carbocyanines and Heart-Arrest

Transport of solutes through brain involves diffusion and convection. The importance of convective flow in the subarachnoid and paravascular spaces has long been recognized; a recently proposed 'glymphatic' clearance mechanism additionally suggests that aquaporin-4 (AQP4) water channels facilitate convective transport through brain parenchyma. Here, the major experimental underpinnings of the glymphatic mechanism were re-examined by measurements of solute movement in mouse brain following intracisternal or intraparenchymal solute injection. We found that: (i) transport of fluorescent dextrans in brain parenchyma depended on dextran size in a manner consistent with diffusive rather than convective transport; (ii) transport of dextrans in the parenchymal extracellular space, measured by 2-photon fluorescence recovery after photobleaching, was not affected just after cardiorespiratory arrest; and (iii)

Topics: Animals; Aquaporin 4; Biological Transport; Carbocyanines; Dextrans; Diffusion; Fluoresceins; Fluorescence Recovery After Photobleaching; Fluorescent Dyes; Gene Expression; Heart Arrest; Injections, Intraventricular; Mice; Mice, Knockout; Models, Biological; Parenchymal Tissue; Rats; Subarachnoid Space