Meth may make memories more persistent in snails

PULLMAN – With snails and a “pinch” of methamphetamine, a team of WSU professors and students is working to conquer the complications of drug addiction.
Barbara Sorg, professor of neuroscience at WSU, has been working to uncover whether snails, when under the influence of methamphetamine, have more persistent memory.
“We decided to use snails for this experiment because they have very simple nervous systems that are easy to understand,” Sorg said. “Any other system would have been too complex at this point.”
Sorg began the experiment by placing two groups of Lymnaea stagnalis snails into two separate tubs of water – one tub treated with a very small, known amount of meth. The snails, after spending a lengthy amount of time at the bottom of the tubs, would need to come up for air.
“As the snails emerged, we would poke their pneumostome (breathing hole), which would cause them to resubmerge in the water without taking time to get air,” Sorg said. “We did this to the snails in both tubs of water, which conditions them to keep their pneumostome closed when they emerge.”
Samuel Kammerzell, a neuroscience graduate and experimental assistant, said the results were interesting.
“While we were able to condition both groups of snails to some extent, the group exposed to meth retained the memory better than the group unexposed – and kept their pneumostome closed,” Kammerzell said. “Luckily, they breathe through their skin as well.”
“Ultimately, the experiment is like a child reaching for a cookie in the jar on the counter,” said Steve Houmes, neuroscience student at WSU and experimental assistant. “Each time he reaches for one, he gets slapped – and eventually learns to stop reaching,” Houmes said. “It’s a similar idea, although a cookie is not quite as necessary as air.”
Yet, Sorg and her project associates believe there are a few necessary insights to be taken from the experiment – some still under investigation.
“This study shows that drugs stimulate neurons which, in turn, enhance the brain’s memory of the drug itself,” Sorg said. “This points to a potential cause of drug-abuse relapse in humans.”
Houmes said that, whether in a snail or human being, drugs of abuse may enhance certain memories about the drugs.
“That’s why so many drug users might relapse years later,” he said.
While drug use is a complicated subject, the team plans to continue the snail research – hoping to further expand the knowledge already compiled on drug abuse and addiction.
“We’re interested in learning how to diminish the drug memory so there’s no more drug
desire or addiction,” Sorg said. “I think the bottom line is that you have to go to a simpler anatomical system to figure it out.”