IL6R and Cognitive impairment: To further investigate the role of IL-6 in surgery-induced cognitive defects in aged rats, an IL-6R antagonist was used, and it was found that blocking the central signaling of IL-6 with a single intracisternal administration of the IL-6R antagonist at the time of surgery was sufficient to suppress surgery-induced cognitive defects, the upregulation of inflammatory cytokines, and activation of NF-κB signaling in aged rats.