Summary
Flexible intracellular micro-electrodes were used to study the effect of changes in muscle length on the end-plate potential in the isolated m. cutaneus pectoris for different frequencies of stimulation (1/60-5 Hz).
A 20% step-wise increase in muscle length within the physiological range increases the end-plate potential immediately by about 50% (range 0–120%) at all frequencies tested. At stimulus frequencies lower than 1/5 Hz this increase is sustained during a period of 15 min stretch. At 1 Hz, however, the initial increase in the end-plate potential amplitude on the average declines within a few minutes to a steady-state value about 35% higher than the steady-state end-plate potential before stretch. At 5 Hz, the initial amplitude increase is followed by a decline of about 15 min duration and the final amplitude is not increased in comparison with the pre-stretch amplitude.
The amplitude of the compound muscle action potential of the gastrocnemius muscle with intact circulation shows a similar time dependent increase upon stretch at different stimulus frequencies.
It is concluded that stretch of a frog muscle gives both an immediate and a sustained increase in transmitter release from the nerve terminals during prolonged stimulation at frequencies up to about 5 Hz. This effect of stretch on transmitter release can improve in vivo neuromuscular impulse transmission.
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References
Braun, M., Schmidt, R. F.: Potential changes recorded from the frog motor nerve terminal during its activation. Pflügers Arch. ges. Physiol.287, 56–80 (1966)
Čapek, R., Esplin, D. W., Salehmoghaddam, S.: Rates of transmitter turnover at the frog neuromuscular junction estimated by electrophysiological techniques. J. Neurophysiol.34, 831–841 (1971)
Castillo, J. del, Katz, B.: Localization of active spots within the neuromuscular junction of the frog. J. Physiol. (Lond.)132, 630–649 (1956)
Ceccarelli, B., Hurlbut, W. P.: The effects of prolonged repetitive stimulation in hemicholinium on the frog neuromuscular junction. J. Physiol. (Lond.)247, 163–188 (1975)
Dreyer, F., Peper, K.: A monolayer preparation of innervated skeletal muscle fibres of the M. cutaneus pectoris of the frog. Pflügers Arch.348, 257–262 (1974)
Edman, K. A. P., Kiessling, A.: The time course of the active state in relation to sarcomere length and movement studied in single skeletal muscle fibres of the frog. Acta physiol. scand.81, 182–196 (1971)
Elmquist, D., Quastel, D. M. J.: A quantitative study of end-plate potentials in isolated human muscle. J. Physiol. (Lond.)178, 505–529 (1965)
Goldman, L.: The effects of stretch on cable and spike parameters of single nerve fibres; some implications for the theory of impulse propagation. J. Physiol. (Lond.)175, 425–444 (1964)
Hutter, O. F., Trautwein, W.: Neuromuscular facilitation by stretch of motor nerve endings. J. Physiol. (Lond.)133, 610–625 (1956)
Ishiko, N.: Changes in resting and action potentials of striated muscle fibres by stretch. Kumamoto med. J.11, 18–31 (1958)
Ishiko, N., Sato, M.: The effect of stretch on the electrical constants of muscle fibre membrane. Jap. J. Physiol.10, 194–203 (1960)
Katz, B., Thesleff, S.: On the factors which determine the amplitude of the miniature end-plate potential. J. Physiol. (Lond.)137, 267–278 (1957)
Kruckenberg, P.: Die Freisetzung von Acetylcholine durch die motorischen Nervenendigungen. Deutung experimenteller Befunde durch ein Analogmodell. KybernetikIV, 113–130 (1968)
Kuno, M., Turkanis, S.A., Weakly, J. N.: Correlation between nerve terminal size and transmitter release at the neuromuscular junction of the frog. J. Physiol. (Lond.)213, 545–556 (1971)
Lass, Y., Halevi, Y., Landau, E. M., Gitter, S.: A new model for transmitter mobilization in the frog neuromuscular junction. Pflügers Arch.343, 157–163 (1973)
Ling, G., Gerard, R.W.: The influence of stretch on the membrane potential of the striated muscle fibre. J. cell. comp. Physiol.34, 397–404 (1949)
Liley, A. W., North, K. A. K.: An electrical investigation of effects of repetitive stimulation on mammalian neuromuscular junction. J. Physiol. (Lond.)16, 509–527 (1953)
Magleby, K. L.: The effect of repetitive stimulation on facilitation of transmitter release at the frog neuromuscular junction. J. Physiol. (Lond.)234, 327–352 (1973)
Peper, K., Dreyer, F., Sandri, C., Akert, K., Moor, H.: Structure and ultra-structure of the frog motor end-plate. Cell Tiss. Res.149, 437–455 (1974)
Takeuchi, A.: The long lasting depression in neuromuscular transmission of the frog. Jap. J. Physiol.8, 102–113 (1958)
Turkanis, S. A.: Effects of muscle stretch on transmitter release at end-plates of rat diaphragm and frog sartorius' muscle. J. Physiol. (Lond.)230, 391–403 (1973)
Ypey, D. L., Kerkhof, P. L. M., Bobbert, A. C.: Muscle length and neuromuscular transmission in the frog. Pflügers Arch.347, 309–322 (1974)
Ypey, D. L.: Feedback of isotonic muscle contraction on neuromuscular impulse transmission in the frog. Pflügers Arch.355, 291–306 (1975)
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Ypey, D.L., Anderson, D. Intra- and extracellular measurements of frog neuromuscular transmission upon stretch of the muscle at different stimulus frequencies. Pflügers Arch. 369, 125–133 (1977). https://doi.org/10.1007/BF00591568
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DOI: https://doi.org/10.1007/BF00591568