To overcome some problems of virus vectors, we developed a novel non-viral vector system, the HVJ-envelope vector (HVJ-E). In this study, we investigated the feasibility of gene transfer into the CNS using the HVJ-E both in vitro and in vivo. Using the Venus reporter gene, fluorescence could be detected in cultured rat cerebral cortex neurons and glial cells. In vivo, the reporter gene (Venus) was successfully transfected into the rat brain by direct injection into the thalamus, intraventricular injection, or intrathecal injection. without inducing immunological change. When the vector was injected after transient occlusion of the middle cerebral artery, fluorescence due to EGFP gene or luciferase activity could be detected only in the injured hemisphere. Finally. luciferase activity was markedly enhanced by the addition of 50 U/ml heparin (P < 0.01). Development of efficient HVJ-E for gene transfer into the CNS will be useful for research and clinical gene therapy. (C) 2002 Elsevier Science (USA). All rights reserved.