Journal of Neurophysiology, Vol 68, Issue 4 1068-1078, Copyright © 1992 by APS

ARTICLES

Force response of rat soleus muscle to variable-frequency train stimulation

S. A. Binder-Macleod and W. J. Barrish
School of Life and Health Sciences, University of Delaware, Newark 19716.

1. The purpose of this study was to study the effects of a high-frequency burst of pulses at the onset of a subtetanic train of pulses on the force output of the rat soleus muscle. 2. The soleus muscle was studied in eight rats deeply anesthetized with urethan. The effects of two-, three-, or four-pulse bursts at the onset of subtetanic trains containing a total of 12 pulses were studied in detail. 3. The results showed that two-pulse bursts at the onset of the train produced approximately 20% augmentation in average force and nearly a 50% reduction in the time required to reach a targeted level of force, compared with a comparable 12-pulse subtetanic constant-frequency train; three- or four- pulse bursts produced progressively less additional improvement. In contrast, the two-pulse bursts produced approximately 13% increase in the force-time integral (Area), the three-pulse burst did not significantly further increase the Area gain, and the use of four-pulse bursts markedly decreased the gain in Area. 4. For all three bursts, the observed force augmentation rapidly declined over the 12-pulse trains. Extrapolation beyond the actual data suggested that the force augmentation should last for between approximately 16 and 19 interpulse intervals. 5. To describe the characteristics of the contractile response of the muscle that explains or predicts the amount of force augmentation seen, we made three measurements of the response to the burst of pulses: 1) the peak force produced by the initial burst of pulses (PeakBURST), 2) the force at the time of arrival of the pulse that followed the burst (CatchBURST), and 3) the rise in force produced by the pulse that followed the burst (PotBURST). Of these three measurements, the CatchBURST was the best predictor of the force augmentation seen. 6. The present results showed 1) the importance of the stimulation pattern on the force output of skeletal muscle; 2) that the force-frequency relationship is multivalued, with force depending on both the stimulation history and stimulation frequency; and 3) that a relatively simple discharge strategy, where each train of pulses begins with one or two brief interpulse interval durations, will produce the maximum force from the muscle and result in a predictable force-frequency relationship.

This article has been cited by other articles:

				D. W. Russ and R. M. Lovering Influence of activation frequency on cellular signalling pathways during fatiguing contractions in rat skeletal muscle Exp Physiol, November 1, 2006; 91(6): 957 - 966. [Abstract] [Full Text] [PDF]

				R B. Keeton and S. A Binder-Macleod Low-Frequency Fatigue Physical Therapy, August 1, 2006; 86(8): 1146 - 1150. [Full Text] [PDF]

				A. Christie and G. Kamen Doublet Discharges in Motoneurons of Young and Older Adults J Neurophysiol, May 1, 2006; 95(5): 2787 - 2795. [Abstract] [Full Text] [PDF]

				F. Abbate, J. D. Bruton, A. De Haan, and H. Westerblad Prolonged force increase following a high-frequency burst is not due to a sustained elevation of [Ca2+]i Am J Physiol Cell Physiol, July 1, 2002; 283(1): C42 - C47. [Abstract] [Full Text] [PDF]

				S. C. K. Lee, C. N. Becker, and S. A. Binder-Macleod Activation of human quadriceps femoris muscle during dynamic contractions: effects of load on fatigue J Appl Physiol, September 1, 2000; 89(3): 926 - 936. [Abstract] [Full Text] [PDF]

				E. van Lunteren and C. B. Sankey Catchlike property of rat diaphragm: subsequent train frequency effects in variable-train stimulation J Appl Physiol, February 1, 2000; 88(2): 586 - 598. [Abstract] [Full Text] [PDF]

				S. C. K. Lee, C. N. Becker, and S. A. Binder-Macleod Catchlike-inducing train activation of human muscle during isotonic contractions: burst modulation J Appl Physiol, November 1, 1999; 87(5): 1758 - 1767. [Abstract] [Full Text] [PDF]

				S. C. Lee, M. L Gerdom, and S. A Binder-Macleod Effects of Length on the Catchlike Property of Human Quadriceps Femoris Muscle Physical Therapy, August 1, 1999; 79(8): 738 - 748. [Abstract] [Full Text] [PDF]

				S. A. Binder-Macleod and D. W. Russ Effects of activation frequency and force on low-frequency fatigue in human skeletal muscle J Appl Physiol, April 1, 1999; 86(4): 1337 - 1346. [Abstract] [Full Text] [PDF]

				S. J. Goldberg, M. A. Meredith, and M. S. Shall Extraocular Motor Unit and Whole-Muscle Responses in the Lateral Rectus Muscle of the Squirrel Monkey J. Neurosci., December 15, 1998; 18(24): 10629 - 10639. [Abstract] [Full Text] [PDF]

				S. A. Binder-Macleod, S. C. K. Lee, A. D. Fritz, and L. J. Kucharski New Look at Force-Frequency Relationship of Human Skeletal Muscle: Effects of Fatigue J Neurophysiol, April 1, 1998; 79(4): 1858 - 1868. [Abstract] [Full Text] [PDF]

				D. T. George, S. A. Binder-Macleod, T. N. Delosso, and W. P. Santamore Variable-frequency train stimulation of canine latissimus dorsi muscle during shortening contractions J Appl Physiol, September 1, 1997; 83(3): 994 - 1001. [Abstract] [Full Text] [PDF]

				T. G. Sandercock and C. J. Heckman Doublet potentiation during eccentric and concentric contractions of cat soleus muscle J Appl Physiol, April 1, 1997; 82(4): 1219 - 1228. [Abstract] [Full Text] [PDF]