Cerebral water content in silicone oil-induced hydrocephalic rabbits

Specific gravity determinations were made on fresh and desiccated samples of hydrocephalic rabbit brains. There was a density gradient in the normal cortical gray matter. Hydrocephalus was accompanied by significantly increased specific gravity of cortical gray matter at 3 days and 1 and 4 weeks. In the latter two periods, there were also significant increases in the specific gravity of white matter in the corpus callosum. These changes represent water loss throughout the whole cerebrum except at the ventricular surface. The specific gravity of solid tissue brain components changed insignificantly. We conclude that short-term brain volume changes in experimental hydrocephalus were due mainly to loss of tissue water.