Figure 8. Loss of cortical perivascular AQP4 polarization is associated with impaired paravascular CSF recirculation.

(A) The association between AQP4 expression, AQP4 polarization or GFAP expression and paravascular CSF tracer was evaluated in the cortex. Linear regression analysis shows that GFAP and AQP4 expression levels were not associated with differences in paravascular CSF tracer penetration in the young or old cortex. Within both the young and old cortex, reduction in perivascular AQP4 polarization were significantly associated with impairment of paravascular CSF recirculation (Young brain: *P<0.05, r² = 0.2149; Old brain: *P<0.05, r² = 0.2485).