The Neurobiology of Relapse





Current Main Project (NIH grant): Molecular events related to the craving reducing effect of environmental enrichment

In this study we are examining brain tissue from rats with a history of sucrose self-administration that had just been allowed to respond for sucrose-paired cues following brief (1 day) or prolonged (30 days) abstinence from sucrose. Some of the rats had also been placed into environmental enrichment for either one night or for 30 days. Our first study with their brain tissue is to identify whether expression of the protein Fos, an indicator of recently activated neurons, correlates with their sucrose craving behavior and/or their experiences with abstinence and/or environmental enrichment. 

Other Projects

Finished (manuscripts in preparation)

With Dr. Kenjiro Aoyama from Doshisha University (Kyoto, Japan) we recently conducted two studies with rats that had self-administered saccharin. In the first study we found that saccharin craving incubates over a period of 1 month forced abstinence. In the second study we found that saccharin craving could be markedly reduced if rats were pre-treated with the dopamine D1 receptor antagonist SCH23390.

We are working on a manuscript to describe how the dopamine D2 receptor blocker eticlopride accelerated extinction of responding for food pellets by rats. This experience also led to a delayed reacquisition of responding for food pellets.

We are working on a manuscript to describe how habituation to the testing environment markedly reduced sucrose craving by rats, yet habituation (satiation) with sucrose had no effect on sucrose craving.


We are just about to start a study examining how various pharmacological agents might “reverse” the anti-craving effect of environmental enrichment.

Copyright 2013, Western Washington University, Behavioral Neuroscience Program