Hopkins Marine Station Student Paper

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(full paper is archived in the Miller Library)

Title: Characteristics of the neuromuscular junction in a flatfish (Citharichthys sordidus)
Student Author(s): Wobig, Roger
Faculty Advisor(s): Gilly, William F.
Pages: 26
Location: Final Papers Biology 175H
Date: June 1989
Keywords: nearshore fishes
Abstract: The neuromuscular junction of the Pacific Sanddabs was studied. Neither fast nor slow muscle fibers in the fin muscles of sanddabs produce action potentials. Muscle activation by indirect stimulation could be inhibited with D-tubocurarine (curare), tetrodotoxin (TTX), and GVIA omega-conotoxin. This indicated some similarities in the neuromuscular system of sanddabs compared to other vertebrates. Motor nerve and synaptic transmission are sensitive to sodium and calcium channel blocks, and acetylcholine is likely to be the neurotransmitter, as suggested by the curare sensitivity of neuromuscular transmission. However, direct stimulation of muscle fibers could be continued after the neuromuscular transmission had been blocked. Although they do not produce action potentials, the muscles do produce end plate potentials. A single end plate potential has proved adequate to produce a muscle twitch.