Erasing the Past

A significant problem for those struggling with drug addiction is the high propensity of users to relapse following long periods of abstinence from drug use. It has been found that environmental stimuli that have been previously associated with the rewarding effects of drugs can often contribute to relapse among addicts. Exposure to drug cues often evokes the memory of the effects of the drug and can induce drug-seeking behavior.

Drugs, Memory, and the Brain

Drug-associated memories go through a process of consolidation in which short-term unstable memories becomes long-term stable memories. When these drug-associated memories are triggered or reactivated at a later time, they go through reconsolidation, wherein the stable memories become unstable and temporarily susceptible to interference.

I have been examining pharmaceutical means to disrupt cue-elicited drug-seeking behavior as a potential therapeutic means to help reduce relapse rates among drug users.

Society for Neuroscience Annual Conference

For the 48th Annual Society for Neuroscience (SfN) conference, I, along with four Vanguard students, Megan Jeske, Alexis Osborne, Tiffany Tadros, and Taylor Underwood, travelled to San Diego to present some our data from last summer’s research through SURP (Summer Undergraduate Research Program).

In our study, we aimed to determine the specificity of a glutamate blocker in interfering with the reconsolidation of two methamphetamine-associated cues. We found that rats administered this blocker after exposer to one methamphetamine-paired compartment disrupted drug-seeking behavior for that particular compartment, but did not disrupt drug seeking behavior for the second methamphetamine paired compartment.

We also sought to determine whether the presence of an olfactory cue of a multi-modal drug-associated memory is sufficient to reactive the memory and make it susceptible to interference of reconsolidation, which we in fact did find. Overall, our findings suggest that similar drug associated memories go through reconsolidation independently, and that reactivation of one modality of a drug-associated memory is sufficient to make the memory susceptible to reconsolidation interference, and thus reducing drug seeking behavior.

Opposite Sides of the Same Coin

The area of reconsolidation is of high interest in the field of neurobiology as “erasing” memories has many important implications. However, at one of the posters I visited, a research group was looking at addressing this problem from another angle.

The group was looking on how to enhance memories of those cues that indicate drug omission and thus reducing drug-seeking behavior. Also, another group was studying how fMRI scans can accurately predict which drug users will relapse after rehabilitation.