Biology subjects

Barde, W.

Publications and source records attributed to Barde, W..

3 recordsLinked to original sources

bioRxiv2026

Mice sense Moon and Sun

Life on earth has always been exposed to the fluctuating Earth's magnetic field, but a magnetic sense affecting behavior has been debated for mammals. We here report that mice, kept under constant laboratory conditions, showed fluctuations in spontaneous behavioral activity with a periodicity of ~14 and ~28 days. This was confirmed in nine cohorts from four facilities on two continents, covering 3 to 41 months. Such oscillations were also maintained in brain Bmal1 knockout mice lacking circadian rhythms, suggesting independence of the circadian clock. The behavioral activity peaked around full and new Moon, and showed a strong alignment with the periodic geomagnetic fluctuations originating in the Earth's iono- and magnetosphere that are modulated by solar rotation and the orbital motion of the Moon. In the ultradian range, this alignment persisted in CRY1/2 knockout mice, suggesting that solar-lunar-driven geomagnetic fluctuations can modulate behavior rhythms independently of CRY1/2.

neuroscience↗

bioRxiv2024

Exploring social modulation: Microglia as a key mediator of individual immune response, plasticity and pathology in App-NL-G-F mouse model of Alzheimer's disease

This study explores the influence of lifestyle on Alzheimers disease (AD) progression using App-NL-G-F mice in a complex enrichment system. Mice exhibited social deficits before plaque pathology or memory impairment, revealing a crucial link between lifestyle, behavior, and neuroinflammation. Plasma analysis indicates early inflammation and apoptosis-related changes, setting the stage for identifying markers predicting plaque manifestation. Beyond pathology, social behavior is linked to adult neurogenesis and microglia coverage, forming a dynamic connection with microglia activation. Further, sc-RNA sequencing unveiled a decrease in interferon-responsive microglia and alteration in antigen processing with enrichment. These findings underscore the beneficial impact of social housing on microglia and interconnected factors, pointing to microglia as a critical mediator of the behavior-pathology-plasticity interplay in AD. The study enhances our understanding of AD complexity and offers insights into potential therapeutic strategies, emphasizing the multifaceted nature of AD progression and the role of lifestyle in shaping its course.

neuroscience↗

bioRxiv2018

Inexpensive, scalable camera system for tracking rats in large spaces

AbstractMost studies focused on understanding the neural circuits underlying spatial navigation are restricted to small behavioral arenas ([≤] 1 m2) because of the limits imposed by the cables extending from the animal to the recording system. New wireless recording systems have significantly increased the recording range. However, the size of arena is still constrained by the lack of a video tracking system capable of monitoring the animals movements over large areas integrated with these recording systems. We developed and benchmarked a novel, open-source, scalable multi-camera tracking system based on commercially available and low-cost hardware (Raspberry Pi computers and Raspberry Pi cameras). This Picamera system was used in combination with a wireless recording system for characterizing neural correlates of space in environments of various sizes up to 16.5 m2. Spatial rate maps generated using the Picamera system showed improved accuracy in estimating spatial firing characteristics of neurons compared to a popular commercial system, due to its better temporal accuracy. The system also showed improved accuracy in estimating head direction cell tuning as well as theta phase precession in place cells. This improved temporal accuracy is crucial for accurately aligning videos from multiple cameras in large spaces and characterizing spatially modulated cells in a large environment.

neuroscience↗