[The phenomenon of conditioned suppression of the generation of action potentials in isolated neurons of the edible snail].

A conditioning procedure was performed with isolated identified neurones of Helix pomatia. Depolarizing intracellular electrical pulses producing spike generation were used as conditioned and unconditioned stimuli (CS and US). The conditioned response consisted in the depression of spike generation evoked before learning by the presentation of CS. These conditioned responses persisted during 12-30 min after 3-5 trials of associated CS-US. An additional stimulus was used to test the specificity of associated learning concerning the stimulated loci of electroexcitable membrane. The results showed the locality and specificity of conditioning. The depression of action potentials evoked by the associated presentations of CS-US is suggested to be a form of modification of initial response to CS, typical for interneurones if the CS is of suprathreshold intensity.