Fig. 3

CX3CL1^−/− mice display impairments in the Barnes maze test for spatial memory that are corrected by treatment with mFKN and sFKN. a Mice were assessed for spatial learning and memory using a Barnes maze task. Mice were subjected to 4 days of training during which they were taught to locate an escape pod beneath one of the holes on the perimeter of the maze. All mice learned the task at a similar rate regardless of treatment of genotype. Data were analyzed by two-way ANOVA for repeated measures (n = 8, F (9, 153) = 1.876, p = 0.059). b On the fifth day, the escape pod was replaced by a false bottom, and mice were allowed to explore the maze for 1 min. The figure shows a map of the Barnes maze zones and representative heat maps for each treatment group. The maze was split into eight zones for scoring purposes as indicated. Representative heatmaps of one animal from each treatment group were generated to illustrate the different exploration strategies observed for each group during the probe test, and indicate the relative amount of time spent at different locations around the maze. c Quantitative assessment of the number of times each mouse poked its head into each hole of the Barnes maze. WT mice explored the target hole more often than any other hole in the maze, with the number of head pokes decreasing as distance from the target hole increased. mFKN- and sFKN-treated animals displayed a similar trend. CX3CL1^−/− mice that were administered GFP displayed a trend towards decreased exploration of the target hole compared to WT animals, although this difference did not reach significance. Mice that received AAV expressing GFP explored the three adjacent holes on either side of the target (zones ⁻ 1 and + 1) the most and made significantly more head pokes in the − 1 zone than their WT counterparts. Mice that were treated with either mFKN or sFKN showed a trend towards increased exploration of the target zone, similar to WT mice, and showed significantly less exploration in the − 1 (mFKN and sFKN) and + 1 (mFKN) zones than mice receiving GFP. Data were analyzed using two-way ANOVA for repeated measures (n = 8, F (21, 329) = 2.482, p < 0.001) with Tukey’s test. *p < 0.05, **p < 0.01, and ***p < 0.001 for each respective zone