The light and electron microscopic localization of intracytoplasmic nucleolus-like bodies in the mouse brain stained by Holmes' silver method.

By light microscopic observation of the mouse brain impregnated by the Holmes' method, intensely stained cytoplasmic inclusion bodies were demonstrated in the nerve cells of the hypothalamus, locus coeruleus and other autonomic regions in addition to the limbic system and some circumventricular organs. Electron microscope observation of ultrathin sections made from vibratome sections impregnated by the Holmes' method revealed that the structures which have been called the nucleolus-like bodies were loaded with large amounts of gold particles. Hence, the Holmes-impregnated cytoplasmic inclusions could be identified with the so-called nucleolus-like bodies. The fine structure, distribution and significance of these bodies were described.