Acetylcholinesterase activity, measured per unit wet weight, is relatively low in the eggs and infective larvae of N. brasiliensis. It increases rapidly during the parasitic phase, especially in the late 3rd- and early 4th-larval stages. Activity in normal adults is extremely high (× 15 egg activity) and this is doubled again in immune-damaged adults. Possible functions of N. brasiliensis acetylcholinesterase are discussed.
It is a pleasure to acknowledge the technical assistance of Miss Anne Cronin and Miss Beryl Crooks.