The structure of the brain allows people to trace memories by context, which ultimately may trigger strong urges associated to the recollection, such as a relapse in drug usage for addicts, according to researchers at Hebrew University of Jerusalem's (HU's) Edmond and Lily Safra Center for Brain Sciences and the Alexander Silberman Institute of Life Science.This discovery may allow for a better understanding of the nature of drug addiction. The mind's dynamic method of recalling may use markers to locate the memory. For example, one may remember where one was as it is attached to a strong memory, such as a trauma or a positive change.This fits the idea of "incentive salience," a process in the brain which allows people to associate a neutral cognitive stimulus with positive reinforcement; for example, a child's reaction to a toy store may be neutral until it is tied to the positive reinforcement of receiving a toy from the store, in which case they attach the image of the storefront to a positive feeling.The claustrum, an obscure and extremely dense section of the brain, seems to be directly related to this process, HU researchers have found, despite the section being particularly difficult to study.They tested the effect of cocaine on the claustrum, where they found that certain neurons pivotal to the formation of an incentive salience lit up during cocaine use, linking context with the pleasure of the drug.HU's Prof. Ami Citri, PhD student Anna Terem and a team of additional researchers placed lab mice in a conditioned-place preference (CPP) test, which teaches them to associate reward with context. They were given the choice of being in a location similar to where they were previously given cocaine and a different, neutral area, and they quickly congregated to the place tied to their drugged high.The researchers performed the test while inhibiting, or limiting, the claustral neurons and found that when doing so, the mice no longer preferred hanging out in the cocaine-related room, even though the memory was surely there. When they activated the neurons, the mice would develop a preference for the context, even without the cocaine.The research backs the claim that in the process of recovery from drug addiction, distancing oneself from contextual cues attached to drug use is imperative."These findings boosted our confidence that the claustrum is indeed integral to incentive salience, heightening the awareness of the mouse to the context in which it experienced the drug high," said Prof. Citri. "We hope this knowledge will lead to the development of new diagnostic tools to identify populations susceptible to addiction, as well as new therapeutic approaches."