Esterases in Crustacean Nervous System. I. Electrophoretic Studies in Lobsters.

Biochemical and pharmacological studies have established that crustacean nervous system contains fairly large amounts of cholinesterase and acetylcholine or acetylcholine-like compounds (Nachmansohn and Rothenburg, '45; Schallek, '45; Augustinsson, '48; Walop, '50, '51; Walop and Boot, '50). The ability of lobster central ganglia to hydrolyze acetylcholine, and the effectiveness of extracts of these tissues in standard bio-assays for acetylcholine, are of magnitudes comparable to those in mammalian sympathetic ganglia (Prosser, '46; Welsh, '61). However, in crustacean central nervous system there is no conclusive evidence to support the existence of cholinergic transmission, and no information to establish any other role of acetylcholine (Prosser, '40; Schallek and Wiersma, '48, '49; Turner et al., '50; Welsh, '61; Wiersma, '61). In the peripheral nervous system, neuromuscular transmission is not cholinergic (Grundfest et al., '59), and the acetylcholine of peripheral nerve is associated with sensory fibers rather than with motor elements (Florey and Biederman, '60). Several years ago, a study of the localization of cholinesterase in cryostat sections of ganglia and nerves in lobsters ( Homarus americanus, Panulirus argus, Panulirus interruptus) was initiated, using the Koelle ('51 ) thiocholine method and several more general esterase methods. These results have been partially reported (Maynard and Maynard, '60a, '60b; Maynard, '60) and will be presented in detail elsewhere (Maynard and Maynard, '64). Eserine-sensitive hydrolysis of acetyland butyrylthiocholine occurred in certain neural and non-neural, or glial, elements, both in regions known to contain many synapses, and in non-synaptic sites, such as the