Delayed Opening of the Blood-Brain Barrier in Direct Infusion Edema Model

Marmarou et al. developed a unique model for studying brain edema by infusing a relatively large amount of fluid into the white matter [2]. Such intraparenchymal infusion did not induce local breakdown of the blood-brain barrier (BBB): the BBB was found intact at 0 hour, 72 hours and at 7 days after the infusion [1]. Therefore, this model could be considered suitable for investigations on the resolution process of brain edema in terms of no new edema fluid supplied from the blood vessels. A recent study using this model showed that the fluid infused into the brain migrated, in an extremely short period after infusion, to the ventricular system and also to the cortical surface [4]. Such a fast movement of fluid along the intraparenchymal vessels may change their permeability in a short time after the infusion. In the present study we reinvestigated the effect of intraparenchymal infusion on the BBB within 24 hours after the infusion.