Figure 4.

Distribution of AQP4 and coverage of cortical astrocyte microdomains at the gliovascular interface. (A) Double immunolabeling of AQP4 (red) and GFAP (green). AQP4 immunolabeling reveals that the entire network of vessels, including capillaries, is covered by astrocyte processes, albeit GFAP negative. Smaller vessels and capillaries are mostly GFAP negative but display intense labeling against the astrocyte-specific channel AQP4. The AQP4 labeling reveals continuous coverage by astrocyte end feet. Scale bar: 60 μm. Reproduced with permission from Society of Neuroscience by Simard et al. (2003). (B) Two-photon imaging of enhanced green-fluorescent protein (eGFP)-expressing astrocytes on the cortical surface in live mouse brain, illustrating the territorial astrocyte domains and the dense array of processes associated with the vasculature. The vasculature was labeled with Texas Red-dextran dye that labels the plasma and outlines the pial vasculature. Scale bar: 20 μm.