Distribution and number of fluorescent granular perithelial cells in coronal sections of rats cerebrum.

The fluorescent granular perithelial cells (F.G.P.) of rats aged 1 week to 2 years were observed under a light microscope to investigate intracellular granules and localization. This study showed that a marked proliferation of F.G.P. occurs within 3 weeks after birth and the total number remains constant for 2 years. The F.G.P. are mainly distributed in the gray matter, and are scarce in the white matter. The number and distribution of F.G.P. seems to reflect a difference of vascularization and function in different cerebral regions.