Neuronal nuclei are rounded and clear, they contain large nucleoli. When nerve cell bodies are stained by aniline dyes, one may detect basophilic clumps and grains of various size and shape. This is a chromatophilic substance (Nissl bodies). Such structures are also distinguished in sites where dendrites branch off, but they are never found in axons nor their tapering basements called axonal hillocks. There are some cells of oligodendroglia around the nerve cell bodies (satellite oligodendrocytes).