Neuronal correlates of aversive learning in command neurons for avoidance behavior of Helix lucorum L

Changes in responsiveness to food and noxious stimuli were studied in interneurons controlling feeding behavior and in putative command neurons for avoidance behavior after 10-15 paired presentations of food and electrical shock in the pulmonate snail Helix lucorum L. It was shown earlier that such aversive learning procedure is associative, and the behavioral aversion to the reinforced type of food in intact snails is maintained for at least 21 days, while normal feeding behavior can be evoked by another type of food. Responses to food presentation in the feeding behavior interneurons changed only in pattern after learning procedure, while in the command neurons for avoidance behavior a new spike reaction appeared, which is assumed to be responsible for the behavioral changes. A possible mechanism of a conditioned reaction in the command neurons for avoidance behavior is discussed.