Fig. 18From: Fluid and ion transfer across the blood–brain and blood–cerebrospinal fluid barriers; a comparative account of mechanisms and rolesA second possible scheme for ion transport by the blood–brain barrier. This differs from the first, shown in Fig. 17, by swapping the positions of NBCe1 and AE2. For the key to lines and colours see the legend to Fig. 17. The consequences of the swap are considered in Sects. 4.6.1, 4.6.2 Back to article page