An in vitro model to study adult neurogenesis in mammals

The wall of the lateral ventricle of bovine brains comprised three distinct layers: ependyma, subependyma (SE) and astroglial net. The wall lining whi te matter had narrow SE and thin, compacted astroglial net. The wall of the striatum and the anterior horn had a wide SE and a thick and slack astrogl ial net. The ependyma was S-100 positive and, in rostro-lateral regions, it developed basal processes and reactivity to GFAP and vimentin. The SE and the subjacent astroglial net displayed beta3 tubulin small cells and some P CNA positive nuclei. These features suggested that adult neurogenesis takes place in the bovine ventricular walls specially in the striatum and the an terior horn. Explants of the ependyma-SE were cultured in serum free medium . The ependymal cells developed a net of intermingled basal processes that became increasingly GFAP, vimentin and BLBP positive. At the same time SE c ells proliferated to produce a population of beta3 tubulin-positive cells. These cells synthesised IGF-1 that acted as a survival factor. These explan ts represent good models to study adult neurogenesis.