[biological_process] axon regeneration <sep> behavioral response to nicotine <sep> intracellular signal transduction <sep> MAPK cascade <sep> p38MAPK cascade <sep> positive regulation of axon extension involved in regeneration <sep> regulation of 3'-UTR-mediated mRNA stabilization <sep> regulation of axon extension involved in axon guidance <sep> regulation of synapse organization <sep> response to osmotic stress