In the rabbit cerebral cortex, preserved by perfusion and stained by the silver carbonate method of Del Rio-Hortega modified by Naoumenko and Feigin for paraffin sections, the oligodendrocytes are situated next to blood vessels or are placed at a short distance from the blood vessels, which they contact with a thickening.

The microglia cells are usually situated in juxtaposition to neurons and are rarely found along blood vessels. They give off long tortuous thick processes with delicate secondary branches, which contact numerous neighboring neurons and terminate either at short distances from branches of adjacent microglia cells or next to vascular walls. Although there are regional variations in the appearance and number of microglia cells, their processes are so profuse that they seem to supply all neurons; these processes cover a small portion of the neuronal surface.

In the cerebral cortex of the rabbit, the oligodendrocytes, because of their rare occurrence, would seem to have a more restricted function, while the microglia cells, because of their profuse distribution, seem to have a more universal function than is usually attributed to them.