New Compound Halts Cocaine Addiction
The Theory: Targeting TAAR 1
Dopamine is a neurotransmitter that is instrumental in many addictions; cocaine is a prime example. It can be thought of as a “pleasure” chemical in the brain, but also contributes to motivation to continue to perform activities that bring that pleasure, and this is why it’s so important in drug addiction. The theory behind this new study revolves around the TAAR 1 receptor, which is closely related to dopamine and is thought to act like a “brake” on dopamine activity. The idea is that by stimulating TAAR 1, the dopamine activity that is central to cocaine addiction can be slowed down, and, therefore addiction will be minimized.
The RO5263397 Study
The researchers tested this theory using a novel compound–with the not-so-catchy name RO5263397—that is known to stimulate TAAR 1 receptors in rats. They tested several specific elements of abuse behavior, such as conditioned place preference (the inclination to stay in a location where cocaine is given) and how hard the animals were willing to work to get an injection of cocaine. The researchers also looked at the effects of “cues” (things that encourage users to relapse) and cocaine itself on the likelihood of relapse when the new compound had been given.
What They Found
On the conditioned-place preference test, a longer time spent in the specific location is interpreted as a measure of the rewarding effects of the drug. When the cocaine-addicted rats were treated with RO5263397, they spent less time in the location, suggesting that the addiction had been “blunted” by the substance.
On the other parts of the test, the results were also broadly positive. They found that relapses were less likely when the rats were given the new compound, because both cocaine itself and cocaine-related cues had their ordinary, relapse-provoking effects “blocked” by the substance. The final element of the test, which looked at the amount of work rats were willing to put in to get a dose of cocaine, also had positive findings, showing that they were willing to put in less work for the drug, and therefore took less of it. However, when the effort required for a dose was minimal, the compound was unable to reduce the frequency of use from the animals.
What Does It Mean?
Said Researcher Jun-Xu Li: “This is the first systematic study to convincingly show that RO5263397 has the potential to treat cocaine addiction.”
The implications of this could be very significant indeed, because the study suggests that a wide range of important, abuse-related behaviors are subverted by the new chemical. The fact that behaviors essential to relapse and the amount of effort the rats were willing to put in to obtain cocaine were minimized means that—if the effect translates well to humans—it could become an effective treatment for addiction. The physiological drive to continue to abuse could be silenced or at least quieted, allowing the individual to focus on the psychological elements of treatment.
Of course, evidence that a compound is effective in rat models is just the first step in determining whether it could help humans, and much more research is needed before it could become a mainstay in human addiction treatment. But the fact that there are no other treatments for cocaine addiction makes the initial positive finding much more encouraging because, even if this compound doesn’t work, it appears that the TAAR-1 receptor is a good target for a drug to treat cocaine abuse and therefore something else could be developed if needed.
Medications to treat cocaine abuse are a hot topic for addiction researchers, and it seems like we’re destined to find an additional tool to help cocaine abusers minimize the grasp of their addiction at some point in the near future. Whether it’s RO5263397 or some other substance, the days of cocaine abusers having to get clean without additional, pharmacological support could be numbered.