Both transcription and the translation blockers prevent LTM formation in Lymnaea. Both transcription and the translation blockers prevent LTM formation in Lymnaea. (A) A naïve group of snails (N=20) was injected with the transcriptional protein synthesis inhibitor Actinomycin D 2.5 h before the 1 h training session (1). Following the 1 h training session the snails were tested for memory 6 h later (MT). Memory was not present. That is, the number of attempted pneumostome openings in the memory test session was not statistically different from the number in the training session (P>0.05). (B) As above, except the translational blocker Anisomycin was injected. Again, no memory was observed. That is, the number of attempted pneumostome openings in the memory test session was not statistically different from the number in the training session (P>0.05). Susan Sangha et al. J Exp Biol 2003;206:1605-1613 © The Company of Biologists Limited 2003