[Postnatal development of granule-containing cells in the paracervical ganglion (Frankenhäuser) of the mouse: an...

Granule-containing cells of the paracervical ganglion were studied by electron microscopy in mice at birth to 60 days of age. In the paracervical ganglion of newborn mice, among nerve cells, there are clusters of small spherical cells, which often contain small granular vesicles, 80 to 150 nm in diameter, in the peripheral zone of the cytoplasm. The cells with few granular vesicles are also observed. After 5 days of age the granule-containing cells are arranged in small groups, scattering in the ganglion. According to the size and distribution of the granular vesicles, granule-containing cells are classified into 3 types (types A, B, and C). The granule-containing cells similar to those in newborn mice are type A. In type B cells, small granular vesicles are distributed throughout the cytoplasm. Type C cells contain large granular vesicles, 150 to 400 nm in diameter, and small granular vesicles which are distributed throughout the cytoplasm. In newborn mice, all of the granule-containing cells are type A. Type A cells decrease with age and they are the smallest in frequency after 20 days of age. Type B cells appear at 5 days of age, increase rapidly, and become 46%, most frequent among 3 types, at 20 days of age, then decrease and become rare like type A cells at 60 days of age. Type C cells also appear at 5 days of age and they are the smallest in frequency at 5 and 10 days. Type C cells increase with age and become about 80% at 60 days. They are the most frequent cells after 35 days of age.(ABSTRACT TRUNCATED AT 250 WORDS)