Fig. 3
Modified from Pollay et al. [39]
Catheter Placement Method in the Vascular System of the Choroid Plexus in Sheep Brain. The midline great vein of Galen is cannulated with flexible silastic tubing and the catheter is advanced into internal cerebral vein on the side of the perfused plexus, while another internal carotid artery branch and the anterior choroidal artery branches are occluded by bipolar electrocoagulation. Donor sheep blood containing 10% dextran is perfused into a silastic tube, which cannulates the internal carotid artery, and outflow is collected from the catheter in the internal cerebral vein. The difference of hematocrit between the anterior chorodial artery and internal cerebral vein is taken to represent CSF production rate in vitro.