Casual light microscopic observations on the intracommissural elements (ICE) of the subcommissural complex in some...

OKSCHE (1969) described secretory processes in glial cells of the canine subcommissural complex which form strands crossing directly from the hypendyma to the membrana limitans gliae superficialis; these observations were corroborated by STERBA et al. (1982). According to OKSCHE (1969) the secretory material is discharged into the blood vessels of the pia mater; empty vesicles are found in widened leptomeningeal spaces. Structural elements of the subcommissural complex situated in the commissura caudalis, but which are actually not intrinsic elements of the latter, should be called "Intercommissural elements" (ICE); they traverse radially the commissura caudalis (nerves, glial cells, blood vessels), thus causing the striped appearance of the commissure in sagittal section. The striation depends on different elements (nerves, astroglia), which can be demonstrated by different techniques. The strands originate out of cone-like projections of the hypendyma which contain numerous cells having the appearance of ependymal cells of the SCO sunk into the hypendyma. The strands consist of bipolar astroglia, which develop the endfeet forming the membrana limitans gliae superficialis.