Morphology of the accessory ciliary ganglion of the cat.

A microdissection of the orbital nerves of the cat was made paying particular attention to the accessory ciliary ganglion. The structures were studied with the light microscope by histological and histochemical techniques. The accessory ciliary ganglion consisted of cells similar to those in the main ganglion. The neurons of the accessory ciliary and those of the main ciliary ganglion emitted no specific fluorescence for catecholamines. After injection of horseradish peroxidase-wheat germ agglutinin conjugates into the chambers of the eye, most ganglion cells of the accessory and main ciliary ganglia were labeled. A few labeled ectopic cells were also found in proximity of the accessory ganglion in the lateral short ciliary nerve or in the communicating branch from the trigeminal nerve. The present results indicate that the accessory ciliary and ectopic ganglion cells are parasympathetic in nature and may innervate the intrinsic eye musculatures.