Cellular and Molecular Neurobiology

, Volume 8, Issue 3, pp 307–314 | Cite as

Strychnine decreases the voltage-dependent Ca2+ current of bothAplysia and frog ganglion neurons

  • Yasuo Oyama
  • Norio Akaike
  • David O. Carpenter


  1. 1.

    The effects of strychnine on the voltage-dependent Ca2+ current (ICa) were studied in physically isolatedAplysia neurons and enzymatically dissociated frog sensory neurons of the dorsal root ganglion. Neurons were studied under the internal perfusion and the voltage clamp condition.

  2. 2.

    Strychnine decreased theICa with threshold concentrations for effect at 1 to 10µM. The depression ofICa increased with strychnine dose without effects on the current-voltage relation ofICa. The effects of low concentrations of strychnine were reversible, but recovery was incomplete at higher concentrations. The potency of strychnine was about 10 times less than that of diltiazem, an organic Ca2+ antagonist. At 100µM theICa ofAplysia neurons was reduced to about half of the control. This concentration of strychnine also reduced the peak amplitude ofICa of frog sensory neurons.

  3. 3.

    These results indicate that, in addition to its actions on transmitter responses and on Na+ and K+ currents, strychnine has effects onICa that have not previously been appreciated.


Key words

strychnine Aplysia neurons frog sensory neurons concentration clamp 


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Copyright information

© Plenum Publishing Corporation 1988

Authors and Affiliations

  • Yasuo Oyama
    • 1
  • Norio Akaike
    • 2
  • David O. Carpenter
    • 1
  1. 1.Wadsworth Center for Laboratories and Research and School of Public Health SciencesNew York State Department of HealthAlbanyUSA
  2. 2.Department of PhysiologyFaculty of Medicine, Kyushu UniversityFukuokaJapan

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