Another study finds that important reversals in addiction related brain adaptations occur in the first 90 days of recovery.
It has been hypothesized that persistent drug seeking alters the brain’s natural reward and motivational system. The current study focuses on how drug seeking alters the communication between brain cells in this critical circuitry. In the normal processes of learning and memory formation there is a well documented strengthening of communication between brain cells, this process is known as “long-term potentiation” (LTP). The new study reports that LTP was similar in the rats that had learned to self administer cocaine, food or sucrose, but with a critical distinction. The increase in LTP due to cocaine persisted for up to three months of abstinence, but the increase in response to natural rewards dissipated after only three weeks. Importantly, the nature of the cocaine experience had a strong effect on the outcome, since rats exposed to cocaine when they did not expect it (passive infusions) displayed no LTP, neither transient nor long lasting. Finally, the study showed that LTP in rats that self-administered cocaine persisted after they were trained to stop drug self-administration behaviors. This indicates that, once established, it is very difficult to reverse the “memory trace” associated with drug reward.