People trying to recover from addiction often talk about trying to erase “old tapes,” that is old memories about habitual addictive behaviors.

Now, a study on rats says that there may be something real to that, and there may be a medical way to help make that happen.

A group of rats was given a chemical in a test to try to make this happen, on old memories in a drinking lab rat’s life:

Dorit Ron, a neuroscientist at the University of California, San Francisco (UCSF), and her team show that strategically blocking the mTORC1 signalling pathway reduces alcoholic relapse by disrupting memories linked to past drinking.

The researchers made rats into “problem drinkers,” then did a chemical intervention with a drug called rapamycin.

The researchers took alcohol away from the animals for 10 days and then gave each of them a tiny drop — just enough for the taste and odour to reawaken alcohol-related memories. Immediately afterwards, some rats received a drug called rapamycin, which inhibits mTORC1 activity.

Result? This:

All the rats had been trained to press a lever to receive alcohol, but those that received rapamycin after memory reactivation showed significantly less inclination to do so over a two-week period.

Caveats apply about small search size, need to replicate this, etc. But, it sounds promising. And in the tested rats, at least, no problematic side effects.

Rapamycin does not seem to affect memory formation, but instead disrupts the reconsolidation of existing memories into long-term storage after they have been reactivated. Preliminary tests suggest that the drug’s effects can be quite specific, and do not affect the animals’ consumption of other desirable substances such as sugar-water.

Stay tuned.

There’s more here on how previous events may affect what are known as “epigenetic markers” on our DNA, how this affects our memory, and how medications may be able to change this.