[Ultrastructural observations on choroid neurons of ciliary ganglia]

In the adult pigeon ciliary ganglia peculiar membrane-limited structures were constantly observed in the peripheral cytoplasm of choroid neurons. They are continuous with profiles of the endoplasmic reticulum and/or interconnected with each other. In addition they contain a marked acetylcholinesterase histochemical reaction. These data on the whole suggest that these structures are an integral part of the endoplasmic reticulum system, possibly acting as storing sites of proteic material moving along the pathways of the endoplasmic reticulum system.