Fine structure of nerve endings and junctions in the superior cervical ganglion of the camel (Camelus dromedarius).

The superior cervical ganglion of the one humped camel was studied using an electron microscope. The ganglion contained presumptive cholinergic endings, presumptive aminergic endings, and presumptive sensory endings. Presumptive cholinergic endings contained numerous small clear vesicles, a few large dense-cored vesicles, and mitochondria. They frequently made synaptic junctions with dendritic processes and, occasionally, with axons in transit. There were few presumptive aminergic endings and they were characterized by a mixed population of dense-cored vesicles and clear vesicles. They only made synaptic junctions with axons in transit. Presumptive sensory endings were characterized by numerous slender mitochondria and had no synaptic junctions of any kind. Symmetrical membrane thickenings (puncta adherens) were frequently encountered in this study, usually between dendritic processes and other neuronal elements of the superior cervical ganglion.