AI Article Synopsis
- The study focuses on the development of twitch and tetanic responses in the embryonic chick's posterior latissimus dorsi muscle during the last week in the egg.
- Normalized forces for both twitch and tetanic contractions increased significantly, with twitch force seeing a 3-fold increase and tetanic force a 12-fold increase.
- It highlights key changes in muscle kinetics, such as a decrease in the time to peak force and a reduction in relaxation times, indicating rapid development and potential for studying muscle differentiation mechanisms.
Article Abstract
The development of the twitch and tetanic responses of the embryonic chick posterior latissimus dorsi muscle has been studied during the last week in ovo. Normalized twitch and tetanic forces increased 3- and 12-fold, respectively, during this period. The changes in the kinetics of the twitch and tetanic responses differed during this developmental period. The time to peak twitch force progressively decreased. The decrease in time to half-peak tetanic force and the increase in the time differential of force production of the tetanic response did not continue after day 18. A prolonged tonic contractile component was described for both the twitch and tetanic responses, particularly in muscles from the younger embryos (days 14-18). A large decrease in the time to one-half relaxation of the twitch response also takes place during the final week in ovo. This detailed description of the development of the contractile properties provides a model system of fast-twitch muscle development in which neurogenic and myogenic components of muscular differentiation can be studied from several approaches.
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| http://dx.doi.org/10.1152/ajpcell.1982.242.1.C52 | DOI Listing |
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