[Relationship between current and voltage in neuromembranes measured by a generator of long-term triangular current]

A generator of triangular current of long duration was constructed to measure the current-voltage relationship (I-V curve) of neuromembranes. Using this instrument, we observed the effect of 5-hydroxytryptamine (5-HT) on the I-V curve of an identified giant neurone (PON) of Achatina fulica Férussac. When two I-V curves (measured in the physiological state and under the 5-HT application) were superimposed by using the firing level as the common standard point, a concordance of two I-V curves in wide range of membrane polarization was observed.