Methods and compositions for modulating blood-neural barrier (BNB) for the treatment of CNS conditions such as edema, and for increased drug delivery efficacy across the BNB. The present invention further relates to improved tPA treatment of ischemic cerebrovascular and related diseases in combination with antagonism of the PDGF signaling pathway. The inventive method and composition is particularly suitable for conjunctive therapy of ischemic stroke using tPA and an anti-PDGF-C antagonist or an anti-PDGFR-α antagonist.