Abstract
1. Voltage clamp experiments on muscle fibres compared transients to 10 mV steps at hyperpolarized voltages between VT = -100 to -185 mV with controls obtained at VC = -85 mV. 2. Membrane capacitance fell by 15%, 13% and 4.5% per 100 mV hyperpolarization fro -85 mV in hypertonic low chloride, hypertonic high chloride and isotonic high chloride-containing solutions respectively. 3. The charge moved by the 'on' and 'off' parts of the applied step was equal over the voltages studied. This suggests that the changes were capacitative rather than ionic in origin. The changes could not be explained in terms of the cable properties of the transverse tubular system. They may therefore reflect non-linear capacitance in the muscle membrane itself. 4. Subtracting control transients at -85 mV from transients obtained at different voltages gave monotonically decaying charge movements. In the frequency domain, these charge movements possessed real and imaginary permittivities resembling those of a 'Debye' particle. 5. It is concluded that muscle membranes have non-linear capacitances even at voltages far hyperpolarized to those in which familiar voltage-dependent processes occur.
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Selected References
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- Adrian R. H., Almers W. Membrane capacity measurements on frog skeletal muscle in media of low ion content. J Physiol. 1974 Mar;237(3):573–605. doi: 10.1113/jphysiol.1974.sp010499. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Adrian R. H., Almers W. The voltage dependence of membrane capacity. J Physiol. 1976 Jan;254(2):317–338. doi: 10.1113/jphysiol.1976.sp011234. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Adrian R. H., Peres A. Charge movement and membrane capacity in frog muscle. J Physiol. 1979 Apr;289:83–97. doi: 10.1113/jphysiol.1979.sp012726. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Adrian R. H., Rakowski R. F. Reactivation of membrane charge movement and delayed potassium conductance in skeletal muscle fibres. J Physiol. 1978 May;278:533–557. doi: 10.1113/jphysiol.1978.sp012323. [DOI] [PMC free article] [PubMed] [Google Scholar]
- FALK G., FATT P. LINEAR ELECTRICAL PROPERTIES OF STRIATED MUSCLE FIBRES OBSERVED WITH INTRACELLULAR ELECTRODES. Proc R Soc Lond B Biol Sci. 1964 Apr 14;160:69–123. doi: 10.1098/rspb.1964.0030. [DOI] [PubMed] [Google Scholar]
- Hodgkin A. L., Nakajima S. The effect of diameter on the electrical constants of frog skeletal muscle fibres. J Physiol. 1972 Feb;221(1):105–120. doi: 10.1113/jphysiol.1972.sp009742. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Schneider M. F., Chandler W. K. Effects of membrane potential on the capacitance of skeletal muscle fibers. J Gen Physiol. 1976 Feb;67(2):125–163. doi: 10.1085/jgp.67.2.125. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Schneider M. F. Linear electrical properties of the transverse tubules and surface membrane of skeletal muscle fibers. J Gen Physiol. 1970 Nov;56(5):640–671. doi: 10.1085/jgp.56.5.640. [DOI] [PMC free article] [PubMed] [Google Scholar]