Biology subjects

Hakataya, S.

Publications and source records attributed to Hakataya, S..

7 recordsLinked to original sources

bioRxiv2026

DiverScan: attention-guided exploratory analysis of animal behaviour across diverse comparative experiments

High-throughput tracking yields rich time-series data of animal behaviour, yet extracting biological insight remains a bottleneck, even for simple control--treatment comparisons. Existing analyses struggle to pinpoint the multiple, nonlinearly intertwined differences hidden in the data and fail to generalise across diverse recording set-ups. Here we present DiverScan, a deep-learning framework for attention-guided exploratory analysis of behavioural time series. DiverScan disentangles condition-dependent behavioural differences by pairing a loss function tailored to data exploration with an attention-branch architecture, and highlights condition-specific behavioural features visually and with explanatory text generated by a large language model. DiverScan is validated on a synthetic benchmark and on datasets from seven laboratories spanning multiple species and both single- and multi-animal behaviour. Beyond recovering known phenotypes, we demonstrate that DiverScan helps researchers generate new hypotheses across these diverse datasets. Available as Jupyter notebooks with a graphical user interface and flexible input formats, DiverScan can integrate into existing behavioural-analysis pipelines.

animal behavior and cognition↗

bioRxiv2025

Rats spontaneously show categorical responses toward familiar or unfamiliar conspecifics in a habituation-dishabituation task using multiple habituation stimuli

Discriminating between familiar and unfamiliar conspecifics is a fundamental aspect of social recognition. Previous studies have shown that familiarity strongly influences rat social behavior, and that rats can be trained to discriminate between olfactory cues from cage-mates and non-cage-mates in a digging task. However, such discrimination did not occur in a lever-pressing task using live conspecifics as stimuli. In the present study, we investigated whether rats could discriminate social familiarity in a simple, less-demanding and naturalistic context using whole-animal stimuli. We employed a habituation-dishabituation paradigm in which multiple cage-mate or non-cage-mate individuals were presented during the habituation phase. We examined whether rats would habituate to the familiarity category among these multiple stimuli and subsequently show dishabituation when the stimulus class switched (cage-mate to non-cage-mate or vice versa). During the habituation phase, exploratory responses declined over successive sessions, suggesting habituation to the common element among multiple cage-mates or non-cage-mates, i.e., familiarity/unfamiliarity. When all subjects were considered together, clear dishabituation was not observed, indicating individual variation in habituation. However, a post-hoc analysis restricted to subjects showing sufficient habituation revealed significant dishabituation to the stimulus class switch. These findings suggest that rats can spontaneously classify multiple conspecifics according to their familiarity without training. Rats may flexibly employ different forms of social recognition and information such as individual identity or familiarity-based heuristics to guide adaptive social behavior in varying contexts. HighlightsO_LIWe tested familiarity discrimination in rats by habituation-dishabituation task C_LIO_LIMultiple cage-mate or non-cage-mate stimuli were presented during habituation C_LIO_LIExploratory responses decreased as habituation sessions progressed C_LIO_LIDishabituation occurred in individuals who exhibited sufficient habituation C_LIO_LIRats showed categorical responses toward familiarity or unfamiliarity C_LI

animal behavior and cognition↗

bioRxiv2024

How does immediate auditory feedback coupled to locomotion influence the spontaneous actions of rats?

Sense of agency is a subjective experience that is difficult to examine in animals and preverbal infants. In animals and infants, the sensory monitoring of self-motion, which is the basis of this sense, and the contingency between self-motion and sensory feedback are investigated. Here, we performed experiments on rats using locomotor movements and auditory feedback of pulsed sounds with real-time changes in pulse interval corresponding to the velocity of locomotion, and tested whether rats change their locomotion depending on the degree of contingency between locomotion and auditory feedback. The results showed that rats increased their locomotion distance when the pulse interval of sound changed in accordance with the velocity of locomotion. However, this effect was not long-lasting. This study provides a simple and convenient method to examine the awareness of the contingency between self-motion and auditory feedback in a wide range of animal species without long-term training, and is expected to be a useful tool for comparisons with humans.

animal behavior and cognition↗

bioRxiv2024

Beyond dichotomy: diversity of rat's ultrasonic vocalizations

Rats emit ultrasonic vocalizations (USVs) in diverse contexts, and these USVs are thought to serve many biological functions, such as socio-coordinating and alarming functions. In particular, rat USVs have been established as a good model for studying emotional expressions. Since the discovery of USVs in rats, it has gradually been revealed that two families of juvenile and adult rat USVs with distinct acoustic features are closely linked to different affective states: 50-kHz (high-short) calls are associated with positive affective states, whereas 22-kHz (low-long) calls are associated with negative affective states. Although various subtypes within high-short and low-long calls have been proposed and used, most studies adopt the dichotomous framework of first dividing USVs into high-short or low-long calls. The diversity of rat USVs may have been overlooked due to this high-short / low-long dichotomous framework, as such labeling could discourage reporting of actual measured acoustic properties. Considering that several recent studies claim to have found new USV categories outside this framework, we conducted a systematic survey of descriptions of rat USVs in the literature. We identified 15 articles reporting USVs that are outside the dichotomous framework. Our results support the existence of diverse USVs beyond the dichotomy, highlighting the importance of research on a broader range of vocalizations that might reflect complex affective states beyond the simple distinction between positive and negative.

animal behavior and cognition↗

bioRxiv2024

Familiarity modulates preference for joint feeding with conspecifics in rats

Rats are highly social mammals that form social groups of various sizes. Interestingly, they are known to show prosocial behaviors, and are socially tolerant of other conspecifics as they feed together, but the specificity of their prosociality has not been fully understood. Here, we investigated what degree rats showed social choice, i.e., preferential joint feeding even with unfamiliar animals by performing a simple feeding site choice task. In the task, subjects were tested to choose between the feeding site where they fed with other rats (social option) or the other site where they could feed alone (solitary option). The results showed that social option choices increased particularly when the partner was a single non-cagemate rat. This result means that high social preference for other individuals occurs spontaneously, even when they are feeding with unfamiliar non-cagemates. This high degree of social tolerance would lead to the suppression of aggressive behavior as well as enhancement of affiliative relationships even in situations when the rats met with unfamiliar conspecifics for the first time. HighlightsO_LIRats are highly socially tolerant mammals as they feed with conspecifics together. C_LIO_LIWe explored how the presence of conspecifics affects feeding site choices in rats. C_LIO_LISocial choices increased when the partners were non-cagemates. C_LIO_LISocial choices decreased as the number of non-cagemates increased. C_LIO_LIJoint feeding with a single non-cagemate is observed particularly frequently. C_LI

animal behavior and cognition↗

bioRxiv2023

An exploratory study of behavioral traits and the establishment of social relationships in female laboratory rats

There is growing evidence that social relationships influence individual fitness through various effects. Clarifying individual differences in social interaction patterns and determinants for such differences will lead to better understanding of sociality and its fitness consequences for animals. Behavioral traits are considered one of the determining factors of social interaction. The purpose of this study was to explore the effects of individual behavioral traits on social relationship building in rats, a highly social species. Initially, the following behavioral characteristics were measured in individuals: tameness (glove test), activity (open field test), exploration (novel object test), sociability (three-chamber test), and boldness (elevated plus maze test). We then used DeepLabCut to behaviorally track three groups of four individuals (12 total) and analyze social behaviors such as approach and avoidance behaviors. Principal component analysis based on behavioral test results detected behavioral traits interpreted as related to exploration, boldness, activity, and tameness, but not sociability. In addition, behavioral tracking results showed consistent individual differences in social behavior indices such as isolation time and partner preference. Furthermore, we found that different components were correlated with different phases of social behavior; exploration and boldness were associated with the early stages of group formation, whereas activity was associated with later stages of relationship building. From these results, we derived hypothesize that personality traits related to the physical and social environment have a larger influence in the relationship formation phase, and the behavioral trait of activity becomes important in the maintenance phase of relationships. Future studies should examine this hypothesis by testing larger group sizes and ensuring there is no bias introduced into group composition.

animal behavior and cognition↗

bioRxiv2021

Decreased synthesis and variable gene transcripts of oxytocin in a domesticated avian species

The Bengalese finch was domesticated more than 250 years ago from the wild white-rumped munia. Similar to other domesticated species, Bengalese finches show a reduced fear response and have lower corticosterone levels, compared to white-rumped munias. Bengalese finches and munias also have different song types. Since oxytocin (OT) has been found to be involved in stress coping and auditory processing, we tested whether the OT sequence and brain expression pattern and content differ in wild munias and domesticated Bengalese finches. We identified intra-strain variability in the untranslated regions of the OT sequence in Bengalese finches in comparison to the munia OT. Several of these changes fall in specific transcription factor binding sites, which show either a conserved or a relaxed evolutionary trend in the avian lineage, and in vertebrates in general. Although in situ hybridization in several hypothalamic nuclei did not reveal significant differences in the number of cells expressing OT between the two strains, real-time quantitative PCR showed significantly lower OT mRNA expression in the diencephalon of the Bengalese finches relative to munias. Our study thus points to a decreased OT synthesis in the domestic strain compared with the wild strain in birds. This is an opposite pattern from that found in some domesticated mammals, suggesting that different processes of OT function might have occurred in mammals and birds under domestication.

neuroscience↗