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Results for “animal behavior and cognition”

Search indexed bioRxiv preprints in genomics, neuroscience, cell biology and bioinformatics. Read source abstracts and check manuscript versions; preprints are not peer reviewed.

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Detection of Frustration-related Operant Behavior in Rats via Machine Learning Methods

Despite its strong link to neuropsychiatric conditions, frustration remains critically understudied in humans and animals alike. Therefore, there is an urgent need to develop tools to understand and therapeutically target frustration-related functions. Interestingly, humans and rats respond similarly during frustrative nonreward by increasing barpress durations. We previously validated barpress duration in rat operant tasks as a reliable measure of frustration-related behavior; however, it is wellknown that in addition to duration of responding, emotional states such as frustration alter other aspects of responding such as force of pressing. One-dimensional, static measures such as maximum force could miss rich information contained within operant data. Thus, the objective of this study is to apply machine learning (ML) to force/time profiles to discriminate frustration-related barpresses from non-frustration-related barpresses. Results showed an AUROC for FR1 (i.e., non-frustrated) vs. extinction (frustrated condition) for individual barpresses of 0.65 that improved to 0.84 with a chunk size of 10. The model generalized well to progressive ratio responding, a different kind of frustration procedure. We conclude that force/time profiling does provide utility beyond one dimensional measures of duration or force separately, meaning that we can indeed infer the internal state of frustration from behavior using ML techniques. Importantly, this project will also serve as proof-of-concept for applying ML to predict other internal states from barpress data.

animal behavior and cognition

Autism-risk gene mutations convergently disrupt sexually dimorphic oxytocin circuits to lower social engagement

Autism arises from diverse genetic risk factors, yet how they converge to produce core symptoms and contribute to its sex bias remains unestablished. Oxytocin increases sociability in multiple murine autism models, presenting an opportunity to identify a potentially shared mechanistic basis across etiologies. Here we show that spontaneous social investigation triggers overlapping patterns of aberrant functional connectivity across social and sensory brain regions in two knockout (KO) mouse models, which are rescued by oxytocin. We also report that, during social investigation, wildtype mice exhibit sexually dimorphic oxytocin release and neuronal activity dynamics in the nucleus accumbens and the amygdala. These patterns are disrupted in both KO models, but can be restored by sex- and circuit-specific stimulation of endogenous oxytocin release, accompanied by enhanced social engagement. These findings identify impaired oxytocin recruitment of sexually dimorphic social circuits as a convergent consequence of autism-risk gene mutations that may underlie low sociability.

animal behavior and cognition

Rapid phase resetting of Aedes aegypti circadian rhythms by transient alterations in light exposure

Circadian clocks enable mosquitoes to anticipate recurring environmental variations and coordinate behaviors critical for survival and disease transmission, such as locomotion, reproduction, host-seeking, and blood-feeding, with times of day when performance is maximal. In Aedes aegypti, locomotor activity follows a robust diurnal rhythm shaped by endogenous circadian clocks and environmental cues, among which light has been shown to be the primary source of temporal information. While early studies established the role of light in regulating locomotor activity, behavior, oviposition and pupation, it remains unclear which features of a light cycle drive changes in circadian rhythms. This question is increasingly relevant as Ae. aegypti is frequently exposed to artificial and dynamic lighting conditions in urban environments. Here, we investigated how transient changes in light schedules influence circadian rhythms in locomotor activity by systematically manipulating the timing, duration, and direction of light exposure. Using a high-throughput assay, we tested over 1900 individuals, including wild-type and timeless knockout mutants, and showed that a single day of al tered lighting is sufficient to induce robust phase shifts, with no evidence of masking effects. A 6-hour light pulse was sufficient to re-entrain mosquitoes regardless of the timing of the pulse, and phase shifts were primarily driven by the offset time of the light pulse, indicating that light-offset acts as a major zeitgeber. Together, these findings challenge conventional assumptions about the timescale of circadian synchronization and highlight the remarkable plasticity of mosquito behavior in response to anthropogenic light. Eventually, these effects could explain the rapid adaptation of the species to urban environments and have potential consequences for disease transmission dynamics.

animal behavior and cognition

Copulation calls indicate fertility but do not reflect female mate competition in wild Guinea baboons

Across different modalities, signals play a core role in attracting mates and influencing mating success. In several non-human primate species, females produce calls during mating that are thought to promote male competition over receptive females. The extent to which social system characteristics modulate the function of copulation calls remains less clear. We studied copulation calls in wild Guinea baboons (Papio papio), who live in a multilevel society structured around units in which females associate and mate almost exclusively with a single male. We hypothesised that females use copulation calls as an indirect form of mate competition, with competition increasing in larger units. In addition, we hypothesised that females are more likely to mate again after calling. We analysed 6116 copulations between 2014 and 2025, involving 99 reproductively active females and 78 subadult and adult males. Females produced copulation calls in 72.7% of copulations, with large inter-individual variation. Neither unit size nor its interaction with the female's swelling size or the presence of simultaneously receptive females affected the probability of calling. A survival analysis with a subset of the data (2353 copulations) revealed no effect of calling on the latency to the next mating. Our results render the hypothesis that female Guinea baboons use calls in indirect mate competition unlikely. Yet, the probability of calling varied with sexual swelling size, suggesting that calls signal female fertility. Possibly, Guinea baboon copulation calls represent an evolutionary remnant, no longer under selective pressure, and can be considered index signals of female fertility.

animal behavior and cognition

Sport expertise and motor imagery abilities shape sensorimotor rhythm modulations during visualisation tasks: Implications for neurofeedback-based cognitive training in athletes

Kinaesthetic motor imagery (kMI) is widely used in sport to enhance motor performance by engaging cortical sensorimotor networks. Neurofeedback may further support kMI, but the optimal neural target to reinforce remains unclear. Maximal sensorimotor event-related desynchronisation (SMR-ERD) represents a relevant target as it may index sensorimotor cortex engagement, yet sport expertise has been associated with reduced SMR-ERD, potentially reflecting neural efficiency. The optimal neurofeedback target may therefore depend on sport expertise, movement expertise, and individual kMI ability. This study examined how these factors influence sensorimotor activity during kMI. We compared 17 basketball players (Experts) and 16 individuals without formal basketball training (Novices). kMI ability and frequency of use were assessed using questionnaires, while SMR-ERD was quantified using electroencephalography (EEG) during kMI. Participants imagined either a basketball-specific movement (Free throw), for which only Experts had extensive experience, or a generic movement (Box lifting), familiar to both groups. Experts reported greater kMI ability and more frequent kMI use than Novices. Only Experts exhibited significant and sustained SMR-ERD during kMI. Moreover, SMR-ERD was stronger in Experts than Novices specifically during Free throw kMI, corresponding to their movement of expertise. Nonetheless, within the Expert group, higher kMI ability was associated with reduced SMR-ERD. These findings suggest that sport expertise initially enhances voluntary recruitment of sensorimotor networks during kMI, whereas greater kMI ability may subsequently promote neural efficiency, resulting in reduced overall sensorimotor cortical activation. These results highlight the need to tailor kMI-based neurofeedback training to users' sport expertise and kMI ability levels.

neuroscience

Layer 5 anterior cingulate cortical neurons engage dorsolateral periaqueductal gray excitatory neurons to facilitate the affective component of pain

Pain is a conscious perceptual experience characterized by its aversive quality and consequent motivation to quench pain perception. The anterior cingulate cortex (ACC) critically contributes to the emotional dimension of pain. In both humans and rodents, ACC neural activity increases during acute and chronic pain, whereas ACC lesioning or excitability reduction decreases emotional reactivity during pain. However, the ACC is connected to many brain regions and is engaged during experiences beyond pain. Thus, it remains unclear through which circuit mechanisms the ACC shapes pain experience, and how specific those circuits are to nociception. Here, we show that excitatory input from the ACC to the dorsolateral periaqueductal gray (dlPAG) facilitates the affective-motivational dimension of pain. We first examined ACC[->]dlPAG connectivity using histology, optogenetics, and electrophysiology. We found that the axons of layer 5 ACC neurons terminate in the dlPAG and monosynaptically excite Slc17a6+ (VGLUT2-expressing) dlPAG neurons. Second, we genetically targeted ACC[->]dlPAG neurons with viral vectors to express the inhibitory DREADD hM4Di and then exposed the animals to an array of pain tests. We found that, across acute and chronic pain states, inhibition of the ACC[->]dlPAG pathway reduced affective-motivational but not reflexive pain behaviors. Third, we used fiber photometry to record neural calcium activity in the ACC in behaving mice and found that ACC[->]dlPAG neurons are engaged during a broad array of aversive experiences, rather than exclusively during pain, and exhibit task-specific activity patterns. Collectively, these results uncover the direct contribution of ACC[->]dlPAG neural activity to pain unpleasantness and the necessity of this pathway for generating aversive behavioral responses in general, rather than specifically for encoding the unpleasant quality of noxious stimuli.

neuroscience

Rapid repurposing of microvillar content drives a flagellate-to-amoeboid switch in the closest relative of animals

Animal cells extensively remodel their cytoskeleton during differentiation and can notably switch between two major motility modes: flagellum-based swimming and actin-based crawling. We previously showed that choanoflagellates, the closest living relatives of animals and classically viewed as obligate flagellated swimmers, can retract their collar complex and adopt an amoeboid form within seconds under spatial confinement, independently of regulated gene expression. Here, using live imaging, ultrastructural expansion microscopy, and cryo-electron tomography in Salpingoeca rosetta, we identify rapid, cell-wide cytoskeletal remodeling as the ultrastructural basis of this switch. Unconfined choanoflagellates lack a detectable actin cortex but display an apical flagellum and cortical microtubules, with F-actin being largely restricted to microvilli. Confinement triggers calcium release from intracellular stores, which induces microvillar retraction and absorption of microvillar material into the cell body, including actin, ezrin-radixin-moesin 1, and plasma membrane. Remodeling of the internalized F-actin and repurposing of associated proteins supports de novo actin cortex formation, which is necessary for amoeboid motility. In parallel, cortical microtubules are disassembled, and the reabsorbed microvillar plasma membrane increases the surface area of the cell body, allowing the cell to flatten under confinement. Cryo-electron tomography reveals stepwise actin reorganization from internalized microvillar bundles to a cortical contractile meshwork combining bundles and scattered filaments. This work reveals considerable ultrastructural plasticity in the cytoskeletal architecture of choanoflagellates and supports an ancestral role for microvilli as reservoirs of membrane and cytoskeleton to potentiate cell phenotypic transitions.

evolutionary biology

AVOCODO: An open-source multimodal annotation platform for developmental EEG

Behavioral annotation of synchronized video recordings is an essential step in developmental electroencephalography (EEG) research, supporting both the identification of behavior-related artifacts and the investigation of brain-behavior relationships. Existing annotation workflows, however, are often fragmented: proprietary EEG software provides limited flexibility for behavioral coding, whereas dedicated behavioral annotation platforms typically lack native integration with EEG data. We developed AVOCODO (Audio/VideO CODing Optimization), an open-source MATLAB-based software platform that integrates synchronized behavioral annotation directly into the EEG workflow. AVOCODO reads native EGI MFF recordings, synchronizes embedded video with EEG, visualizes the audio spectrogram to facilitate precise annotation of vocalizations, and writes user-defined behavioral events directly back into the original MFF recording as native EEG event markers while simultaneously exporting annotations as CSV files. The software supports fully customizable behavioral coding schemes, optional EEG visualization for quality control, and reloading of previously annotated recordings for review and inter-rater verification. Since its initial development in 2024, AVOCODO has been applied internally across five developmental EEG studies involving approximately 500 pediatric participants and more than 3,000 EEG recordings. By bridging behavioral annotation and EEG preprocessing within a unified open-source workflow, AVOCODO has the potential to improve the efficiency, reproducibility, and scalability of behavioral annotation in developmental EEG research.

bioinformatics

Entorhinal grid coding as a functional link between tau accumulation and episodic memory in human aging

Episodic memory decline is a common feature of cognitively normal aging, but its extent varies markedly across individuals. Although entorhinal tau pathology is thought to be a key contributor to episodic memory impairment, the neural mechanisms linking early tau accumulation to memory differences remain unclear. Grid-cell computations in the entorhinal cortex, which provide scaffolds for organizing experiences into episodic memories, offer one candidate mechanism. Here, we combined virtual-reality functional MRI, multivariate analysis, tau PET, and delayed word-list recall in cognitively normal older adults to test whether tau-related alterations in entorhinal coding are associated with worse episodic memory. Weaker left entorhinal grid-cell-like signal was associated with poorer memory performance, and individuals with higher left entorhinal tau burden showed weaker grid-cell-like signal. This association was specific to the canonical six-fold signal and was not explained by entorhinal volume, mean diffusivity, or intracortical myelination. A cross-sectional Bayesian mediation analysis further demonstrated that bilateral medial temporal tau burden is related to memory indirectly through left entorhinal grid-cell-like signal. Together, these findings provide evidence that entorhinal grid codes may constitute a functional pathway linking tau accumulation to memory variability in normal aging.

neuroscience

Linking continuous behavior to aesthetic enjoyment in a walkable virtual-reality museum tour: effects of agency and a painting-level analysis framework

Museum visits typically follow curator-defined routes that constrain how visitors shape their own experience, yet choice is widely held to heighten engagement, autonomy, and enjoyment. Virtual reality (VR) offers a setting in which to study these processes because it combines ecological immersion with precise, continuous behavioral measurement. We investigated (i) whether VR- derived behavioral signals are associated with self-reported enjoyment during a virtual museum tour, and (ii) whether the level of agency afforded to visitors influences enjoyment. Forty-eight adults completed a room-scale, life-size VR tour (8 * 4 m) of seven paintings from the Tel Aviv Museum of Art, each accompanied by a synchronized audio guide. Synchronized gaze and head- position streams were logged continuously (50 Hz) and segmented into painting-level viewing episodes using a trial-and-tile pipeline that intersects each painting's trial interval with an empirically defined spatial window in front of the canvas. Participants were randomly assigned to one of three agency conditions, Active (choice before every artwork), Semi-Active (choice for the first three), or Passive (fixed route),while the artwork sequence was held identical. Self- reported enjoyment at the tour and painting levels did not differ reliably across agency conditions. Among VR-derived measures, gaze engagement during the audio guide showed the clearest (though modest) association with painting-level liking, whereas locomotion and pacing measures were weak and inconsistent predictors. Agency nonetheless reliably modulated several gaze- and time-based viewing measures. The findings reveal a dissociation between subjective enjoyment and the micro-structure of viewing, and establish a reusable framework for full-tour, painting-level behavioral analysis in immersive settings.

neuroscience

SEDATION DIFFERENTIALLY AFFECTS DISTORTION-PRODUCT AND STIMULUS-FREQUENCY OTOACOUSTIC EMISSIONS IN CHINCHILLAS

Purpose: Otoacoustic emissions (OAEs) are used to assess outer hair cell (OHC) function. Clinical interpretation of OAE responses, however, is often limited to a present/absent binary since both physiological factors and measurement variability affect the measured OAE amplitude. Prior work showed elevated OAE responses in sedated compared to awake chinchillas, pointing to the potential influence of the medial olivocochlear (MOC) efferents on amplitudes, but this finding is inconsistent across species and OAE type. Here, we aimed to further investigate the effect of anesthesia on distortion- and reflection-type emissions in chinchillas using swept stimuli and more reliable calibration methods. Methods: Swept distortion-product (DP) and stimulus-frequency (SF) OAEs were measured in chinchillas with and without ketamine/xylazine sedation. Stimuli were presented using in-ear forward pressure level calibrations. DPOAE and SFOAE amplitudes and estimated Qerb from SFOAE group delays were compared across the two conditions. Results: We found that low-frequency DPOAE amplitudes were elevated when animals were sedated. The difference in SFOAE amplitudes was more variable across animals but appeared mildly reduced in sedated animals. Qerb estimates were slightly higher in sedated animals at some frequencies. The effect of sedation was not different across sexes. Conclusion: Taken together, these findings suggest that sedation impacts OAE measurements in chinchillas. MOC modulation could account for the present findings and differences across species. For diagnostic precision, OAE responses should be considered in the context of not only intrinsic OHC function but also extrinsic physiological processes that can modulate OHCs.

physiology

Identification of a pan-orthoebolavirus-reactive antibody from an rVSV-EBOV vaccinated individual

Orthoebolaviruses such as Ebola virus (EBOV), Sudan virus (SUDV) and Bundibugyo virus (BDBV) can cause severe disease with high case-fatality rates. While licensed EBOV vaccines and therapeutic antibodies protect against EBOV infection, no single monoclonal antibody currently provides broad protection across multiple orthoebolaviruses. Here, we analyzed the humoral immune response of an rVSV-EBOV vaccinee to identify pan-orthoebolavirus-neutralizing antibodies. Using BDBV- and SUDV-glycoproteins for single B cell-sorting, we identified B10, which neutralized authentic EBOV and SUDV, with potent activity against SUDV compared with established cross-reactive antibodies. Structural analysis mapped antibody B10 binding to the pan-orthoebolavirus conserved GP2-stalk/HR2 region, associated with asymmetric trimer destabilization and spike opening. In vivo, B10 showed significant prophylactic efficacy in an EBOV mouse model and partial protection with antiviral activity in a SUDV mouse model. Together, these findings demonstrate that rVSV-EBOV vaccination induced the development of a broadly orthoebolavirus-neutralizing antibody that holds exeptional therapeutic potential.

immunology

Both environmental filtering and intraspecific variation shape small mammals' elementomes

The biogeochemical niche hypothesis (BNH) proposes the multi-elemental composition of organisms - their elementome - as a new ecological dimension. However, which ecological factors shape elementome assembly remains little known, especially in animals. Here, we studied the mandibular elementome of two sympatric small mammals - Apodemus flavicollis and Clethrionomys glareolus - to assess how intraspecific variability (ontogenetic changes in body mass and sex under the vertebrate bone hypothesis; VBH) and environmental filtering (season and habitat) shape essential and non-essential elementome assembly. Species showed moderate elementome segregation and seasonal niche partitioning, with implications for coexistence. Ontogenetic body mass predicted elemental variation and calcium substitution, with several hypermetric scalings in autumn indicating strong departures from mass-invariant homeostasis. Finally, our results suggest a dichotomy: essential elementomes were mainly driven by intraspecific variation, whereas non-essential elementomes were rather shaped by environmental filtering. Our results position animal elementomes as an integrative ecological dimension linking organismal biology, species interactions, and environmental filtering across individuals, populations, and species.

ecology

The Microbiota Dictates Vendor-Derived Differences in a Murine Clostridioides difficile Infection Model

Clostridioides difficile infection (CDI) is the leading cause of healthcare-associated infectious diarrhea and remains a major burden to healthcare systems worldwide. The development of novel therapeutics for CDI requires robust and reproducible preclinical models. However, the microbiota has emerged as a major source of variability in animal studies. Here, we found that genetically similar mice obtained from two commercial vendors, Jackson Laboratory (JAX) and Charles River Laboratories (CRL), exhibited marked differences in susceptibility to CDI, with JAX mice developing fulminant disease and CRL mice remaining resistant. Using full-length 16S rRNA gene sequencing, we show that JAX and CRL mice harboured distinct gut microbiota, and that cohousing susceptible JAX mice with resistant CRL mice was sufficient to shift the JAX microbiota toward the CRL community structure and confer resistance to CDI. Differential abundance analysis identified taxa distinguishing resistant and susceptible mice, providing candidates for future mechanistic investigation. These findings demonstrate that vendor-derived variation in the gut microbiota drives differential susceptibility to CDI in mice, and that this phenotype is transferable via cohousing, highlighting the importance of accounting for the microbiota when designing and interpreting animal models of infectious disease.

microbiology

GABAB Receptors Gate Sex-Specific Synaptic Plasticity in the Nucleus Accumbens

Excitatory synaptic plasticity within the nucleus accumbens (NAc) drives motivated behaviors, and dysregulation is implicated in several psychiatric disorders marked by impaired reward processing. The NAc integrates glutamatergic input, which conveys information about reward, context, and behavioral goals, with local GABAergic signaling that regulates excitatory transmission and medium spiny neuron (MSNs) output. However, little is known regarding GABA-dependent modulation of activity-dependent excitatory synaptic plasticity. Here, we investigated GABAB receptor (GABABR) regulation of plasticity at hippocampus (Hipp)-NAc synapses, at which plasticity is a key mediator of reward-related behaviors. Using whole-cell electrophysiological recordings in mouse brain slices, we found that pharmacological inhibition of GABABRs converts long-term potentiation (LTP) into long-term depression (LTD) selectively in females, identifying a sex-specific role for GABABRs in modulating long-term plasticity of Hipp-MSN synapses. This LTD required mGluR5 activation and estrogen receptor alpha (ER) in both D1- and D2-expressing MSN subtypes, while only D1-MSNs suggested that LTD was expressed presynaptically through a CB1 receptor-dependent mechanism. Notably, GABABR inhibition did not alter basal synaptic transmission, indicating a specific role for these receptors in gating plasticity beyond regulation of basal excitatory drive. Together, these findings identify a novel, sex-specific mechanism by which GABABRs control the direction of synaptic plasticity.

neuroscience

Characterization and pharmacological modulation of Alzheimers disease-associated human microglial states

Microglia are central mediators of Alzheimers disease (AD) pathogenesis, yet the mechanisms driving disease-associated microglial states and their therapeutic modulation remain poorly understood. Here, we integrated single-nucleus transcriptomic datasets across the AD spectrum and identified disease- and lipid-associated microglia (DLaM) as a major AD-enriched population linked to genetic risk, neuropathology and cognitive decline. To model this state experimentally, we screened AD-relevant perturbations in human induced pluripotent stem cell (hiPSC)-derived microglia and found that ferric ammonium citrate (FAC) reproducibly induced a DLaM-like state characterized by lipid accumulation, lysosomal dysfunction and impaired A{beta} phagocytosis. Using a transcriptomics-based state-reversion screen, we identified LY2090314 as a potent modulator that restored microglial function and induced a distinct lysosomal-metabolic state. These findings establish a framework for transcriptomic disease-state-guided therapeutic discovery in AD.

neuroscience

Preserved brain hierarchy supports residual vision without awareness after visual cortex damage

Damage to the primary visual cortex causes loss of conscious vision, yet some patients retain the ability to respond to stimuli despite reporting no visual experience. Why similar lesions produce such different behavioral phenotypes remains unclear. While research to date has focused primarily on spared pathways that bypass V1, here we asked whether these divergent outcomes are also linked to the brain's intrinsic functional architecture. In the largest resting-state fMRI cohort of patients with unilateral V1 damage reported to date, we quantified information sharing between regions across cortical and subcortical parcels in blindsight-positive and blindsight-negative patients, as well as in age-matched healthy controls. Despite comparable lesions, the two patient groups displayed distinct hierarchical patterns on the cortex: B+ patients preserved a sensory-to-association organization as in healthy controls, whereas B- patients exhibited a marked flattening of this hierarchy. The effect was driven by abnormally low shared-information coupling within unimodal cortices and scaled continuously with single-subject behavioral blind-field detection performance. A thalamic region consistent with the pulvinar, linking the contralesional visual cortex and the frontal eye field, discriminated B+ from B- patients. These findings highlight the system-level consequences of V1 damage supporting blindsight, suggesting that the unimodal-transmodal axis might track not only global states of consciousness, but also whether sensory information can guide behavior without awareness.

neuroscience

The pursuit of motivational goals reduces pain through an opioidergic mechanism

Pain promotes protective behavior but can interfere with other biologically important goals. Survival may require overcoming pain to obtain rewards, secure resources or escape danger, yet evidence for pain modulation by competing demands and endogenous modulatory systems during goal pursuit is lacking. We developed a paradigm in which participants chose whether to pursue monetary rewards despite painful heat stimulation during fMRI, under placebo or opioid receptor blockade with naloxone. Actively pursuing motivational goals during painful stimulation reduced perceived pain and increased fMRI signal in pain-modulatory cortical regions, including multiple subregions of the rostral anterior cingulate cortex (rACC) and dorsolateral prefrontal cortex, alongside enhanced rACC-periaqueductal gray coupling, consistent with recruitment of the descending pain modulatory system. Behavioral and neural effects were attenuated by naloxone, supporting a mediating role for endogenous opioids. These findings provide convergent evidence that active goal pursuit engages opioidergic pain modulatory mechanisms to reduce pain in humans.

neuroscience