Abstract
A monoclonal antibody, B30, obtained with whole cells from embryonic brain as an immunogen, recognizes a neuronal cell surface antigen that appears only in 2 distinct systems in the developing mouse brain: the trigeminal system and the cerebellum. In the trigeminal system, B30 labels the surface of neurons, including their axons and their transient dendrites, in 2 groups of cells: the centrally located mesencephalic trigeminal nucleus and the peripheral trigeminal ganglion. Immunoreactivity is detectable during axon outgrowth, peaks around the seventh postnatal day, and disappears around 2 weeks after birth. In the cerebellum, B30 labels 2 layers of cells during development. Perinatally, and for about a week after birth, the layer of premigratory granule cells stains. After their maturation, Purkinje cells start to stain and by 12 d postnatally all the Purkinje cell bodies, their axons, and their dendritic trees show strong immunoreactivity. Subsequently, and in the adult, this staining is lost from some cells to reveal bands of antigen positive and negative Purkinje cells. Initial biochemical characterization of the epitope shows that it is carried on 2 minor gangliosides.