Home-cage monitoring methods reveal age- and strain-related differences in motor, thermal, and cognitive functions in male mice of two inbred strains

BACKGROUND: Aging is associated with cognitive decline and behavioral alterations linked to neurobiological changes. Rodent models are crucial for investigating age-related variations in cognitive flexibility, anxiety, and circadian rhythms. Comparing two inbred strains, C57BL/6 J and 129S2/SvPasCrl, helps clarify how genetic background influences these aging-related outcomes. NEW METHOD: Advanced RFID-based automated home-cage platforms (Mouse Matrix and IntelliCage) were utilized to quantify circadian locomotor activity, core body temperature dynamics, and cognitive performance in group-housed mice. These systems enable continuous, high-resolution monitoring of behavioral and physiological data within an automated, ethologically relevant environment. RESULTS: Significant age- and strain-dependent differences were observed in temperature rhythms, locomotor activity, anxiety-like behavior, and adaptability to environmental changes. Aged mice showed reduced activity and impaired anticipatory behavior, indicating disrupted circadian regulation. The 129S2/SvPasCrl strain displayed higher anxiety and slower adaptation, whereas C57BL/6 J mice exhibited greater cognitive flexibility and more rapid learning. COMPARISON WITH EXISTING METHODS: Conventional behavioral tests performed outside the home-cage, such as open field or maze-based tasks, rely on brief, experimenter-dependent sessions that may introduce handling stress and novelty effects. In contrast, MM and IC provide continuous, unbiased assessment within the familiar home-cage environment, reducing stress and improving ecological validity. CONCLUSIONS: Advanced home-cage monitoring systems offer reliable platforms for detecting strain- and age-specific behavioral and physiological differences. These findings highlight the importance of automated, naturalistic approaches for improving reproducibility and translational relevance in aging and neuropsychiatric research.