PROTEIN-SYNTHESIS INHIBITORS MIMIC NOCICE PTIVE SENSITIZATION EFFECTSON DEFENSE AND FEEDING-BEHAVIOR OF HELIX-LUCORUM SNAIL

Effects of translation inhibitors on defence and feeding behaviour and command neurons of defence behaviour (L-RPl1) were studied in Helix l ucorum snail. It was found that anisomycin and cycloheximide facilitat ed defence reactions and neuronal responses evoked by tactile or chemi cal stimuli 60-80 min after inhibitor application. At the same time fe eding behaviour and neuronal responses (L-RMtc1 neurons) evoked by a f ood stimulus were suppressed. Effects of inhibitors were obtained with in 30 min of their application or single injection in intact snail. Ef fects of inhibitors were absent after continuous application or double injection with 50 min interval. Duration of the inhibitor effects dep ended on modality of a sensory stimulus. In particular, inhibitor effe cts on behavioural and neuronal responses evoked by tactile stimuli la sted 1 h., by weak quinine solution -2-3 h., and by a food stimulus - 1.5 h. Cycloheximide suppressed only appetitive phase of feeding behav iour but did not affect consummatory phase of feeding behavior. Some p arameters of the behavioural and neuronal effects were similar to thos e obtained during sensitization development. It was suggested that tra nslation inhibitors induced activation of synthesis of protein molecul es with a short lifetime, functions of which consisted in selective re gulation of synaptic transmission.