The peripheral Atf3+ neuronal population is responsible for nerve regeneration at the early stage of nerve injury revealed by single-cell RNA sequencing

• Single-cell RNA sequencing identifies a novel CCI-induced neuronal population (CIP) marked by Atf3 that emerges at day 3 post-injury and expresses high levels of regeneration-associated genes. • CIP neurons exhibit a pro-regenerative transcriptomic signature and are enriched in regeneration-related GO terms, suggesting they play a key role in early nerve regeneration. • Intercellular communication analysis reveals that CIP neurons specifically transmit strong Fgf3-Fgfr1 signaling to satellite glial cells, potentially initiating regenerative transcriptional changes in these glial cells. • Immunohistochemistry confirms that ATF3 expression increases at 3 days post-CCI and decreases by 1 month, indicating that regenerative processes are active at the early stage of nerve injury.