Acute neuroinflammation dramatically impaired context discrimination. a, Experimental design for testing. b, The mean ± SEM percentage freezing during testing. SAL subjects (n = 8) exhibited significantly more freezing in context A than context A′ during testing, whereas LPS (n = 9) and ND (n = 5) subjects did not. c, The discrimination ratio during testing was significantly higher in the SAL group than the LPS and ND groups, which did not differ from each other. d, Freezing scores for individual subjects in contexts A and A′. All subjects in the SAL group exhibited higher freezing in context A than context A′ during testing, whereas individual subjects in both the LPS and ND groups froze either in both contexts A and A′ or in neither context A nor context A′. *p < 0.05.