Key points are not available for this paper at this time.
The extracellular space of the rat brain was visualized by electron roscopy in sections of cerebral cortex fixed by freeze-substitution. The volume tissue occupied by the extracellular space was estimated stereomnetrically, and found to decrease from 20.8 percent in 3-month-old rats to 9.6 percent in escent animals, 26 months of age. This decrease in extracellular space indicates age-associated change in the microenvironment of nerve cells.
Bondareff et al. (Fri,) studied this question.