Light and electron microscopic observations on the postnatal development of the rat paracervical (Frankenhäuser) ganglion.

Abstract

The ultrastructure of the rat paracervical (frankenhauser) ganglion was studied during postnatal development after immersion or perfusion fixation with the glutaraldehyde, followed by postosmification. Three different neuronal cell types were found in the ganglion: (1) Primitive sympathetic nerve cells. They had a “primitive” structure and contained, in one section, one to two dense cored vesicles (DCV) of 700–1100 A in diameter. They were not found after the fourth day of postnatal development. (2) Principal neurons grew in size during the whole period of postnatal development. Part of them were already well developed in the ganglia of the newborn rat, and no particular changes in the content of their cytoplasmic organelles occurred thereafter. (3) Small granule-containing (SGC) cells. They usually occurred in small groups, often close to blood capillaries of the fenestrated type and were sometimes devoid of their satellite cell sheath in this region. They became slightly smaller in size as the animal aged. The size of their granulated vesicles (GV) varied mainly between 800–1400 A in all age groups in most of the cells. In addition, another type of SGC-cell containing larger GV up to 3000 A in diameter were observed in the ganglia of 32-day old and older rats.