Induction of phosphorylated c-Jun in neonatal spinal motoneurons after axonal injury is coincident with both motoneuron death and regeneration

This study investigates the role of c-Jun activation in injured motoneurons of neonatal rats using a nerve crush model. Researchers observed two distinct groups of motoneurons: one that degenerated after injury (60%) and another that survived and regenerated (40%). Interestingly, all motoneurons showed phosphorylated-c-Jun-immunoreactivity (p-c-Jun-IR) early on (3 days after injury), suggesting c-Jun is activated regardless of the eventual fate of the neuron. These findings support the idea that active c-Jun is involved in both neuronal degeneration and regeneration processes. The research highlights the complex role of c-Jun in neuronal response to injury.

• 1
  Nerve crush injury in neonatal rats leads to two distinct outcomes for motoneurons: approximately 60% undergo degeneration, while 40% survive and regenerate.
• 2
  All injured motoneurons, regardless of their eventual fate (degeneration or regeneration), express phosphorylated c-Jun (p-c-Jun) at the early stage (3 days) following nerve crush.
• 3
  Crushed neonatal motoneurons can regenerate and reconnect with their target muscles, as confirmed by neurofilament and bungarotoxin staining.