CD200 and ischemic stroke: Interestingly, CD200 signaling was close to zero in models of ischemic stroke (Ritzel et al., 2019), while in an in vivo study, reduced expression of neuronal CD200 was observed in the hippocampus of aged and β-amyloid treated animals, providing evidence that neurons may reduce microglial activation through CD200 signaling (Ngwa and Liu, 2019).