Snails on Meth: It's Harder To Forget Memories Formed While on Meth

The Study

Researchers studied the pond snail known as Lymnaea stagnalis in order to examine the effects of meth use on memory. Pond snails have a simple neuron network that holds memories of when to breathe. The researchers trained the snails to keep their breathing tubes (pneumostomes) closed under low oxygen levels by poking them with a stick, a lesson they would remember for 24 hours under normal conditions. They then trained the snails in water laced with meth to see what affect this would have on memory.

Even after being trained while under the influence of meth, the snails didn't remember their training when placed in normal pond water 24 hours later. However, when meth was added to the water, the snails suddenly remembered that they were supposed to keep their pneumostomes closed.

The researchers also found that receiving a dose of meth before training improved snails' memories, to the point where they recalled a lesson that they normally would have forgotten. Memories formed while under the influence of meth were also much stronger and harder to replace with other memories.

Why Is This Important?

Drugs like meth are known to enhance memory, which may be one reason why a meth addiction is so hard to overcome. When a memory is formed while under the influence of meth, it is stronger and harder to forget than a normal memory. The experiment with the pond snails also suggests that memories formed while on meth may be triggered by exposure to meth-related surroundings, possibly explaining why returning to places associated with drug use can bring back powerful memories of addiction.

Memory plays a very important role in addiction, so better understanding the effects of meth on memory will help us better understand and treat meth addiction.