Skip to main content
PMC home page
The Journal of Physiology logoLink to The Journal of Physiology
. 1982 Jan;322:365–387. doi: 10.1113/jphysiol.1982.sp014042

Fluctuation analysis of neutral amino acid responses in cultured mouse spinal neurones.

J L Barker, R N McBurney, J F MacDonald
PMCID: PMC1249675  PMID: 6279829

Abstract

1. Intracellular recordings using the voltage-clamp technique were made at room temperature (24 +/- 1.5 degrees C) from mouse spinal and sensory neurones growing in dissociated cell culture. 2. Membrane current responses could be elicited by ionophoresis of the neutral amino acids, gamma-aminobutyric acid (GABA), beta-alanine (BALA) and glycine to the cell body and processes of these neurones. 3. All membrane current responses were associated with increases in current fluctuations. Most of the analysis presented here was applied to responses generated at the cell body. 4. Many of the fluctuations in membrane current occurring during the responses could be interpreted as reflecting the kinetic behaviour of a single population of two-state Cl- ion-channels. 5. The properties of channels estimated during the desensitized phase of an amino acid-induced current response were not significantly different from those estimated during the peak of the response. 6. The properties of the amino acid-activated channels were relatively constant over the -40 to -90 mV range of membrane potential. 7. There was considerable variation in the estimated average conductance, gamma, and duration, tau, of the elementary events evoked by the neutral amino acids on spinal cord neurones. The properties of the elementary channel events activated by one of the amino acids were significantly different from those activated on the same neurones by either of the other amino acids. 8. In sensory neurones the average gamma and tau values for GABA-activated ion-channels were also determined and these values fell within the range of those for channels activated by GABA in spinal neurones. 9. The results indicate that different naturally occurring neutral amino acids activate channels with unique properties in cultured mouse spinal neurones. The relative charge transfer associated with these channels averages 1.00:0.74:0.32; GABA:glycine:beta-alanine.

Full text

PDF
365

Images in this article

369Fig. 1
on p.369

Selected References

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

  1. Anderson C. R., Stevens C. F. Voltage clamp analysis of acetylcholine produced end-plate current fluctuations at frog neuromuscular junction. J Physiol. 1973 Dec;235(3):655–691. doi: 10.1113/jphysiol.1973.sp010410. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Barker J. L., MacDonald J. F., Mathers D. A., McBurney R. N., Oertel W. GABA receptor functions in cultured mouse spinal neurons. Adv Biochem Psychopharmacol. 1981;29:281–293. [PubMed] [Google Scholar]
  3. Barker J. L., McBurney R. N. GABA and glycine may share the same conductance channel on cultured mammalian neurones. Nature. 1979 Jan 18;277(5693):234–236. doi: 10.1038/277234a0. [DOI] [PubMed] [Google Scholar]
  4. Barker J. L., McBurney R. N. Phenobarbitone modulation of postsynaptic GABA receptor function on cultured mammalian neurons. Proc R Soc Lond B Biol Sci. 1979 Dec 31;206(1164):319–327. doi: 10.1098/rspb.1979.0108. [DOI] [PubMed] [Google Scholar]
  5. Barker J. L., Ransom B. R. Amino acid pharmacology of mammalian central neurones grown in tissue culture. J Physiol. 1978 Jul;280:331–354. doi: 10.1113/jphysiol.1978.sp012387. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Conti F., Wanke E. Channel noise in nerve membranes and lipid bilayers. Q Rev Biophys. 1975 Nov;8(4):451–506. doi: 10.1017/s0033583500001967. [DOI] [PubMed] [Google Scholar]
  7. Dudel J., Finger W., Stettmeier H. Inhibitory synaptic channels activated by gamma-aminobutyric acid (GABA) in crayfish muscle. Pflugers Arch. 1980 Sep;387(2):143–151. doi: 10.1007/BF00584265. [DOI] [PubMed] [Google Scholar]
  8. Faber D. S., Korn H. Single-shot channel activation accounts for duration of inhibitory postsynaptic potentials in a central neuron. Science. 1980 May 9;208(4444):612–615. doi: 10.1126/science.6245449. [DOI] [PubMed] [Google Scholar]
  9. Jackson M. B., Lecar H. Single postsynaptic channel currents in tissue cultured muscle. Nature. 1979 Dec 20;282(5741):863–864. doi: 10.1038/282863a0. [DOI] [PubMed] [Google Scholar]
  10. Katz B., Miledi R. Further observations on acetylcholine noise. Nat New Biol. 1971 Jul 28;232(30):124–126. doi: 10.1038/newbio232124b0. [DOI] [PubMed] [Google Scholar]
  11. Katz B., Miledi R. Membrane noise produced by acetylcholine. Nature. 1970 Jun 6;226(5249):962–963. doi: 10.1038/226962a0. [DOI] [PubMed] [Google Scholar]
  12. Katz B., Miledi R. The statistical nature of the acetycholine potential and its molecular components. J Physiol. 1972 Aug;224(3):665–699. doi: 10.1113/jphysiol.1972.sp009918. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Mathers D. A., Barker J. L. (-)Pentobarbital opens ion channels of long duration in cultured mouse spinal neurons. Science. 1980 Jul 25;209(4455):507–509. doi: 10.1126/science.6248961. [DOI] [PubMed] [Google Scholar]
  14. McBurney R. N., Barker J. L. GABA-induced conductance fluctuations in cultured spinal neurones. Nature. 1978 Aug 10;274(5671):596–597. doi: 10.1038/274596a0. [DOI] [PubMed] [Google Scholar]
  15. Neher E., Sakmann B. Single-channel currents recorded from membrane of denervated frog muscle fibres. Nature. 1976 Apr 29;260(5554):799–802. doi: 10.1038/260799a0. [DOI] [PubMed] [Google Scholar]
  16. Neher E., Stevens C. F. Conductance fluctuations and ionic pores in membranes. Annu Rev Biophys Bioeng. 1977;6:345–381. doi: 10.1146/annurev.bb.06.060177.002021. [DOI] [PubMed] [Google Scholar]
  17. Nistri A., Constanti A. Pharmacological characterization of different types of GABA and glutamate receptors in vertebrates and invertebrates. Prog Neurobiol. 1979;13(2):117–235. doi: 10.1016/0301-0082(79)90016-9. [DOI] [PubMed] [Google Scholar]
  18. Peacock J. H., Nelson P. G., Goldstone M. W. Electrophysiologic study of cultured neurons dissociated from spinal cords and dorsal root ganglia of fetal mice. Dev Biol. 1973 Jan;30(1):137–152. doi: 10.1016/0012-1606(73)90053-5. [DOI] [PubMed] [Google Scholar]
  19. Ransom B. R., Neale E., Henkart M., Bullock P. N., Nelson P. G. Mouse spinal cord in cell culture. I. Morphology and intrinsic neuronal electrophysiologic properties. J Neurophysiol. 1977 Sep;40(5):1132–1150. doi: 10.1152/jn.1977.40.5.1132. [DOI] [PubMed] [Google Scholar]
  20. Schmechel D. E., Brightman M. W., Barker J. L. Localization of neuron-specific enolase in mouse spinal neurons grown in tissue culture. Brain Res. 1980 Jan 13;181(2):391–400. doi: 10.1016/0006-8993(80)90621-6. [DOI] [PubMed] [Google Scholar]
  21. Smith T. G., Jr, Barker J. L., Smith B. M., Colburn T. R. Voltage clamping with microelectrodes. J Neurosci Methods. 1980 Dec;3(2):105–128. doi: 10.1016/0165-0270(80)90020-5. [DOI] [PubMed] [Google Scholar]

Articles from The Journal of Physiology are provided here courtesy of The Physiological Society

RESOURCES