KL and ischemia: In the present study, 4 weeks after lentivirus transfection with a bilateral intracerebroventricular injection of LV-KL (2.1 × 107 TU/ml) in the lateral ventricles, the mice were subjected to brain ischemia that was induced by 20 min of 2VO, followed by collection of the choroid plexus to determine Klotho expression 72 h after ischemia.