Clearance of brain edema and macromolecules through the cortical extracellular space

• DOI: 10.3171/jns.1992.77.3.0387
• Publication Date: 2009-05-26T19:47:01Z
• Authors: Kenji Ohata; Anthony Marmarou
• Keywords: Subarachnoid space; Perivascular space

✓ The transit routes of fluid and particulate matter through brain tissue remain unclear. object this study was to examine the movement macromolecules further clarify clearance pathways edema proteins as they migrate toward cortex. For purpose, albumin solution (20 µl rat diluted 65 mg/ml with mock cerebrospinal (CSF)) intracerebrally infused into caudate putamen, migration well ultrastructure cortical surfaces explored using an immunocytochemical technique. authors observed immunoreactive product on glial limitans pial lining in extracellular space neuropil at 24 hours postinfusion, confirming that protein had reached surface. To confirm efflux subarachnoid CSF, 71,200 D fluorescein isothiocyanatedextran (FITC-dextran 71,200) infused; brains removed en bloc coronal sections were macroscopically under ultraviolet illumination 15 minutes postinfusion. It FITC-dextran mainly localized white putamen infusion site postinfusion by distributed entire cortex hemisphere. However, dynamics lower-molecular-weight substances completely different. spatial distribution 4400 diverged upward surface spread more extensively than 71,200. These observations consistent a diffusion process tracer dependent upon molecular size. studies provide compelling evidence other bulk flow involved normal sink space. concluded CSF pathway via is primary route for process.