Fig. 11. Behavioural data of intact Lymnaea after the single 0.5 h training procedure in either PW or CE. The single training session (TS1) in PW (black bars) results in a 3 h memory (3 h TM; intermediate-term memory, ITM) but does not result in LTM (i.e. a memory lasting 24 h; black bars, N=44, P>0.05). However, the single training session (TS1) in CE (orange) results in LTM. That is, the number of attempted pneumostome openings in the memory test sessions (TM) at 24 and 48 h is significantly lower than in TS1 (i.e. memory at 24 and 48 h; 24 h TM, N=35, ^*P<0.01; 48 h TM, N=41, ^*P<0.01). Snails did not demonstrate memory formation in 24 and 48 h yoked control groups (blue bars; N=30, P>0.05 and N=20, P>0.05 for 24 and 48 h yokes, respectively) or 72 h after training (N=22, P>0.05). [Reproduced with permission from Orr and Lukowiak (Orr and Lukowiak, 2008).]