Acetylcholinesterase distribution in the central nervous system of the Megalobulimus oblongus (Gastropoda, Pulmonata).

The acetylcholinesterase (AChE) in the central nervous system (CNS) of the Megalobulimus oblongus was demonstrated by using Koelle and Friedenwald's procedure. The AChE positive reaction was revealed in the nervous cell bodies and processes in the different ganglia of the CNS. The largest number of strong positive neuronal subsets reside in pedal and buccal ganglia. Other positive cell bodies are also located in clusters in the left portion of the visceral ganglion, meso and postcerebrum, and pleural ganglia. In some neurons the enzymatic reaction only appeared at trophospongium level. The neuropilian synaptic areas also exhibited AChE reactivity. These data provide further evidence that AChE is present in neuronal bodies of the CNS of this pulmonate snail, and in some areas is probably involved in cholinergic circuits.