Morphological and immunocytochemical characterisation of mixed glial cell cultures derived from neonatal canine brain.

Three different regions from neonatal dog brain were mechanically dissociated and cultured. At seven, 10, 14 and 19 days, cultures were harvested and studied with immunocytochemical techniques for the demonstration of astrocytes, oligodendrocytes and fibroblasts. The canine brain cultures were confluent at seven days and contained fibroblasts, both types of glial cells and several small fragments of undissociated brain tissue. Many cells were myelin associated glycoprotein (MAG) positive. In the older cultures increasing numbers of myelin basic protein (MBP) positive oligodendrocytes were also demonstrated. Double labelling studies demonstrated that MBP and MAG were produced by the same cells. MAG positive cells were therefore identified as oligodendrocytes. Most intensive oligodendroglial growth occurred in the vicinity of undissociated tissue fragments. The results were discussed in respect to glial differentiation and the question of whether the canine cultures may contain neurons.