Volumetric characterization of CNS Extracellular Space using thick Hippocampal tissue cryosections

<title>Abstract</title> <p>Volumetric characterization of extracellular micro-spatial distribution within the CNS, is an underinformed component of biology. This condition enables two important factors of CNS biology, the flow of CSF fluid to maintain steady states and motile cells’ movement. Upon evaluation of fixed and unfixed thick undehydrated 60-micron cryosections the non-solid space within fresh and cultured CNS tissue was encountered and appraised to be highly porous An analysis of solid vs empty space yielded that 25+% of volumetric layout of CNS tissue is devoted to empty space, which gives it the porosity appearance. The porosity was presented as narrow openings in-between tissue, and much larger voids adjacent to vasculature which ranged from 10–200 microns in diameter. These findings are in line with what is understood about CSF flow and a peculiar similarity in the structure of CNS cells of post blood-brain compartment. Taken together, with the utilization of a simple and informative technique, thick cryosections, the results of this study inform and reconcile spatial aspects of CNS tissue which give greater resolution to its microvolumetric layout.</p>