Figure 1: Testing of spatial learning and memory in AD models and controls by Morris water maze. (a) The swim paths and time of finding the hidden platform in the control group was significantly shorter than that of the AD group, indicating that intranasal LPS impairs spatial learning and memory (n = 10/group). (b) Significant difference of escape latency between AD and control groups was observed at the last three days in the fourth and fifth months ( p<0.05) (n = 10/group). (c) Significant difference of the frequency of crossing the target platform between AD and control groups ( p<0.05). Data are expressed as the mean ± standard error of the mean (SEM)(n = 10/group). (d) The image shows the control group had a crossing frequency approximately 2 times the AD group (n = 10/group).