CAMK2A and memory impairment: To figure out the causal link between S1PR1 and chronic pain-related memory impairment, we generated recombinant adeno-associated virus 2/9 (AAV2/9) expressing a small hairpin RNA targeting S1pr1 (rAAV-CaMKIIa-EGFP-5′miR-30a-shRNA(S1pr1)-3′-miR30a-WPREs, the shRNA sequence is provided in Supplementary file 1a).