Light and electron microscopic examination of isolated neurons, astrocytes and oligodendrocytes

Astrocytes and neuronal and oligodendroglial perikarya isolated by the method of Norton and Poduslo (1970) were examined by transmission and scanning electron microscopy and inverted phase contrast microscopy. The viability of the cells, as determined by the eosin exclusion method, was also determined. The three cell fractions showed only slight cross-contamination, but the astrocyte fraction contained significant amount of small debris. The ultrastructural appearance of the cells indicated that much of the in situ properties were retained, with bundles of fibrils preserved in astrocytes with well-defined plasma membranes. Oligodendroglial perikarya were found to be the best preserved of the cell types. The viability studies indicated that about 90% of the cells excluded eosin. Scanning electron microscopy revealed the neuronal cell surface to be rough and studded with knob-like bodies. Oligodendrocytes tended to aggregate and demonstrated a much smoother surface than the neurons.