14 | NewScientist | 5 June 2010

RNA drug tackles Ebola infection

Snails could speed the path to recovery for meth addicts

POND snails make unlikely speed freaks. But dosing

the gastropods on methamphetamine is helping us

understand how certain “pathological memories” form

in human addicts.

Meth users develop long-term memories of their

highs, which is why the sight of places and people

connected with a high can cause recovering addicts to

relapse. “It’s hard to get rid of those memories in addicts,”

says Barbara Sorg at Washington State University in

Pullman. So potent is meth’s effect on memory that, in

low doses, the drug can be used as a “cognitive enhancer”

OSF

IN BRIEF

When a year lasts just a few hours

in children with attention-deficit hyperactivity disorder.

To probe the drug’s effects, Sorg’s team placed pond

snails in two pools of low-oxygen water, one of which

was laced with meth. In low-oxygen conditions snails will

surface and use their breathing tubes to access more

oxygen. By poking the snails, Sorg’s team trained them to

associate using the tubes with an unpleasant experience,

and so keep them shut. Only the snails on speed

remembered their training the following morning, and it

took longer for them to “unlearn” the memory (Journal of Experimental Biology, DOI: 10.1242/jeb.042820).

Humans are obviously more complicated, says Sorg,

but “the snails still provide a model of how meth affects

memory”. The team’s goal is to work out how to diminish

specific memories, and so help addicts recover.

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