Intraneuronal Nanotracers in Axonal Transport.

Axonal transport is fundamental to neuronal function, ensuring the movement of organelles, proteins, and other cellular components necessary for growth, signaling, and repair. Disruptions in this transport system are implicated in various neurodegenerative and neurodevelopmental disorders. Recent advances in tracking methods, both in vivo and in vitro, have deepened our understanding of transport defects, their molecular mechanisms, and their potential applications in diagnostics and therapeutics. This review discusses key scientific and technical breakthroughs in axonal transport visualization, revisiting the core principles of transport machinery. We examine critical components involved in axonal transport, including microtubules, motor proteins and their adaptors, and organelle cargoes. Additionally, we highlight recent developments in nanomaterial-based tracing methods, present notable examples, and outline future challenges and research directions.