We would never have suspected that you can train snails to do anything.
But, if you poke a submerged great pond snail, or Lymnaea stagnalis, with a stick a few times, you can actually teach it to keep a snorkel-like breathing tube closed and instead absorb oxygen only through its skin.
Now, if you're a neuroscientist, you can use trained snails like these to test how water-soluble chemicals might affect memory. Say, for instance, how does methamphetamine-laced water affect a snail remembering to keep its snorkel shut?
Scientists from Washington State University and the University of Calgary did a bunch of experiments like that and found just a little meth helped the snails learn and hold on to their lessons. Even when researchers tried to confuse the snails by getting them to remember something else, the meth-exposed snails kept the memories firm in their slimy minds.
Why would you want to go to all this trouble with hundreds of snails, as these scientists did? Well, the simple circuitry of snails makes it a lot easier to study how neural systems works than, say, the complicated brains of humans. And the findings in snails confirm the memory-enhancing effects of the drug in other animals, like humans.
The results appear in current issue of the Journal of Experimental Biology.