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Maternal immune activation (MIA) is a risk factor for schizophrenia. Since memory for sequence and stimulus order are disrupted in individuals with schizophrenia, we tested whether MIA animals showed deficits in a sequence learning and object-place recency memory task. In experiment one, control and MIA-challenged rats were required to nose poke five ports in a cued sequence. The sequences were presented randomly except for one structured sequence that was repetitive and initiated from the same port. Both groups were more accurate on the structured sequence and learned the task at similar rates. When a new structured sequence was presented, control animals were able to respond flexibly and take advantage of the structure, whereas the performance of MIA animals was similar for random and structured sequences. Experiment two tested MIA and control rats were evaluated in a Temporal Ordering for Spatial Locations task (TOSL). Control animals had a significant preference for the object in the least-recent location, indicating a novelty preference, while MIA animals did not, although the between-group difference failed to reach significance. Exploration patterns changed differentially over time, possibly because of variation in habituation processes. As a result, MIA animals were significantly less likely to explore the object at the least-recent location during the second half of the exploration session, compared to control animals. Collectively these studies indicate that while MIA animals are unimpaired in simple sequence learning, they display changes in behaviour compared to controls. Differences may result from habituation rate or inflexibility when responding to change., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Prof David Bilkey reports financial support was provided by Health Research Council of New Zealand. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2025 Elsevier B.V. All rights reserved.)

The rodent whisker system provides an excellent model to study experience dependent plasticity in neural morphology, circuitry, and behavior. Rodents use bilateral whisker sensation to gather information about their environment. Unilateral whisker denervation disrupts whisker circuitry but its impact on task specific behavior is largely unknown. Adult mice with unilateral whisker denervation display a preference to using the intact whisker set to inspect objects, but do not have altered open field navigation. An object localization task requiring only the intact whisker set did not detect any change in performance, but gap crossing was impaired after unilateral whisker denervation. Finally, chronic whisker denervation led to increased anxiety-like behavior which was rescued by training on the gap cross task. These findings indicate that mice use behavioral strategies to adapt to life with only one set of intact whiskers., Competing Interests: Declaration of Competing Interest The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The opinions and assertions expressed herein are those of the author(s) and do not reflect the official policy or position of the Uniformed Services University of the Health Sciences or the Department of Defense., (Published by Elsevier B.V.)

Humans are excellent at modifying our behaviour depending on context. For example, we will change how we explore when losses are possible compared to when losses are not possible. However, it remains unclear what specific cognitive and neural processes are modulated when exploring in different contexts. Here, we had participants learn within two different contexts: in one the participants could lose points while in the other the participants could not. Our goal was to determine how the inclusion of losses impacted human exploratory behaviour (experiment one), and whether we could explain the neural basis of these effects using EEG (experiment two). In experiment one, we found that participants preferred less-variable choices and explored less often when losses were possible. In addition, computational modelling revealed that participants engaged in less random exploration, had a lower rate of learning, and showed lower choice stickiness when losses were possible. In experiment two, we replicated these effects while examining a series of neural signals involved in exploration. During exploration, signals tied to working memory and learning (P3b), attention orienting (P3a) and motivation (late positive potential; an exploratory analysis) were enhanced when losses were possible. These neural differences contribute to why exploratory behaviour is changed by different learning contexts and can be explained by the theoretical claim that losses recruit attention and lead to increased task focus. These results provide insight into the cognitive processes that underlie exploration, and how exploratory behaviour changes across contexts., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2025 The Author(s). Published by Elsevier B.V. All rights reserved.)

Individual differences in response strategies may be utilized to identify those at risk for the development of neuropsychiatric disorders such as depression, anxiety, and substance use. One behavioral attribute that has been used to predict later mood disorders and substance use disorders is an organism's predisposition for novelty-seeking, modeled in rodents as increased exploration of novel environments or stimuli. Despite documented correlations of locomotor response to a novel environment and disease-specific tendencies, it remains unclear whether the "response to novelty trait" is stable across time and environments. Adolescence is an important transitional time, associated with vulnerability for neuropsychiatric disorders. Only a few studies have assessed whether variations in novelty-seeking behaviors in adolescent animals translate to variations of susceptibility to neuropsychiatric disorders later in life, and it is unclear whether initial locomotor responses to novelty are stable across time and development. We examined whether locomotor response to a novel environment is a stable attribute across time in a series of Open Field tests in early adolescent (postnatal day [p] 23-25) late adolescent (p58-59) and adult (p72 and older) male Sprague-Dawley rats. We also examined the relation between the locomotor response to a novel environment and other measures of responding to novelty. Results suggest that locomotor response to a novel environment does not emerge as a stable behavioral attribute until late adolescence. They also suggest that locomotor response to a novel environment and novelty-seeking, as assessed with the Novelty Place Preference paradigm, capture nonoverlapping behavioral tendencies., (© 2025 The Author(s). Developmental Psychobiology published by Wiley Periodicals LLC.)

Novelty exposure and the upregulation of the noradrenergic (NA) system have been suggested as crucial for developing cognitive reserve and resilience against neurodegeneration. Openness to experience (OE), a personality trait associated with interest in novel experiences, may play a key role in facilitating this process. High-OE individuals tend to be more curious and encounter a wider range of novel stimuli throughout their lifespan. To investigate the relationship between OE and the main core of the NA system, the locus coeruleus (LC), as well as its potential mediation of IQ-a measure of cognitive reserve-MRI structural analyses were conducted on 135 healthy young adults. Compared with other neuromodulators' seeds, such as dorsal and median raphe-5-HT, ventral tegmental area-DA-, and nucleus basalis of Meynert-Ach-, the results indicated that higher LC signal intensity correlated with greater OE and IQ. Furthermore, mediation analyses revealed that only the LC played a mediating role between OE and IQ. These findings shed light on the neurobiology of personality and emphasize the importance of LC-NA system integrity in a novelty-seeking behavior. They provide a psychobiological explanation for how OE expression can contribute to the maintenance of the NA system, enhancing cognitive reserve and resilience against neurodegeneration., (© 2024 Massachusetts Institute of Technology. Published under a Creative Commons Attribution 4.0 International (CC BY 4.0) license.)

With age, people increasingly emphasize intent when judging transgressions. However, people often lack information about intent in everyday settings; further, they may wonder about reasons underlying pro-social acts. Three studies investigated 4-to-6-year-olds', 7-to-9-year-olds', and adults' (data collected 2020-2022 in the northeastern United States, total n = 669, ~50% female, predominantly White) desire for information about why behaviors occurred. In Study 1, older children and adults exhibited more curiosity about transgressions versus pro-social behaviors (ds = 0.52-0.63). Younger children showed weaker preferences to learn about transgressions versus pro-social behaviors than did older participants (d = 0.12). Older children's emphasis on intent, but not expectation violations, drove age-related differences (Studies 2-3). Older children may target intent-related judgments specifically toward transgressions, and doing so may underlie curiosity about wrongdoing., (© 2024 The Author(s). Child Development © 2024 Society for Research in Child Development.)

Exploration is an important strategy for reducing the uncertainty that pervades daily life. Yet the evolutionary roots of adaptive exploration are poorly understood. We harness and adapt the human decisions-from-experience paradigm to investigate exploration under uncertainty in chimpanzees. In our study, chimpanzees (N = 15; eight females) are simultaneously confronted with an uncertain option (with outcome variance) and a safe option (without outcome variance) and tested in both stable and changing environments. Results reveal that, as in human exploration, how and how much chimpanzees explore depends on the environment. One key environmental property is change: Chimpanzees explore more across trials in changing than in stable conditions. Consistent with the assumption of classic economic models that variance indicates risk, chimpanzees also explore more when they experience variance in the options' outcomes. Individual risk and uncertainty preferences did not have a statistically significant effect on exploratory efforts. These findings suggest that chimpanzees and humans share key similarities in the way they respond to risk and uncertainty., Competing Interests: Competing interests: The authors declare no competing interests., (© 2025. The Author(s).)

Animals face uncertainty about their environments due to initial ignorance or subsequent changes. They therefore need to explore. However, the algorithmic structure of exploratory choices in the brain still remains largely elusive. Artificial agents face the same problem, and a venerable idea in reinforcement learning is that they can plan appropriate exploratory choices offline, during the equivalent of quiet wakefulness or sleep. Although offline processing in humans and other animals, in the form of hippocampal replay and preplay, has recently been the subject of highly informative modelling, existing methods only apply to known environments. Thus, they cannot predict exploratory replay choices during learning and/or behaviour in the face of uncertainty. Here, we extend an influential theory of hippocampal replay and examine its potential role in approximately optimal exploration, deriving testable predictions for the patterns of exploratory replay choices in a paradigmatic spatial navigation task. Our modelling provides a normative interpretation of the available experimental data suggestive of exploratory replay. Furthermore, we highlight the importance of sequence replay, and license a range of new experimental paradigms that should further our understanding of offline processing., Competing Interests: Competing interests: The authors have no competing interests., (© 2025. The Author(s).)

Male and female rodents display unique search strategies when exploring new and familiar environments. Sex differences are well-documented in the literature and may be observed in tasks that rely on spontaneous exploration (e.g., recognition memory tests). Therefore, we assessed patterns of male and female rat behavior in the object-in-place (OiP) test, a common recognition memory paradigm involving object-location associations. Twelve male and 12 female adult Long Evans rats were tested four times in the 1-h OiP test and exploratory behaviors were compared during habituation, sample, and test phases. Results revealed that females moved faster and farther than males, showed increased immobility frequency and reduced immobility duration, reduced outer zone mobility duration, and increased inner zone entrances, compared to males during habituations. During sample phases, female rats moved faster than males, displayed reduced immobility frequency in the inner zone, and demonstrated consistent distance travelled across repeated sessions; conversely, male rats moved less in later sessions and exhibited increased mobility frequency in the outer zone. Analyses comparing test phase behavior revealed females continued to move faster than males; however, no other sex differences were observed. These findings are consistent with previous literature highlighting unique sex differences in explorative behaviors during recognition testing. Sex differences in locomotion and mobility state behaviors may be more indicative of individual motivation and search strategy between the sexes and less indicative of recognition memory., Competing Interests: Declaration of Competing Interest The authors have no competing interests to declare., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Aging affects emotional, cognitive, and social functions, increasing susceptibility to neuropsychiatric conditions. C57BL/6 mice are commonly used to study aging mechanisms, yet differences between C57BL/6J and C57BL/6N substrains remain underexplored. This study compared aging-related behavioral changes in these substrains. Aging reduced exploratory activity and heightened anxiety in C57BL/6J, but not C57BL/6N, mice. Conversely, aging reduced social novelty preference in C57BL/6N, but not C57BL/6J, mice. Male mice of both substrains exhibited increased female urine sniffing with age. These findings highlight substrain-specific aging effects, underscoring the importance of substrain selection in behavioral studies of aged mice for drug development., Competing Interests: Declaration of competing interest The authors declare that there are no conflicts of interest associated with this manuscript., (Copyright © 2025 The Authors. Published by Elsevier B.V. All rights reserved.)

Phosphodiesterase 2 A (PDE2A) function is stimulated by cGMP to catabolize cAMP. However, neurological and neurochemical effects of PDE2A deficiency are poorly understood. To address this gap, we studied behavioral characteristics and cerebral morpho-chemical changes of adult male heterozygous C57BL/6-PDE2A+/- (HET), and wild type C57BL/6-PDE2A+/+ (WT) mice. Behavioral functions of mice were evaluated by a wide test battery. HET mice exhibited greater tendency to explore novel environments in comparison to WT mice, but spatial working memory, anxiety, and sociability were similar in adult HET and WT mice. In HET mice, PDE2A mRNA, PDE2A protein expression, and cGMP hydrolyzing enzymatic activity were consistently reduced by about 50 %. Consequently, the cyclic nucleotide levels were significantly increased in HET mice, but unexpectedly the mean percentage variation was higher for cGMP equal to 153.23 %, and lower for cAMP equal to 16.41 %. Therefore, to try to explain the preponderant increase of cGMP to cAMP we evaluated other PDE enzymes functionally related to PDE2A. Surprisingly, results were quite contradictory: in HET mice protein levels of the other dual-specificity enzyme PDE3A and PDE10A were reduced, whereas the expressions of PDE5A and PDE9A that selectively hydrolyze cGMP were increased. Therefore, we investigated the involvement of neuronal nitric oxide synthase (nNOS) expression, as determinant of a possible increased synthesis of NO/cGMP signaling. Interestingly, in HET mice the expression level of brain nNOS, measured by western blot and immune-histochemistry was significantly increased, particularly in interneurons from the striatum. In conclusion, the deficiency of PDE2A could be compensated in the striatum by upregulating nNOS/NO/cGMP pathway, which in turn likely upregulates PDE2A-dependent cAMP hydrolysis. The neuroanatomical correlation between striatal nNOS upregulation and the behavioral phenotype of increased exploratory behavior in HET mice is advanced., Competing Interests: Declaration of competing interest All the authors do not report any disclosures., (Copyright © 2025 The Authors. Published by Elsevier Inc. All rights reserved.)

Neophobia and exploratory behavior are personality traits through which organisms evaluate and respond to environment changes by adjusting their behavior. The Kelp Gull (Larus dominicanus) is a generalist seabird that consumes a wide variety of prey. Neophobia levels and exploratory behavior in novel circumstances were analyzed in urban adult (n = 13) and immature (n = 15) Kelp Gulls captured in the landfill of Mar del Plata city. These personality traits were not significantly affected by the age of the bird. Longer feeding latencies were observed in presence of novel objects, and neophobia levels were higher in the presence of a transparent box. The exploratory events were brief and influenced by the physical properties of the objects; gulls favored complex and yellow objects. Higher neophobia levels were associated with a longer time to start the exploration and spending less time investigating the objects. Exposure to an urban environment can modulate the novelty response, partially explaining lack of difference in neophobia levels and exploratory behavior between ages, as well as the apparent absence of intrinsic attraction to unfamiliar objects when not associated with a food source. Furthermore, in relation to complex objects, unfamiliar objects likely offer richer information, driving gulls' exploratory preference., Competing Interests: Declaration of Competing Interest We declare no conflicts of interest., (Copyright © 2025 Elsevier B.V. All rights reserved.)

Murayama and Jach point out that we do not sufficiently understand the constructs and mental computations underlying higher-order motivated behaviors. Although this may be generally true, we would like to add and contribute to the discussion by outlining how interdisciplinary research on novelty-evoked exploration has advanced the study of learning and curiosity.

Beta-frequency oscillations (20-30 Hz) are prominent in both human and rodent electroencephalogram (EEG) recordings. Discrete epochs of beta (or Beta2) oscillations are prevalent in the hippocampus and other brain areas during exploration of novel environments. However, little is known about the spatial distribution and temporal relationships of beta oscillations across the cortex in response to novel contexts. To investigate this, mice fitted with 30-channel EEG-style multi-electrode arrays underwent a single recording session in a novel environment. While changes to spectral properties of cortical oscillations were minimal, there was a profound increase in the rate of beta bursts during the initial part of the recording session, when the environment was most novel. This was true across the cortex but most notable in recording channels situated above the retrosplenial cortex. Additionally, novelty was associated with greater connectivity between retrosplenial areas and the rest of the cortex, specifically in the beta frequency range. However, it was also found that the cortex in general, is highly modulated by environmental novelty. This data further suggests the retrosplenial cortex is an important hub for distinguishing environmental context and highlights the diversity of functions for beta oscillations across the brain, which can be observed using high-density EEG., Competing Interests: Declarations. Competing interests: The authors declare no competing interests., (© 2025. The Author(s).)

Orexin signaling in the ventral tegmental area and substantia nigra promotes locomotion and reward processing, but it is not clear whether dopaminergic neurons directly mediate these effects. We show that dopaminergic neurons in these areas mainly express orexin receptor subtype 1 (Ox1R). In contrast, only a minor population in the medial ventral tegmental area express orexin receptor subtype 2 (Ox2R). To analyze the functional role of Ox1R signaling in dopaminergic neurons, we deleted Ox1R specifically in dopamine transporter-expressing neurons of mice and investigated the functional consequences. Deletion of Ox1R increased locomotor activity and exploration during exposure to novel environments or when intracerebroventricularely injected with orexin A. Spontaneous activity in home cages, anxiety, reward processing, and energy metabolism did not change. Positron emission tomography imaging revealed that Ox1R signaling in dopaminergic neurons affected distinct neural circuits depending on the stimulation mode. In line with an increase of neural activity in the lateral paragigantocellular nucleus (LPGi) of Ox1R ΔDAT mice, we found that dopaminergic projections innervate the LPGi in regions where the inhibitory dopamine receptor subtype D2 but not the excitatory D1 subtype resides. These data suggest a crucial regulatory role of Ox1R signaling in dopaminergic neurons in novelty-induced locomotion and exploration., Competing Interests: XX, GY, FE, AC, HB, PK, AH No competing interests declared, (© 2023, Xiao et al.)

Spatial exploration is a complex behavior that can be used to gain information about developmental processes, personality traits, or mental disorders. Typically, this is done by analyzing movement throughout an unknown environment. However, in human research, until now there has been no overview on how to analyze movement trajectories with regard to exploration. In the current paper, we provide a discussion of the most common movement measures currently used in human research on spatial exploration, and suggest new indices to capture the efficiency of exploration. We additionally analyzed a large dataset (n = 409) of human participants exploring a novel virtual environment to investigate whether movement measures could be assigned to meaningful higher-order components. Hierarchical clustering of the different measures revealed three different components of exploration (exploratory behavior, spatial shape, and exploration efficiency) that in part replicate components of spatial exploratory behavior identified in animal studies. A validation of our analysis on a second dataset (n = 102) indicated that two of these clusters are stable across different contexts as well as participant samples. For the exploration efficiency cluster, our validation showed that it can be further differentiated into a goal-directed versus a general, area-directed component. By also sharing data and code for our analyses, our results provide much-needed tools for the systematic analysis of human spatial exploration behavior., Competing Interests: Declarations. Ethics approval: Not applicable (see Schomaker et al., 2022; as well as Brunec et al., 2022). Consent for publication: Not applicable (see Schomaker et al., 2022; as well as Brunec et al., 2022). Conflicts of interest: The authors declare no competing interests., (© 2025. The Author(s).)

The formation of new social interactions is vital for social animals, but the underlying neural mechanisms remain poorly understood. We identified CeA Npbwr1 neurons, a population in central amygdala expressing neuropeptide B/W receptor-1 (NPBWR1), that play a critical role in these interactions. CeA Npbwr1 neurons were activated during encounters with unfamiliar, but not with familiar, mice. Manipulations of CeA Npbwr1 neurons showed that their excitation is essential for maintaining physical interactions with novel conspecifics. Activation of CeA Npbwr1 neurons alleviated social deficits induced by chronic social defeat stress, suggesting therapeutic potential. Conversely, overexpression of human NPBWR1 in CeA Npbwr1 neurons reduced activity of these neurons and impaired social interactions with unfamiliar mice. This effect was absent in a polymorphic variant of the human NPBWR1 gene (404A>T). These findings highlight how CeA Npbwr1 neurons promote social novelty seeking and reveal a complex interplay between NPBWR1 genetic variations and social behavior.

According to the Projective Consciousness Model (PCM), in human spatial awareness, 3-dimensional projective geometry structures information integration and action planning through perspective taking within an internal representation space. The way different perspectives are related to and transform a world model defines a specific perception and imagination scheme. In mathematics, such a collection of transformations corresponds to a 'group', whose 'actions' characterize the geometry of a space. Imbuing world models with a group structure may capture different agents' spatial awareness and affordance schemes. We used group action as a special class of policies for perspective-dependent control. We explored how such a geometric structure impacts agents' behaviors, comparing how the Euclidean versus projective groups act on epistemic value in active inference, drive curiosity, and exploration. We formally demonstrate and simulate how the groups induce distinct behaviors in a simple search task. The projective group's nonlinear magnification of information transformed epistemic value according to the choice of frame, generating behaviors of approach toward objects with uncertain locations due to limited sampling. The Euclidean group had no effect on epistemic value: no action was better than the initial idle state. In structuring a priori an agent's internal representation, we show how geometry can play a key role in information integration and action planning. Our results add further support to the PCM., (© 2025. The Author(s).)

This study explores adolescents' inherent curiosity about nature through the production of self-generated questions during a field visit to a nature-rich environment, followed by descriptive-interpretative analysis using focus groups. Utilizing cultural probes and content-free question tokens, we collected 164 valid questions produced by 36 adolescents during the field session. Biotic elements, like species, turned out to be more intriguing than abiotic elements, originating 89.6% of the questions. The predominant topics were related to species adaptation, extinction, dispersion, and diversity, with younger adolescents showing a notable interest in nature conservation, while older adolescents highlighted biodiversity dynamics. These findings were corroborated by the ranking of the TOP-5 most interesting questions, where biodiversity dynamics, nature conservation and plant physiology occupied the same relative positions. Our results indicate that in a nature-rich environment and through an inquiry-based approach, adolescents were encouraged to express curiosity about nature. This approach could be a valuable educational strategy to enhance their connection to nature, promote conservation responsibility, and benefit the environment., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2025 Arroz et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Tail biting is one of the biggest welfare problems in pigs. However, depending on the individuals involved (e.g., tail biter/victim), pigs seem to change their behaviour prior to tail biting events, which raises the possibility of early detection and thus prediction and prevention of tail biting. In this retrospective explorative study, we used datasets from four different studies with 9 trials of rearing (4 pens/trial with 24 pigs/pen) and fattening (8 pens/trial with 12 pigs/pen) that focused on the exploration behaviour of undocked pigs towards plant-based enrichment materials. From this dataset, we identified 8 pens from rearing (n = 192 pigs) and 6 pens from fattening (n = 72 pigs) in which individual tail biters were identified. From this dataset, we investigated whether any a priori behavioural changes in exploration or feeding could be identified with respect to tail biting. Furthermore, the effects of weight parameters from suckling to fattening were examined. Using linear mixed effects models, we found that exploration duration was linked to days prior to tail biting in rearing, depending on CatPig (category of pigs: biter, victim, neutral pig) (P = 0.001), in fattening independent of CatPig (P<0.0001), and by duration, amount and frequency of feed consumption in fattening (P<0.0001). Some weight parameters covaried with CatPig in rearing (weight-gain suckling: P = 0.0018; weaning weight: P = 0.019) and fattening (weaning weight: P = 0.07; start weight at fattening: P = 0.03; weight-gain rearing: P = 0.02). Suitable indicators for future early detection trials of tail biting could be exploration duration in rearing and fattening and feeding data in fattening. Moreover, weight parameters in rearing and fattening and exploration duration in rearing may be used to identify individual pigs that might become tail biters in an upcoming tail biting event. The retrospective explorative nature of our analysis revealed interesting patterns; however, further studies are needed to confirm our findings., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2025 Kauselmann et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Ethanol (EtOH) is one of the most widely consumed substance, affecting neurobehavioral functions depending on multiple environmental and biological factors. Although EtOH modulates zebrafish (Danio rerio) anxiety-like behaviors in novelty-based paradigms, the potential role of biological sex and populational variability in the exploratory dynamics in the open field test (OFT) is unknown. Here, we explored whether a repeated EtOH exposure protocol modulates the spatio-temporal exploration and homebase-related parameters in a population- and sex-dependent manner. Male and female fish from the short-fin (SF) and leopard (LEO) phenotypes were exposed to EtOH for 7 days (1 % v/v, 20 min per day). On the 8th day, the OFT was performed to assess locomotor and exploratory behaviors. We verified significant populational differences in the baseline spatio-temporal exploration patterns, supporting a pronounced anxiety in LEO with a higher homebase index compared to SF. We also found sex-dependent differences in EtOH sensitivity, where SF was more sensitive to EtOH, especially in females, which showed marked alterations in thigmotaxis and homebase occupancy. Conversely, only LEO female subjects showed increased center occupancy following EtOH. Principal component analysis (PCA) showed the main components that explained data variability, which were sex- and population-dependent. Overall, our novel findings support the utility of zebrafish-based models to assess how EtOH influences the exploratory profile in the OFT, as well as to elucidate potential differences of sex and population in the neurobehavioral responses of alcohol exposure in a translational perspective., Competing Interests: Declaration of competing interest The authors declare no conflict of interests., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Our choices are typically accompanied by a feeling of confidence-an internal estimate that they are correct. Correctness, however, depends on our goals. For example, exploration-exploitation problems entail a tension between short- and long-term goals: finding out about the value of one option could mean foregoing another option that is apparently more rewarding. Here, we hypothesised that after making an exploratory choice that involves sacrificing an immediate gain, subjects will be confident that they chose a better option for long-term rewards, but not confident that it was a better option for immediate reward. We asked 250 subjects across 2 experiments to perform a varying-horizon two-arm bandits task, in which we asked them to rate their confidence that their choice would lead to more immediate, or more total reward. Confirming previous studies, we found a significant increase in exploration with increasing trial horizon, but, contrary to our predictions, we found no difference between confidence in immediate or total reward. This dissociation is further evidence for a separation in the mechanisms involved in choices and confidence judgements., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2025 Solopchuk, Dayan. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

The selection of information by individuals is a basic process in democratic institutions, including journalism. Publishers attempt to attract readers with "curiosity gap" headlines that offer vague descriptions rather than summarize an article. Lab and field experiments that compare the influence of these two styles have found conflicting results on their efficacy. In this registered report, we propose a theory, based on the psychology of curiosity, to harmonize these results. We introduce and validate an automated linear scale of headline concreteness to differentiate summary and curiosity gap headlines. In a meta-analysis of 8977 headline experiments, we confirm that the effects of headline concreteness on clickthrough rates vary with the overall concreteness of other headlines. When the baseline headline is too vague, higher headline concreteness increases clickthrough rates. When headlines are too concrete, higher headline concreteness decreases clickthrough rates. These findings suggest a curvilinear relationship between information selection decisions and the amount of information conveyed in text, implying that headlines that convey just the right amount of information maximize clickthrough rates at scale. PROTOCOL REGISTRATION: The protocol for this study was pre-registered following in-principle acceptance at https://osf.io/fbzvw/ on September 21st, 2023. The stage 1 protocol for this Registered Report was accepted in principle on 30/08/23. The protocol, as accepted by the journal, can be found at: https://doi.org/10.17605/OSF.IO/FBZVW ., Competing Interests: Competing interests: The authors declare no competing interests., (© 2025. The Author(s).)

The novel object recognition test (NORT) is one of the most commonly employed behavioral tests in experimental animals designed to evaluate an animal's interest in and recognition of novelty. However, manual procedures, which rely on researchers' observations, prevent high throughput analysis. In this study, we developed an automated analysis method for NORT utilizing machine learning-assisted exploratory behavior detection. We recorded the exploratory behavior of the mice using a video camera. The coordinates of the mouse nose and tail base in recorded video files were detected using a pre-trained machine learning model, DeepLabCut. Each video was then segmented into frame images, which were categorized into "exploratory," or "non-exploratory" frames based on manual observation. Mouse feature vectors were calculated as vectors from the nose to the vertices of the object and were utilized for SVM training. The trained SVM effectively detected exploratory behaviors, showing a strong correlation with human observer assessments. Upon application to NORT, the duration of mouse exploratory behavior towards objects predicted by the SVM exhibited a significant correlation with the assessments made by human observers. The novelty discrimination index derived from the SVM predictions also aligned well with that from human observations., Competing Interests: Declaration of Competing Interest Koji Kobayashi and Takahisa Murata belong to endowed course (Food and Animal Systemics) provided by the Revamp Corporation (Tokyo, Japan). Takuya Kishi, Takashi Minato, and Misato Kida are employees of Revamp Corporation., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Spatial tasks are often goal-directed or reward-facilitated confounding the assessment of "pure" recent and remote spatial memories. The current work re-exposed preadolescent and postadolescent male rats to a non-reinforced, free exploration task to investigate cFos patterns within the hippocampus and anterior cingulate cortex (ACC) associated with recent and remote periods. Male rats were exposed to an open field task for one, 30 min session on postnatal day (P) 20, 25, or 50 and re-exposed for 30 min at either a recent (24 hours) or remote (3 weeks) timepoint. Distance traveled in the open field was measured as well as cFos labeling. In the P20 age group, there was elevated exploration at the 24-hour and 3-week tests compared to training and compared to the other age groups. In the hippocampus CA1, cFos levels were higher after the remote test than the recent test in the P20 group but higher after the recent test than remote test in the P25 and P50 groups. cFos labeling in the ACC was higher in all remote-tested groups compared to the recent-tested groups across all ages. In the P20, the 24-hour test was associated with less CA1 activity than the other age groups supporting the hypothesis that the hippocampus is not fully developed at this time point. In the P20 group, the remote representation of this task did not seem to be complete as there continued to be CA1 activity along with ACC activity following the remote test associated with elevated exploration. These results indicate the utility of unreinforced spatial navigation tasks for exploring systems consolidation processes over the lifespan and show that a fully developed hippocampus is required for optimal systems consolidation., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Animal models enable investigation of the impact of stress on emotional-behavioral performance to facilitate understanding of posttraumatic stress symptoms experienced in humans. Refinement of animal stress models could lead to a reduction in the number of subjects needed to detect statistically significant stress effects, in accordance with Russel and Burch's three Rs of research. We assessed whether performance of experimental procedures (that is, stress exposure and poststress behavioral testing) during the dark or light phases of the 12-h light/12 h-dark cycle is a refinement that could accomplish this reduction. At 3 h into either the light or dark phase, male and female adult Sprague-Dawley rats underwent a single-day traumatic stress exposure. Rats then underwent behavioral testing for exploratory behaviors, startle responses, and conditioned fear responses at 2 h, 1 d, and 9 d after stress exposure. Distance traveled in the elevated plus maze (EPM) by both male and female rats was significantly reduced in the dark phase compared with the light phase. Male rats of the dark phase group also spent less time in the open arms of the EPM, and traveled less, spent less time in the center, and spent more cumulative time freezing in the open field. Female rats of the dark phase group spent more cumulative time freezing in the EPM and exhibited significantly more tone-cued conditioned freezing responses. Our results suggest that performing experimental procedures during the dark phase of the light cycle may be a useful refinement mechanism, as procedures performed during this period had the greatest effect on behavioral outcomes in both males and females. Light cycle phase is an experimental variable that should be considered when designing experiments to maximize behavioral effects, including those in response to stress.

Infants explore the world around them based on their intrinsically motivated curiosity. However, the cognitive mechanisms underlying such curiosity-driven exploratory behaviour remain largely unknown. Here, infants could freely explore two novel categories, triggering a new exemplar from a category by fixating on either of the two associated areas on a computer screen. This gaze-contingent design enabled us to distinguish between exploration - switching from one category to another - and exploitation - consecutively triggering exemplars from the same category. Data from 10 to 12-month-old infants (N = 68) indicated that moment-to-moment sampling choices were non-random but guided by the infants' exploration history. Self-generated sequences grouped into three clusters of brief yet explorative, longer exploitative, and overall more balanced sampling patterns. Bayesian hierarchical binomial regression models indicated that across sequence patterns, infants' longer trigger time, shorter looking time, and more gaze-shifting were associated with trial-by-trial decisions to disengage from exploiting one category and making an exploratory switch, especially after consecutively viewed stimuli of high similarity. These findings offer novel insights into infants' curiosity-driven exploration and pave the way for future investigations, also regarding individual differences., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Background: Protein ubiquitination is a common post-translational modification involved in protein degradation and various life processes in cells. NEDL1 is a ubiquitin ligase that is highly expressed primarily in the brain. However, the functions of NEDL1 in social approach/novelty preference, anxiety, learning and memory remain poorly understood., Methods: Nedl1 knockout mice (Nedl1 -/- ) and wild-type mice (Nedl1 +/+ ) were tested using three-chamber test, elevated plus maze, and Barnes maze. Then, brain tissue was stained, and blood was collected for metabolic analysis., Results: Compared with Nedl1 +/+ mice, Nedl1 -/- mice showed no differences in social approach/novelty preference and anxiety behavior. Nedl1 -/- mice displayed impaired learning and memory. Nedl1 knockout did not affect the number of neurons and oligodendrocytes in the hippocampus. Astrocytes proliferated in the hippocampus of Nedl1 -/- mice. The amino acid metabolism of Nedl1 +/+ and Nedl1 -/- mice is different, especially the increase in proline and tryptophan., Conclusion: This study showed that Nedl1 knockout impaired learning and memory, which may be related to astrocyte proliferation and amino acid metabolism change. Nedl1 knockout did not affect social style/novelty preference and anxiety behavior in mice. The preliminary study of NEDL1 in neurobehavioral function could help understand the role of NEDL1 in the nervous system., Competing Interests: Declaration of competing interests The authors have no competing interests., (Copyright © 2024. Published by Elsevier Inc.)

The ability to recognize and act on others' emotions is crucial for navigating social interactions successfully and learning about the world. One way in which others' emotions are observable is through their movement kinematics. Movement information is available even at a distance or when an individual's face is not visible. Infants have been shown to be sensitive to emotions in movement kinematics of transporting actions, like moving an object from one to another place. However, it is still unknown whether they associate the manipulated object with the emotions contained in moving it, and whether they use this information to guide their own exploration of this object. In this study, 12-month-old infants watched actors transporting two toys with positive or negative emotional valence. Then, infants were given the possibility to interact with the same toys. We expected the infants to look at and touch the toy handled in a positive manner more, compared to the toy handled in a negative manner. Our results showed that infants looked at the positive toys more than at the negative toys, but that infants touched both toys for the same amount of time. Also, there was no difference in which toy they manually explored first., (© 2025 The Author(s). Infancy published by Wiley Periodicals LLC on behalf of International Congress of Infant Studies.)

Object exploration is considered a driver of motor, cognitive, and social development. However, little is known about how early childhood education and care settings facilitate object exploration. This study examined if children's exploration of objects during free play was facilitated by the use of particular spatial components (floor, tables, and activity centers) and types of play (solitary, social, and parallel). Participants were 61 children (aged 11 to 48 months and 50.8% boys, socioeconomic levels representative of the Dutch population). Intraindividual variability in children's object exploration was predicted by the use of particular spatial components and the social setting, with small-to-medium effect sizes. Solitary and parallel play were positively associated with complex object exploration, especially when sitting or standing at child-height tables. During social play, object exploration was mostly absent., (© 2024 The Author(s). Child Development published by Wiley Periodicals LLC on behalf of Society for Research in Child Development.)

Humans are driven by an intrinsic motivation to learn, but the developmental origins of curiosity-driven exploration remain unclear. We investigated the computational principles guiding 4-year-old children's exploration during a touchscreen game (N = 102, F = 49, M = 53, primarily white and middle-class, data collected in the Netherlands from 2021-2023). Children guessed the location of characters that were hiding following predictable (yet noisy) patterns. Children could freely switch characters, which allowed us to quantify when they decided to explore something different and what they chose to explore. Bayesian modeling of their responses revealed that children selected activities that were more novel and offered greater learning progress (LP). Moreover, children's interest in making LP correlated with better learning performance. These findings highlight the importance of novelty and LP in guiding children's exploration., (© 2024 The Author(s). Child Development published by Wiley Periodicals LLC on behalf of Society for Research in Child Development.)

In response to stressors, individuals manifest varied behavioral responses directed toward satisfying physiological survival needs. Although the enduring effects of adolescent stress on both humans and animals are well-documented, the underlying mechanisms remain insufficiently elucidated. Utilizing immunofluorescence, viral injections, and brain slice electrophysiological recordings, we have delineated that heightened excitability among glutamatergic neurons in the basolateral amygdala (BLA) is responsible for inducing heightened exploratory behaviors in adolescent mice subjected to mild, chronic restraint stress. Activation of BLA glutamatergic neurons through chemogenetics increases exploratory behaviors in emotional assessments, whereas inhibition of these neurons diminishes exploratory behaviors in measures such as the open field and elevated plus maze test. Furthermore, an upregulation of glutamate receptor expression and a concomitant downregulation of GABA receptor expression in BLA glutamatergic neurons have been associated with enhanced exploratory behaviors, validated through in vivo receptor antagonists. These findings unveil the protective role of mild stress exposure during adolescence against adversity, providing novel insights for addressing stressful events., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

The novel object recognition (NOR) test is an efficient way to measure nonspatial memory in rodents. The NOR performance of female and male rats is sexually dimorphic because memory performance is better in the former than in the latter. In females, maternal experience enhances spatial memory. We used the NOR test to evaluate short- and long-term recognition memory in both sexes in the high- and low-yawning sublines of rats (HY and LY, respectively), which were generated via a strict inbreeding process from the Sprague‒Dawley (SD) strain for more than ninety generations. Additionally, we evaluated the effect of maternal experience using nulliparous, primiparous, biparous, and multiparous HY, LY and SD dams. Our results revealed that LY rats presented less thigmotaxis, with lower central square crosses and more vertical exploration in the open-field arena, suggesting that they experienced anxiety. Additionally, LY males performed significantly better than LY females in short- and long-term NOR memory, and LY males performed significantly better than SD rats did. Among females, two maternal experiences negatively affected short-term memory in the LY and HY sublines with respect to primiparous dams, and HY dams had better memory performance in the NOR test than did SD dams. Our findings suggest that the yawning sublines are suitable for studying the neurobiological basis of different memory processes under different endocrine conditions in highly inbred groups of rats., Competing Interests: Declaration of competing interest The authors declare that they have no conflicts of interest., (Copyright © 2024 Benemérita Universidad Autónoma de Puebla. Published by Elsevier Inc. All rights reserved.)

During the 1990s and early 2000s, research in humans and in the nonhuman primate model of human amnesia revealed that tasks involving free viewing of images provided an exceptionally sensitive measure of recognition memory. Performance on these tasks was sensitive to damage restricted to the hippocampus as well as to damage that included medial temporal lobe cortices. Early work in my laboratory used free-viewing tasks to assess the neurophysiological correlates of recognition memory, and the use of naturalistic visual exploration opened rich avenues to assess other aspects of the impact of eye movements on neural activity in the hippocampus and entorhinal cortex. Here, I summarize two main lines of this work and some of the stories of the trainees who made essential contributions to these discoveries., (© 2024 The Author(s). Hippocampus published by Wiley Periodicals LLC.)

The alterations in the basal ganglia circuitry are core pathological hallmark in Huntington's Disease (HD) and traditionally linked to its sever motor symptoms. Recently it was shown that optogenetic stimulation of cortical afferences to the striatum is able to reverse motor symptoms in HD mice. However, the specific contribution of the direct and indirect striatal output pathways from the dorsolateral (DLS) and dorsomedial striatum (DMS) to the motor phenotype is still not clear. Here, we aim to uncover the contributions of these striatal subcircuits to motor control in wild type (WT) and HD mice by using the symptomatic R6/1 mice. We systematically evaluated locomotion, exploratory behavior, and motor learning effects of the selective optogenetic stimulation of D1 or A2A expressing neurons (direct and indirect pathway, respectively), in DLS or DMS. Bilateral optogenetic stimulation of the direct pathway from DLS and the indirect pathway from DMS resulted in subtle locomotor enhancements, while unaltering exploratory behavior. Additionally, bilateral stimulation of the indirect pathway from the DLS improved performance in the accelerated rotarod task, suggesting a role in motor learning. In contrast, in HD mice, stimulation of these pathways did not modulate any of these behaviors. Overall, this study highlights that selective stimulation of direct and indirect pathways from DLS and DMS have subtle impact in locomotion, exploratory activity or motor learning. The lack of responses in HD mice also suggests that strategies involving cortico-striatal circuits rather than striatal output circuits might be a better strategy for managing motor symptoms in movement disorders., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Rationale: The accumulation of beta-amyloid peptide (Aβ) in the forebrain leads to cognitive dysfunction and neurodegeneration in Alzheimer's disease. Studies have shown that individuals with a consistently cognitively active lifestyle are less vulnerable to Aβ toxicity. Recent research has demonstrated that intrahippocampal Aβ can impact catecholaminergic release and spatial memory. Interestingly, exposure to novelty stimuli has been found to stimulate the release of catecholamines in the hippocampus. However, it remains uncertain whether repeated enhancing catecholamine activity can effectively alleviate cognitive impairment in individuals with Alzheimer's disease., Objectives: Our primary aim was to investigate whether repeated exposure to novelty could enable cognitive resilience against Aβ. This protection could be achieved by modulating catecholaminergic activity within the hippocampus., Methods: To investigate this hypothesis, we subjected mice to three different conditions-standard housing (SH), repeated novelty (Nov), or daily social interaction (Soc) for one month. We then infused saline solution (SS) or Aβ (Aβ 1-42 ) oligomers intrahippocampally and measured spatial memory retrieval in a Morris Water Maze (MWM). Stereological analysis and extracellular baseline dopamine levels using in vivo microdialysis were assessed in independent groups of mice., Results: The mice that received Aβ 1-42 intrahippocampal infusions and remained in SH or Soc conditions showed impaired spatial memory retrieval. In contrast, animals subjected to the Nov protocol demonstrated remarkable resilience, showing strong spatial memory expression even after Aβ 1-42 intrahippocampal infusion. The stereological analysis indicated that the Aβ 1-42 infusion reduced the tyrosine hydroxylase axonal length in SH or Soc mice compared to the Nov group. Accordingly, the hippocampal extracellular dopamine levels increased significantly in the Nov groups., Conclusions: These compelling results demonstrate the potential for repeated novelty exposure to strengthen the dopaminergic system and mitigate the toxic effects of Aβ 1-42 . They also highlight new and promising therapeutic avenues for treating and preventing AD, especially in its early stages., Competing Interests: Declarations. Conflict of interest: The authors declare no conflicts of interest., (© 2024. The Author(s).)

Children are more likely than adults to explore new options, but is this due to a top-down epistemic-uncertainty-driven process or a bottom-up novelty-driven process? Given immature cognitive control, children may choose a new option because they are more susceptible to the automatic attraction of perceptual novelty and have difficulty disengaging from it. This hypothesis is difficult to test because perceptual novelty is intertwined with epistemic uncertainty. To address this problem, we designed a new n-armed bandit task to fully decouple novelty and epistemic uncertainty. By having adults and 4- to 6-year-olds perform the task, we found that perceptual novelty predominated 4-year-olds' (but not adults' or older children's) decisions even when it had no epistemic uncertainty and had the lowest reward value. Additionally, 4-year-olds showed such a novelty preference only when the option's novelty was directly observable, but not when it could only be anticipated, providing new evidence that perceptual novelty alone can drive elevated exploration in early development in a bottom-up manner., (© 2025 The Author(s). Developmental Science published by John Wiley & Sons Ltd.)

Fragile X Syndrome (FXS) stands out as a prominent cause of inherited intellectual disability and a prevalent disorder closely linked to autism. FXS is characterized by substantial alterations in social behavior, encompassing social withdrawal, avoidance of eye contact, heightened social anxiety, increased arousal levels, language deficits, and challenges in regulating emotions. Conventional behavioral assessments primarily focus on short-term interactions within controlled settings. In this study, we conducted a comprehensive examination of the adaptive group behavior of Fmr1 KO male mice over a three-day period, without introducing experimental interventions or task-based evaluations. The data unveiled intricate behavioral anomalies, with the most significant changes manifesting during the initial adaptation to unfamiliar environments. Notably, certain behaviors exhibited a gradual return to typical patterns over time. This dynamic Fmr1 KO phenotype exhibited heightened activity, featuring increased exploration, amplified social interest, and an unconventional approach to social interactions characterized by a higher frequency of shorter engagements. These findings contribute to the growing understanding of social behavior in individuals with FXS and underscore the significance of comprehending their adaptive responses in various environmental contexts., Competing Interests: Declaration of competing interest The authors declare that they have no competing interest., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Early life stress (ELS) during the stress hypo-responsive period (SHRP) alters the curiosity-like behavior later during adolescence. Previous studies have shown maternal separation (MS) stress-induced heightened curiosity and associated risk-taking behavior in the object retrieval task (ORT). However, the neural correlates of curiosity in adolescent rats predisposed to early life stress remain unexplored. Hence, the present study aimed to investigate the neural oscillatory patterns and network characteristics in the regions implicated in curiosity behavior, such as the Prelimbic cortex (PL), Nucleus Accumbens (NAc), and CA1 of the Hippocampus. The local field potentials data were analysed to understand the neural activity patterns in these areas during the risky zone crossing and object retrieval phase of the ORT in MS rats and compared with the normal control (NC) group., Results: In comparison to NC, MS rats showed a reduction in the theta power at 8-12 Hz, beta power at 12-20 Hz, and gamma power at 20-40 Hz range in the PL during risky zone crossing time. MS rats also showed reduced cross-correlation between PL-CA1 and reduced theta coherence between NAc-CA1 during risky zone crossing. During the object retrieval phase, the MS rats showed reduced peak cross-correlation between PL-CA1 and PL-NAc. Behaviourally, MS rats displayed an increased preference for the curiosity platform and retrieved more hidden objects, thus accounting for a higher curiosity index than controls., Conclusion: In summary, a reduced synchronization between the PL, NAc, and CA1 during the object retrieval task indicates how early MS stress during a critical developmental period impacts the limbic circuit connectivity. This corresponded with enhanced curiosity index in adolescent MS rats, predicting an altered intrinsic motivation and hence a higher susceptibility to substance use disorders during adolescence., Competing Interests: Declarations. Ethics approval and consent to participate: All experiments were performed after obtaining the approval by the Institutional Animal Ethics Committee (AEC/72/474/N.P.) and were carried out according to the guidelines of the Committee for the Purpose of Control and Supervision of Experiments on Animals (CPCSEA), Government of India. Consent for publication: We confirm that the manuscript has been approved and given consent for publication by all named authors. We understand that the corresponding author is the sole contact for the editorial process and responsible for communicating with the other authors about progress, submissions of revisions and final approval of proofs. Competing interests: The authors declare no competing interests., (© 2024. The Author(s).)

Rapid adaptation to novel environments is crucial for survival, and this ability is impaired in many neuropsychiatric disorders. Understanding neural adaptation to novelty exposure therefore has therapeutic implications. Here, I found that novelty induces time-dependent theta (4-12Hz) oscillatory dynamics in brain circuits including the medial prefrontal cortex (mPFC), ventral hippocampus (vHPC), and ventral tegmental area (VTA), but not dorsal hippocampus (dHPC), as mice adapt to a novel environment. Local field potential (LFP) recordings were performed while mice were freely behaving in a novel or a familiar arena for 10 min. Initially, mice exhibited increased exploratory behavior upon exposure to novelty, which gradually decreased to levels observed in mice exposed to the familiar arena. Over the same time course, the mPFC, vHPC, and VTA displayed progressively increasing theta power through novelty exposure. Additionally, theta coherence and theta phase synchrony measures demonstrated that novelty weakened the connectivity between these areas, which then gradually strengthened to the level observed in the familiar group. Conversely, mice exposed to the familiar arena showed steady and consistent behavior as well as theta dynamics in all areas. Treatment with a dopamine D1-receptor (D1R) antagonist in the vHPC disrupted neurophysiological adaptation to novelty specifically in the vHPC-mPFC and vHPC-VTA circuits, without affecting behavior. Thus, novelty induces distinct theta dynamics that are not readily dictated by behavior in the mPFC, vHPC, and VTA circuits, a process mediated by D1Rs in the vHPC. The observed time-dependent circuit dynamics in the key learning and memory circuit would provide new insights for treating neuropsychiatric disorders that often show impaired novelty processing., Competing Interests: Declarations. Ethics approval and consent to participate: Not applicable. Consent for publication: Not applicable. Competing interests: The author declares that they have no competing interests., (© 2024. The Author(s).)

Social connections are essential for human health. While curiosity and empathy are crucial psychological factors for a fulfilling life connected with others, it is unclear if acquired environmental factors influence them. In this cross-sectional observational study, 1,311 men and women aged 20-79 years living in Japan were observed to explore how lifestyle factors such as diet, sleep, and leisure activities (such as exercise and hobbies) impact curiosity and empathy. A hierarchical multiple regression analysis revealed that diet and leisure activities impacted curiosity, whereas hobbies influenced cognitive empathy but not affective empathy. Structural equation modeling indicated that men's curiosity was influenced by diet, leisure activities, and work, whereas women's curiosity was influenced by leisure activities and work. These findings suggest that diet and leisure activities can enhance curiosity and cognitive empathy, leading to improved well-being., Competing Interests: I have read the journal’s policy and the authors of this manuscript have the following competing interests: S.M., T.S., H.T., Y.K., T.I., and Y.N. are employees of Suntory Wellness Ltd. K.N. and T.K. have declared that no competing interests exist., (Copyright: © 2024 Morita et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Stress-related disorders are commonly associated with abnormalities in hypothalamic-pituitary-adrenal (HPA) axis activity. Preliminary studies with cortisol administration in the aftermath of trauma suggest that this HPA axis hormone can potentially prevent maladaptive behavioral and biological stress responses. However, the efficacy of glucocorticoid administration during the peripuberty period has not been tested yet, although this lifetime is a critical time window in brain development and is highly sensitive to the harmful effects of stress. To further examine the short and long-lasting impact of glucocorticoids treatment given during the post-peripubertal stress period, the present study utilized a rat model of peripubertal stress-induced psychopathology and animals were subjected to a battery of tests to assess anxiety-like behaviors, exploratory behavior and reactivity to novelty at late adolescence and sociability, anhedonia and stress coping behaviors at adulthood. All the experiments were performed in males and females to evaluate the potential behavioral sex differences. Overall, our results demonstrated that rats exposed to peripubertal stress show decreased sociability in adulthood without differences in anxiety and depression-like behaviors. Moreover, this study shows that the administration of corticosterone after stress exposure at peripuberty does not prevent stress-induced behavioral alterations. However, we observed that some stress-induced behavioural alterations and corticosterone responses are sex-specific. Thus, the data obtained highlight that delineating sex differences in stress-related studies may ultimately contribute to the development of effective therapeutic interventions for each sex., Competing Interests: Declaration of Competing Interest None, (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Exposure to artificial light during the night is known to promote disruption to the biological clock, which can lead to impaired mood and metabolism. Metabolic hormone secretion is modulated by the circadian pacemaker and recent research has shown that hormones such as insulin and leptin can also directly affect behavioral outcomes and the circadian clock. In turn, obesity itself is known to modulate the circadian rhythm and alter emotionality. This study investigated the behavioral and metabolic effects of constant light exposure in two models of obesity - a leptin null mutant (OB) and diet-induced obesity via high-fat diet. For both experiments, mice were placed into either a standard Light:Dark cycle (LD) or constant light (LL) and their circadian locomotor rhythms were continuously monitored. After 10 weeks of exposure to their respective lighting conditions, all mice were subjected to an open field assay to assess their explorative behaviors. Their metabolic hormone levels and inflammation levels were also measured. Behaviorally, exposure to constant light led to increased period lengthening and open field activity in the lean mice compared to both obesity models. Metabolically, LL led to increased cytokine levels and poorer metabolic outcomes in both lean and obese mice, sometimes exacerbating the metabolic issues in the obese mice, independent of weight gain. This study illustrates that LL can produce altered behavioral and physiological outcomes, even in lean mice. These results also indicate that obesity induced by different reasons can lead to shortened circadian rhythmicity and exploratory activity when exposed to chronic light., Competing Interests: Declaration of competing interest The authors declare no competing financial interests., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Biological age-based competitions have been suggested to mitigate maturation bias among youth football players. This study analysed the physical demands and spatial exploration behaviour when playing football matches against biological or chronological age-based opposition. One-hundred and sixteen U-13 and U-14 male regional-level football players were recruited from five Portuguese football academies. Each player completed eight games, four per condition (chronological and biological-based), on the same day. Games were played in 7 vs. 7 formats, with 20-min duration, and conformed to standard officiating and rule procedures. The following variables were considered from GPS-data in each game: distance covered, high-intensity accelerations and decelerations, body impacts, and average and peak speeds. Furthermore, average, and peak heart rates (HR peak ) and spatial exploration index were collected. Players covered significantly less distance (ES = 1.11), performed fewer decelerations (ES = 0.82), achieved lower average speeds (ES = 1.15), had fewer body impacts (ES = 0.94), and recorded lower HR peak (ES = 0.56) in the biological age-based competition compared to the chronological-age-based. No significant differences were found between the two formats in spatial exploration. Both game formats offer distinct physical demands at the external and internal levels. Finally, practitioners can manipulate the type of opposition to get distinct physical demands to mitigate the effect of maturation bias during development.

The accurate detection and quantification of rodent behavior forms a cornerstone of basic biomedical research. Current data-driven approaches, which segment free exploratory behavior into clusters, suffer from low statistical power due to multiple testing, exhibit poor transferability across experiments and fail to exploit the rich behavioral profiles of individual animals. Here we introduce a pipeline to capture each animal's behavioral flow, yielding a single metric based on all observed transitions between clusters. By stabilizing these clusters through machine learning, we ensure data transferability, while dimensionality reduction techniques facilitate detailed analysis of individual animals. We provide a large dataset of 771 behavior recordings of freely moving mice-including stress exposures, pharmacological and brain circuit interventions-to identify hidden treatment effects, reveal subtle variations on the level of individual animals and detect brain processes underlying specific interventions. Our pipeline, compatible with popular clustering methods, substantially enhances statistical power and enables predictions of an animal's future behavior., Competing Interests: Competing interests: E.C.O. was employed by F. Hoffmann-La Roche AG Switzerland at the time of study conduct and manuscript submission. O.S. was funded by a Roche postdoctoral fellowship. The other authors declare no competing interests., (© 2024. The Author(s).)

Exploratory behaviors can serve an adaptive role within novel or changing environments. Namely, they facilitate information gain, allowing an organism to maintain accurate beliefs about the environment and select actions that better maximize reward. However, finding the optimal balance between exploration and reward-seeking behavior - the so-called explore-exploit dilemma - can be challenging, as it requires sensitivity to one's own uncertainty and to the predictability of one's surroundings. Given the close relationship between uncertainty and anxiety, a body of work has now also emerged identifying associated effects on exploration. In particular, the field of computational psychiatry has begun to use cognitive computational models to characterize how anxiety may modulate underlying information processing mechanisms, such as estimation of uncertainty and the value of information, and how this might contribute to psychopathology. Here, we review computational modeling studies investigating how exploration is influenced by anxiety. While some apparent inconsistencies remain to be resolved, studies using reinforcement learning tasks suggest that directed (but not random) forms of exploration may be elevated by trait and/or cognitive anxiety, but reduced by state and/or somatic anxiety. Anxiety is also consistently associated with less exploration in foraging tasks. Some differences in exploration may further stem from how anxiety modulates changes in uncertainty over time (learning rates). Jointly, these results highlight important directions for future work in refining choice of tasks and anxiety measures and maintaining consistent methodology across studies., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Early puppy development is a crucial period that significantly influences a dog's lifelong health, behavior and personality. In this study, the behavioral development of Kangal puppies was investigated through repeated open-field testing, focusing on exploratory behavior, mobility, and responses to novel stimuli. Thirty-three Kangal puppies (20 males and 13 females) from various breeding centers in Sivas Province, Türkiye, were evaluated. The puppies were tested in a controlled open-field environment at 5, 6, and 8 weeks of age. Tests included a novel environment test at 5 weeks and novel object tests at 6 and 8 weeks. Mobility rate, exploration rate, and total distance parameters were measured using automated tracking software (ToxTrac). Qualitative behavioral assessments (QBAs) were performed to evaluate three distinct behavioral and emotional aspects: curiosity, comfort, and fearfulness. The results of these assessments revealed significant increases in curiosity and comfort scores over the testing weeks, with a concomitant decrease in fearfulness. Additionally, tracking data showed increased mobility and decreased exploration rates throughout the testing weeks. Significant correlations were found between curiosity and exploratory behavior, as well as between mobility and comfort scores. Overall, our findings suggest that Kangal puppies exhibit expected behavioral developments in repeated open field testing, with patterns consistent across multiple analyses. These results provide valuable insights into the behavioral development of Kangal puppies and underscore the importance of considering curiosity and other internal motivations in understanding animal behavior., Competing Interests: Declarations. Consent to participate: Informed consent was obtained from the dog breeders prior to the study. Consent to publish: Not applicable. Ethics approval: The research strictly adhered to ethical principles, as approved by the Sivas Cumhuriyet University Animal Experiments Local Ethics Committee, decision dated April 20, 2021, and protocol numbered 65202830-050.04.04/526. All procedures were conducted in accordance with the ARRIVE guidelines. Competing interests: The authors declare no competing interests., (© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)

A-kinase anchoring protein 12 (AKAP12) is a key scaffolding protein that regulates cellular signaling by anchoring protein kinase A (PKA) and other signaling molecules. While recent studies suggest an important role for AKAP12 in the brain, including cognitive functions, its role in middle-aged mice and potential sex differences are not fully understood. Therefore, this study investigated the effects of AKAP12 on cognitive and exploratory behavior in middle-aged mice, focusing on sex differences. Cognitive function was assessed using the spontaneous Y-maze test and the novel object recognition test (NORT). No significant sex differences in cognitive function were found in middle-aged C57BL/6J mice; however, female mice showed greater exploratory behavior during the NORT. In addition, both middle-aged male and female Akap12 knockout (KO) mice performed similarly to wild-type (WT) mice in the Y-maze test, but had lower discrimination indices in the NORT, suggesting a potential role for AKAP12 in short-term memory. Notably, exploratory behavior was suppressed in female Akap12 KO mice compared to WT mice, whereas male Akap12 KO mice did not show this effect. There were no significant differences in movement distance and velocity during the Y-maze test and NORT between WT and KO mice of either sex. These results indicate that AKAP12 affects cognitive function and exploratory behavior in middle-aged mice and that these effects differ between sexes., Competing Interests: Declarations. Ethics approval and consent to participate: No human participants, human data, and human tissue were involved in this study. All experimental procedures using animals followed NIH guidelines and received approval from Massachusetts General Hospital Institutional Animal Care and Use Committee. Consent for publication: Not applicable. Competing interests: The authors declare no competing interests., (© 2024. The Author(s).)

Reaching and inspecting objects is an intricate part of human life, which is shared by a diversity of animals across phyla. In addition to appendages like legs and antennae, some insects use their mouthparts to reach and inspect targets. Hawkmoths of the family Sphingidae (Lepidoptera) use their extremely long and straw-like proboscis to drink nectar from flowers. As they approach flowers, hawkmoths uncoil their proboscis and explore the floral surface while hovering to target the proboscis to the nectary hole. Several sensory modalities provide feedback to control and guide these extremely versatile proboscis movements. The control task faced by the hawkmoths' nervous system during such behaviors is not unlike that of an animal guiding limbs or a robotic agent guiding a manipulator to a target. Hawkmoths perform these reaching maneuvers while simultaneously hovering, and hence require rapid and continuous coordination between the proboscis, neck, and flight motor systems, thereby providing a unique invertebrate model for studying appendage guidance and reaching. Here, we review what is known about how hawkmoths use their proboscis for floral inspection and nectar discovery, as well as the role of various sensors in proboscis guidance. We give a brief overview of the morphology and muscular apparatus of the hawkmoth proboscis, and discuss how multimodal sensory feedback might be turned into motor action for appendage guidance., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology.)

Sensory experience affects not only the corresponding primary sensory cortex, but also synaptic and neural circuit functions in other brain regions in a cross-modal manner. However, it remains unclear whether oligodendrocyte (OL) generation and myelination can also undergo cross-modal modulation. Here, we report that while early life short-term whisker deprivation from birth significantly reduces in the number of mature of OLs and the degree of myelination in the primary somatosensory cortex(S1) at postnatal day 14 (P14), it also simultaneously affects the primary visual cortex (V1), but not the medial prefrontal cortex (mPFC) with a similar reduction. Interestingly, when mice were subjected to long-term early whisker deprivation from birth (P0) to P35, they exhibited dramatically impaired myelination and a deduced number of differentiated OLs in regions including the S1, V1, and mPFC, as detected at P60. Meanwhile, the process complexity of OL precursor cells (OPCs) was also rduced, as detected in the mPFC. However, when whisker deprivation occurred during the mid-late postnatal period (P35 to P50), myelination was unaffected in both V1 and mPFC brain regions at P60. In addition to impaired OL and myelin development in the mPFC, long-term early whisker-deprived mice also showed deficits in social novelty, accompanied by abnormal activation of c-Fos in the mPFC. Thus, our results reveal a novel form of cross-modal modulation of myelination by sensory experience that can lead to abnormalities in social behavioral, suggesting a possible similar mechanism underlying brain pathological conditions that suffer from both sensory and social behavioral deficits, such as autism spectrum disorders., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)