Age dependent contribution of entry via the CSF to the overall brain entry of small and large hydrophilic markers

ConclusionsIn the developing brain the apparent higher brain entry of a small hydrophilic marker such as sucrose can be attributed to its higher entry into the CSF and subsequent diffusion into the brain. By contrast, movement of a larger marker like 70  kDa dextran is restricted firstly by choroid plexus epithelial tight junctions and secondly by specialised junctions in the neuroependymal interface between the CSF and brain. Brain/plasma ratios of 70 kDa dextran were similar in fetal and adult rats. Therefore 70 kDa dextran should be considere d an appropriate marker if brain residual vascular space is to be measured, especially in younger animals.
Source: Fluids and Barriers of the CNS - Category: Neuroscience Source Type: research