Innervation of abdominal paraganglia: An ultrastructural study

✍ Scribed by Joe A. Mascorro; Robert D. Yates

• Book ID: 102903898
• Publisher: John Wiley and Sons
• Year: 1974
• Tongue: English
• Weight: 860 KB
• Volume: 142
• Category: Article
• ISSN: 0362-2525
• DOI: 10.1002/jmor.1051420204

✦ Synopsis

Abstract

Abdominal extra‐adrenal chromaffin tissue, or paraganglia, was examined at the ultrastructural level to elucidate the innervation of this adrenal medullary homologue. Paraganglia display unmyelinated nerve fibers surrounded by Schwann cell cytoplasm. These nerves are separated from the paraganglion Type I (granule‐containing) cells by cytoplasmic projections of paraganglion Type II (satellite) cells. However, serial sections show that the nerves eventually make synaptic contact with the Type I cell. At the axon‐chromaffin cell junction, only the outer aspect of the nerve is covered by the satellite cell. The presynaptic endings contain numerous synaptic vesicles, mitochondria and glycogen particles. The vesicles are predominantly of the clear‐cored variety, but a few possess centers which are elecron opaque. The pre‐ and postsynaptic membranes are separated bya subsynaptic space and occasionally exhibit the membranal densities usually associated with synaptic areas. These ultrastructural studies establish definite evidence that abdominal paraganglion cells are innervated.