Search bioRxiv⌕ Search
Home/Archive/bioRxiv

bioRxiv · 10.1101/2024.02.04.578825

The role of ultradian rhythms in post-deprivationrebounds and diurnal rhythms of sleep and wakefulness in rats

Lim, J.·Stephenson, R.
View original source ↗Export metadata ↓

Abstract

The temporal organization of ultradian rhythms in sleep and wakefulness during post-sleep deprivation (TSD) rebound were investigated in 15 rats under contant bright light (LL). Following baseline recordings, rats were subjected to TSD using gentle manual stimulation. Post-TSD rebounds in cumulative wakefulness (WAKE), rapid eye movement sleep (REM) and non-REM sleep (NREM) were analyzed in WAKE-dominant ({upsilon}w) and sleep-dominant ({upsilon}s) ultradian phases. Rebounds in WAKE and NREM were present only when data were analyzed on a full ultradian cycle basis, and were absent in {upsilon}s and {upsilon}w phases alone. These rebounds were approximately 50% complete and not proportional to TSD excess/deficit. Rebounds in REM were present in full ultradian cycles and partially expressed in {upsilon}s but absent in {upsilon}w. REM rebounds fully compensated for REM deficit. Rebounds were mediated mainly by a reduction in the duration of the {upsilon}w ultradian phase, and by decreased probability of arousal in the {upsilon}s ultradian phase. These mechanisms were also found to partially mediate diurnal rhythms in 10 rats under a 12:12 h LD cycle. This study implicates an ultradian timing mechanism in the control of post-TSD rebounds and suggests that rebounds in all three states are mainly mediated by post-TSD adjustments in WAKE-promoting mechanisms. Ultradian rhythms should be taken into account to avoid errors in data analysis. HighlightsO_LISleep-wake state exhibits circadian rhythms and ultradian rhythms. C_LIO_LIThese rhythms interact with rebounds after sleep deprivation. C_LIO_LICircadian amplitude and sleep rebound are partially mediated by ultradian timing. C_LIO_LIArousal-related processes control these sleep-wake patterns in both states. C_LIO_LIMeasuring ultradian rhythms is necessary for accurate analysis of data. C_LI

Explore related subjects

animal behavior and cognitionPreprint

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Lim, J., Stephenson, R.. 2024-02-05. The role of ultradian rhythms in post-deprivationrebounds and diurnal rhythms of sleep and wakefulness in rats. https://doi.org/10.1101/2024.02.04.578825

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

KEEP EXPLORING

Related preprints

bioRxiv2026

Automated pup-level analysis reveals distinct effects of prenatal CBD and THC exposure on maternal retrieval

This study examined how prenatal CBD and {Delta}9-tetrahydrocannabinol (THC) exposure affects maternal caregiving in C57BL/6J mice. We developed the Machine-Automated Scoring of the Pup Retrieval Test (MAS-PRT) to overcome limitations of manual behavioral scoring. MAS-PRT integrates Multi-Animal DeepLabCut for dam and pup tracking with Detectron2 for dynamic nest reconstruction. Validated against 170 manually annotated retrieval trials, the pipeline showed high concordance with manual measurements and enabled reproducible extraction of encounter latency, retrieval latency, and locomotor trajectories. Prenatal exposure did not impair general nest-building or overall home-cage maternal care. However, pups from both CBD and THC groups showed reduced body weight at postnatal day 5. Cox proportional hazards modeling revealed divergent effects by compound: CBD-exposed dams exhibited a weight-dependent increase in probability of encountering and retrieving lighter pups, independent of pup sex. Spatial tracking further showed that dams traversed significantly shorter total trajectories when retrieving female progeny exposed to either compound. Longitudinal trial-by-trial analysis indicated intact task acquisition in controls and CBD dams, whereas THC dams displayed a flattened learning curve driven by lower retrieval latencies on initial trials. Together, these findings indicate that prenatal cannabinoid exposure does not produce generalized disruption of maternal care but instead induces compound-specific alterations in maternal reactivity, retrieval kinematics, and learning dynamics.

animal behavior and cognition↗
bioRxiv2026

A comparison of female competitive traits: Female aggression peaks at nest building but female song spans multiple contexts in a temperate songbird

Female-female competition is increasingly recognized as a key driver of female ornamentation, including birdsong, which often functions in intrasexual competition. However, the specific resources females use elaborate traits to compete for remain unclear. In addition, few studies have simultaneously investigated the use of multiple competitive traits in females, despite growing independent interest in these traits (e.g., female song and aggression). We investigated the competitive contexts of female song, aggression and calling behavior in northern house wrens (Troglodytes aedon) to determine which resources females compete for across the breeding season. We simulated conspecific territorial intrusions using female song at three breeding stages representing different contexts: arrival (mate and territory acquisition), nest building (nest site and breeding status defense), and egg laying (brood defense). We tested whether female song and physical aggression varied as reproductive resources shifted across the breeding cycle. Females were significantly more aggressive during nest building, showing 5.8 times greater odds of a higher-intensity aggressive response during nest building compared to arrival. Female song output was similar across early stages but declined during egg laying, though this was not statistically significant after correction for multiple comparisons and individuals varied substantially in overall singing propensity. Non-song vocalizations varied by call type and breeding stage. Calls associated with aggression occurred most frequently during nest building, consistent with peak physical aggression responses. Together, these results identify nest building as the stage of highest female aggression, consistent with heightened competition over nest cavities and associated breeding status in this cavity-nesting species. In contrast, female song occurred across all stages and appears to function in multiple competitive contexts. This study provides evidence for context and mode-specific female signaling in a temperate songbird and highlights that females strategically use aggression, calls, and song to mediate social conflict across breeding contexts.

animal behavior and cognition↗
bioRxiv2026

Tracking human foragers and their prey reveals adaptive predator-prey dynamics

Hunting for mobile prey is thought to have played a key role in hominin evolution, by providing high-quality nutrition that supported the development of the exceptionally large human brain. However, human-prey dynamics remain poorly understood because studies have not yet tracked human foragers and their prey simultaneously. Here, we employ high resolution tracking of groups of human foragers (ice-fishers) and their prey (fish shoals) to study human-prey dynamics. Our results show that foragers adaptively combined personal and social information in deciding where to forage and for how long, closely matching the prey distribution. Prey responded dynamically to human exploitation, showing increased attraction to fishing activity, alongside decreased biting probability. Furthermore, we found that foragers adaptively relied on memory, preferentially returning to areas with high prey presence, particularly when their current return rate was low. Our results show how human foragers overcome the challenges of extracting invisible, mobile and reactive prey by tightly tuning patch-selection, patch-leaving and patch-return decisions to the distribution and behaviour of their prey.

animal behavior and cognition↗