MFN2 and transient ischemic attack: To determine the impact of transient cerebral ischemia on mitochondrial fusion and fission proteins in the transgenic mice in vivo, we first measured the expression levels of major mitochondrial fusion proteins including optic atrophy 1 (OPA1) and mitofusin 2 (MFN2) in the mitochondria isolated from the four groups of mice by immunoblotting.