Neuronal stem cells express vesicular monoamine transporter 2 immunoreactivity in the adult rat

In the adult CNS, proliferating cells persist only in the olfactory epithelium, olfactory bulb and subventricular zones. The cells of the subventricular zone are believed to constitute the cells in the adult mammalian brain, including the human brain, which can be stimulated to proliferate in response to epidermal growth factor or basic fibroblast growth factor. These cells are of particular interest, as they may be amenable to genetic engineering with markers such as tyrosine hydroxylase, and they may represent a long-term source of modified neurons suitable for transplantation therapy. Recent work by Lois and Alvarez-Buylla, in the mouse, has shown that labelled subventricular zone cells can migrate from the subventricular zone to the olfactory bulb, where they contribute to the granule cell population. In this study we have used an antibody we raised recently against the carboxy-terminal sequence of the vesicular monoamine transporter 2 (also known as the synaptic vesicle monoamine transporter) to detect vesicular monoamine transporter 2-like immunoreactive subventricular zone cells in the rat, and to visualize them as they migrate from the edge of the ventricle, through the olfactory bulb to locate them as differentiated neurons in the granule cell layer of the olfactory bulb. These data show that the subventricular zone cells express a vesicular monoamine transporter 2-like antigen and demonstrate that this protein may be a useful developmental marker for rat neuronal stem cells.