bioRxiv Science⌕ Search
Home/Archive/bioRxiv

bioRxiv · 10.64898/2026.10.19.760292

Social Approach Dynamics in Freely-Moving Rat Dyads are Not Impacted by Lesions to the Retrosplenial Cortex

Lowrie, M. I.·Smith, J. E. M.·Le, A. T. N.·Marrone, D. F.·Insel, N.
View original source ↗Export metadata ↓

Abstract

Social interaction in rodents can involve a dynamic interplay of approach and withdrawal movements, requiring the brain to rapidly update information about where others are and where they may intend to go. In mammals, the posterior parietal cortex (PPC) and adjacent, reciprocally-connected retrosplenial cortex (RSC) are high-level hubs for spatial information processing. To test the role of these regions in dynamic social approach, we evaluated rats' relative orientation, movement, and position (ROMP) with a freely-moving social-stimulus rat following bilateral lesions to the PPC or anterior RSC. RSC animals showed overall more and faster movements, and greater attention to environment boundaries across multiple behavioral conditions (open field, social, object, static social, and dynamic object) compared with sham-lesioned controls. Increased attention to boundaries was correlated with reduced orienting to a social stimulus; however, this appeared to have little observable impact on the social interactions themselves. Rear-sniffing was lower in RSC rats, but only during the latter half of the 10 minute social exposures, and there were no detected differences in the dynamics of their social approach compared with sham controls. PPC lesion spread was more limited, and social behavior was mostly indistinguishable from sham controls, though this group was more likely to chase the dynamic object. Results suggest that social approach within short (peripersonal) distances is largely accomplished through sensorimotor adjustments that do not require higher-level, spatial-predictive processing taking place in the RSC.

Explore related subjects

animal behavior and cognitionPreprint

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Lowrie, M. I., Smith, J. E. M., Le, A. T. N., Marrone, D. F., Insel, N.. 2026-10-21. Social Approach Dynamics in Freely-Moving Rat Dyads are Not Impacted by Lesions to the Retrosplenial Cortex. https://doi.org/10.64898/2026.10.19.760292

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

bioRxiv2026

Development of the Highly Sensitive Horse questionnaire to assess horses' sensory processing sensitivity

It is well established that individuals vary in how they respond to situations, but might they also perceive their environment differently? Sensory Processing Sensitivity (SPS) is a multidimensional trait describing individual variation in the perception and response to sensory, emotional, and social stimuli. While extensively studied in humans, its presence in animals remains underexplored. We investigated whether horses might exhibit a comparable trait and developed the Highly Sensitive Horse questionnaire to assess equine SPS. A 104-item questionnaire was developed and refined using data from an online survey of 121 horses. The remaining 45 items were evaluated in an independent survey of 561 horses. Exploratory and confirmatory factor analyses identified a robust two-factor, 12-item structure reflecting dimensions similar to the human SPS dimensions of: Overstimulation, describing a tendency to become overwhelmed by intense or prolonged stimuli, and Sensitivity to subtleties, describing heightened perception of subtle environmental changes. The scale showed high internal consistency, excellent intra-rater and moderate inter-rater reliability. Although eSPS was associated with established behavioural traits, including fearfulness, it also explained unique behavioural variation beyond these traits. These findings suggest that horses differ in how they perceive their environment, providing a foundation to better understand equine behaviour, and opening new avenues for comparative sensory-processing research.

animal behavior and cognition↗
bioRxiv2026

Behavioral divergence across replicated predation regimes is species-specific in two sympatric poeciliid fishes

Predation is a potent driver of behavioral divergence across prey populations, yet whether shared predation regimes generate similar responses in coexisting prey species remains unclear. Species differences in reproductive and foraging traits may alter vulnerability to predators, generating species-specific responses. We compared behavior and cognition of two poeciliid fishes (Gambusia affinis and Poecilia latipinna) that differ in body size, the presence of male ornamentation, and mating tactics. We sampled both species across replicate high- and low-predation regimes and measured exploration, shyness, boldness, social motivation, and detour solve latency (N = 509). Multivariate behavior and cognition differed between predation regimes, and the magnitude of divergence varied with species but not body size. Consistent with the multivariate pattern, the more conspicuous P. latipinna exhibited higher boldness and overall lower exploration under high-predation, while high- and low-predation populations of G. affinis did not differ. These findings suggest either that the more conspicuous species experiences greater predation risk or that the less conspicuous species reduces its predation risk through alternative phenotypic responses. More broadly, species differences in reproductive phenotypes associated with sexual selection may help explain why shared predation regimes generate variable patterns of behavioral divergence across taxa.

animal behavior and cognition↗
bioRxiv2026

Capturing the rhythm: methodological choices shape inference from circadian activity data

Abstract 1. Statistical tools and analytical decisions for analysing animal activity data are often limited and poorly justified, particularly with respect to model choice, sampling design and temporal aggregation. These shortcomings can constrain our ability to draw accurate and biologically meaningful inferences about behaviour. 2. We interrogated 24 h activity data taken from individual males and females derived from five Drosophila melanogaster populations to generate a general framework for collecting and analysing activity data that systematically compares common model classes, continuous verses fragmented sampling strategies, and alternative temporal aggregation choices (time-bin sizes). 3. Our analyses identified generalised additive mixed models (GAMMs) applied to high-frequency continuous data with small-moderate bin sizes (1-5 minutes) as providing the most robust and interpretable inference for our complex, high-frequency activity data. 4. However, our interrogation of the data set confirmed that analytical and sampling decisions need to be tailored to the study species, the timing of activities and the nature of the behaviour of interest. Accordingly, polynomial and cosinor generalised linear models, increased but biologically targeted snapshot sampling, and bin sizes smaller than one hour yielded adequate analyses with similar biological conclusions when appropriately matched to the system. 5. Our approach provides an accessible decision-making framework for activity analyses that allows researchers across behavioural, ecological and evolutionary studies to justify and optimise choices about data collection and modelling. Such an approach improves the biological relevance of inference and supporting the use of modern tracking and analytical technologies.

animal behavior and cognition↗