The localization of acetylcholinesterase activity in the spinal ganglia of the adult fowl studied by electron microscope histochemistry

Summary AChE activity was localized in spinal ganglia of adult fowls at the electron microscope level using Karnovsky’s method. Controls with BW 284 C 51 were carried out. In the neuronal bodies, AChE activity was evident within the rough-surfaced cisternae of the endoplasmic reticulum, including the perinuclear cisterna and the subsurface cisternae, and sometimes in the innermost cisternae of the Golgi complex. AChE activity was also demonstrated along the axolemma and associated with smooth-surfaced vesicles and tubules in the initial segment of the axon, in all the ganglionic myelinated fibers examined by serial section analysis and in more than half of the ganglionic unmyelinated fibers examined by this method. In the myelinated fibers the reaction product appeared more abundant at the level of the nodes of Ranvier than in the internodal segments. Both in the myelinated and unmyelinated fibers a considerable quantitative variability of reaction product was observed among the various sections of the same fiber. These results were compared with those previously obtained in the spinal ganglia of the chick embryo using the same histochemical method. This research was supported by a grant of the National Research Council (C.N.R.), Italy, and of the Deutsche Forschungsgemeinschaft (DFG), Federal Republic of Germany. 1 AChE=acetylcholinesterase (=true or specific cholinesterase); ACh=acetylcholine; ChAc=choline acetylase (=choline acetyltransferase).