Summary
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1.
The effects of strychnine and desipramine on excitatory responses to acetylcholine (ACh) were compared with those of hexamethonium and atropine over a range of membrane potentials in voltage clampedAplysia neurons.
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2.
All these compounds reduced the steady-state ACh-induced current at the membrane potentials studied (-60 to -120 mV).
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3.
The blockade produced by hexamethonium and atropine was markedly voltage dependent, the degree of antagonism increasing with hyperpolarization.
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4.
In contrast, the antagonistic effects of strychnine and desipramine displayed no voltage dependency.
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5.
Unlike the presumed channel blocking drugs hexamethonium and atropine, strychnine and desipramine appear to act either at the receptor or at some other site not influenced by membrane potential.
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Slater, N.T., Carpenter, D.O. Blockade of acetylcholine-induced inward currents inAplysia neurons by strychnine and desipramine: Effect of membrane potential. Cell Mol Neurobiol 2, 53–58 (1982). https://doi.org/10.1007/BF00735067
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DOI: https://doi.org/10.1007/BF00735067