Biology subjects

Banerjee, A.

Publications and source records attributed to Banerjee, A..

At least 91 records · Page 5Linked to original sources

bioRxiv2024

Aging distorts the representation of emotions by amplifying prefrontal variability

Understanding the mechanisms behind the variability of neural signals holds the key to the characterization of developmental and lifespan aging trajectories. Here we propose that tracking temporally structured neural fluctuations or volatility in brain areas during naturalistic tasks provides a more salient characterization of ageing trajectories compared to measures based on mean and resting-state variability. Compared to other prefrontal regions, the orbitofrontal cortices (OFC) exhibit higher BOLD signal variability in aged individuals. Neural latent state analysis revealed that, in contrast to the stable representations in younger adults, the OFC in older adults exhibited more temporally distorted representations, mirroring their distinct affective experiences. Furthermore, lower OFC volatility during the movie was associated with participants bias toward positive responses in a separate emotional reactivity task. This suggests orbitofrontal neural volatility might be a general adaptive response to affective computations. To investigate this further, a Bayesian learning model of valence dynamics was employed, which revealed that older adults exhibit heightened uncertainty in neural representations while estimating affective states. Collectively, these results indicate that neural volatility identified through BOLD variability carries unique information about older adults affective experiences and how naturalistic neuroimaging can chart a way forward in understanding this better.

neuroscience↗

bioRxiv2024

Unusual lineage plasticity revealed by YY1 knockout in pro-B cells

During B cell development, cells progress through multiple developmental stages with the pro-B cell stage defining commitment to the B cell lineage. YY1 is a ubiquitous transcription factor that is capable of both activation and repression functions. We find here that knockout of YY1 at the pro-B cell stage eliminates B lineage commitment. YY1 knockout pro-B cells can generate T lineage cells in vitro using the OP9- DL4 feeder system, as well as in vivo after injection into sub-lethally irradiated Rag1-/- mice. These T lineage-like cells lose their B lineage transcript profile and gain a T cell lineage profile. Single cell-RNA-seq experiments showed that as YY1 knockout pro-B cells transition into T lineage cells, various cell clusters adopt transcript profiles representing a multiplicity of hematopoietic lineages indicating unusual lineage plasticity. Given the ubiquitous nature of YY1 and its dual activation and repression functions, YY1 likely regulates commitment in multiple cell lineages.

developmental biology↗

bioRxiv2024

Emotion arousal but not valence is strongly represented in aperiodic EEG activity stemming from thalamocortical interactions

Oscillatory EEG signals contain both periodic and aperiodic (1/f components), segregating which is important for gaining insights into the underlying neural computations. Several studies have explored the periodic features underlying neural basis of emotion processing, while 1/f component is less explored. Hence, the present study sought to determine whether seeing emotionally laden music video clips have an impact on aperiodic components along with the periodic components and their underlying basis by conceptualizing a biophysically realistic computational model. Using the publicly available Data for Emotional Analysis using Physiological Signals (DEAP) dataset we elucidate that there is a significant increase in exponent and offset of aperiodic background during high arousal compared to low arousal trials. In contrast, there were no discernible variations between the aperiodic components during the high and low valence categories. In high arousal, we also discovered reduction in alpha power in line with previous studies. Finally, to elucidate the underlying mechanisms, we employed a biophysically realistic and previously established thalamo-cortical model of neural field activity, which which allowed us to characterize that heightened emotional arousal appears emerge from an increased cooperation in information communication between neuronal populations in reticular and relay nuclei of thalamus. Significance statementDissociation of emotion and valence and arousal is an established theory in affective neuroscience. Are these dimensions represented in aperiodic background of macrocscopic electrophysiological scales of EEG? We sought to ask this question in the publicly available DEAP data. Our findings of increased aperiodic components during high arousal in contrast to low arousal suggest heightened neural activity alongside an inhibitory influence. Using a neural field model of thalamo-cortical interactions reveals a mechanistic approach that suggests heightened arousal corresponds to an enhanced inhibitory coupling between thalamic reticular and relay neuronal populations. In essence, this study advances our understanding of the intricate relationship between electrophysiological signals and emotion dimensions, shedding light on the mechanisms underlying arousal-related emotional responses.

neuroscience↗

bioRxiv2024

Blocking Src-PSD-95 interaction rescues glutamatergic signaling dysregulation in schizophrenia.

The complex and heterogeneous genetic architecture of schizophrenia inspires us to look beyond individual risk genes for therapeutic strategies and target their interactive dynamics and convergence. Postsynaptic NMDA receptor (NMDAR) complexes are a site of such convergence. Src kinase is a molecular hub of NMDAR function, and its protein interaction subnetwork is enriched for risk-genes and altered protein associations in schizophrenia. Previously, Src activity was found to be decreased in post-mortem studies of schizophrenia, contributing to NMDAR hypofunction. PSD-95 suppresses Src via interacting with its SH2 domain. Here, we devised a strategy to suppress the inhibition of Src by PSD-95 via employing a cell penetrating and Src activating PSD-95 inhibitory peptide (TAT-SAPIP). TAT-SAPIP selectively increased post-synaptic Src activity in humans and mice, and enhanced synaptic NMDAR currents in mice. Chronic ICV injection of TAT-SAPIP rescued deficits in trace fear conditioning in Src hypomorphic mice. We propose blockade of the Src-PSD-95 interaction as a proof of concept for the use of interfering peptides as a therapeutic strategy to reverse NMDAR hypofunction in schizophrenia and other illnesses.

neuroscience↗

bioRxiv2024

Proteomic analysis of gut in Labeo rohita reveals ECM as Key Player in host's Response to Aeromonas hydrophila Infection

In the aquaculture sector, one of the challenges include disease outbreaks such as bacterial infections, particularly from Aeromonas hydrophila (Ah), impacting both wild and farmed fish. In this study, we conducted a proteomic analysis of the gut tissue in Labeo rohita following Ah infection to elucidate the protein alterations and its implications for immune response. Our findings reveal significant dysregulation in extracellular matrix (ECM) associated proteins during Ah infection, with increased abundance of elastin and Collagen alpha-3(VI) contributing to matrix rigidity. Pathway and enrichment analysis of differentially expressed proteins (DEPs) highlights the involvement of ECM-related pathways, including Focal adhesions, Integrin cell surface interactions, and actin cytoskeleton organization. Focal adhesions, crucial for connecting intracellular actin bundles to the ECM, play a pivotal role in immune response during infections. Increased abundance of integrin alpha 1, integrin beta 1, and Tetraspanin suggests their involvement in the hosts response to Ah infection. Proteins associated with actin cytoskeleton reorganization, such as myosin, tropomyosin, and phosphoglucomutase, exhibit increased abundance, influencing changes in cell behavior. Additionally, upregulated proteins like LTBP1 and Fibrillin-2 contribute to TGF-{beta} signaling and focal adhesion, indicating their role in immune regulation. The study also identifies elevated levels of laminin, galectin 3, and tenascin-C, which interact with integrins and other ECM components, influencing immune cell migration and function. These proteins, along with decorin and lumican, act as immunomodulators, coordinating pro- and anti-inflammatory responses. ECM fragments released during pathogen invasion serve as "danger signals," initiating pathogen clearance and tissue repair through Toll-like receptor signaling. IMPORTANCEThe study underscores the critical role of the extracellular matrix (ECM) and its associated proteins in the immune response of aquatic organisms during bacterial infections like Aeromonas hydrophila (Ah). Understanding the intricate interplay between ECM alterations and immune response pathways provides crucial insights for developing effective disease control strategies in aquaculture. By identifying key proteins and pathways involved in host defense mechanisms, this research lays the groundwork for targeted interventions to mitigate the impact of bacterial infections on fish health and aquaculture production.

microbiology↗

bioRxiv2024

Contributions of sub-community based on short and long-range white matter tracts in personalized age-associated neurocompensatory mechanism

Brain function is shaped by the local and global connections between its dynamical units and biological parameters. With aging, the anatomical connectivity undergoes significant deterioration (e.g., long-range white matter fiber loss), which affects the brains overall function. Despite the structural loss, previous research has shown that normative patterns of functions remain intact across the lifespan, defined as the compensatory mechanism of the aging brain. However, the crucial components in guiding the compensatory preservation of the dynamical complexity and the underlying mechanisms remain uncovered. Moreover, it remains largely unknown how the brain readjusts its biological parameters to maintain optimal brain dynamics with age; in this work, we provide a parsimonious mechanism using a whole-brain generative model to uncover the role of sub-communities comprised of short-range and long-range connectivity in driving the dynamic compensation process in the aging brain. We utilize two neuroimaging datasets to demonstrate how short--and long-range white matter tracts affect compensatory mechanisms. We unveil their modulation of intrinsic global scaling parameters, such as global coupling strength and conduction delay, via a personalized large-scale brain model. Our two key findings suggest that (1) the optimal coupling strength and delay play complementary roles in preserving the brains optimal working state. (2) Short-range tracts predominantly amplify global coupling strength with age, potentially representing an epiphenomenon of the compensatory mechanism. This mechanistically explains the significance of short-range connections in compensating for the major loss of long-range connections during aging. This insight could help identify alternative avenues to address aging-related diseases where long-range connections are significantly deteriorated.

neuroscience↗

bioRxiv2024

BATMAN: Improved T cell receptor cross-reactivity prediction benchmarked on a comprehensive mutational scan database

Predicting T cell receptor (TCR) activation is challenging due to the lack of both unbiased benchmarking datasets and computational methods that are sensitive to small mutations to a peptide. To address these challenges, we curated a comprehensive database, called BATCAVE, encompassing complete single amino acid mutational assays of more than 22,000 TCR-peptide pairs, centered around 25 immunogenic human and mouse epitopes, across both major histocompatibility complex classes, against 151 TCRs. We then present an interpretable Bayesian model, called BATMAN, that can predict the set of peptides that activates a TCR. We also developed an active learning version of BATMAN, which can efficiently learn the binding profile of a novel TCR by selecting an informative yet small number of peptides to assay. When validated on our database, BATMAN outperforms existing methods and reveals important biochemical predictors of TCR-peptide interactions. Finally, we demonstrate the broad applicability of BATMAN, including for predicting off-target effects for TCR-based therapies and polyclonal T cell responses.

immunology↗

bioRxiv2024

Fluoride export is required for competitive fitness of pathogenic microorganisms in dental biofilm models

Microorganisms resist fluoride toxicity using fluoride export proteins from one of several different molecular families. Cariogenic species Streptococcus mutans and Candida albicans extrude intracellular fluoride using a CLCF F-/H+ antiporter and FEX fluoride channel, respectively, whereas commensal eubacteria, such as Streptococcus gordonii, export fluoride using a Fluc fluoride channel. In this work, we examine how genetic knockout of fluoride export impacts pathogen fitness in single-species and three-species dental biofilm models. For biofilms generated using S. mutans with genetic knockout of the CLCF transporter, exposure to low fluoride concentrations decreased S. mutans counts, synergistically reduced the populations of C. albicans, increased the relative proportion of commensal S. gordonii, and reduced properties associated with biofilm pathogenicity, including acid production and hydroxyapatite dissolution. Biofilms prepared with C. albicans with genetic knockout of the FEX channel also exhibited reduced fitness in the presence of fluoride, but to a lesser degree. Imaging studies indicate that S. mutans is highly sensitive to fluoride, with the knockout strain undergoing complete lysis when exposed to low fluoride for a moderate amount of time, and biochemical purification the S. mutans CLCF transporter and functional reconstitution establishes that the functional protein is a dimer encoded by a single gene. Together, these findings suggest that fluoride export by oral pathogens can be targeted by specific inhibitors to restore biofilm symbiosis in dental biofilms, and that S. mutans is especially susceptible to fluoride toxicity. ImportanceDental caries is a globally prevalent condition that occurs when pathogenic species, including Streptococcus mutans and Candida albicans, outcompete beneficial species, such as Streptococcus gordonii, in the dental biofilm. Fluoride is routinely used in oral hygiene to prevent dental caries. Fluoride also has antimicrobial properties, although most microbes possess fluoride exporters to resist its toxicity. This work shows that sensitization of cariogenic species Streptococcus mutans and Candida albicans to fluoride by genetic knockout of fluoride exporters alters the microbial composition and pathogenic properties of dental biofilms. These results suggest that the development of drugs that inhibit fluoride exporters could potentiate the anticaries effect of fluoride in over-the-counter products like toothpastes and mouth rinses. This is a novel strategy to treat dental caries.

microbiology↗

bioRxiv2023

Metastability indexes global network effects post brain stimulation

Several studies have shown that coordination among neural ensembles is a key to understand human cognition. A well charted path is to identify coordination states associated with cognitive functions from spectral changes in the oscillations of EEG or MEG. A growing number of studies suggest that the tendency to switch between coordination states, sculpts the dynamic repertoire of the brain and can be indexed by a measure known as metastability. In this article, we characterize perturbations in the metastability of global brain network dynamics following Transcranial Magnetic Stimulation that could quantify the duration for which information processing is altered, thus, allowing researchers to understand the network effects of brain stimulation, standardise stimulation protocols and design experimental tasks. We demonstrate the effect empirically using publicly available datasets and use a digital twin (a whole brain connectome model) to understand the dynamic principles that generate such observations. We observed a significant reduction in metastability, concurrent with an increase in coherence following single-pulse TMS reflecting the existence of a window where neural coordination is altered. The reduction in complexity was validated by an additional measure based on the Lempel-Ziv complexity of microstate labelled EEG data. Interestingly, higher frequencies in the EEG signal showed faster recovery in metastability than lower frequencies. The digital twin shed light on how the phase resetting introduced by the single-pulse TMS in local cortical networks can propagate globally across the whole brain and give rise to changes in metastability and coherence.

neuroscience↗

bioRxiv2023

A Perturbation Approach for Refining Boolean Models of Cell Cycle Regulation

Considerable effort is required to build mathematical models of large protein regulatory networks. Utilizing computational algorithms that guide model development can significantly streamline the process and enhance the reliability of the resulting models. In this article we present a perturbation approach for developing data-centric Boolean models of cell cycle regulation. We assign a score to a network based on the steady states of the network-dynamics, and the dynamical trajectories corresponding to the initial conditions. Then, perturbation analysis is used to find new networks with lower scores, in which dynamical trajectories traverse through the correct cell cycle path with high frequency. We apply this method to refine Boolean models of cell cycle regulation in budding yeast and mammalian cells.

systems biology↗

bioRxiv2023

Bacterial pore-forming toxin pneumolysin drives pathogenicity through shed toxin-loaded host extracellular vesicles

Streptococcus pneumoniae is a global priority respiratory pathogen that kills over a million people annually and produces the pore-forming cytotoxin, pneumolysin (PLY). Host cells expel membrane assembled toxin by shedding microvesicles, but the composition and pathophysiological sequelae of the toxin-induced host extracellular vesicles (EVs) are unknown. Here, we found that EVs shed from PLY-challenged monocytes (PLY-EVs) harbor membrane-bound toxin that induced cytotoxicity upon fusion with recipient cells. EVs from human monocytes challenged with recombinant PLY as well as PLY-expressing pneumococcal strains, but not the isogenic PLY mutant, primed dendritic cells and evoked higher pro-inflammatory cytokines upon infection. Proteomic analysis revealed that PLY-EVs are enriched for key antimicrobial and inflammatory host proteins such as IFI16, NLRC4, PTX3 and MMP9. In vivo, zebrafish and mice administered with PLY-EVs showed mortality, pericardial edema, tissue damage and inflammation. Our findings show that host EVs bearing the cytotoxin PLY constitute a previously unexplored mechanism of pneumococcal pathogenesis.

microbiology↗

bioRxiv2023

Microevolution of clade II isolates of Candida auris highlights multifaceted intra-clade heterogeneity in acquiring resistance towards amphotericin B

Candida auris exhibits high-level resistance to amphotericin B (AmB). Mechanisms such as ergosterol biosynthesis malfunction, oxidative damage mismanagement, and increased drug efflux contribute to AmB resistance in C. auris. In this study, we experimentally evolved two East Asian drug-susceptible clade II isolates of C. auris (P2428 and CBS10913T) isolated from different geographical locations to develop resistance against AmB. We analysed alterations in karyotype, genome sequence, and gene expression profiles to uncover the mechanisms driving AmB resistance. The independently evolved clade II adaptors displayed up to 4-16-fold higher MIC50, as compared to the parental cells. AOX2 (alternative oxidase) and the cell wall integrity pathway have been identified as critical in the development of AmB resistance. However, we noted certain intra-clade heterogeneity in the associated mechanisms. While in P2428 adaptors (P-lines), the ergosterol and sphingolipid pathways appear to play a crucial role, this was not the case for CBS10913T adaptors (A-lines), which acquired resistance independent of lipid-associated changes. The transcriptomic, WGS, and phenotypic analyses also confirm that the evolved AmB-resistant isolates follow distinct trajectories for adaptation, Furthermore, unlike the fluconazole-resistant isolates, as reported previously, changes in ploidy do not seem to contribute to the differential mechanisms of AmB resistance. Overall, this study not only provides insights into the mechanisms and pathways involved in AmB resistance but also highlights intra-clade-heterogeneity that exists within clade II of C. auris. ImportanceCandida auris demonstrates significant resistance to amphotericin B (AmB) that stems from factors like alteration of ergosterol biosynthesis, perturbation of the oxidative damage response, etc. A comprehensive understanding of underlying mechanisms can be studied in a holistic manner by subjecting resistant as well as susceptible clinical isolates to a comparative genome-level analysis. An alternate and more dynamic approach is to expose susceptible isolates to a certain concentration of drug which is not lethal but can trigger the resistance mechanisms. In the present study, we evolved C. auris towards AmB and observed novel and differential mechanisms of resistance development, in two different isolates despite belonging to the same clade. This study provides insights into the intra-clade heterogeneous behavior of C. auris towards AmB.

microbiology↗

bioRxiv2023

Structural and functional insights into the enzymatic plasticity of the SARS-CoV-2 NiRAN Domain

The enzymatic activity of the SARS-CoV-2 nidovirus RdRp-associated nucleotidyltransferase (NiRAN) domain is essential for viral propagation, with three distinct activities associated with modification of the nsp9 N-terminus, NMPylation, RNAylation, and deRNAylation/capping via a GDP-polyribonucleotidyltransferase reaction. The latter two activities comprise an unconventional mechanism for initiating viral RNA 5-cap formation, while the role of NMPylation is unclear. The structural mechanisms for these diverse enzymatic activities have not been properly delineated. Here we determine high-resolution cryo-electron microscopy structures of catalytic intermediates for the NMPylation and deRNAylation/capping reactions, revealing diverse nucleotide binding poses and divalent metal ion coordination sites to promote its repertoire of activities. The deRNAylation/capping structure explains why GDP is a preferred substrate for the capping reaction over GTP. Altogether, these findings enhance our understanding of the promiscuous coronaviral NiRAN domain, a therapeutic target, and provide an accurate structural platform for drug development.

biophysics↗

bioRxiv2023

Gestures Of Hunger: Uncovering Intentional Gestural Communication In Free-Ranging Hanuman Langurs

Contrary to previous beliefs, intentional gestural communication (IGC) is not exclusive to the hominoid lineage but is also present in other non-human primates. Here, we report the presence of IGC among free-ranging Hanuman langur troop in Dakshineswar, West Bengal, India. These langurs exhibit a food-requesting behaviour wherein they use several gestures to communicate with the humans nearby. Moreover, they can also assess the recipients mental state and persistently check if the signal (food request) has been received, waiting until they receive the desired food item. We have identified eight begging gestures used by langurs of all ages, except infants. The most common gesture is by holding cloth (BGc), but provocation-initiated begging (BGpi) and begging by embracing legs (BGe) efficiently direct these events to its success. The frequency of successful begging events is higher in the evening due to increased human interactions. Our findings suggest that ontogenetic ritualization might be at play here among these troop members as this gestural communication has been learned through imitation and reinforced by the reward of receiving food. Moreover, these successful begging events serve as an effective foraging strategy for urban-adapted langurs, allowing them to acquire high-calorie processed food items within a human-modified urban ecosystem.

animal behavior and cognition↗

bioRxiv2023

How repetition hinders priority switching in visual working memory states: An EEG study

Visual Working memory (VWM) is a limited-capacity system where working memory items compete for retrieval. Some items are maintained in the working memory in the "region of direct access," which holds information readily available for processing, while other items are in a passive or activated long-term memory state and require cognitive control. Moreover, their recognition requires moving from the most active template in VWM to another one with the shift of attention. Stimulus properties based on similarity can link items together, which can facilitate their retrieval due to prioritization. To investigate the neural dynamics of differential processing of repeated versus not-repeated items in working memory, we designed a modified Sternberg task for testing recognition in a VWM-based EEG study where human participants respond to a probe for an items presence or absence in the representation of an encoded memory array containing repeated and not repeated items. Significantly slower response times and comparatively poor accuracy for recognising not-repeated items suggest that they are not prioritized. We identified specific differences in spectral perturbations for sensor clusters in the power of different frequency bands as the neural correlate of probe matching for not-repeated vs. repeated conditions, reflecting biased access to VWM items. For not-repeated item probe matching, delay in beta desynchronization suggests poor memory-guided action selection behaviour. An increase in frontal theta and parietal alpha power demonstrated a demand for stronger cognitive control for retrieving items for not-repeated probe matching by shielding them from distracting repeated items. In summary, our study provides crucial empirical evidence of facilitation and prioritization of repeated items over non-repeated items and explains the probable role of different EEG rhythms in facilitated recognition of repeated items over goal-relevant, not-repeated items in VWM.

neuroscience↗

bioRxiv2023

Trans-Omics analysis of post injury thrombo-inflammation identifies endotypes and trajectories in trauma patients.

Understanding and managing the complexity of trauma-induced thrombo-inflammation necessitates an innovative, data-driven approach. This study leveraged a trans-omics analysis of longitudinal samples from trauma patients to illuminate molecular endotypes and trajectories that underpin patient outcomes. We hypothesized that trans-omics profiling reveals underlying clinical differences in severely injured patients that may present with similar clinical characteristics but ultimately have different responses to treatment and outcomes. Here we used proteomics and metabolomics to profile 759 of longitudinal plasma samples from 118 patients at 11 time points and 97 control subjects. Patients were stratified by shock and injury severity, revealing a spectrum of responses to trauma and treatment that are fundamentally tied to their unique underlying biology. Ensemble models were employed, demonstrating the predictive power of these molecular signatures with area under the receiver operating curves of 80 to 94% for key outcomes such as death. Then, transomics-based patient states were defined to create a map of unique pathophysiologic states encountered by trauma patients across time. Last, distinct longitudinal patient trajectories were identified that group patients according to their path through trauma transomics state maps. Unsupervised clustering of longitudinal trans-omics data identified specific clinical phenotypes while omics-based trajectories increased resolution on outcome prediction. The molecularly defined endotypes and trajectories provide an unprecedented lens to understand and potentially guide trauma patient management, opening a path towards precision medicine. This strategy presents a transformative framework that aligns with our understanding that trauma patients, despite similar clinical presentations, might harbor vastly different biological responses and outcomes. One-sentence summaryTransomic analyses of longitudinal plasma samples from severely injured patients identifies endotypes and trajectories that predict clinical outcomes.

biochemistry↗

bioRxiv2023

A host AAA-ATPase exhibits bacteriolytic activity for clearance of microbial infection

An array of host cytosol guarding factors impede bacterial proliferation and preserve cellular sterility. Amongst them, proteasomal degradation of ubiquitinated pathogens has emerged as a critical mechanism for ensuring cytosolic sanctity. We wondered how proteasomes, with their small size and inability to extract membrane-bound proteins, can eradicate pathogens. Here, we unveil a unique strategy, wherein VCP/p97, a host AAA-ATPase, eliminates pathogens by exerting mechanical force that physically unfolds and pulls out ubiquitinated proteins from bacterial membrane. Combining a single-molecule approach along with molecular dynamic simulation and in-vitro reconstitution, we demonstrate that protein extraction by p97 causes extensive membrane lysis and release of cytosolic contents from phylogenetically diverse microbes. Additionally, in an in-vivo mouse sepsis model, this segregase-dependent bactericidal effect of p97 abrogated microbial proliferation in host tissues. Overall, we discovered a distinct innate antimicrobial function of p97, that protects the host against lethal bacterial infections. One Sentence SummaryA host AAA-ATPase exhibits bacteriolytic activity.

microbiology↗

bioRxiv2023

Neuropathic pain has sex-specific effects on oxycodone seeking and drug-seeking ensembles in the dorsomedial prefrontal cortex

Approximately 50 million Americans suffer from chronic pain, and opioids are commonly prescribed for such individuals. Unfortunately, nearly a quarter of chronic pain patients have reported misusing their prescription. We are investigating the effect of chronic pain on drug-seeking behavior at the neuronal level. Repeated drug-seeking is associated with reactivation of an ensemble of neurons sparsely scattered throughout the dorsomedial prefrontal cortex (dmPFC). Prior research has demonstrated that chronic pain increases intrinsic excitability of dmPFC neurons, which may increase the likelihood of reactivation during drug seeking. We tested the hypothesis that chronic pain would increase oxycodone seeking behavior, and that the pain state would differentially increase intrinsic excitability in dmPFC drug seeking ensemble neurons. TetTag mice self-administered intravenous oxycodone. After 7 days of forced abstinence, a drug seeking session (extinction conditions) was performed and the ensemble was tagged. Mice received spared nerve injury (SNI) to induce chronic pain during the period between a first and second seeking session, and we measured persistence of seeking between the two sessions to determine if the SNI exacerbated seeking. Following the second seeking session we performed electrophysiology on individual neurons within the dmPFC to assess intrinsic excitability of the drug-seeking ensemble and non-ensemble neurons. We found significant sex differences in the effect of SNI on oxycodone seeking and electrophysiology, such that the induction of chronic pain could modulate seeking behavior in mice that have previously self-administered oxycodone prior to injury. HighlightsO_LIOxycodone seeking was higher in females following SNI that came after the 10-day SA timeline. C_LIO_LIAn increase in intrinsic excitability was detected among non-ensemble neurons from female mice that received SNI, and this correlated with an increase in seeking behavior. C_LI

pharmacology and toxicology↗