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Lab Animal

○ Springer Science and Business Media LLC

Preprints posted in the last 90 days, ranked by how well they match Lab Animal's content profile, based on 11 papers previously published here. The average preprint has a 0.01% match score for this journal, so anything above that is already an above-average fit.

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Multi-Lab Testing of Early Preclinical Discoveries Identifies Promising Treatments

Pellegrini, P.; Rotter, S. C.; Arroyo-Araujo, M.; Carneiro, C. F. D.; Drude, N. I.; Martinez Gamboa, L.; Banito, A.; Bernhardt, N.; Boulesteix, A.-L.; Buttgereit, F.; Dempfle, A.; Duran-Hernandez, N.; Gaber, T.; Groettrup, M.; Habelt, B.; Haller, B.; Hamza, H.; Hettmer, S.; Kliesow Remes, A.; Kobold, S.; Kochan, M.; Konietschke, F.; Lehmann, L. H.; Löhning, M.; Matzen, A.; Meinhardt, M. W.; Morrison, H.; Müller, O. J.; Planz, O.; Richter, G. H. S.; Riecken, L. B.; Rosahl, S. K.; Rubarth, K.; Schmidt-Bleek, K.; Schuler, L.; Sharma, A.; Skorodumov, I.; Spanagel, R.; Teichert-von Lüttichau, I.

2026-09-25 scientific communication and education 10.64898/2026.09.21.753112 medRxiv
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A fundamental challenge in drug development is the frequent failure of early laboratory research to translate into clinical benefit. One promising solution is to confirm findings from exploratory single-laboratory studies across multiple laboratories before clinical testing. We investigated this approach following the conduct of preclinical multi-laboratory studies across different fields of medicine. For this, we evaluated effect sizes, experimental rigor, and a set of criteria to identify determinants of confirmation success. When tested under increased rigor, only a fraction of multi-laboratory studies confirmed the initial results. The underlying effect size reduction was associated with outcome-relevant experimental differences between exploratory and confirmatory stages. In summary, multi-laboratory studies proved highly informative and served as an effective filter for promising treatments.

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Schrodinger's mouse: human observation erases a drug-induced behavioral phenotype

Krausz, T. A.; Roseberry, T. K.; Williams, G.; Tingley, D.

2026-10-01 animal behavior and cognition 10.64898/2026.09.25.754328 medRxiv
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Animal studies primarily rely on human monitoring for health and behavioral outcomes. The presence of a human, however, can induce stress and potentially alter experimental results. We sought to answer whether human observation alone is enough to change experimental outcomes and obscure the effect of interest. Our automated home-cage behavioral phenotyping system provided the ideal platform to test this hypothesis. Two cohorts received semaglutide (0.03 mg/kg, intraperitoneally) on separate consecutive days. The first cohort was recorded without inspection after dosing; the second underwent a brief visual health check with no handling. Recordings from the checked cohort on the preceding day, without injection or inspection, provided a matched baseline. A single brief check produced large, time-locked changes across the behavioral repertoire. The changes began before the cage door was opened, indicating a response to experimenter proximity. In addition to adding variance, the semaglutide-treated animals' behavior during observation was more similar to the no-injection baseline than to the semaglutide/no-check reference, transiently erasing the drug phenotype. Brief human observation is therefore not a neutral measurement operation; over the minutes surrounding it, it is a perturbation in itself that is large enough to mask the drug effect it is meant to record.

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zAcademy: an open-source programmable conditioning arena reveals sex- and genotype-dependent avoidance learning in adult zebrafish

Huang, S.; He, B.; Geng, Y.

2026-09-16 animal behavior and cognition 10.64898/2026.09.11.750830 medRxiv
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Zebrafish are widely used to study learning and memory. Here, we describe zAcademy, a programmable conditioning arena released in full as open hardware and open software. zAcademy combines a 3D-printed dual-chamber arena, bottom-mounted LED matrices that generate visual patterns under software control, graphite rod electrodes gated by an Arduino-controlled relay, an overhead infrared camera, and a position-based analysis workflow. In one 180-min session, adult zebrafish were classically conditioned to associate a checkerboard light pattern beneath the arena (conditioned stimulus, CS) with a mild shock (unconditioned stimulus, US). Conditioned avoidance was assessed in six unreinforced CS-alone probes: one immediately after training to test learning, the remaining five at 30-min intervals to test memory. Spatial preference was quantified as a performance index (PI; occupancy of the dark zone). Wild-type fish shifted toward the dark zone immediately after training, whereas shank3 KO fish did not. The wild-type response was carried primarily by females rather than males. In addition, among initial responders, females sustained elevated PI at more later probes. zAcademy provides an inexpensive, fully documented, and readily modified platform for comparing experience-dependent behavioral change across genotypes and sexes.

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AFIDs-Validator: An Open-Access AI-Guided Platform for Learning Anatomical Landmark Placement

Taha, A.; Bansal, D.; Kai, J.; Kuehn, T.; Stanley, O. W.; Park, P.; Thurairajah, A.; Snyder, M.; Gilmore, G.; Abbass, M.; Mahmoudian, B.; Liu, V. M.; Thrower, J.; Khan, A. R.; Lau, J. C.

2026-08-24 scientific communication and education 10.64898/2026.08.20.746086 medRxiv
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Accurate localization of anatomical landmarks is a foundational skill in anatomy and imaging that is often taught informally through expert mentorship, requiring access to data and desktop software. There is no openly accessible, interactive resource that teaches neuroanatomy with quantitative feedback. We present the AFIDs-Validator (validator.afids.io), an open-access, browser-based platform that pairs guided instruction with quantitative assessment. The platform combines (1) a learning mode in which a language-model neuroanatomy tutor operates inside an MRI viewer, giving anatomy-first instruction that responds to the learner's current image slice, orientation, and cursor position; and (2) a validation engine that accepts a learner's landmark file and returns per-landmark Euclidean error against expert-annotated references spanning 21 brain templates. To make the feedback interpretable, we analyzed 15,000 landmark annotations across 132 human subjects and found that landmark difficulty varies fourfold (median error ranged from 0.37 mm at the anterior commissure to 1.50 mm at the temporal horns) with heavy-tailed distributions at every landmark. These distributions are compiled into per-landmark reliability priors, so learners are scored against the empirical spread of trained raters rather than an arbitrary threshold, and difficult landmarks are not mistaken for poor performance. The AFIDs-Validator requires no installation, licensed software, or local data, and all code, reference data, and tutor design are openly released.

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Endomicroscopic fluorescence lifetime imaging enables molecular detection and targeted sampling in the distal human lung

Dickson, S. R.; Gaughan, E. E.; Pellicoro, A.; Mills, B.; Haloubi, T.; Demirel, M.; Stewart, H.; Bain, L.; Williams, G. O.; Marshall, A. D.; Wood, H. A.; Young, V.; Bruce, A. M.; Antonelli, J.; Stone, J. M.; Akram, A. R.; Quinn, T. M.; Craven, T.; Haslett, C.; Finlayson, K.; O'Connor, R. A.; Shankar-Hari, M.; Dhaliwal, K.

2026-08-04 microbiology 10.64898/2026.08.04.742476 medRxiv
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PurposeAccurate molecular characterisation of infection and inflammation within the distal human lung remains challenging, particularly in critically ill patients, due to limited access to the alveolar space and delayed diagnostic workflows. Molecular imaging approaches capable of real-time detection and targeted sampling could substantially improve diagnostic precision and the future translational development of molecular imaging probes and therapeutics. MethodsIn a preclinical setting, we evaluated a clinic-ready endomicroscopic fluorescence lifetime imaging microscopy (eFLIM) platform combined with molecularly targeted SmartProbes for in situ detection of bacteria and activated neutrophils in the distal human lung. A multifunctional 1.9-mm diameter imaging and sampling catheter (Eyes on Target; EoT) enabled real-time fluorescence intensity and lifetime imaging alongside directed alveolar microlavage via a 1.2-mm working channel. Fluorescence intensity and lifetime signatures of Gram-negative bacteria, Gram-positive bacteria, and activated neutrophils were characterised using three wash-free SmartProbes: NBD-PMX, Merocy-Van, and a neutrophil activation probe (NAP). Imaging and sampling performance were assessed in ventilated ex vivo human lungs. ResultsEoT reliably navigated to alveolar regions across all lung lobes in both phantom and ventilated human lung models. eFLIM distinguished alveolar microanatomy and enabled probe-specific molecular detection within the distal lung. Increased NBD-PMX signal was detected in Escherichia coli-instilled lobes, while Merocy-Van lifetime signatures selectively identified Staphylococcus aureus-instilled regions. Activated neutrophils were detected throughout lung tissue following NAP administration. Directed alveolar microlavage enabled recovery of cellular material and bacterial DNA from imaged regions for downstream analysis. ConclusioneFLIM using EoT combined with molecular SmartProbes enables real-time molecular imaging and targeted sampling within the distal human lung. This platform provides a translatable approach for evaluating infection and inflammation at the alveolar level and supports the clinical development of molecular imaging probes for pulmonary disease.

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A Wireless Wearable Platform for Intravenous Drug Self-Administration in Freely Behaving Rats

Jeong, E. Y.; Teague, C. D.; Reimert, A.; Cho, S.; Lee, J.; Althoff, T.; Lin, K.; Nair, M.; Leong, T.; Silva, E.; Parker, K. E.; Cahill, C. M.; McCall, J. G.; Jeong, J.-W.; Massaly, N.

2026-09-14 neuroscience 10.64898/2026.09.08.750146 medRxiv
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Studying how drugs act on neuronal circuits requires delivering them with temporal precision while behavior proceeds undisturbed, a combination that tethered infusion systems cannot provide. We developed WEARIT (Wireless Equipment for Autonomous Rat Infusion Tasks), a wearable, tetherless infusion platform that gives freely moving rats intravenous access under either remote or closed-loop operant control. The device houses a reservoir, miniaturized pump, rechargeable battery and Bluetooth circuitry in a 3D-printed enclosure worn on the back. By measuring spontaneous locomotion, amphetamine-induced hyperlocomotion and food-reinforced operant responding, we show that WEARIT leaves these behaviors unchanged. Remotely triggered fentanyl infusions yielded reliable delivery with physiological responses confirmed by pulse oximetry, and self-administration acquisition and dose-response functions were comparable to conventional tethered systems. WEARIT removes a longstanding constraint on intravenous pharmacology, opening self-administration paradigms to naturalistic and enriched environments and to concurrent imaging or optogenetic manipulation of the circuits engaged by drug reinforcement.

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Adapting Social Operant Paradigms to Measure Postpartum Maternal Motivation

Ku, S. A.; Nyakoa, J.; Miranda, G.; Bangasser, D. A.

2026-08-25 animal behavior and cognition 10.64898/2026.08.20.746000 medRxiv
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Operant paradigms are powerful tools to quantify motivation and reward. Traditionally, operant conditioning research has been limited to food and drug reinforcers. Recent advances in commercially available operant equipment, however, allow for the quantification of social motivation. These operant assays are an improvement over commonly used social preference tasks, as they enable direct measurement of the effort and motivation driving social behavior. Based on a design by Venniro et al. (2020), the MedPC social operant boxes modify the traditional operant box setup for social interactions. The experimental rat can lever-press to raise a door for an interaction with a target rat behind a porous barrier. These social operant boxes have been widely adapted to test social behavior in adult and adolescent rodents and investigate how a range of conditions (e.g. stress, drug taking, etc.) affect social motivation. However, there is a gap in assessing maternal motivation for pups during the postpartum period, despite ample evidence that postpartum social behavior is highly relevant for offspring health outcomes. Here, we detail 3D-printed modifications to the standard Med PC social operant boxes to adapt the social target chamber to safely house neonatal pups. We have also developed testing protocols to assess motivation during the limited postpartum period. These data demonstrate that, with simple modifications to social operant chambers and testing protocols, the field can implement advanced behavioral approaches to directly assess maternal motivation.

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Evaluating home-cage-activity metrics for detecting postprocedural pain in a plantar incision mouse model

Malmberg, M. E.; Bertelsen, T.; Bollen, P.; Abelson, K.; Hestehave, S.; Kalliokoski, O.

2026-09-25 animal behavior and cognition 10.64898/2026.09.23.753854 medRxiv
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Detection of postoperative pain in mice is challenging, and there is a need for unbiased, automated methods. Home-cage monitoring systems are promising, but their ability to detect mild pain remains unclear. We evaluated whether home-cage activity measures can be used to detect pain-related changes in a plantar incision model of postoperative pain. First, we confirmed the presence of local hypersensitivity using von Frey filaments on 48 C57BL/6JRj mice (24 males, 24 females). Subsequently, we pair-housed 64 mice (32 males, 32 females) and allocated them to receive either a 4 mm plantar incision on the hind paw under anaesthesia, or anaesthesia alone. Baseline locomotion and voluntary wheel-running activity were recorded over five days, followed by four days of postprocedural monitoring in the home cages. Both procedure groups (incision and anaesthesia-only) showed reduced locomotion and running wheel activity relative to baseline. However, activity measures did not differ between incised and anaesthesia-only mice, and we detected no sex-related effects. Under these conditions, home cage activity measures did not reliably discriminate pain-related behavioural changes in the model, despite the model showing local mechanical hypersensitivity in the von Frey test. Together, these findings indicate that, given the mild and localised nature of the plantar incision mouse model, commonly used home-cage metrics cannot yet reliably detect subtle pain-related behavioural changes.

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PixelPaws: a low-cost, open-source integrated platform for automated scoring of mouse behaviors

Slivicki, R. A.; Wang, H.; Mwirigi, J. M.; Kucz, K.; Hua, H.; Creed, M. C.; Gereau, R. W.

2026-09-24 neuroscience 10.64898/2026.09.19.752787 medRxiv
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Behavioral scoring is central to preclinical pain research but is typically performed manually, which is inherently low-throughput and subject to variability between observers. Automated alternatives exist, but cost and programming expertise limit adoption beyond the laboratories that build them. Here we describe PixelPaws, an open-source platform combining a near-infrared imaging enclosure built from consumer parts for under $300, multi-camera acquisition software, a bundled pose-estimation network, and eight classifiers in a graphical user interface. We evaluated the platform across standard assays of pain, itch, and opioid withdrawal. Licking, scratching, and jumping classifiers were validated against trained human observers by leave-one-session-out evaluation. In the formalin assay, classifier-scored licking followed the expected biphasic time course and was reduced dose-dependently by oxycodone, with a phase 2 potency estimate comparable to blinded manual scoring. Chloroquine roughly tripled scratching, and naloxone precipitated a burst of jumping in oxycodone-treated mice. From the same recordings we derived a set of paw contour metrics. Contour intensity fell after formalin and tracked the oxycodone dose series, and contour area shifted toward symmetry after oxycodone in nerve-injured mice. Behavioral sequencing revealed distinct changes in the transi

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Modeling Risk Group 4 virus infection and antiviral treatment in microfluidic lung organ-on-chips in maximum containment laboratories

Bhosle, S. M.; Tran, J. P.; Yu, S.; Geiger, J.; Das, A.; Anthony, S. M.; Pahar, B.; Bernbaum-Cutler, R.; Rivera, D. F. P.; Crozier, I.; Wada, J.; Crane, A.; Palacios, G.; Kleinstreuer, N. C.; Kuhn, J. H.; Worwa, G.

2026-08-25 microbiology 10.64898/2026.08.24.745299 medRxiv
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Development of candidate countermeasures against human pathogens frequently includes nonhuman animal experimentation. Preclinical animal pathogen exposure studies are conducted to model diseases and accumulate preliminary and hypothetically translatable data to inform and justify the design of clinical trial evaluation of countermeasure safety and efficacy. In addition to frequent ethical critiques, challenges associated with animal experimentation include considerable resources needed to achieve statistical power and robustness, replicability and reproducibility concerns, potentially compromised objectivity through lack of blinding, fundamental species-specific biological differences, and risk of unpredictable pathogen adaptation to the experimental animal. Recent U.S. and U.K. government initiatives aim to reduce animal experimentation by complementing or potentially replacing them with new approach methodologies (NAMs), i.e., increasingly sophisticated in silico, in chemico, and in vitro approaches. We piloted development of one type of NAM, organ-on-chips (OOCs), in the highly challenging environment of a maximum (biosafety level 4) containment laboratory. Using a Risk Group 4 virus, Nipah virus (NiV), and two types of lung OOCs seeded with human or porcine cells, we demonstrated the recapitulation of key features of NiV lung infection, including viral infection, replication, and translocation, that are associated with proinflammatory cytokine secretion, immune cell recruitment, and disruption of the air-liquid interface barrier. We reproduced the known anti-NiV activity of remdesivir and evaluated that of another potential antiviral, zotatifin. Our results pave the way for similar applications of advanced microphysiological systems for modeling infections caused by high-consequence viruses.

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Translational Pharmacokinetics and Pharmacodynamics of a Cationic mRNA-Lipid Nanoparticle from Mice to Non-Human Primates

Dunne, C. M.; Radloff, K.; Gkionis, L.; Kahwaji, N.; Hartl, N.; Keil, O.; Fischer, A.; Maass, G.; Santel, A.; Tondera, D.; Kaufmann, J.

2026-09-29 pharmacology and toxicology 10.64898/2026.09.23.749423 medRxiv
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Cationic lipid nanoparticles have demonstrated unique potential for extrahepatic mRNA delivery, particularly enabling selective targeting of the pulmonary endothelium. However, their translational development has been hampered by reports of infusion-related immune reactions and innate immune system activation, most notably transient complement activation. Here, we present a case study illustrating the discovery and translational advancement of a selected cationic LNP into non-human primates (NHPs) for initial pharmacokinetic assessment and evaluation of potential immunostimulatory side effects. We show surface charge dependent organ-selective expression of reporter mRNAs from different LNPs in vivo. An mRNA encoding the Tie2 agonist COMP-Angl, was formulated with LNP002, and respective pharmacokinetic and pharmacodynamic readouts were analyzed in two independent non-human primate studies. Notably, dose-dependent transient complement activation could be abrogated by extending the infusion time. Finally, we identified the blood-borne pharmacodynamic biomarker PDGFB for LNP002/mRNA-76 treatment reflecting activated Tie2-signalling in healthy pulmonary endothelium in vivo supported by single cell sequencing and cluster-alignment of downstream effector genes with the same spatial profile as the delivered mRNA.

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Toward standardized behavioral analysis in IntelliCage experiments

Musacchio, F.; Fuhrmann, M.

2026-09-13 animal behavior and cognition 10.64898/2026.09.06.749703 medRxiv
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Automated home-cage systems measure individual behavior in social groups for days to months. Among these systems, the IntelliCage has become a widely used platform for longitudinal and socially embedded behavioral phenotyping. Yet the analysis layer often remains less standardized than the experiment itself: raw exports, phase definitions, exclusion rules, time alignment, and derived behavioral metrics are transformed by lab-specific scripts that are difficult to audit, compare, or reuse. We present ic-analysis, an open-source Python toolkit for standardized, scriptable, and shareable IntelliCage workflows. The toolkit separates user-defined experiment metadata and workflow scripts from a reusable analysis core with modular analysis and plotting functions, allowing users to flexibly assemble experiment-specific pipelines without editing package internals. Due to its modular design, the analysis core can be applied to a broad range of experimental paradigms, including general activity, exploratory, motivational, cognitive, and social readouts, rather than being limited to a single fixed protocol. It aligns biological phase windows across staggered cage runs and exports plots together with quantitative result tables, applied settings, and audit files that support reproducible and FAIR reporting. Here, we demonstrate this flexible design in a realistic synthetic place-learning/place-reversal experiment with two mouse groups and deliberately offset cage starts. The workflow recovered the implanted behavioral differences while preserving the required experimental-time alignment. Group A showed stronger endpoint saccharin preference (81.7 +/- 1.7% vs. 27.4 +/- 3.4%, p = 1.9e-), higher liquid uptake, faster place-learning onset (56.6 +/- 8.1 vs. 278.3 +/- 33.2 visits), and better reversal performance (64.1 +/- 1.3% vs. 25.6 +/- 1.7% rewarded correct-corner visits) compared to Group B. This demonstration shows how standardized, explicitly defined readouts can turn complex IntelliCage exports into interpretable behavioral profiles while preserving the analysis history needed for inspection and reuse. ic-analysis therefore provides both a working analysis scaffold and an extensible, community-friendly route toward IntelliCage workflows that are easier to reproduce, compare, extend, and share.

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Socially dominant male mice in social hierarchies identified via automated RFID tracking exhibit elevated activity levels and circulating markers of higher metabolic demand

Seese, S. O.; Milewski, T. M.; Fusillo, M.; Curley, J.

2026-08-27 animal behavior and cognition 10.64898/2026.08.26.747333 medRxiv
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Dominance hierarchies are a fundamental aspect of social organization, enabling animals to minimize aggression and optimize access to resources. Previous studies have highlighted the energetic and physiological demands of dominant status, as well as the behavioral flexibility required of subordinates to navigate these hierarchies. Despite advancements in automated behavior tracking, limitations persist in tracking fine-scale, real-time interactions within complex social environments. Here, we developed and validated a novel RFID-based system to continuously monitor dominance hierarchies in group-housed male mice over 10 days. This system enabled unbiased behavioral inference across light phases and revealed spatial and temporal patterns of dominance behavior undetectable through traditional live-scored methods. Automated tracking accurately identified alpha individuals and consistently inferred linear hierarchies across cohorts, with greater precision for higher-ranked individuals. Behavioral metrics, such as transition frequencies and proximity to food zones, were consistent with dominance driven activity. Hormonal analyses revealed that higher-ranked mice exhibited increased leptin and peptide YY, consistent with heightened activity and satiety signaling, while lower C-peptide levels reflected greater metabolic demands of dominance. Furthermore, dominance rank was associated with differences in light-dark activity, which were in turn related to circulating hormone profiles. This study demonstrates the utility of automated RFID tracking in capturing dominance hierarchies with temporal and spatial granularity, while revealing links between social rank, metabolic regulation, and activity patterns advancing our understanding of social behavior dynamics.

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NC4touch: An open-source networked touchscreen apparatus for rodent behavioral testing

Modara, G.; Lester, A. W.; Cooke, M.; Schwein, I.; Li, V.; Zhang, J.; Wong, A.; Cid, L.; Snyder, J. S.; Madhav, M.

2026-08-04 animal behavior and cognition 10.64898/2026.07.30.741621 medRxiv
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In recent years, rodent touchscreen-based paradigms have gained popularity for their flexible task design, automated data collection and improved standardization. These devices minimize experimenter intervention and contribute to more replicable and reliable research. However, the high costs and proprietary hardware / software associated with commercially available systems present a financial barrier for smaller labs or researchers with limited resources. To address this issue, we developed "NC4Touch", an open-source scalable, modular rodent testing apparatus. It features three independent touchscreens and a feeding port for easy use in a wide array of tests comparable to those available with standard operant chambers, with the added benefit that visual stimuli can be highly customized. The system includes a user-friendly graphical interface that offers real-time control, task customization, video recording, and data management. We demonstrate its effectiveness in a visual discrimination task using both rats and mice. Several devices can be operated in parallel from the same computer and user interface, allowing high- throughput data collection. We provide detailed assembly instructions for the hardware and well- documented and easily-configurable software. We hope that the affordable open-source nature of NC4Touch will expand the scope of behavioral testing, allowing researchers to overcome traditional financial barriers and create a more collaborative community. Significance StatementTouchscreen-based testing is a powerful tool for assessing cognition in rodent models, however commercial systems remain cost-prohibitive for many researchers. NC4Touch is a rodent touchscreen apparatus that provides an open-source, customizable, and affordable alternative that enables high-throughput, cognitive testing in both mice and rats. By lowering financial barriers and promoting hackability, this system enables greater accessibility and collaboration in research.

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Ultrasonic potentiation of ketamine neuromodulation

Sinha Roy, K.; Martinez, P.; Ewbank, S.; Shinozuka, K.; Purohit, M.; Xiang, Y.; Airan, R.

2026-08-04 pharmacology and toxicology 10.64898/2026.07.29.741494 medRxiv
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The psychiatric utility of ketamine is limited by its dissociative and systemic side effects. Recently, to enable precision ketamine pharmacotherapy, we introduced SonoKet, ketamine-loaded acoustically activatable liposomes that enable focused ultrasound (FUS)-targeted ketamine delivery to millimeter-sized brain regions. In initial studies, we observed that SonoKet uncaging targeted ketamine to the ultrasound-treated brain region, while inducing greater electrophysiologic and behavioral functional effects than dose-matched free ketamine. To further define these uncaging-potentiated neuromodulatory effects, we used solid-phase microextraction (SPME) coupled to LC-MS/MS to investigate the effect of ultrasound and SonoKet uncaging on key neurotransmitters in real-time. SPME probes were used to sample ketamine, its metabolites, and glutamate, GABA, serotonin (5-HT), and dopamine in the medial prefrontal cortex (mPFC), nucleus accumbens (NAc), and retrosplenial cortex (RsC) of awake rats. Sampling occurred before and after intravenous administration of either SonoKet, free ketamine, or saline, with FUS targeted to either a frontolimbic or caudal brain region. FUS alone did not yield significant changes in neurotransmitter concentration, nor did it affect the pharmacodistribution of free ketamine. In contrast, FUS generally increased the neurotransmitter response to free ketamine, suggesting an ultrasonic potentiation of ketamine neuromodulation. SonoKet (0.75 mg/kg) uncaging with FUS elicited further elevations in glutamate, GABA, and 5-HT within the FUS-targeted region, along with an increase in dopamine in the NAc when the frontolimbic region was sonicated. These increases were similar to or higher than those induced by 10 mg/kg free ketamine alone or 0.75 mg/kg free ketamine combined with FUS, especially with frontolimbic SonoKet uncaging. Altogether, FUS potentiates ketamine-induced neuromodulation, with spatially specific and synergistically greater effects when ketamine is spatially localized via ultrasonic uncaging. This strategy could augment ketamine pharmacotherapy for psychiatric diseases, while limiting its dissociative and abuse liabilities. HighlightsO_LIFocused ultrasound potentiated ketamine-driven glutamate, serotonin, and dopamine release C_LIO_LILocalized ketamine delivery with SonoKet uncaging drove synergistically greater region-specific neurochemical responses C_LIO_LIUncaging boosts ketamine effects at a fraction of the ketamine dose C_LI Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=152 SRC="FIGDIR/small/741494v1_ufig1.gif" ALT="Figure 1"> View larger version (52K): org.highwire.dtl.DTLVardef@1745214org.highwire.dtl.DTLVardef@1b8e06borg.highwire.dtl.DTLVardef@95a840org.highwire.dtl.DTLVardef@15924ed_HPS_FORMAT_FIGEXP M_FIG C_FIG

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Impact of opioid-based versus opioid-free anaesthesia on postoperative recovery, circulating inflammatory cytokines and brain-derived neurotrophic factor.

Gricourt, Y.; Lin, K.; Althoff, T.; Nguyen, E.; Mattern, A.; Nair, M.; Leong, T.; Silva, E.; Grogan, T. R.; Massaly, N.

2026-10-01 animal behavior and cognition 10.64898/2026.09.25.754530 medRxiv
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Background Opioid-free anaesthesia (OFA) has emerged as an alternative to opioid-based anaesthesia (OBA), but its benefit over OBA for postoperative quality of recovery (QoR) remains unclear. To address this question while limiting variability inherent in clinical studies, such as analgesic regimens and patient psychosocial factors, we investigated the effects of OFA versus OBA on postoperative recovery in a controlled preclinical mouse model. Methods Adult male and female C57BL/6J mice underwent laparotomy or sham procedures under isoflurane anaesthesia, and were randomly assigned to saline (control), fentanyl (OBA), or dexmedetomidine (OFA) as intraoperative analgesic adjuncts. All mice received multimodal postoperative analgesia, including carprofen. We adapted a standardised multidimensional recovery model using six behavioural endpoints reflecting human QoR domains: body weight, food intake, locomotor activity, mechanical sensitivity, sucrose preference, and social interaction. These endpoints were assessed on postoperative days 1, 2, 3, and 7. Plasma inflammatory cytokine and brain-derived neurotrophic factor (BDNF) concentrations were also measured in parallel as potential biological correlates of recovery. Results Over the study period, we observed no treatment effect across behavioural endpoints in laparotomised mice, including body weight (P=0.157), food intake (P=0.884), locomotor activity (P=0.864), mechanical sensitivity (P=0.628), sucrose preference (P=0.615), and social interaction (P=0.442). Composite QoR scores did not differ between OFA and OBA groups (P=0.569), with no differences in postoperative circulating inflammatory cytokine or BDNF concentrations. Conclusions Dexmedetomidine-based OFA and fentanyl-based OBA produced similar postoperative behavioural recovery, circulating inflammatory cytokine and BDNF trajectories in laparotomised mice receiving multimodal postoperative analgesia.

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Xenon improves autism-like behaviors in mice through potentiation of PVT-CeA glutamatergic neurotransmission

Zhu, J.; Ruan, Y.; Weng, J.; Xu, X.; Wu, Z.; Yu, Y.; Li, H.; Li, X.; Tong, J.; Ou, Y.; Shu, Q.; Ma, D.

2026-09-25 animal behavior and cognition 10.64898/2026.09.23.753714 medRxiv
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Autism spectrum disorder (ASD) is a common neurodevelopmental disease with no currently effective treatments. In this study, Xenon (Xe), a noble gas used clinically as an anesthetic and a neuroprotectant, has been investigated for its potential therapeutic effects in ASD. Two genetic ASD mouse models (Mef2c mutant and Shank3-/- mice) were exposed to a low concentration of xenon (25%) mixed with oxygen (30%) and balanced with nitrogen for a single exposure of 30 min or for 10 min per day for 10 days. These Xe exposure paradigms rescued ASD-like behaviors in both male and female mice. The behavioral improvements persisted for up to 10 days following termination of the 10-day exposure paradigm. Mechanistically, Xe reduced glutamic acid decarboxylase expression in the inhibitory neurons (verified with RNAseq) of the paraventricular thalamic nucleus (PVT) and decreased GABA release during social interaction. Targeted infusion of the GABAA receptor agonist muscimol into the PVT abolished the Xe-mediated behavioral improvements. Reduced GABAergic transmission following Xe exposure increased PVT glutamatergic neuronal activity. Chemogenetic inhibition of these neurons eliminated the therapeutic effects of Xe, whereas chemogenetic activation mimicked the Xe-induced behavioral improvements. Furthermore, opto-inhibition of PVT glutamatergic projections to the central amygdala (CeA) blocked Xe-mediated behavioral improvement. Opto-activation of the PVT-CeA glutamatergic circuit reversed ASD-like behaviors. These findings demonstrate that Xe ameliorates ASD-like phenotypes in mouse models by modulating the PVT Glu-CeA circuit, supporting Xe as a novel potential therapy for ASD.

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Multispecies translational evaluation of an NMDA receptor modulator reveals analgesic, autonomic-stabilizing, and stress mitigating effects without evidence of abuse liability

Tuohy, J.; Ishihara, T.; Govindasamy, S.; Anandakrishnan, R.; Davis, J. L.; Harrison, F. E.; Huang, Y.; Chen, S.-R.; Pan, H.-L.; Costa, B.

2026-09-18 pharmacology and toxicology 10.64898/2026.09.14.751462 medRxiv
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CNS4 is an agonist concentration-biased NMDAR modulator exhibiting GluN2 subtype-dependent activity. Here we evaluated the translational pharmacology of CNS4 across mice, rats, and client-owned surgical oncology dogs. In mice, CNS4 did not produce conditioned place preference, indicating lack of reward liability. CNS4 produced dose-dependent reductions in locomotor activity without motor impairment on accelerating rotarod testing. CNS4 also maintained body temperature 0.5 to 1 degree Celsius above the vehicle group in mice and dogs, consistent with NMDAR-dependent thermoregulatory activity and contrasting with hypothermic effects reported for NMDAR channel blockers such as ketamine. In fear-conditioning paradigms, CNS4 did not impair fear learning, memory consolidation, or fear expression. CNS4 reduced acute stress-induced sucrose preference, suggesting modulation of stress-responsive neural circuits. In a rat spinal nerve ligation model of neuropathic pain, both single-dose and three-day repeated CNS4 administration significantly reversed mechanical, pressure, and thermal hypersensitivity, supporting analgesic efficacy with no apparent evidence of rapid tolerance development. In client-owned surgical oncology dogs undergoing standard veterinary procedures, preliminary findings from 14 dogs (8 CNS4-treated, 6 vehicle-treated) demonstrated stable intraoperative mean arterial pressure and heart rate. Postoperatively, CNS4-treated dogs exhibited normal physiological recovery, with respiratory rate, heart rate, and body temperature returning toward the normal canine range, and required approximately 8% less propofol for anesthetic induction. Collectively, these findings support CNS4 as a novel NMDAR modulator with thermoregulatory, anti-agitative, analgesic, and autonomic-stabilizing properties without evidence of abuse liability, supporting continued translational development for neuropathic pain and possibly neuropsychiatric disorders.

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Internal Grant Review: A Pre-Submission Program for Early-Career Clinical and Translational Researchers

Harrigan, A. M.; Johnston, K. C.; Kirkham, J.; Papin, J. A.

2026-09-28 scientific communication and education 10.64898/2026.09.21.753152 medRxiv
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The iTHRIV Scholars Mentored Career Development Program initiated an Internal Grant Review (IGR) program in 2020 for current and recently graduated Scholars seeking funding through K and R awards from the NIH. The IGR program is designed to replicate the NIH review process and provide Scholars the opportunity to receive valuable feedback on their applications prior to NIH submission. A key characteristic of the program is the integration of REDCap, enabling automation and year-round offering while improving tracking and reporting efforts and capabilities. Results of the program have been overall positive, both in proposal development and participant feedback. IGR is a sustainable, valuable resource for early-career faculty competing for limited resources in the pursuit to become independently funded clinical translational scientists.

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LNP-CpG: deploy the self-adjuvant role of mRNA vaccines

Luan, N.; Cao, H.; Zhang, X.; Yang, F.; Lu, C.; He, Y.; Li, Q.; Bi, Y.; He, Z.; Fan, S.; Liu, L.; Wan, S.; Liu, C.

2026-08-23 immunology 10.64898/2026.08.19.745633 medRxiv
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With the rapid advancement of mRNA vaccines, lipid nanoparticles (LNPs) have emerged as pivotal carriers and adjuvants for non-mRNA vaccine modalities, driven by their superior nucleic acid delivery efficiency and intrinsic self-adjuvanting properties. In this study, we systematically evaluated various formulation strategies combining LNPs and the CpG adjuvant within a varicella-zoster virus glycoprotein E (VZV-gE) subunit vaccine framework. We demonstrated that uniform nanoparticles formed by LNP-encapsulated CpG (LNP-CpG), when simply admixed with the gE antigen, elicited superior immunogenicity compared to alternative encapsulation configurations. Intramuscular administration of a two-dose (LNP-CpG)+gE regimen significantly augmented both humoral and cellular immune responses in mice, markedly outperforming the commercial vaccine Shingrix (administered at a 1/10 human dose). Crucially, the identical regimen induced robust, comparable immune profiles to a full human dose of Shingrix in rhesus macaques. Furthermore, LNP-CpG displayed broad-spectrum utility across diverse vaccine platforms, demonstrating efficacy against both respiratory (RSV) and neurotropic (HSV) pathogens, compatibility with multiple modalities, including subunit (VZV-gE, RSV-Pre-F), live-attenuated (LA-HSV), and inactivated (i-HSV) vaccines; and versatile implementation in a combined VZV+RSV formulation. Collectively, our findings position LNP-CpG as a versatile, safe, highly efficacious adjuvant platform with substantial clinical translational potential, offering a compelling paradigm for next-generation vaccine development.