocytosis. Recently, however, we discovered that some GPCRs interact with βarrs exclusively through their phosphorylated C-terminal tails. Since βarrs do not block the G protein-binding site in this `tail' conformation, the receptor can associate with βarrs and G proteins simultaneously to form GPCR–G protein– βarr `megaplexes.' The assembly of these megaplexes allows the receptor to continue to stimulate G protein signaling while being internalized into endosomes by βarrs. Thus, the existence of the core and tail GPCR–βarr complex conformations suggests that βarrs act as spatiotemporal master regulators of G protein signaling: When bound to the receptor core, βarrs regulate the duration of G protein signaling whereas βarrs control the cellular location from where G proteins are activated from when associated with the receptor C-terminal tail. As the underlying properties that promote these two complex conformations remain elusive, my research objectives over the next 5 years involve determining these molecular driving forces on a general scale. Our preliminary data suggest that phosphorylation site clusters located within the receptor C-terminal tail are required for the association with βarrs in the tail conformation. Therefore, we plan to establish whether the presence of these phosphorylation site clusters correlates with the capacity of GPCRs to engage in mechanisms that lead to sustained endosomal G protein signaling. In regards to the GPCR–βarr core conformation, the fingerloop domain (FLD) of βarrs inserts itself into the transmembrane core of most GPCRs via its hydrophobic tip and receptor- specific residues. To characterize this interaction on a general scale, we will examine whether these receptor- specific βarr-FLD residues correlate with G protein subtype coupling of different GPCRs. Finally, βarrs modulate the activity of phosphodiesterases (PDEs), which terminate Gs-cAMP signaling. However, our preliminary data raise the possibility that this modulation occurs specifically by βarrs in the core conformation. Therefore, we will apply a combination of cell biological, biochemical, and proteomics approaches to examine whether modulation of PDEs and other desensitization mechanism is mediated specifically by distinct βarr conformations. My vision with this research program is to elucidate how GPCR signaling is regulated spatiotemporally by βarrs, which may lead to differentiated physiological responses. The knowledge acquired here will be used to design new and innovative therapeutics that specifically target GPCRs in time and space.

NIH Research Projects · FY 2025 · 2022-08

PROJECT SUMMARY Suicide attempts increased by 73% among Black adolescents, and suicide attempts requiring hospitalization increased by 122% for Black adolescent boys between the years 1991-2017. Many suicidal Black youth are unidentified, fewer than half are referred to treatment following an emergency department visit, and many referred youth do not adhere to treatment. Yet, prior research has not examined the effectiveness of a system of care for Black youth that combines suicide risk screening with an intervention to enhance linkage to quality mental health services. Our goal is to increase risk identification, treatment referral and engagement, and, in turn, reduce suicidal ideation and behavior among Black youth, addressing NIMH goals for this RFA and, more broadly, the National Action Alliance goals for youth suicide. The study's aims are to: 1) Inform and facilitate implementation of a system of care for Black youth at risk for suicide who present to the ED by assessing multiple stakeholders' (youth, parents, clinicians, support staff, administrators) perspectives regarding the WeCare system of care. We will use established implementation science frameworks to: a) determine barriers, facilitators, and recommended adaptations to WeCare before, during, and after the trial; b) ascertain WeCare acceptability and feasibility; and c) produce a WeCare implementation package that trains existing clinicians in the WeCare system of care through a user-friendly manual, training protocol, and fidelity assessment, and 2) Conduct a randomized clinical effectiveness trial with 2,200 Black Youth at risk for suicide to examine the effectiveness of WeCare. Approximately 4,257 youth, ages 12 to 17 years, enrolled from two hospital EDs in New York City, will be assessed on enrollment for risks associated with suicide, and moderate/high risk youth will be randomly assigned to WeCare vs. usual services. Survey assessments will be conducted at 3-, and 6-month follow-up, with medical record review through 12 months. As exploratory aims, we will a) examine whether impacts of WeCare are moderated by youth sex, sexual minority status, age (12-14, 15-17 years), and baseline risk for suicidality; b) conduct a cost effectiveness analysis to inform implementation, and c) understand how level of suicide risk (assessed via the CASSY) is associated with treatment engagement among those youth assigned to WeCare.

NIH Research Projects · FY 2024 · 2022-07

PROJECT SUMMARY A hallmark of functional motor skill is adaptability—tailoring movements to changes in the body or environment. The proposed project focuses on adaptability in infant walking because infants must learn to walk in the midst of continual changes in their bodies and environments. Changes in the body (due to physical growth, carrying objects, footwear, etc.) and environment (varying ground surfaces, obstacles, etc.) alter the biomechanical constraints on balance, propulsion, and braking. Moreover, walking is a foundational motor skill, endemic in everyday activity, and central to clinical assessment and intervention. The central hypothesis is that infants acquire adaptability via everyday walking experience. That is, infants learn strategies for modifying their walking patterns (footfalls and joint angles) as they navigate an ever-changing environment in a continually changing body. A century of research shows that infants’ age and everyday walking experience (elapsed time since walk onset) predict their skill when walking barefoot over flat ground. But little work examined infants’ ability to modify their walking patterns (speed, step length, joint angles, etc.) to cope with changes in their body or environment. Thus, the proposed project fills an empirical gap in scientific knowledge that is fundamental to developmental theory. The proposed experiment tests the role of everyday walking experience in the development of adaptability in infant walking. Because age and walking experience are confounded, the proposed experiment uses a within-subjects, age-held-constant design—all 14-month-old infants to control for age while walking experience (0-4 months) varies freely. Infants will be tested in a baseline condition (walking barefoot over a flat walkway) and in 4 novel conditions that require adaptability—2 body conditions (walking over a flat walkway wearing shoes that tilt their toes 10° up or 10° down); and 2 environment conditions (walking barefoot over a sloping walkway tilted 10° up or 10° down). The shoe conditions affect infants’ balance; the slope conditions affect balance, propulsion, and braking. Spatiotemporal footfall measures, joint angles, and gait disruptions will characterize how infants modify their walking to cope with the novel challenges. Aim 1 tests whether infants display different walking patterns in each condition, and whether walking experience is related to the type and diversity of patterns. Aim 2 assesses the similarity in walking between conditions for each infant, and tests whether walking experience amplifies the similarity or dissimilarity between conditions. Both aims leverage the power of machine learning analyses (density peak clustering and similarity matrices) to fully characterize infants’ walking within and across conditions. The within-subjects, age-held-constant design, innovative body-environment test conditions, and analytic techniques provide a strong test of the long-term objective: to understand the role of experience in the development of adaptability in infant motor skill. Findings promise to inform early intervention practices to support children’s locomotor development.

NIH Research Projects · FY 2025 · 2022-07

Summary: The human genome is highly dynamic, yet the principles governing its movement are not known. Locally, chromatin undergoes constant remodeling and rearrangement associated with processes such as transcription, replication and DNA repair. At large length scales, chromatin dynamics is coherent over microns and seconds. How the local gene-level processes contribute to nucleus-wide chromatin motions remains an open question. To address this question, our overall approach is to map spatially and temporally resolved chromatin dynamics across the nucleus in mammalian cells in vivo, while connecting it with motion and transcriptional activity of specific genomic loci in real time. To do so, we will develop crosscutting tools integrating synergistically quantitative approaches derived from the physical sciences with the latest techniques from molecular biology and biochemistry. We will build an integrated experimental and analytical platform enabling simultaneous measurements of nucleus-wide and gene-specific motions in real time in vivo (Aim 1). Specifically, we will establish a data collection and analytical pipeline mapping chromatin motions across the nucleus in vivo using displacement correlation spectroscopy (DCS), while monitoring motions of genes visualized by CRISPR/dCas9 technology and tracked via new machine-learning assisted algorithms. In addition, our platform will monitor the spatiotemporal heterogeneity of chromatin across nucleus and toggle transcriptional activity of the tracked genes. Using this integrated platform, we will address the fundamental question of how gene-level transcription activity contributes to genome-wide motions (Aim 2). We will measure maps of chromatin motions and compaction across the whole genome, while simultaneously determining the local compaction and mobility of specific genes (MUC4, IL6) as a function of their transcriptional activity. Our findings will paint a new picture of the complexity and interconnectedness of gene- and genome-level dynamics and spatial heterogeneity. Finally, we will extend this approach to study interphase chromatin dynamics and compaction before and after cell differentiation of mouse embryonic stem cells (Aim 3). By linking gene-level activity to genome-wide compaction and motions, these results will have important implications for elucidating the role of chromatin dynamics in gene regulation and expression. Moreover, such knowledge will provide a framework for a mechanistic picture of chromatin dynamics in mammalian cells.

NIH Research Projects · FY 2026 · 2022-07

Neurons critically depend on mitochondria function to maintain membrane excitability and execute complex functions, such as neurotransmission and plasticity. Neurons are highly differentiated cells that require large amounts of ATP to perform these functions and ensure long-term viability. The unique complexity of neurons is reflected by the extremely long segments that can extend up to a meter long and the functional heterogeneity for each neuronal compartment. The neuron has specialized mechanisms to transport mitochondria to the most distal parts to maintain proper neuronal function and survival. In turn, peripheral mitochondria rely on the transport of cellular components, such as mRNA and proteins, to sustain mitochondrial homeostasis without the need to travel back to the soma. The current proposal focuses on this aspect of mitochondrial maintenance, mitochondrial transcripts' ability to be trafficked to the axons for local translation, and how this influences mitochondrial and neuronal health and function. This project's significance is focused on PINK1, an essential mitochondrial kinase that is mutated in a hereditable form of Parkinson's disease. PINK1 protein will not survive transport down the axon because of its short half-life. To this end, our laboratory described an innovative mechanism by which mitochondria carry PINK1 mRNA on its surface to axons. Synaptojanin 2 (SYNJ2) was found to be responsible for tethering PINK1 mRNA to the mitochondria for axonal localization and local protein synthesis. The study of this neuronal-specific model suggests that the RNA binding function of SYNJ2 is required for PINK1-mediated processes (such as mitophagy); however, this has yet to be explored. The work planned in this proposal will explore the physiological and pathological consequence of disrupting the RNA binding function of SYNJ2, and; this unique approach is of critical importance for understanding mitochondrial mRNA transport and translation for preserving mitochondrial health. Thus, I hypothesize that: The RNA Recognition Motif of SYNJ2 causes PINK1 mRNA to colocalize with and be transported with mitochondria in a manner critical for PINK1 functions in axons and dendrites and thereby for maintaining neuronal health. I have assembled an advisory committee to provide conceptual and technical guidance as I explore the following Specific Aims: Aim 1: Examine the function of endogenous SYNJ2 and its RNA recognition motif in mice. Aim 2: Establish the role of peripheral SYNJ2 in mediating axonal mitochondrial function and neuronal health Aim 3: Investigate the impact of SYNJ2 RNA binding function in modulating axonal degeneration and regeneration in vivo.

NIH Research Projects · FY 2024 · 2022-07

Abstract. Reducing stigma to ensure viral load (VL) suppression for women with serious mental illness (SMI) and HIV is a global priority, including in Botswana, where the intersectional stigma of SMI, HIV and womanhood is marginalizing in ways that impede adherence to both psychiatric medications and antiretroviral therapy (ART), which can threaten VL suppression. We apply our novel ‘what matters most’ (WMM) approach to target intersectional stigma faced by women with SMI and HIV in Botswana via a stigma-reduction intervention in the high-risk transition period after discharge from an initial psychiatric hospitalization. WMM conceptualizes how stigma is felt most acutely when people are unable to achieve ‘full personhood’ by participating in the activities that ‘matter most’ in their local context. In prior research, we found the core value for ‘full womanhood’ in Botswana is achieved by being the ‘foundation of the household’ and is threatened by perceived: 1) incompetence in fulfilling the duties of a family caregiver associated with SMI and 2) promiscuity associated with having HIV. In Botswana, family acceptance as a viable ‘family caregiver’ is also key to achieving ‘full status’ as a woman. As such, the risks of being identified as having SMI and HIV (e.g., partner/family abandonment) can deter psychiatric and ART treatment adherence. Promoting capabilities that ‘matter most’ for achieving ‘full womanhood’ could enable longer-term stigma reduction after psychiatric discharge, when women are reintegrating into their communities, and improve ART adherence and promote sustained VL suppression. Our group-based WMM stigma intervention is co-led by a peer woman who has coped effectively with SMI and HIV stigma. The WMM stigma intervention model was piloted among pregnant women with HIV in Botswana with promising reductions in stigma and depressive symptoms up to 4-months postpartum. We now test whether a WMM intervention tailored for women with SMI and HIV will reduce intersectional stigma and facilitate VL suppression. We propose a two-arm randomized controlled trial (RCT; N=180) with a 4-month follow-up to compare the effectiveness of 1) WMM-based intersectional stigma intervention delivered as clients transition from psychiatric hospitalization to outpatient care (‘WMM Stigma Intervention;’ n=90); and 2) attention control following a similar format to isolate the effects of the intervention (n=90). Because family are commonly involved in the care of people with SMI and face severe stigma, we propose a parallel, group stigma intervention among family members, as addressing familial stigma could facilitate treatment adherence. Finally, because intersectional stigma is reinforced at systemic levels, we seek to empower women with SMI and HIV to influence structural change by coleading policymaker workshops to reduce stigma among policymakers and spur policymakers to address the unique needs of women with SMI and HIV via future policies.

NIH Research Projects · FY 2025 · 2022-07

Project Summary The adverse health impact of cigarette smoking on persons living with HIV is profound and effective treatments for long-term abstinence remain elusive. There is an acute need for interventions that address patient barriers to quitting and clinical barriers to effectively treating a broad heterogeneous population of smokers living with HIV (SLWH). This study’s long-term goal is to improve clinical outcomes among SLWH by providing optimized smoking cessation interventions in HIV clinical care. This proposal will use the Multiphase Optimization STrategy (MOST) to test four intervention components aimed at barriers to quitting among SLWH, with the objective of selecting the set that constitutes a cost-effective, sustainable, scalable smoking cessation package for HIV clinical care. Components include: Motivational Interviewing (Off/On); Peer Mentoring (Off/On); Text-messaging (Off/On); Varenicline or Combination Nicotine Replacement Therapy (Off/On). These components have shown promise in research but are under-utilized to help SLWH quit and have not been tested in an optimization trial. The proposed MOST factorial optimization trial is a highly efficient method for estimating the main effect contribution of each intervention component and all interactions between components. This approach addresses weaknesses in prior studies, which are not able to assess the contribution of individual components of multicomponent interventions. The proposal will also include a rigorous evaluation of the implementation process and theory-driven assessment of barriers to and facilitators of intervention implementation, sustainability and scalability in HIV clinical care. Aims include: (1) Assess the effectiveness of four smoking cessation intervention components on long-term abstinence among SLWH by conducting a highly efficient factorial optimization trial (i.e., MOST) with 500 SLWH in HIV clinical care. (2) Assess costs and the implementation process, including factors that affect the potential for sustainability and scalability of cessation treatment in HIV care settings serving SLWH. Guided by Proctor’s Implementation Outcomes Framework and the Consolidated Framework for Implementation Research, we will collect mixed methods data on reach, fidelity, acceptability and appropriateness among SLWH, stakeholders and study interventionists. (3) Identify the optimized intervention by conducting an innovative multi-criteria decision analysis to select the subset of the four components that achieves the highest level of cost-effectiveness and is both scalable and sustainable in HIV clinical care. Working in collaboration with New York City Health and Hospitals (H+H), the largest municipal public healthcare system in the U.S., and a team with unparalleled expertise in intervention optimization, smoking cessation and HIV/AIDS, the proposed study responds directly to the National Cancer Institute’s (NCI) call for smoking research that “optimizes intervention effectiveness, implementation and sustainability.” The optimized intervention will have a significant public health impact and add to scientific knowledge by providing a clear basis for further improvement of cessation interventions for SLWH in future research.

NIH Research Projects · FY 2025 · 2022-07

PROJECT SUMMARY Acute disasters like hurricanes, floods, heatwaves, and wildfires, as well as gradual-onset environmental events like sea level rise and coastal erosion, are growing in frequency and severity. These events disproportionately affect the health and well-being of older adults (65+) due to chronic health conditions, cognitive limitations, and depleted social networks. Across all age groups, older adults are the least likely to be prepared for disasters, are the most at-risk during all phases of a disaster (e.g., mitigation, preparedness; response; recovery) and, they have the highest rate of disaster-related deaths. In addition to increasing the morbidity and mortality of older adults, disaster exposure can also disrupt the ability of community-dwelling older adults to successfully age. Despite their vulnerability, disaster resilience interventions and activities are not usually tailored for community-dwelling older adults. The rapidly growing older adult population—along with the mounting risk of disasters—makes it imperative to understand the factors that influence older adult resilience in the context of disasters (e.g., disaster resilience) and how this adaptive process can be nurtured to promote successful aging (SA). The main research objective of this career development award is to generate data that will inform future R-level awards, led by the candidate, that address resilience-building strategies to promote SA, despite growing disaster risk. This proposed research aims to promote successful aging by identifying the factors that increase the disaster resilience of community-dwelling older adults, and subsequently leveraging these factors in the design and piloting of an intervention for those aging in disaster- prone areas. We hypothesize that a direct relationship between disaster exposure and SA can be mediated by increased disaster resilience. To test this hypothesis, the broad goals of this project are to (1) test a conceptual model that theorizes the relationship among disaster exposure, individual disaster resilience and SA; (2) identify the factors that contribute to disaster resilience among older adults with qualitative data; and (3) design and pilot an intergenerational intervention that aims to increase disaster resilience among community-dwelling older adults. The main training objective of this CDA is to provide the PI with skills in (1) advanced quantitative methods; and (2) intervention science. The mentoring team includes an exceptional multidisciplinary group of scholars with expertise in intervention design and implementation; social gerontology; public health disaster science; resilience theory; and biostatistics. To accomplish these goals, the PI and mentoring team have co- designed a training plan with didactic, mentored, and experiential learning that will provide the PI with dedicated time to focus on research, dissemination of findings, and the collection of pilot data to inform future research. With mentorship from her team of senior researchers, additional coursework, and applied experience, the PI will be able to transition into a successful independent researcher who can effectively bridge gerontology, public health disaster science, and intervention science.

NIH Research Projects · FY 2025 · 2022-05

PROJECT SUMMARY Background: Approximately 300,000 Hispanic individuals experience respiratory failure each year in the U.S. Hispanic patients are twice as likely to die from respiratory failure as non-Hispanic patients. There is an urgent need to identify and remediate mechanisms that increase risk of death from respiratory failure. The team’s preliminary work identified two potential mechanisms: Hispanic patients with respiratory failure are more likely to be deeply sedated and less likely to receive physical therapy than non-Hispanic patients, which are both associated with mortality and poor long-term functional outcomes. The overall objective of this proposal is to improve outcomes for patients with respiratory failure through changes in intensive care unit (ICU) practice. Specific Aims and Project Methods: Aim 1: Evaluate trajectories of long-term functional outcomes for Hispanic and non-Hispanic survivors of respiratory failure. An analysis of a unique registry of patients with respiratory failure will examine risk-adjusted trajectories of six-month mortality and functional outcomes among 96 Hispanic and 96 matched non-Hispanic control patients. Aim 2: Characterize care delivery for respiratory failure. Detailed site visits at ten heterogeneous U.S. hospitals will be integrated with interviews and surveys of ICU clinicians to understand delivery of deep sedation and other care processes that preliminary work demonstrate to be differentially applied by ethnicity. Aim 3: Refine and pilot an intervention to promote guideline-concordant care. The team’s preliminary intervention will be iteratively refined through patient, family, and clinician engagement and piloted at two U.S. ICUs. Unique Aspects of this Proposal: This proposal tackles an enduring problem in critical care—detecting, understanding, and eliminating disparities—by uniting a sociologist with expertise in disparities research and intervention design with a critical care physician with expertise in health services research. With an experienced team of co-investigators, preeminent National Advisory Board, and rigorous mixed-methods design, the PIs are uniquely equipped to address this pressing challenge. Anticipated Impact: NHLBI priorities call for robust evidence and innovations in intervention design to improve respiratory health. The outcome of this study will be a characterization of care delivery contributing to worse outcomes among Hispanic patients with respiratory failure and an intervention aimed at reducing mortality from respiratory failure.

NIH Research Projects · FY 2026 · 2022-04

ABSTRACT In the US, approximately 50,000 oral and pharyngeal cancers (OPCs) are diagnosed annually (10/100,000 incidence). Further, oral epithelial dysplasia (OED) is about 15 times more common than OPC. Patients diagnosed with OED are known to be at risk for malignant transformation (MT), and those treated for oral squamous cell carcinoma (OSCC) are known to be at elevated risk for cancer recurrence (CR). There is little consensus about the optimal clinical surveillance pathways for these patients. Individuals with a history of OSCC and potentially malignant oral lesions (PMOLs) harboring OED/OSCC can have widely variable clinical presentation that overlaps with oral lesions of no malignant potential. Thus, clinicians may be reluctant to perform serial scalpel biopsies on these patients. Commercially available diagnostic adjuncts lack adequate clinical validation across the lesion disease spectrum. When OSCC or high-grade OED is diagnosed early, there is an opportunity to provide appropriate timely treatment, and patient outcomes can improve dramatically. Thus, there is a compelling need for new highly effective non-invasive precision oral lesion diagnostic technologies that can be tailored for the needs of individual patients. This multi-institution prospective cohort study seeks to utilize and optimize first Point-of-Care Oral Cytopathology Tool (POCOCT), a microfluidics ensemble and single cell image-based data acquisition system employing artificial intelligence with interpretation of >100 image features including nuclear F-actin for precision oral lesion diagnostics to be completed. Portable diagnostic tools and embedded algorithms will be optimized for secondary and tertiary care settings for the first time. In this R01 study, POCOCT-derived OSCC CR and OED MT models will be developed to elucidate population and patient-specific dynamic changes in numerical index that yield key information related to CR and risk of MT. While past efforts focused on a single time point, this same multimodal chip-based approach will be used to sample repeatedly during surveillance to identify the value of speed of change to MT and CR. The overarching goals of this R01 study are: (1) to determine whether cytological signatures, when examined serially over time, can lead to better risk prediction for CR, (2) to determine if the same signatures can lead to earlier detection of local recurrence than the traditional clinical pathway, and (3) to further optimize the POCOCT for precision lesion diagnostics of MT and CR using newly identified biomarkers, including nuclear F-actin, and rare cell phenotypes identified by deep learning. This R01 will leverage unique NIDCR-Grand Opportunity databases for a new paradigm of precision diagnostics. High risk patients will be longitudinally monitored in secondary and tertiary care settings at intervals, and their risk trajectory will be established over time using personalized multivariate cytological signatures as well as initial values. This prospective longitudinal cohort study has potential for more accurate lesion diagnosis, improving patient survival and overall quality of life.

NIH Research Projects · FY 2026 · 2022-04

PROJECT SUMMARY Understanding the causal interactions in large neural ensembles is key for developing techniques to alter cognitive behavior through targeted manipulation of the brain. This is a challenging goal because commonly used methods for recording neural responses in the human brain do not provide information about physical connections of neurons and allow only extremely sparse sampling of neurons in a circuit (typically <1%). Here, we develop an innovative path forward using a multi-disciplinary approach that combines recent theoretical and experimental advances by the two PIs (Kiani and Mazzucato). In Aim 1, we introduce a novel theoretical framework to infer a map of causal functional connectivity (CFC) based on sparse sampling from neurons in a circuit. Our framework successfully recovers the structure of functional interactions, identifies hub neurons in the circuit, and has multi-scale properties that make it applicable on a variety of data, ranging from spiking of individual neurons to aggregated spiking of clusters of neighboring neurons to local field potentials. In Aim 2, we test if the CFC inferred from a population of simultaneously recorded prefrontal neurons successfully predicts how microstimulation perturbs neural activity in the circuit. Specifically, we show the existence of hub neural clusters, identified through CFC, whose microstimulation has large and predictable impacts on the population response dynamics. Finally, in Aim 3, we explore if the CFC and perturbation effects at rest predict how microstimulation alters behavior during a perceptual decision-making task. We hypothesize that resting CFC combined with the population activity prior to microstimulation successfully predicts the effect of microstimulation both on the circuit activity and the behavior. The approach, data and analyses proposed in each of these aims are novel and the combination will provide a practical solution for a long-standing problem in systems neuroscience.

NIH Research Projects · FY 2026 · 2022-02

PROJECT SUMMARY Skill acquisition can be facilitated by social experience, usually through exposure to a conspecific performing a well-defined behavior. In fact, social learning (SL) is pivotal to the acquisition of many core behaviors, including aural communication. Although the neural bases for auditory SL remain uncertain, one plausible hypothesis is that social experience may induce experience-dependent plasticity in auditory cortex (AC), as found for many forms of learning, thereby facilitating auditory task acquisition. Social learning may also have implications for developmental hearing loss (HL), a prevalent sensory impairment that is associated with persistent deficits in speech and language acquisition, especially since social factors are thought to facilitate language acquisition in children with HL. Three Aims test predictions that emerge from this hypothesis: Aim 1 first demonstrates the positive impact of SL on task learning: Naïve Observer gerbils receive five days of exposure to a trained Demonstrator performing an amplitude modulation rate discrimination task. An opaque divider separates Observer and Demonstrator, such that visual cues are absent. Observer gerbils are then permitted to practice the auditory task, and the rate of learning assessed. To test the prediction that AC activity is required, AC will be inactivated during social experience. Aim 1 will go on to test the prediction that dopaminergic neuromodulation within AC is be necessary for social learning. We will first determine whether dopamine is released in AC during social experience, using fiber photometry and a genetically expressed dopamine sensor. We will then block dopamine receptors in AC during social exposure to determine whether the benefits of social experience are diminished. Aim 2 tests the prediction that AC neuron sensitivity to auditory cues will be enhanced during SL. Gerbils will be instrumented with electrode arrays in AC, and recorded during five days of social exposure. Single neuron and population responses to auditory task stimuli will be assessed to determine if improved neural sensitivity during observation can explain the rate of task acquisition rate during practice. To test the contribution of an auditory social cue (i.e., Demonstrator vocalizations), recordings will be obtained from Observers exposed to auditory task cues plus playback of demonstrator vocalizations. Aim 3 tests the prediction that SL will improve task acquisition in hearing loss-reared animals. Juvenile gerbils will receive either permanent (malleus removal) or transient (earplugs) conductive HL. Animals will then be instrumented with electrode arrays in AC, and assessed as in Aim 2. Innovations in this proposal are to: (i) extend current auditory learning paradigms to include social cues, (ii) use wireless recordings during learning to make within- animal comparisons of neural and behavioral sensitivity, and (iii) shift the current emphasis in HL research from a focus on degraded sensory processing to one that considers how social factors may facilitate auditory skills. If successful, the project will identify a CNS mechanism that mediates socially-enhanced auditory learning, and provide a novel approach to remediate sensory and cognitive barriers in children with HL.

NIH Research Projects · FY 2026 · 2021-12

Project Summary Itch is a complex physiological process that incorporates detection of irritants by sensory neurons in the skin which activate spinal interneurons and ultimately, cortical projection neurons to generate a response. G protein-coupled receptors (GPCRs) play an integral role at each level of itch sensation and transmission. Although conventionally considered cell surface receptors that are desensitized and internalized following ligand binding, new evidence has established the ability of GPCRs to signal from endosomes. However, little is known about the mechanisms that regulate endosomal signaling of GPCRs and nothing is known about the role of endosomal GPCRs signaling in itch or whether endosomal GPCRs are a viable therapeutic target for itch. This proposal hypothesizes that: 1. Gastrin releasing peptide receptor (GRPR) and neurokinin 1 receptor (NK1R), two key receptors in itch transmission in the spinal cord, can recruit and assemble multi- protein complexes from the endosomal compartment that facilitate endosomal signaling and mediate prolonged hyperexcitability of spinal interneurons. That the ability of GRPR and NK1R to signaling from endosomes leads to itch transmission in the spinal cord and endocytic inhibitors that block GRPR and NK1R endosomal signaling can inhibit scratching behavior in mice. 2. Targeting endosomal signaling of GRPR and NK1R using nanoparticles is a more effective strategy in inhibiting itch than targeting cell surface receptors. Endosomal signaling of GRPR and NK1R will be characterized in model cell lines, spinal interneurons that mediate itch transmission, and in intact animals. Pharmaceutical and genetic approaches will be used to inhibit endosomal trafficking of GRPR and NK1R. Aim 1 will characterize the importance of endosomal trafficking and signaling of GRPR and NK1R in spinal interneurons for the transmission of itch. The role of endosomal signaling in itch will be addressed by electrophysiology, and by itch behavioral assays in intact animals. Aim 2 will characterize the ability of GRPR to traffic to endosomes and assemble the multi-protein complexes that result in subcellular specific signaling events. These signaling complexes will be studied using advanced biophysical and imaging approaches with high spatiotemporal resolution. Aim 3 will use advanced chemical biology, nanoengineering and nanoparticle encapsulation to deliver GRPR and NK1R antagonists to endosomes, probing the importance of endosomal signaling of GRPR and NK1R in itch transmission and to determine whether endosomal GPCRs are a viable therapeutic target.