Nav: Home

Study using animal model provides clues to why cocaine is so addictive

August 01, 2016

WINSTON-SALEM, N.C. - Aug. 1, 2016 - Scientists at Wake Forest Baptist Medical Center are one step closer to understanding what causes cocaine to be so addictive. The research findings are published in the current issue of the Journal of Neuroscience.

Cocaine addiction is a debilitating neurological disorder that affects more than 700,000 people in the United States alone, according to the Substance Abuse and Mental Health Services Administration. With repeated use, tolerance may develop, meaning more of the drug is required to achieve the same euphoric effect. Cocaine addiction can be characterized by repeated attempts at abstinence that often end in relapse.

"Scientists have known for years that cocaine affects the dopamine system and dopamine transporters, so we designed our study to gain a better understanding of how tolerance to cocaine develops via the dopamine transporters," said Sara R. Jones, Ph.D., professor of physiology and pharmacology at Wake Forest Baptist and lead author of the study.

"Currently there isn't any effective treatment available for cocaine addiction so understanding the underlying mechanism is essential for targeting potential new treatments."

Using an animal model, the research team replicated cocaine addiction by allowing rats to self-administer as much cocaine as they wanted (up to 40 doses) during a six-hour period. Six-hour-a-day access is long enough to cause escalation of intake and tip animals over from having controlled intake to more uncontrolled, binge-like behavior, Jones said.

Following the five-day experiment, the animals were not allowed cocaine for 14 or 60 days. After the periods of abstinence, the researchers looked at the animals' dopamine transporters and they appeared normal, just like those in the control animals that had only received saline.

However, a single self-administered infusion of cocaine at the end of abstinence, even after 60 days, fully reinstated tolerance to cocaine's effects in the animals that had binged. In the control animals that had never received cocaine, a single dose did not have the same effect.

These data demonstrate that cocaine leaves a long-lasting imprint on the dopamine system that is activated by re-exposure to cocaine, Jones said. This 'priming effect,' which may be permanent, may contribute to the severity of relapse episodes in cocaine addicts.

"Even after 60 days of abstinence, which is roughly equivalent to four years in humans, it only took a single dose of cocaine to put the rats back to square one with regard to its' dopamine system and tolerance levels, and increased the likelihood of binging again," Jones said. "It's that terrible cycle of addiction."

Jones added that hope is on the horizon through preclinical trials that are testing several amphetamine-like drugs for effectiveness in treating cocaine addiction.
-end-
The research was supported by National Institutes of Health grants RO1 DAO21325, RO1DAO30161, F31DAO37710 and T32AA00757565.

Co-authors are Cody A. Siciliano, Ph.D., and Steve C. Fordahl, Ph.D., of Wake Forest Baptist.

Wake Forest Baptist Medical Center

Related Cocaine Articles:

Cocaine addiction leads to build-up of iron in brain
Cocaine addiction may affect how the body processes iron, leading to a build-up of the mineral in the brain, according to new research from the University of Cambridge.
Potential new treatment for cocaine addiction
A team of researchers led by Cardiff University has discovered a promising new drug treatment for cocaine addiction.
Study using animal model provides clues to why cocaine is so addictive
Scientists at Wake Forest Baptist Medical Center are one step closer to understanding what causes cocaine to be so addictive.
Magnetic stimulation of the brain may help patients with cocaine addiction
Baltimore, MD Targeted magnetic pulses to the brain were shown to reduce craving and substance use in cocaine-addicted patients.
New insights on how cocaine changes the brain
The burst of energy and hyperactivity that comes with a cocaine high is a rather accurate reflection of what's going on in the brain of its users, finds a study published Nov.
UK awarded $6 million to further develop treatment for cocaine abuse
University of Kentucky College of Pharmacy Professor Chang-Guo Zhan, along with fellow UK Professors Fang Zheng and Sharon Walsh, and Professor Mei-Chuan Ko from Wake Forest University, recently received $6 million in funding over five years to further develop a potential treatment for cocaine abuse.
Cocaine addiction, craving and relapse
One of the major challenges of cocaine addiction is the high rate of relapse after periods of withdrawal and abstinence.
Which is most valuable: Gold, cocaine or rhino horn?
Elephants, rhinoceroses, hippopotamuses, gorillas and the majority of other very large animal species are threatened with extinction, an international team of scientists reported this month in the open-access online journal Science Advances.
Cocaine changes the brain and makes relapse more common in addicts
Cocaine use causes 'profound changes' in the brain that lead to an increased risk of relapse due to stress -- according to new research from the University of East Anglia.
WSU researchers see way cocaine hijacks memory
Washington State University researchers have found a mechanism in the brain that facilitates the pathologically powerful role of memory in drug addiction.

Related Cocaine Reading:

The Cocaine Kids
by Terry Williams (Author)

Cocaine + Surfing: A Sordid History of Surfing's Greatest Love Affair
by Rare Bird Books, A Vireo Book

Cocaine Blues: Phryne Fisher #1 (Phryne Fisher Mysteries)
by Poisoned Pen Press

Kings of Cocaine: Inside the Medellín Cartel - An Astonishing True Story of Murder, Money and International Corruption
by Garrett County Press

The Cocaine Diaries: A Venezuelan Prison Nightmare
by Mainstream Digital

American Desperado: My Life - From Mafia Soldier to Cocaine Cowboy to Secret Government Asset
by Random House Audio

From Silver to Cocaine: Latin American Commodity Chains and the Building of the World Economy, 1500–2000 (American Encounters/Global Interactions)
by Steven Topik (Editor), Zephyr Frank (Editor), Carlos Marichal (Editor)

Cocaine: History & Culture
by Publishing (Author)

Crack Money With Cocaine Dreams
by Royalty Publishing House

Crack Money With Cocaine Dreams 3
by Royalty Publishing House

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Don't Fear Math
Why do many of us hate, even fear math? Why are we convinced we're bad at it? This hour, TED speakers explore the myths we tell ourselves and how changing our approach can unlock the beauty of math. Guests include budgeting specialist Phylecia Jones, mathematician and educator Dan Finkel, math teacher Eddie Woo, educator Masha Gershman, and radio personality and eternal math nerd Adam Spencer.
Now Playing: Science for the People

#518 With Genetic Knowledge Comes the Need for Counselling
This week we delve into genetic testing - for yourself and your future children. We speak with Jane Tiller, lawyer and genetic counsellor, about genetic tests that are available to the public, and what to do with the results of these tests. And we talk with Noam Shomron, associate professor at the Sackler School of Medicine at Tel Aviv University, about technological advancements his lab has made in the genetic testing of fetuses.