01 October 2018. Vol.9 No.5
Figure 4. Changes of in ISF flow in the ECS between the caudate nucleus and cortex. In normal deep brain, ISF flows from the caudate nucleus to the cortex along myelinated fibers, whereas it is cleared from the brain along paravenous routes in the cortex. The flow of ISF is facilitated by AQP4-dependent astroglial water flux, which drives fluid dispersion into the subarachnoid CSF. In the brains of knockout rats, AQP4 deficiency led to obstruction of ISF clearance and accumulation of ISF in the cortex and caudate nucleus, resulting in a decrease in tortuosity and an increase in the volume fraction and molecular diffusion rate in the ECS within the caudate nucleus.