CD200 and brain ischemia: In addition, it was reported that the expression level of CD200 mRNA in the ischemic core of rat brain following transient focal brain ischemia by MCAO was sharply decreased, reached the minimum amount at 5 days after MCAO, and then increased again up to 14 days after MCAO, showing that CD200 was detected in Iba-1-immunoreactive macrophage-like cells isolated in the ischemic core at 7 days after MCAO [22].