By Ryan Gierach, West Hollywood, California
Move over, Cocaine Anonymous.
Until now a person addicted to cocaine specifically had only one place to turn for help in behavior modification – the rooms of Cocaine Anonymous.
Today, though, a singular announcement portended change on the recovery front.
University of Buffalo (NY) researchers announced results of a study that found a novel compound that targets an important brain receptor has a dramatic effect against a host of cocaine addiction behaviors – including relapse behavior.
The press release for the study said, “The research provides strong evidence that this may be a novel lead compound for treating cocaine addiction, for which no effective medications exist.”
The UB research was published as an online preview article in Neuropsychopharmacology last week. In the study, the compound, RO5263397, severely blunted a broad range of cocaine addiction behaviors.
“This is the first systematic study to convincingly show that RO5263397 has the potential to treat cocaine addiction,” said Jun-Xu Li, MD, PhD, senior author and assistant professor of pharmacology and toxicology in the UB School of Medicine and Biomedical Sciences.
“Our research shows that trace amine associated receptor 1 – TAAR 1—holds great promise as a novel drug target for the development of novel medications for cocaine addiction,” he said. TAAR 1 is a receptor in the brain that is activated by minute amounts of brain chemicals called trace amines.
The findings are especially important, Dr. Li added, since despite many years of research, there are no effective medications for treating cocaine addiction. The compound targets TAAR 1, which is expressed in key drug reward and addiction regions of the brain.
“Because TAAR 1 anatomically and neurochemically is closely related to dopamine – one of the key molecules in the brain that contributes to cocaine addiction – and is thought to be a ‘brake’ on dopamine activity, drugs that stimulate TAAR 1 may be able to counteract cocaine addiction,” Dr. Li explained.
The UB research tested this hypothesis by using a newly developed TAAR 1 agonist RO5263397, a drug that stimulates TAAR 1 receptors, in animal models of human cocaine abuse.
West Side and KLEAN Treatment Center addiction specialist Kim Farber, MA, a Registered Marriage and Family Therapist Intern and PhD Candidate, asked an intriguing baseline question.
“I’m curious to know what they mean by addiction?” she asked. “There’s a synergy between the physical behaviors and the underlying psychological factors.”
“The study talks blocking rewards centers,” said Ms. Farber. “But there are other substances or processes” by which treating cocaine alone an addictive personality could end up in transferal to other drugs.
According to the university’s spokesperson Ellen Goldbaum, “One of the ways that researchers test the rewarding effects of cocaine in animals is called conditioned place preference. In this type of test, the animal’s persistence in returning to, or staying at, a physical location where the drug was given, is interpreted as indicating that the drug has rewarding effects.”
The scientists say that, in the UB study, RO5263397 dramatically blocked cocaine’s rewarding effects. “When we give the rats RO5263397, they no longer perceive cocaine rewarding, suggesting that the primary effect that drives cocaine addiction in humans has been blunted,” said Dr. Li.
According to the National Institute of Drug Abuse, in the normal communication process, dopamine is released by a neuron into the synapse, where it can bind to dopamine receptors on neighboring neurons.
Normally, dopamine is then recycled back into the transmitting neuron by a specialized protein called the dopamine transporter.
If cocaine is present, it attaches to the dopamine transporter and blocks the normal recycling process, resulting in a buildup of dopamine in the synapse, which contributes to the pleasurable effects of cocaine.
The Buffalo University scientists claim they can short-circuit that dopamine pulse. The compound also markedly blunted cocaine relapse in the animals.
“Cocaine users often stay clean for some time, but may relapse when they re-experience cocaine or hang out in the old cocaine use environments,” said Dr. Li. “We found that RO5263397 markedly blocked the effect of cocaine or cocaine-related cues for priming relapse behavior.
“Also, when we measured how hard the animals are willing to work to get an injection of cocaine, RO5263397 reduced the animals’ motivation to get cocaine,” said Dr. Li. “This compound makes rats less willing to work for cocaine, which led to decreased cocaine use.”
Ms. Farber said that may be true for the physical addiction that lab rats suffer, but human beings are a bit more complex living in a whirlwind world. “No one should ever think that a pill or medical treatment alone can help them become addiction free,” she said. “There are many, many forms addictions take, and I find that patients often transfer one for another, such as shopping, or gambling, or sex.”
She stresses that people with substance abuse problems treat the whole body, the physical and the emotional and psychological aspects that often underlie addictions.
The UB researchers plan to continue studying RO5263397, especially its effectiveness and mechanisms in curbing relapse to cocaine addiction.
In addition to Dr. Li, co-authors are David A. Thorn, a technician and PhD candidate; Li Jing, PhD, postdoctoral fellow, Yanyan Qiu, research scientist, Amy M. Gancarz-Kausch, PhD, postdoctoral fellow, and David M. Dietz, PhD, assistant professor, all of the UB Department of Pharmacology and Toxicology; Chad M. Galuska, PhD, of the College of Charleston; and Yanan Zhang, PhD, of Research Triangle Institute.
The research was funded by the National Institutes of Health.