Dopamine inhibits burst-firing of neurosecretory cell R 15 in Aplysia californica: establishment of a dose-response relationship.
Burst-firing in neurosecretory cell R 15 of Aplysia californica is inhibited by the bath application of dopamine. Voltage-clamp analysis reveals a complex series of changes in the current-voltage relationship of R 15. Dopamine reduces the inward current in the region of negative slope conductance and tends to linearize the current-voltage curve. A variable increase in potassium conductance is frequently observed. The loss of inward current in the region of negative slope conductance is dose-dependent, highly reproducible and relatively resistant to desensitization, and for these reasons a valid dose-response relationship can be described. The dose-response curve is sigmoidal in shape and rises from a minimal effect near 50 microM to a maximal effect near 500 microM. This dose-response curve is useful as a standard of comparison in studies of agonists and antagonists. A protocol for the quantitative study of this system is described, and the constellation of changes in the current-voltage curve produced by dopamine is discussed.
D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D001048:Aplysia / Q000502:physiology; D002462:Cell Membrane / Q000187:drug effects; D004298:Dopamine / Q000378:metabolism / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D007099:Imipramine / Q000494:pharmacology; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D010293:Pargyline / Q000494:pharmacology
D010293:Pargyline; D007099:Imipramine; D004298:Dopamine