Cellular and Molecular Neurobiology

, Volume 13, Issue 1, pp 59–68 | Cite as

Dendrotoxin blocks a class of potassium channels that are opened by inhibitory presynaptic modulators in rat cortical synaptosomes and slices

  • Gabor Zoltay
  • Jack R. Cooper


  1. 1.

    Rat cortical synaptosomes were prelabeled with radioactive acetylcholine and the release induced by veratridine was determined in the absence and presence of the inhibitory presynaptic modulators, 2-chloroadenosine, carbamylcholine, clonidine, and morphine. All four agents inhibited the evoked release of acetylcholine and this inhibition was reversed by dendrotoxin.

  2. 2.

    Using perfused cortical slices and an extracellular K-sensitive electrode, all modulators again increased K efflux that was blocked by dendrotoxin. In contrast, glybenclamide and tetraethylammonium did not block the modulatorinduced efflux.


Key words

Dendrotoxin 2-chloroadenosine carbamylcholine morphine clonidine K channels presynaptic modulation 


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  1. 1.
    Aghajanian, G. K., and Wang, Y. Y. (1987). Common a2 and opiate effector mechanisms in the locus coerulius: intracellular studies in brain slices.Neuropharmacology 26793–799.Google Scholar
  2. 2.
    Amman, D., Chao, P., and Simon, W. (1987). Valinomycin-based K+ selective microelectrodes with low electrical membrane resistance.Neurosci. Lett. 74221–226.Google Scholar
  3. 3.
    Anderson, A. J., and Harvey, A. L. (1988). Effects of the potassium channel blocking dendrotoxins on acetylcholine release and motor nerve terminal activity.Br. J. Pharmacol. 93215–221.Google Scholar
  4. 4.
    Aronson, J. K. (1991). Potassium channels in nervous tissue.Biochem. Pharmacol. 4311–14.Google Scholar
  5. 5.
    Benishin, C. G. (1990). Purinergic modulation of hippocampal acetylcholine release involvesα-dendrotoxin-sensitive potassium channels.J. Neurochem. 552086–2090.Google Scholar
  6. 6.
    Benishin, C. G., Sorensen, R. G., Brown, W. E., Krueger, B. K., and Blaustein, M. P. (1988). Four polypeptide components of green mamba venom selectively block certain potassium channels in rat brain synaptosomes.Mol. Pharmacol. 34152–159.Google Scholar
  7. 7.
    Cass, W. A., and Zahniser, N. R. (1991). Potassium channel blockers inhibit D2 dopamine but not A1 adenosine, receptor-mediated inhibition of striatal dopamine release.J. Neurochem. 57147–152.Google Scholar
  8. 8.
    Castle, N. A., Haylett, D. G., and Jenkinson, D. H. (1989). Toxins in the characterization of potassium channels.Trends Neurosci. 1259–65.Google Scholar
  9. 9.
    Cooper, J. R. (1989). A simple method to determine released acetylcholine in the presence of choline.Life Sci. 452041–2042.Google Scholar
  10. 10.
    Cooper, J. R., Bloom, R. E., and Roth, R. H. (1991).The Biochemical Basis of Neuropharmacology, 6th ed., Oxford University Press, pp. 111-132.Google Scholar
  11. 11.
    Halliwell, J. L., Othman, I. B., Pelcher-Mathews, A., and Dolly, J. O. (1986). Central actions of dendrotoxin: Selective reduction of a transient K conductance in hippocampus and binding to localized acceptors.Proc. Natl. Acad. Sci. USA 83493–497.Google Scholar
  12. 12.
    Harvey, A. L., and Karlsson, E. (1980). Dendrotoxin from the green mamba, Dendroaspis angusticeps: A neurotoxin that enhances acetylcholine release at neuromuscular junctions.Nauyn-Schmiedeberg Arch. Pharmacol. 3121–6.Google Scholar
  13. 13.
    Hu, P. S., Benishin, C., and Fredholm, B. B. (1991). Comparison of the effects of four dendrotoxin peptides, 4-aminopyridine and tetraethylammonium on the electrically evoked [3H]noradrenaline release from rat hippocampus.Eur. J. Pharmacol. 20987–93.Google Scholar
  14. 14.
    Lowry, O. H., Rosebrough, N. J., Farr, A. L., and Randall, R. J. (1951). Protein measurement with the Folin phenol reagent.J. Biol. Chem. 193265–275.Google Scholar
  15. 15.
    Lucchesi, K., and Moczydlowski, E. (1990). Subconductance behavior in a maxi Ca2+-activated K+ channel induced by dendrotoxin-1.Neuron 2141–148.Google Scholar
  16. 16.
    Michaelis, M. L., Johe, K. K., Moghadam, B., and Adams, R. N. (1988). Studies on the ionic mechanism for the neuromodulatory actions of adenosine in the brain.Brian Res. 473249–260.Google Scholar
  17. 17.
    Moczydlowski, E., Lucchesi, K., and Ravindran, A. (1988). An emerging pharmacology of peptide toxins targeted against potassium channels.J. Membr. Biol. 10791–111.Google Scholar
  18. 18.
    Nagy, A., and Delgado-Escueta, A. V. (1984). Rapid preparation of synaptosomes from mammalian brain using non-toxic isosmotic gradient material (Percoll).J. Neurochem. 431114–1123.Google Scholar
  19. 19.
    North, R. A. (1989). Drug receptors and the inhibition of nerve cells.Br. J. Pharmacol. 9813–28.Google Scholar
  20. 20.
    Rudy, B. (1988). Diversity and ubiquity of K channels.Neuroscience 25729–749.Google Scholar
  21. 21.
    Trussel, L. O., and Jackson, M. B. (1987). Dependence of an adenosine-activated potassium current on a GTP-binding protein in mammalian central neurons.J. Neurosci 73306–3316.Google Scholar
  22. 22.
    Weller, U., Bernhardt, V., Siemen, D., Dreyer, F., Vogel, W., and Habermann, E. (1985). Electrophysiological and neurobiochemical evidence for the blockade of a potassium channel by dendrotoxin.Naunyn-Schmiedeberg Arch. Pharmacol. 33077–83.Google Scholar
  23. 23.
    Zoltay, G., and Cooper, R. R. (1990). Ionic basis of inhibitory presynaptic modulation in rat cortical synaptosomes.J. Neurochem. 551008–1012.Google Scholar

Copyright information

© Plenum Publishing Corporation 1993

Authors and Affiliations

  • Gabor Zoltay
    • 1
  • Jack R. Cooper
    • 1
  1. 1.Department of PharmacologyYale University School of MedicineNew HavenUSA

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