Spaced taste avoidance conditioning in Lymnaea

Neurobiol Learn Mem. 2014 Jan;107:79-86. doi: 10.1016/j.nlm.2013.10.022. Epub 2013 Nov 13.


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.

Keywords: ANOVA; Bryo; CS; High voltage stimulus; ITM; LTM; Long term memory; Massed training; NS; PKC; Protein kinase C; STM; Short term memory; Spaced training; TAC; Taste avoidance conditioning; US; analysis of variance; bryostatin; conditional stimulus; intermediate-term memory; long-term memory; not significant; protein kinase C; short-term memory; taste avoidance conditioning; unconditional stimulus.

MeSH terms

  • Animals
  • Avoidance Learning* / drug effects
  • Bryostatins / pharmacology
  • Conditioning, Psychological*
  • Electric Stimulation
  • Enzyme Activators / pharmacology
  • Lymnaea
  • Memory, Long-Term / drug effects
  • Memory, Short-Term / drug effects
  • Sucrose
  • Taste*
  • Time Factors


  • Bryostatins
  • Enzyme Activators
  • Sucrose