Involvement of IL-1β on cognitive impairment after experimental pneumococcal meningitis. (INM1P.432)

Abstract

Abstract Pneumococcal meningitis is associated with high rates of mortality and long-term cognitive impairment. In the current study, we evaluated the effects of an interleukin (IL)-1β receptor antagonist (IL-1Ra) on memory, cytokine, and BDNF levels in experimental pneumococcal meningitis. Adult Wistar rats were divided into four groups: control/saline, control treated with IL-1Ra, meningitis/saline and meningitis treated with IL-1Ra. The animals were killed at 24 h post-infection. In the meningitis/saline group IL-1β and CINC-1 levels increased at 24 h post-infection; however, treatment with IL-1Ra reversed these increases in the hippocampus. In a second experiment, the rats received antibiotic and were subjected to behavioural tasks (open field, step-down inhibitory avoidance and object recognition), cytokine and BDNF levels ten days after meningitis induction. In the open-field task, the meningitis group did not exhibit differences in motor and exploratory activity, indicating habituation memory impairment. The same impairment occurred in the novel object recognition memory and step-down inhibitory avoidance task (aversive memory) in the meningitis group; however, adjuvant treatment with IL-1Ra prevented memory impairment. The IL-4, IL-6, IL-10 and BDNF levels were increased in the meningitis/saline and meningitis/IL-1Ra groups. These findings illustrate a neuroprotective role of IL-1Ra inhibitor and the involvement of IL-1β on cognitive impairment after pneumococcal meningitis.