IL-1-induced changes in the number of entry error in 8-arm radial maze during testing phase. Before the training, 8 arms were baited with a single 45-mg food pellet at the cup in the end of each arm. In the training phase, four arms chosen randomly were opened, and the remaining arms were blocked. Each rat was allowed 5 minutes to retrieve the food from the four open arms. During the memory test phase, all arms were opened and rats were allowed to explore the maze until they had retrieved food located in the four arms that were blocked during training, or until 5 minutes had elapsed. Errors were recorded as entries into unbaited arms. (A) On day 5, subacute IL-1 significantly increased the error number, **
P <0.01 versus saline-treated group (n = 7). (B) IL-1 receptor antagonist (IL-1RA) reversed subacute IL-1-induced changes in memory retrieval, *
P <0.01 versus saline group (n = 8), #
P <0.01 versus IL-1 group (n = 8).