Fig. 2.

LPS-induced working memory deficits and validation of T-maze alternation. (a) Performance of ME7+LPS (n = 12), ME7+saline (n = 11), NBH+LPS (n = 13) and NBH+saline (n = 11) animals in the novel T-maze alternation task at baseline (−22, −24 hours), posttreatment with saline or LPS (3, 5, 7 hours) and upon recovery (24, 26 hours). Schematic representation of this T-maze is shown on right, illustrating forced entry to 1 arm on the sample run and alternation on the choice run. Simple main effects analysis revealed an effect of LPS specifically in the ME7 group and this is denoted by * (p < 0.001). (b) Performance of similar groups in the egocentric Y-maze (shown on right), 3 hours posttreatment, assessed as 2 blocks of 6 trials. Repeated measures analysis of variance (ANOVA) revealed no effect of treatment, but a main effect of block (denoted as *, p < 0.0001). n = 15, ME7+LPS; n = 13, NBH+LPS; n = 9, ME7+saline, and NBH+saline. (c) Performance of the T-maze alternation spatial working memory task (after training: 10 blocks of 10 trials) in normal C57BL6 mice treated with LPS 200 μg/kg (n = 9) or sterile saline (n = 9). There were no effects of treatment. (d) Training of hippocampal-lesioned (n = 8) and sham-operated animals (n = 12) on the spatial working memory T-maze task. A main effect of lesion group (p = 0.0021) in a 2-way ANOVA analysis is denoted by *. (e) Cresyl violet-stained coronal sections from representative sham-operated and hippocampal-lesioned animals.