Fig. 5.
Enriched motor experience ameliorates motor learning and synaptic deficits in mice receiving multiple ketamine–xylazine (KX) exposures. (A) Experimental design. Mice received three injections of KX during P14 to P18 and were then housed in enriched environment (EE) where they had access to a freely rotating wheel for 10 days. Motor performance on the rotarod task was examined from P30 to P32. (B) Rotarod performance in saline- and KX-treated mice. Rotarod performance was similar in all three groups in the first training session at P30. After 2-day training, rotarod performance was significantly higher in the KX group with voluntary running activity than without. Comparisons were performed using a one-way ANOVA followed by Neuman–Keuls multiple comparison post hoc test. (C) Percentage of newly formed dendritic spines from P30 to P32. EE following KX exposure ameliorated anesthesia-induced deficits in spine formation after motor training. Comparisons were carried out using a two-tailed unpaired Student t test. (D) Percentage of spines eliminated from P30 to P32. There was no significant difference in spine elimination among all groups of animals. Comparisons were performed using a two-tailed unpaired Student t test. (E) Motor learning–induced increase in total spine number was comparable between saline-injected control mice and mice housed in EE after early KX exposure. Comparisons were carried out using a two-tailed unpaired Student t test. Data are presented as mean with 95% CIs. *P < 0.05. **P < 0.01. ***P < 0.001.