Spaced taste avoidance conditioning in Lymnaea

•15 Repeated paired presentations of sucrose and high voltage resulted in STM and LTM.•8 Repeated paired presentations of CS–US with interposing 3h interval resulted in STM and LTM.•Memory consolidated was enhanced with activation of PKC. We succeeded in taste avoidance conditioning with sucrose as the conditional stimulus (CS) and an electrical stimulus (∼1000V, 80μA) as the unconditional stimulus (US). With 15 paired CS–US presentations on a single day, we were able to elicit both short-term memory (STM) and long-term memory (LTM) persisting for at least one week. However, while STM was elicited with 5, 8, 10, and 20 paired presentations of the CS–US on a single day, LTM was not. We found, however, that if we inserted a 3h interval between a first and a second set of CS–US pairings that both 8 and 20 paired CS–US presentations on a single day was now sufficient to cause LTM formation. Exposing snails to bryostatin before or during training enhanced LTM formation such that 8 paired presentations of the CS–US resulted in LTM.