*4.2. Groups and Treatment of ATX*

The gerbils were blindly and randomly divided into four groups: (1) vehicle treated and sham operated group (sham group, *n* = 14), which was treated with vehicle (saline) and received sham IR; (2) vehicle-treated and IR-operated group (IR group, *n* = 21), which was treated with saline and received IR; (3) ATX-treated and sham-operated group (ATX-sham group, *n* = 14), which was treated with ATX and received sham; (4) ATX-IR group (*n* = 21), which was treated with ATX and received IR.

The chemical structure of ATX (SML0982; Sigma-Aldrich, St. Louis, MO, USA) and the plan schedule of the experiment are shown in Figure 1A. ATX (100 mg/kg) was dissolved in saline and injected intraperitoneally once a day for three consecutive days before IR. The dosage and duration of ATX treatment were selected based on a recent study showing that pretreatment with 100 mg/kg of ATX provided robust neuroprotection against transient focal cerebral ischemia-induced brain injury in rats [45].

The gerbils (*n* = 7, respectively) in the IR groups on day 1, day 2, and day 5 after IR, and the ones (*n* = 7, respectively) in the sham groups were sacrificed at 0 h and five days after IR to reduce the numbers
