Delayed-onset amnesia caused by protein synthesis inhibition in odor-taste associative memory of the terrestrial slug Limax valentianus.

The terrestrial slug Limax avoids the odor of innately preferred food after it is presented with the aversive taste of quinidine. This type of associative memory persists for several weeks. We investigated effects of protein synthesis inhibitors on the retention of this odor-taste associative memory. Anisomycin or cycloheximide applied to the slug 30 min prior to conditioning impaired the memory retention as late as two or more days after the conditioning, while the retention of a short-term memory was normal for up to 24 h. In contrast, the inhibition of protein synthesis by these inhibitors decays within several hours. In Limax, the onset of amnesia is unusually delayed when protein synthesis is suppressed at the time of conditioning.