Appetitive learning in snails shows characteristics of conditioning in vertebrates

The snail Lymnaea stagnalis can be rapidly conditioned to produce feeding response to a previously neutral tactile stimulus, repeatedly and specifically paired with positive reinforcement (food). The conditioned response has many of the same characteristics seen in appetitive learning in vertebrates. The relative simplicity of the molluscan CNS and the detailed knowledge of the neural circuitry underlying feeding in Lymnaea will facilitate the neurophysiological analysis of appetitive learning as well as stimulus generalization, discriminative learning and generalization of extinction all described in the present paper.