ABSTRACT
During nervous system development, an overabundance of neurons, axons, and synapses is selectively eliminated to establish functional circuits. Axons compete for trophic cues, with winners stabilizing and losers degenerating. This chapter explores molecular pathways involved in axon degeneration, focusing on progressive axon stabilization pathways (e.g., PI3K-AKT, MAPK/ERK, calpastatin, etc.) and regressive pro-degenerative pathways (e.g., death receptors, JNK, DLK, calcium, calpain, etc.). Additionally, distinct axonal death pathways include soma-derived pro- and anti-degenerative cues. A more comprehensive understanding of the molecular mechanisms behind axon degeneration, the transitions between early and late degeneration phases, and the role of cell death pathways will provide invaluable insights into not only the development of the nervous system but also related diseases.
