Uncovering motor impairments in duchenne muscular dystrophy: 24-hour automated behavioral analysis of DBA/2N-mdx mice

Abstract

Duchenne muscular dystrophy (DMD) is a severe X-linked genetic disorder caused by mutations in the dystrophin gene. Although the C57BL/10 background mdx mouse (B10-mdx) model is widely used for DMD research, it presents milder symptoms than observed in human patients. In contrast, the DBA/2N-mdx model exhibits more severe pathology, making it a promising model for evaluating disease mechanisms and therapies. In this study, we employed a 24-h behavioral monitoring system to investigate spontaneous locomotor activity and gait characteristics in DBA/2N-mdx mice. We observed significantly reduced movement and shorter active periods during the dark (active) phase at 4 and 8 weeks of age in DBA/2N-mdx mice compared to controls. Subsequent gait analysis revealed shorter walking distances, slower speeds, and reduced body extension during straight walking. These findings suggest that the DBA/2N-mdx mouse model exhibits distinct behavioral abnormalities that parallel DMD symptoms in humans. Our noninvasive, continuous monitoring approach provides an innovative method for assessing motor impairments and may facilitate more accurate preclinical assessments of potential therapies for DMD.