Intracellular localization of acetylcholinesterase in nerve terminals and capillaries of the rat superior cervical ganglion.

The ultrastructural localization of acetylcholinesterase (AChE) has been studied in the superior cervical ganglion of the rat. Previous descriptions of the general pattern of localization were confirmed, but in addition, AChE reaction product was found within vesicles in preganglionic nerve terminals, and in pinocytotic vesicles and along the basement lamina of capillaries. There was indication of a continuity between AChE reaction product in the cisternae of the rough endoplasmic reticulum of the principal ganglion cells and extracellular reaction product. These observations are discussed with particular reference to AChE as a secretory protein.