Fig. 1.

Timeline and design of the in vivo mouse experiments. Mice aged 3 and 14 mo started their dietary lead up of 12 wk. After the dietary period, the mice now aged 6 and 17 mo were maintained on their diets and were treated with an injection of sphingosine-1-phosphate analog FTY720 every other day for 4 wk. After the treatment period, mice now aged 7 and 18 mo underwent high-frequency electrical stimulation (HFES) and tissue collection 1 h later. FAT, 7 mo, 60% fat/kcal; OLD, 18 mo, 10% fat/kcal; YNG, 7 mo, 10% fat/kcal diet.