DefinePK

Abstract

The cranial cervical ganglion (CCG) is a part of the cervical sympathetic chain located in the head and neck where it provides sympathetic input to their structures. In addition, CCG is associated with some neuropathies including Horner’s syndrome. S-100 is a biologically active protein that is initially detected in peripheral nerves and glial cells. Its immunoreaction in mammalian peripheral nervous system has been thoroughly illustrated. Similar data, however, seem to be lacking regarding dromedary camels. This study aimed to describe the histological structure and S-100 immuno-reactivity of dromedary camel CCG using conventionally processed microscopic slides. The CCG was covered by a dense capsule of connective tissue which sent connective tissue septa to form ganglionic units; the units mainly contained principal ganglion neurons (PGNs), satellite glial cells (SGCs), and small intensely fluorescent cells (SIFCs). Myelinated and non-myelinated nerve fibers, Schwann cells, collagen fibers, fibroblasts, and blood capillaries were also present between the ganglionic units. Small-sized, medium-sized, and large-sized PGNs were detected with significantly different diameter lengths (P<0.05). S-100 immuno-staining was negative in the connective tissue septa, ganglionic connective tissue capsule, fibroblasts, blood vessels, and SIFCs. PGNs were S-100 positive with some neurons exhibiting negative to weak reactions. S-100 immunoreactivity was present in the glial capsules, SGCs, myelinated axons, and Schwann cells. In conclusion, as in other mammals, the ganglionic units of dromedary camel CCG are mainly formed of PGNs, glial cells, and SIFCs comprising the ganglion’s morphological triads. Further, the study indicated the immuno-reactivity of S-100 protein both in neuronal and glial elements of camel CCG.