Hopkins Marine Station Student Paper

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(full paper is archived in the Miller Library)

Title: Physiology of a novel kind of fast twitch fiber in sand dab fin muscles
Student Author(s): Aladjem, Eva
Faculty Advisor(s): Gilly, William
Pages: 26
Location: Final Papers Biology 175H
Date: June 1984
Keywords: movement
Abstract: In a sand dab fin muscle preparation, the electrical and mechanical properties of a fast twitch muscle have been studied. The "long" (presumably multiply innervated) fast fibers have resting potentials of -75 to -80 mV and are taken to threshold for contraction (-40 mV) by depolarizing junction potentials. All-or-nothing action potentials are not seen, even when suprathreshold shocks are applied. Twitches are very fast; contraction reaches a peak within 10 ms and relaxation is complete within 20 ms at 18 degrees C. Direct stimulation produces unfused tentant up to at least 200 Hz.