Skip to main content
PMC home page
The Journal of General Physiology logoLink to The Journal of General Physiology
. 1978 Jun 1;71(6):683–698. doi: 10.1085/jgp.71.6.683

Ionic basis of the receptor potential in primary endings of mammalian muscle spindles

PMCID: PMC2215112  PMID: 149839

Abstract

The effect of changing the ionic composition of bathing fluid on the receptor potential of primary endings has been examined in isolated mammalian spindles whose capsule was removed in the sensory region. After impulse activity is blocked by tetrodotoxin, ramp-and-hold stretch evokes a characteristic pattern of potential change consisting of a greater dynamic depolarization during the ramp phase and a smaller static depolarization during the hold phase. After a high-velocity ramp there is a transient post-dynamic undershoot to below the static level. On release from hold stretch, the potential shows a postrelease undershoot relative to base line. The depolarization produced by stretch is rapidly decreased by the removal of Na+ and Ca2+. Addition of normal Ca2+ partly restores the response. Stretch appears to increase the conductance to Na+ and Ca2+ in the sensory terminals. The postdynamic undershoot is diminished by raising external K+ and blocked by tetraethylammonium (TEA). It apparently results from a voltage- dependent potassium conductance. The postrelease undershoot is decreased by raising external K+, but is not blocked by TEA. It is presumably caused by a relative increase in potassium conductance on release. Substitution of isethionate for Cl- or the addition of ouabain does not alter the postdynamic and postrelease undershoots.

Full Text

The Full Text of this article is available as a PDF (1.5 MB).

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Baker P. F., Glitsch H. G. Voltage-dependent changes in the permeability of nerve membranes to calcium and other divalent cations. Philos Trans R Soc Lond B Biol Sci. 1975 Jun 10;270(908):389–409. doi: 10.1098/rstb.1975.0018. [DOI] [PubMed] [Google Scholar]
  2. Chandler W. K., Meves H. Voltage clamp experiments on internally perfused giant axons. J Physiol. 1965 Oct;180(4):788–820. doi: 10.1113/jphysiol.1965.sp007732. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. DIAMOND J., GRAY J. A., INMAN D. R. The relation between receptor potentials and the concentration of sodium ions. J Physiol. 1958 Jul 14;142(2):382–394. doi: 10.1113/jphysiol.1958.sp006024. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. EDWARDS C., TERZUOLO C. A., WASHIZU H. THE EFFECT OF CHANGES OF THE IONIC ENVIRONMENT UPON AN ISOLATED CRUSTACEAN SENSORY NEURON. J Neurophysiol. 1963 Nov;26:948–957. doi: 10.1152/jn.1963.26.6.948. [DOI] [PubMed] [Google Scholar]
  5. Fukami Y., Hunt C. C. Structures in sensory region of snake spindles and their displacment during stretch. J Neurophysiol. 1977 Sep;40(5):1121–1131. doi: 10.1152/jn.1977.40.5.1121. [DOI] [PubMed] [Google Scholar]
  6. Hille B. The permeability of the sodium channel to organic cations in myelinated nerve. J Gen Physiol. 1971 Dec;58(6):599–619. doi: 10.1085/jgp.58.6.599. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Hunt C. C., Ottoson D. Impulse activity and receptor potential of primary and secondary endings of isolated mammalian muscle spindles. J Physiol. 1975 Oct;252(1):259–281. doi: 10.1113/jphysiol.1975.sp011143. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Hunt C. C., Ottoson D. Initial burst of primary endings of isolated mammalian muscle spindles. J Neurophysiol. 1976 Mar;39(2):324–330. doi: 10.1152/jn.1976.39.2.324. [DOI] [PubMed] [Google Scholar]
  9. Hunt C. C., Ottoson D. Responses of primary and secondary endings of isolated mammalian muscle spindles to sinusoidal length changes. J Neurophysiol. 1977 Sep;40(5):1113–1120. doi: 10.1152/jn.1977.40.5.1113. [DOI] [PubMed] [Google Scholar]
  10. Jansen J. K., Nicholls J. G. Conductance changes, an electrogenic pump and the hyperpolarization of leech neurones following impulses. J Physiol. 1973 Mar;229(3):635–655. doi: 10.1113/jphysiol.1973.sp010158. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Kuffler S. W., Nicholls J. G. The physiology of neuroglial cells. Ergeb Physiol. 1966;57:1–90. [PubMed] [Google Scholar]
  12. Meech R. W. Intracellular calcium injection causes increased potassium conductance in Aplysia nerve cells. Comp Biochem Physiol A Comp Physiol. 1972 Jun 1;42(2):493–499. doi: 10.1016/0300-9629(72)90128-4. [DOI] [PubMed] [Google Scholar]
  13. OTTOSON D. THE EFFECT OF SODIUM DEFICIENCY ON THE RESPONSE OF THE ISOLATED MUSCLE SPINDLE. J Physiol. 1964 May;171:109–118. doi: 10.1113/jphysiol.1964.sp007365. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Obara S. Effects of some organic cations on generator potential of crayfish stretch receptor. J Gen Physiol. 1968 Aug;52(2):363–386. doi: 10.1085/jgp.52.2.363. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Obara S., Grundfest H. Effects of lithium on different membrane components of crayfish stretch receptor neurons. J Gen Physiol. 1968 May;51(5):635–654. doi: 10.1085/jgp.51.5.635. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Roberts A., Bush B. M. Coxal muscle receptors in the crab: the receptor current and some properties of the receptor nerve fibres. J Exp Biol. 1971 Apr;54(2):515–524. doi: 10.1242/jeb.54.2.515. [DOI] [PubMed] [Google Scholar]

Articles from The Journal of General Physiology are provided here courtesy of The Rockefeller University Press

RESOURCES