Fig. 11.
Dexmedetomidine prevent lipopolysaccharide-induced decrease in freezing behavior in an α2 receptor–dependent manner in older mice. Four groups of randomly assigned 12-month-old mice (n = 12/group) were administered saline vehicle (control), lipopolysaccharide, lipopolysaccharide + dexmedetomidine, or yohimbine + lipopolysaccharide + dexmedetomidine and subjected to trace fear conditioning training. Testing for freezing behavior in the same context was undertaken 3 days later. Freezing time data are expressed as means ± SD and were analyzed by one-way ANOVA and Tukey post hoc test. **P < 0.01 for comparisons shown.