Fig. 5

Amyloid-β drainage from brain parenchyma. (a) Schematic model of the protocol used to evaluate the cleaance of Aβ in the central nervous system of mice. Amyloid-β (1–42) Hylexa Fluor-488 was stereotaxically injected into the striatum and six hours post-injection, the fluorescence of Aβ were assessed after cryosection of brains and lymphnodes. (b) Brain section that exhibits the maximum fluorescence intensity among all sections at the injection site was analyzed together with lymph nodes sections. The red dotted line indicates the region where fluorescence levels were detectable. Cell nuclei were stained with DAPI (in blue). Note that the fluorescence intensity of amyloid-β in WT appears lowers than AQP4ex-KO at the point of injection while the ipsilateral cervical lymph nodes have markedly higher levels of fluorescence in WT mice compared to AQP4ex-KO mice. Scale bar 50 μm. (c) Aβ fluorescence values plotted as a function of distance from the injection site in the striatum. Quantification of fluorescent signal quantified using the space constant λ (µm⁻¹). (d) Quantification of Aβ in cortical (left) and medullar (right) regions of ipsilateral lymph node of WT and AQP4ex-KO mice (n = 4). Unpaired t-test, *p < 0.05