Fig. 6. Too much stress and LTM formation. Snails that received a 30–35s KCl bath before 30 min of tactile training, and then another 30–35s KCl bath afterwards, did not have a significant decrease in pneumostome openings in a MT 24 h later. When snails had the KCl bath and then training, but had the second KCl bath replaced with exposure to pond water (PW) there was memory, i.e. there was a significant decrease in attempted openings, 24 h later (^**P<0.01). [Reprinted from Martens et al. (Martens et al., 2007a), with permission from Elsevier.]