In the CA3 field of the ischemia group, the change in CD200 level triggered by tFI was similar with those in the hippocampal CA1 field until 12 h after tFI (Figure 1D) (79.1% at 6 h and 114.4% at 12 h post-tFI compared to those in the sham group). This evidence concerns the gene CD200 and ischemia.