Expression of Thy-1, H-2 and NS-4 cell surface antigens and tetanus toxin receptors in early postnatal and adult mouse cerebellum

The expression of several cell surface components (Thy-1, H-2 and NS-4 antigens and tetanus toxin receptors) was studied by indirect immunofluorescence in situ using histological sections and in vitro using freshly dissociated and cultured cells from mouse cerebellum. Thy-1 alloantigen is expressed in adult cerebellum predominantly in neuron-rich regions, i.e. molecular, Purkinje cell, and granular layers, however, it is not detectable at postnatal day 8. In cerebellar cultures of 6-day-old mice Thy-1 is absent from more than 99% of all cells when these are maintained as monolayers in vitro for up to 3 days. After 4 days in vitro some GFA protein-positive astrocytes and some fibronectin-positive fibroblast-like cells start to express Thy-1 antigen. After 14 days in vitro not all fibroblast-like cells and astrocytes are Thy-1 antigen-positive. Neurons with small cell bodies and oligodendrocytes never express Thy-1 at any stage examined. H-2 is not expressed sufficiently to be detectable in histological sections in early postnatal or adult cerebellum. In cerebellar cultures of 6-day-old mice H-2 becomes detectable on some fibroblast-like cells and some astrocytes after 7 days in culture. In histological sections of adult and early postnatal cerebellum NS-4 antigen and tetanus toxin receptors are expressed predominantly in neuron-rich regions. In the developing cerebellum both are expressed at higher levels on more mature granule cells. In cerebellar cultures NS-4 antigen and tetanus toxin receptors are expressed on neurons. Occasionally some astroglia can also show detectable levels of expression. NS-4 antigen is also present on some 04 antigen-positive oligodendrocytes, while tetanus toxin receptors are never detectable on these cells.