Abstract
Based on the newly established taste avoidance conditioning paradigm, Lymnaea can learn the temporal sequence of sucrose application and subsequent applied high voltage with small current resulting in significant suppression of feeding response to sucrose. The most efficient condition to acquire the long-term memory (LTM) is obtained by 15 paired presentations of a conditional stimulus (CS) and an unconditional stimulus (US). This repetition number for LTM acquisition is different among the taste avoidance conditioning employed as US, such as KCl, mechanical tapping and electrical high voltage, however the behavioral modification is thought to activate the same neuronal circuit via RPeD11 which is the inter neuron to control the whole-body withdrawal response. All of these USs are thought to be recognized as a noxious stimulus sensing at RPeD11.