Biology subjects

Midzyanovskaya, I.

Publications and source records attributed to Midzyanovskaya, I..

2 recordsLinked to original sources

bioRxiv2024

Novel method to assess group dynamics in rats reveals deficits in behavioral contagion in KM rats

Behavioral copying is a key process in group actions, but it is challenging for individuals with Autism Spectrum Disorder (ASD). We investigated behavioral contagion, or instinctual replication of behaviors, in Krushinky-Molodkina (KM) rats (n=16), a new rodent model for ASD, compared to control Wistar rats (n=15). A randomly chosen healthy Wistar male ("demonstrator rat") was introduced to the homecage of experimental rats ("observers") 10-14 days before the experiments to become a member of the group. For the implementation of the behavioral contagion experiment, we used the IntelliCage system, where rats can live in a group of 5-6 rats and their water visits can be fully controlled. During the experiment, the demonstrator was taken out of IntelliCage for 24 hours of water deprivation and then placed back. As a result, a drinking behavior of the water-deprived demonstrator rat prompted activated behaviors in the whole group. Unlike the Wistar controls, KM observers showed fewer visits to the drinking bottles, particularly lacking inspection visits. The control group, in contrast, exhibited a dynamic, cascade-like visiting of the water corners. The proportion of activated observers in KM rats was significantly lower, as compared to Wistar ones, and they did not mimic other observer rats. KM rats, therefore, displayed an attenuated pattern of behavioral contagion, highlighting social deficits in this ASD model. This study suggests that measuring group dynamics of behavioral contagion in an automated, non-invasive setup offers valuable insights into social behavior in rodents, particularly for studying social deficits in ASD models. HighlightsO_LIThirsty demonstrators triggered an avalanche of observers visits to the water corners C_LIO_LIThe contaged behavior was attenuated in observer KM rats C_LIO_LIBehavioral contagion test provides a new tool for objective, automated phenotyping in rodent models of social deficits C_LI

animal behavior and cognition↗

bioRxiv2024

Two modes in the velocity statistics in cautious walks of laboratory rodents

We have analyzed a large number of rodent tracks in open-field tests, in order to elucidate the statistics of their velocities. We found that the probability distribution of the absolute velocity of rodents can be approximated by a superposition of two Rayleigh distributions, with distinct characteristic velocities v1 and v2 with v1 < v2; this is in contrast to the single Rayleigh distribution for the velocity of a Brownian particle executing 2D random motion. We propose that the part of the distribution near the larger velocity, v2, characterizes rodents progressions in space, while the part near v1 describes other types of motion, such as lingering and body micromovements. We observed that the animals switched randomly between these two modes. While both velocities, v1 and v2, increase with age, their ratio, v2/v1, also grows with age, implying an increased efficacy of switches between the two modes in older animals. Since the existence of the modes is observed both in preweaned, blind pups and in older animals, it cannot be ascribed to foraging, but instead reflects risk assessment and proactive inhibition. We called such motion "cautious walks". Statistical analysis of the data further revealed a biphasic decline in the velocity auto-correlation function, with two characteristic times,{tau} s < {tau}l, where{tau} s characterizes the width of velocity peaks, and{tau} l is associated with the timing of the switches between progression and lingering. To describe the motion, we propose a stochastic model, which assumes the existence of two interfering processes: impulses to move that arrive at random times, and continuous deceleration. Its 2D Langevin-like equation has a damping coefficient that switches between two values, representing mode switching in rodents. Techniques developed here may be applicable for locomotion studies in a wide variety of contexts, as long as tracking data of sufficient resolution are available.

biophysics↗