Contextual fear response is ameliorated by pre-emptive IL-1 Ra. Within 30 minutes following training, mice were injected with lipopolysaccharide (LPS). Three days later, rodents were exposed to the same context in which fear conditioning was previously carried out. Contextual fear response reveals a clear hippocampal-dependent memory impairment (** P < 0.005 vs naive). Pre-treatment with IL-1Ra abolished the main symptoms of sickness behavior and significantly ameliorated the memory retention at day 3 (+ P < 0.05 vs LPS). Data are expressed as mean ± standard error of the mean (n = 9 for acute behavior) and compared by one-way analysis of variance and Student-Newman-Keuls method.