Biology subjects

Kraus, S.

Publications and source records attributed to Kraus, S..

5 recordsLinked to original sources

bioRxiv2024

IntelliR: A comprehensive and standardized pipeline for automated profiling of higher cognition in mice

In the rapidly evolving field of rodent behavior research, observer-independent methods facilitate data collection within a social, stress-reduced, and thus more natural environment. A prevalent system in this research area is the IntelliCage, which empowers experimenters to design individual tasks and higher cognitive challenges for mice, driven by their motivation to access reward. The extensive amount and diversity of data provided by the IntelliCage system explains the growing demand for automated analysis among users. Here, we introduce IntelliR, a standardized pipeline for analyzing raw data generated by the IntelliCage software, as well as novel parameters including the cognition index, which enables comparison of performance across various challenges. With IntelliR, we provide the tools to implement and automatically analyze 3 challenges that we designed, encompassing spatial, episodic-like, and working memory with their respective reversal tests. Using results from 3 independent control cohorts of adult female wildtype mice, we demonstrate their ability to comprehend and learn the tasks, thereby improving their proficiency over time. To validate the sensitivity of our approach for detecting cognitive impairment, we used adult female NexCreERT2xRosa26-eGFP-DTA mice after tamoxifen induced diphtheria toxin-mediated ablation of pyramidal neurons in cortex and hippocampus. We observed deterioration in learning capabilities and cognition index across several tests. IntelliR can be readily integrated into and adapted for individual research, thereby improving time management and reproducibility of data analysis. HIGHLIGHTSO_LIIntelliR is a standardized pipeline for analyzing raw data of IntelliCage software. C_LIO_LIDomains include spatial, episodic-like, and working memory with reversals. C_LIO_LIWT mice (3 cohorts) comprehend, learn and improve proficiency over time. C_LIO_LICognition index permits comparison of performance across cognitive domains. C_LIO_LIMice with ablation of pyramidal neurons decline mainly in working memory. C_LI

animal behavior and cognition↗

bioRxiv2023

Phage-induced efflux down-regulation boosts antibiotic efficacy

The interactions between a virus and its host vary in space and time and are affected by the presence of molecules that alter the physiology of either the host or the virus. Determining the molecular mechanisms underpinning these interactions is paramount for predicting the fate of bacterial and phage populations and for designing rational phage-antibiotic therapies. We study the interactions between stationary phase Burkholderia thailandensis and the phage {Phi}Bp-AMP1. Although heterogeneous genetic resistance to phage rapidly emerges in B. thailandensis, the presence of phage enhances the efficacy of three major antibiotic classes, the quinolones, the beta-lactams and the tetracyclines, but antagonizes tetrahydrofolate synthesis inhibitors. We discovered that enhanced antibiotic efficacy is underpinned by reduced antibiotic efflux in the presence of phage. This new phage-antibiotic therapy allows for eradication of stationary phase bacteria, whilst requiring reduced antibiotic concentrations, which is crucial for treating infections in sites where it is difficult to achieve high antibiotic concentrations.

microbiology↗

bioRxiv2023

Synergistic olfactory processing for social plasticity in desert locusts

1Desert locust plagues threaten the food security of millions. Central to their formation is crowding-induced social plasticity from solitarious to gregarious phenotypes. We investigated the impact of population density changes on locusts foraging choices and their neurobiology by examining how relevant food and social odors are coded in the antennal lobe. Our analysis shows that gregarious locusts are highly attentive to social cues during foraging, with olfaction playing an essential role. Using calcium imaging, we show that corresponding odors are encoded by projection neurons, revealing a stable combinatorial response map. Transient dynamics in the glomeruli converge into temporally evolving response motifs in the somata that differ between gregarious and solitarious insects. The dynamics of response motifs facilitate a crowding-dependent synergy between olfactory processing of food-related and social odors. Our study demonstrates the effectiveness of calcium imaging for locust olfaction, suggesting a crowding-induced adaptation to enhance food detection in swarms. 2 TeaserIn dense swarms, desert locusts optimize foraging efficiency by exhibiting an enhanced olfactory response to food odors.

neuroscience↗

bioRxiv2022

Supplementation in vitamin B3 counteracts the negative effects of tryptophan deficiencies in bumble bees

Increasing evidence highlights the importance of diet content in 9 essential amino acids for bee physiological and behavioral performance. However, the tenth essential amino acid, tryptophan, has been overlooked as its experimental measurement requires a specific hydrolysis. Tryptophan is the precursor of serotonin and vitamin B3, which together modulate cognitive and metabolic functions in most animals. Here, we investigated how tryptophan deficiencies influence the longevity and behavior of bumble bees. Tryptophan-deficient diets led to a moderate increase in food intake, aggressiveness and mortality compared to the control diet. Vitamin B3 supplementation in tryptophan-deficient diets tended to buffer these effects on food intake and survival, and significantly reduced workers aggressiveness. Considering that the pollens of major crops and common plants, such as corn and dandelion, are deficient in tryptophan, these effects could have a strong impact on bee populations and their pollination service.

physiology↗

bioRxiv2021

Poor adult nutrition impairs learning and memory in a parasitoid wasp

Animals have evolved cognitive abilities whose impairment can incur dramatic fitness costs. While malnutrition is known to impact brain development and cognitive functions in vertebrates, little is known in insects, whose small brain appears particularly vulnerable to environmental stressors. Here, we investigated the influence of diet quality on learning and memory in the parasitoid wasp Venturia canescens. Newly emerged adults were exposed for 24h to either honey, sucrose solution 20%, sucrose solution 10%, or no food, before being conditioned in an olfactory associative learning task in which an odor (orange) was associated to a reward (host larvae). Wasps fed honey showed 3.5 times higher learning performances and 1.5 times longer memory retention times than wasps fed sucrose solutions and starved wasps. Poor diets also reduced longevity and fecundity. Our results demonstrate the importance of early adult nutrition for optimal cognitive function in these parasitoid wasps that must quickly develop olfactory memories for choosing high quality hosts for their progeny.

animal behavior and cognition↗