KDR and Cognitive impairment: We previously reported using a senescence-accelerated mouse model that aging induces dysfunction of the VEGF/VEGFR2 and PDGF/PDGFR signaling systems in the brain and that reversal of impaired VEGF/VEGFR2 and PDGF/PDGFR signaling systems is a part of the mechanism(s) underlying the ameliorative effects of CTS on spatial and non-spatial cognitive deficits caused by aging[20].