Fig. 2

Evaluation of behavioral analysis 30 days post-TBI. a In the open-field task, all mice traveled the same distance in the center zone compared to the perimeter zone. CX3CR1 WT-TBI spent less time in the perimeter zone of the open-field chamber compared to CX3CR1 KO-TBI (two-way ANOVA (F = 3, 72, **p = 0.01). Total distance traveled in the chamber was significantly different between CX3CR1 sham WT and CX3CR1 sham KO mice. Two-way ANOVA (F = 1, 36, **p = 0.001) and between shams and TBI groups two-way ANOVA (F = 1, 36, **p = 0.001). CX3CR1 sham WT (n = 10 white bar), CX3CR1 sham KO (n = 10 green bar), CX3CR1 WT-TBI (n = 10 red bar), and CX3CR1 KO-TBI (n = 10 blue bar) mice. b Rota-rod. CX3CR1 sham WT mice performed significantly better than CX3CR1 sham KO mice, over the 2 days of training (repeated measures ANOVA, *p = 0.5). No difference between injured groups was observed in the learning ability in the rota-rod task during the first day of training. On the second day of training (trials 5–8), CX3CR1 sham WT mice learned the rota-rod task as demonstrated by their ability to remain on the rod for longer periods compared to CX3CR1 WT-TBI (**p = 0.01). CX3CR1 KO-TBI mice showed a significantly worse performance than CX3CR1 WT-TBI wild-type (*p = 0.5). Neither the CX3CR1 KO-TBI nor the CX3CR1 WT-TBI mice showed significant improvement in motor coordination with training when compared to sham WT. CX3CR1 sham WT (n = 10; white open square). CX3CR1 WT-TBI (n = 10; red square). CX3CR1 sham KO (n = 10; green square). CX3CR1 KO-TBI (n = 10; blue squares). c–e Morris water maze. c Mean latency to escape from a pool to a hidden platform across training days. All groups spent more time in learning to find the platform compared to sham WT. CX3CR1 sham WT (n = 8; white bar). CX3CR1 WT-TBI (n = 9; red square). CX3CR1 sham KO (n = 8; green square). CX3CR1 KO-TBI (n = 9; blue squares). d A probe test was performed on day 8 to determine the number of pseudo platform crossings in the target quadrant. All TBI groups crossed less number of time the target quadrant zone when compared to CX3CR1 sham WT. CX3CR1 KO-TBI mice crossed the target quadrant less number of time than CX3CR1 sham KO and CX3CR1 WT-TBI. e No difference was observed in the average swim speed between groups. CX3CR1 sham WT (n = 8; white bar). CX3CR1 WT-TBI (n = 9; red square). CX3CR1 sham KO (n= 8; green square). CX3CR1 KO-TBI (n = 9; blue squares). All data are presented as mean ± SEM p < 0.01