FINE STRUCTURAL LOCALIZATION OF ACETYLCHOLINESTERASE IN SINGLE AXONS

The walking leg nerves of lobster are particularly suitable for cytochemical localization of acetylcholinesterase. They are sensitive to acetylcholine and demonstrate physiological properties similar to those seen in neuromuscular junctions. Incubation of these axons in media containing acetylthiocholine and iso-OMPA (an inhibitor of nonspecific cholinesterases) demonstrated acetylcholinesterase end products in the Schwann cell-axon interspace near the axolemma. Axoplasmic vacuoles and microtubules also exhibited activity. Butylcholinesterase, on the other hand, was almost entirely limited to the thick sheath which surrounds each axon. These observations and other biochemical and pharmacological data suggest the involvement of the acetylcholine system in conduction of impulses along lobster nerves. © 1969 Academic Press, Inc.