A TRANSIENT IMMUNOGLOBULIN-LIKE REACTIVITY IN THE DEVELOPING CEREBRAL-CORTEX OF RODENTS

SPECIES-SPECIFIC antisera against rat or mouse immunoglobulins, such as the commercial ones currently used as secondary antibodies in immunohistochemistry, revealed an intense, developmentally regulated immunostaining of the cerebral cortex in the homospecific rodent species. The immunostaining showed evident anatomical restrictions, favouring the subplate in prenatal animals. In Western blots, the antisera recognized the protein moiety of a 93 kDa glycoprotein. Both tissue and Western blot immunostaining were completely prevented by preadsorption of the antisera with the corresponding homospecific immunoglobulin. The present results show that a novel molecule, related to immunoglobulins, is transiently expressed in the developing cerebral cortex of rodents, and stress the need for exquisite controls in immunohistochemical studies.