Morphological, histochemical and immunohistological studies of the paracervical ganglion in prepubertal, pregnant and adult, non-pregnant guinea-pigs.

The morphology and ultrastructure of the paracervical ganglion were examined in prepubertal and pregnant guinea-pigs using the light and electron microscope. The neuropeptide and acetylcholinesterase content of the neuronal perikarya and SIF cells, nerve fibres and nerve terminals of the ganglion were examined in prepubertal, adult, non-pregnant and pregnant guinea-pigs. The ganglion consisted of up to seven different sized clusters of neuronal perikarya lying parallel to the long axis of the uterovaginal junction, with 60 or more neuronal perikarya in any one cluster in the paracervical connective tissues. The number of neuronal perikarya within each cluster was related to the total area of each cluster. The light and electron microscopy of the clusters was typical of autonomic ganglia, though no vacuolated neurons were observed as has been reported in the rat. The neuropeptide and acetylcholinesterase content of the ganglionic clusters was not different in prepubertal and adult, non-pregnant guinea-pigs. In pregnant guinea-pigs there was an apparent small decrease in numbers of neuronal perikarya containing the neuropeptides VIP, NPY or TH immunoreactivities, though no quantitative studies were undertaken. In pregnancy no SIF cells were detected, though in prepubertal and non-pregnant, adult guinea-pigs these cells contained TH, NPY or SP immunoreactivity.