Impaired axon regeneration and heightened synaptic dynamics in the injured aged mammalian cortex.

ABSTRACT: Aging is a key risk factor for impaired neural repair, yet its effects on axon regeneration and synaptic remodeling in the brain remain unclear. To investigate age-related repair mechanisms in neural circuits, we developed an axonal injury model in the aged (>2 years) mouse somatosensory cortex and tracked fluorescently labeled axons using in vivo multiphoton imaging. Axon degeneration rates were similar to young adults, but regeneration was markedly reduced. Six hours post-lesion, en passant boutons (EPBs)-the most common cortical synapse-showed transient increases in number and size. To assess functional consequences, we used a recurrent neural network model to simulate memory dynamics, revealing distinct changes compared to young adults. Our results suggest that increased

SUBMITTER: Bass C 

PROVIDER: S-EPMC12613038 | biostudies-literature | 2025 Nov

REPOSITORIES: biostudies-literature