Neuronal and glial cells in the superficial layers of early postnatal mouse neocortex: immunofluorescence...

Sections of immature (postnatal day 5) mouse cerebral cortex was examined for several cell-type specific immunological markers. Glial fibrillary acidic (GFA) protein or vimentin were detected in astrocytic cell processes and--more rarely--cell bodies located in the superficial layers, but not within putative Cajal-Retzius cells (CRs). These cells did, however, react with cholera toxin, tetanus toxin and NS-4 antibodies. In agreement with previous ultrastructural observations, we conclude that CRs are neurons, or at least cells which display the basic characteristics of neurons.