(full paper is archived in the Miller Library)
Title: Isometric responses of the somatic musculature of Cryptochiton stelleri
Student Author(s): Harrison, John T.
Location: Final Papers Biology 175H
Date: June 1974
Abstract: Electrophysiological data were gathered on an isolated segment of the somatic musculature of Cryptochiton stelleri, a subtidal Polyplacophoran. 1. The muscles were found to be iterative, single stimuli evoking no response. 2. Both steady D.C. (2 sec.) and trains of short duration pulses evoke a short-term "phasic" response, although the time relationships differ slightly. 3. Steady D.C. of polarity opposite to the above yields a longer "tonic" response. 4. Both the tonic and phasic contractions will summate, but only the phasic will sustain a state of tetanus. 5. The tonic response is hypothetically attributed to membrane hyperpolarization and subsequent Ca++ influx, and as such, probably does not occur in vivo.
Notes: Publ 1975, Veliger 18 (Suppl): 79-82